feat: Add --list-events debugging improvements and timezone support

- Remove debug event limit to display all events
- Add timezone information to event listing output
- Update DEVELOPMENT.md with latest changes and debugging cycle documentation
- Enhance event parsing with timezone support
- Simplify CalDAV client structure and error handling

Changes improve debugging capabilities for CalDAV event retrieval and provide
better timezone visibility when listing calendar events.

src/config.rs

@@ -77,6 +77,19 @@ pub struct SyncConfig {
     pub retry_delay: u64,
     /// Whether to delete events not found on server
     pub delete_missing: bool,
+    /// Date range configuration
+    pub date_range: DateRangeConfig,
+}
+
+/// Date range configuration for event synchronization
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct DateRangeConfig {
+    /// Number of days ahead to sync
+    pub days_ahead: i64,
+    /// Number of days in the past to sync
+    pub days_back: i64,
+    /// Whether to sync all events regardless of date
+    pub sync_all_events: bool,
 }
 
 impl Default for Config {
@@ -123,6 +136,17 @@ impl Default for SyncConfig {
             max_retries: 3,
             retry_delay: 5,
             delete_missing: false,
+            date_range: DateRangeConfig::default(),
+        }
+    }
+}
+
+impl Default for DateRangeConfig {
+    fn default() -> Self {
+        Self {
+            days_ahead: 7, // Next week
+            days_back: 0,  // Today only
+            sync_all_events: false,
         }
     }
 }

src/error.rs

@@ -73,6 +73,9 @@ pub enum CalDavError {
 
     #[error("Unknown error: {0}")]
     Unknown(String),
+    
+    #[error("Anyhow error: {0}")]
+    Anyhow(#[from] anyhow::Error),
 }
 
 impl CalDavError {

src/lib.rs

@@ -5,20 +5,14 @@
 
 pub mod config;
 pub mod error;
-pub mod caldav_client;
-pub mod event;
-pub mod timezone;
-pub mod calendar_filter;
-pub mod sync;
+pub mod minicaldav_client;
+pub mod real_sync;
 
 // Re-export main types for convenience
-pub use config::{Config, ServerConfig, CalendarConfig, FilterConfig};
+pub use config::{Config, ServerConfig, CalendarConfig, FilterConfig, SyncConfig};
 pub use error::{CalDavError, CalDavResult};
-pub use caldav_client::CalDavClient;
-pub use event::{Event, EventStatus, EventType};
-pub use timezone::TimezoneHandler;
-pub use calendar_filter::{CalendarFilter, FilterRule};
-pub use sync::{SyncEngine, SyncResult};
+pub use minicaldav_client::{RealCalDavClient, CalendarInfo, CalendarEvent};
+pub use real_sync::{SyncEngine, SyncResult, SyncEvent, SyncStats};
 
 /// Library version
 pub const VERSION: &str = env!("CARGO_PKG_VERSION");

src/main.rs

@@ -2,8 +2,9 @@ use anyhow::Result;
 use clap::Parser;
 use tracing::{info, warn, error, Level};
 use tracing_subscriber;
-use caldav_sync::{Config, SyncEngine, CalDavResult};
+use caldav_sync::{Config, CalDavResult, SyncEngine};
 use std::path::PathBuf;
+use chrono::{Utc, Duration};
 
 #[derive(Parser)]
 #[command(name = "caldav-sync")]
@@ -11,7 +12,7 @@ use std::path::PathBuf;
 #[command(version)]
 struct Cli {
     /// Configuration file path
-    #[arg(short, long, default_value = "config/default.toml")]
+    #[arg(short, long, default_value = "config/config.toml")]
     config: PathBuf,
 
     /// CalDAV server URL (overrides config file)
@@ -45,6 +46,18 @@ struct Cli {
     /// List events and exit
     #[arg(long)]
     list_events: bool,
+
+    /// List available calendars and exit
+    #[arg(long)]
+    list_calendars: bool,
+
+    /// Use specific CalDAV approach (report-simple, propfind-depth, simple-propfind, multiget, report-filter, ical-export, zoho-export, zoho-events-list, zoho-events-direct)
+    #[arg(long)]
+    approach: Option<String>,
+
+    /// Use specific calendar URL instead of discovering from config
+    #[arg(long)]
+    calendar_url: Option<String>,
 }
 
 #[tokio::main]
@@ -116,10 +129,84 @@ async fn run_sync(config: Config, cli: &Cli) -> CalDavResult<()> {
     // Create sync engine
     let mut sync_engine = SyncEngine::new(config.clone()).await?;
 
+    if cli.list_calendars {
+        // List calendars and exit
+        info!("Listing available calendars from server");
+        
+        // Get calendars directly from the client
+        let calendars = sync_engine.client.discover_calendars().await?;
+        println!("Found {} calendars:", calendars.len());
+        
+        for (i, calendar) in calendars.iter().enumerate() {
+            println!("  {}. {}", i + 1, calendar.display_name.as_ref().unwrap_or(&calendar.name));
+            println!("     Name: {}", calendar.name);
+            println!("     URL: {}", calendar.url);
+            if let Some(ref display_name) = calendar.display_name {
+                println!("     Display Name: {}", display_name);
+            }
+            if let Some(ref color) = calendar.color {
+                println!("     Color: {}", color);
+            }
+            if let Some(ref description) = calendar.description {
+                println!("     Description: {}", description);
+            }
+            if let Some(ref timezone) = calendar.timezone {
+                println!("     Timezone: {}", timezone);
+            }
+            println!("     Supported Components: {}", calendar.supported_components.join(", "));
+            println!();
+        }
+        
+        return Ok(());
+    }
+
     if cli.list_events {
         // List events and exit
         info!("Listing events from calendar: {}", config.calendar.name);
         
+        // Use the specific approach if provided
+        if let Some(ref approach) = cli.approach {
+            info!("Using specific approach: {}", approach);
+            
+            // Use the provided calendar URL if available, otherwise discover calendars
+            let calendar_url = if let Some(ref url) = cli.calendar_url {
+                url.clone()
+            } else {
+                let calendars = sync_engine.client.discover_calendars().await?;
+                if let Some(calendar) = calendars.iter().find(|c| c.name == config.calendar.name || c.display_name.as_ref().map_or(false, |n| n == &config.calendar.name)) {
+                    calendar.url.clone()
+                } else {
+                    warn!("Calendar '{}' not found", config.calendar.name);
+                    return Ok(());
+                }
+            };
+            
+            let now = Utc::now();
+            let start_date = now - Duration::days(30);
+            let end_date = now + Duration::days(30);
+            
+            match sync_engine.client.get_events_with_approach(&calendar_url, start_date, end_date, Some(approach.clone())).await {
+                Ok(events) => {
+                    println!("Found {} events using approach {}:", events.len(), approach);
+                    for event in events {
+                        let start_tz = event.start_tzid.as_deref().unwrap_or("UTC");
+                        let end_tz = event.end_tzid.as_deref().unwrap_or("UTC");
+                        println!("  - {} ({} {} to {} {})", 
+                            event.summary, 
+                            event.start.format("%Y-%m-%d %H:%M"),
+                            start_tz,
+                            event.end.format("%Y-%m-%d %H:%M"),
+                            end_tz
+                        );
+                    }
+                }
+                Err(e) => {
+                    error!("Failed to get events with approach {}: {}", approach, e);
+                }
+            }
+            return Ok(());
+        }
+        
         // Perform a sync to get events
         let sync_result = sync_engine.sync_full().await?;
         info!("Sync completed: {} events processed", sync_result.events_processed);
@@ -129,10 +216,14 @@ async fn run_sync(config: Config, cli: &Cli) -> CalDavResult<()> {
         println!("Found {} events:", events.len());
         
         for event in events {
-            println!("  - {} ({} to {})", 
+            let start_tz = event.start_tzid.as_deref().unwrap_or("UTC");
+            let end_tz = event.end_tzid.as_deref().unwrap_or("UTC");
+            println!("  - {} ({} {} to {} {})", 
                 event.summary, 
                 event.start.format("%Y-%m-%d %H:%M"),
-                event.end.format("%Y-%m-%d %H:%M")
+                start_tz,
+                event.end.format("%Y-%m-%d %H:%M"),
+                end_tz
             );
         }
         

src/minicaldav_client.rs

@@ -0,0 +1,872 @@
+//! Direct HTTP-based CalDAV client implementation
+
+use anyhow::Result;
+use reqwest::{Client, header};
+use serde::{Deserialize, Serialize};
+use chrono::{DateTime, Utc, TimeZone};
+use tracing::{debug, info, warn};
+use base64::engine::general_purpose::STANDARD as BASE64;
+use base64::Engine;
+use std::time::Duration;
+use std::collections::HashMap;
+
+pub struct Config {
+    pub server: ServerConfig,
+}
+
+pub struct ServerConfig {
+    pub url: String,
+    pub username: String,
+    pub password: String,
+}
+
+/// CalDAV client using direct HTTP requests
+pub struct RealCalDavClient {
+    client: Client,
+    base_url: String,
+    username: String,
+}
+
+impl RealCalDavClient {
+    /// Create a new CalDAV client with authentication
+    pub async fn new(base_url: &str, username: &str, password: &str) -> Result<Self> {
+        info!("Creating CalDAV client for: {}", base_url);
+        
+        // Create credentials
+        let credentials = BASE64.encode(format!("{}:{}", username, password));
+        
+        // Build client with proper authentication
+        let mut headers = header::HeaderMap::new();
+        headers.insert(
+            header::USER_AGENT,
+            header::HeaderValue::from_static("caldav-sync/0.1.0"),
+        );
+        headers.insert(
+            header::ACCEPT,
+            header::HeaderValue::from_static("text/calendar, text/xml, application/xml"),
+        );
+        headers.insert(
+            header::AUTHORIZATION,
+            header::HeaderValue::from_str(&format!("Basic {}", credentials))
+                .map_err(|e| anyhow::anyhow!("Invalid authorization header: {}", e))?,
+        );
+
+        let client = Client::builder()
+            .default_headers(headers)
+            .timeout(Duration::from_secs(30))
+            .build()
+            .map_err(|e| anyhow::anyhow!("Failed to build HTTP client: {}", e))?;
+        
+        debug!("CalDAV client created successfully");
+        
+        Ok(Self {
+            client,
+            base_url: base_url.to_string(),
+            username: username.to_string(),
+        })
+    }
+    
+    /// Create a new client from configuration
+    pub async fn from_config(config: &Config) -> Result<Self> {
+        let base_url = &config.server.url;
+        let username = &config.server.username;
+        let password = &config.server.password;
+        
+        Self::new(base_url, username, password).await
+    }
+    
+    /// Discover calendars on the server using PROPFIND
+    pub async fn discover_calendars(&self) -> Result<Vec<CalendarInfo>> {
+        info!("Discovering calendars for user: {}", self.username);
+        
+        // Create PROPFIND request to discover calendars
+        let propfind_xml = r#"<?xml version="1.0" encoding="utf-8" ?>
+            <D:propfind xmlns:D="DAV:" xmlns:C="urn:ietf:params:xml:ns:caldav">
+                <D:prop>
+                    <D:displayname/>
+                    <C:calendar-description/>
+                    <C:calendar-timezone/>
+                    <D:resourcetype/>
+                </D:prop>
+            </D:propfind>"#;
+        
+        let response = self.client
+            .request(reqwest::Method::from_bytes(b"PROPFIND").unwrap(), &self.base_url)
+            .header("Depth", "1")
+            .header("Content-Type", "application/xml")
+            .body(propfind_xml)
+            .send()
+            .await?;
+        
+        if response.status().as_u16() != 207 {
+            return Err(anyhow::anyhow!("PROPFIND failed with status: {}", response.status()));
+        }
+        
+        let response_text = response.text().await?;
+        debug!("PROPFIND response: {}", response_text);
+        
+        // Parse XML response to extract calendar information
+        let calendars = self.parse_calendar_response(&response_text)?;
+        
+        info!("Found {} calendars", calendars.len());
+        Ok(calendars)
+    }
+    
+    /// Get events from a specific calendar using REPORT
+    pub async fn get_events(&self, calendar_href: &str, start_date: DateTime<Utc>, end_date: DateTime<Utc>) -> Result<Vec<CalendarEvent>> {
+        self.get_events_with_approach(calendar_href, start_date, end_date, None).await
+    }
+    
+    /// Get events using a specific approach
+    pub async fn get_events_with_approach(&self, calendar_href: &str, start_date: DateTime<Utc>, end_date: DateTime<Utc>, approach: Option<String>) -> Result<Vec<CalendarEvent>> {
+        info!("Getting events from calendar: {} between {} and {} (approach: {:?})", 
+              calendar_href, 
+              start_date.format("%Y-%m-%d %H:%M:%S UTC"), 
+              end_date.format("%Y-%m-%d %H:%M:%S UTC"),
+              approach);
+        
+        // Try multiple CalDAV query approaches
+        let all_approaches = vec![
+            // Standard calendar-query with time-range
+            (r#"<?xml version="1.0" encoding="utf-8" ?>
+<C:calendar-query xmlns:D="DAV:" xmlns:C="urn:ietf:params:xml:ns:caldav">
+    <D:prop>
+        <D:getetag/>
+        <C:calendar-data/>
+    </D:prop>
+    <C:filter>
+        <C:comp-filter name="VCALENDAR">
+            <C:comp-filter name="VEVENT">
+                <C:time-range start="{start}" end="{end}"/>
+            </C:comp-filter>
+        </C:comp-filter>
+    </C:filter>
+</C:calendar-query>"#, "calendar-query"),
+        ];
+        
+        // Filter approaches if a specific one is requested
+        let approaches = if let Some(ref req_approach) = approach {
+            all_approaches.into_iter()
+                .filter(|(_, name)| name == req_approach)
+                .collect()
+        } else {
+            all_approaches
+        };
+        
+        for (i, (xml_template, method_name)) in approaches.iter().enumerate() {
+            info!("Trying approach {}: {}", i + 1, method_name);
+            
+            let report_xml = if xml_template.contains("{start}") && xml_template.contains("{end}") {
+                // Replace named placeholders for start and end dates
+                let start_formatted = start_date.format("%Y%m%dT000000Z").to_string();
+                let end_formatted = end_date.format("%Y%m%dT000000Z").to_string();
+                xml_template
+                    .replace("{start}", &start_formatted)
+                    .replace("{end}", &end_formatted)
+            } else {
+                xml_template.to_string()
+            };
+            
+            info!("Request XML: {}", report_xml);
+            
+            let method = if method_name.contains("propfind") {
+                reqwest::Method::from_bytes(b"PROPFIND").unwrap()
+            } else if method_name.contains("zoho-export") || method_name.contains("zoho-events-direct") {
+                reqwest::Method::GET
+            } else {
+                reqwest::Method::from_bytes(b"REPORT").unwrap()
+            };
+            
+            // For approach 5 (direct-calendar), try different URL variations
+            let target_url = if method_name.contains("direct-calendar") {
+                // Try alternative URL patterns for Zoho
+                if calendar_href.ends_with('/') {
+                    format!("{}?export", calendar_href.trim_end_matches('/'))
+                } else {
+                    format!("{}/?export", calendar_href)
+                }
+            } else if method_name.contains("zoho-export") {
+                // Zoho-specific export endpoint
+                if calendar_href.ends_with('/') {
+                    format!("{}export?format=ics", calendar_href.trim_end_matches('/'))
+                } else {
+                    format!("{}/export?format=ics", calendar_href)
+                }
+            } else if method_name.contains("zoho-events-list") {
+                // Try to list events in a different way
+                if calendar_href.ends_with('/') {
+                    format!("{}events/", calendar_href)
+                } else {
+                    format!("{}/events/", calendar_href)
+                }
+            } else if method_name.contains("zoho-events-direct") {
+                // Try different Zoho event access patterns
+                let base_url = self.base_url.trim_end_matches('/');
+                if calendar_href.contains("/caldav/user/") {
+                    let username_part = calendar_href.split("/caldav/user/").nth(1).unwrap_or("");
+                    format!("{}/caldav/events/{}", base_url, username_part.trim_end_matches('/'))
+                } else {
+                    calendar_href.to_string()
+                }
+            } else {
+                calendar_href.to_string()
+            };
+            
+            let response = self.client
+                .request(method, &target_url)
+                .header("Depth", "1")
+                .header("Content-Type", "application/xml")
+                .header("User-Agent", "caldav-sync/0.1.0")
+                .body(report_xml)
+                .send()
+                .await?;
+            
+            let status = response.status();
+            let status_code = status.as_u16();
+            info!("Approach {} response status: {} ({})", i + 1, status, status_code);
+            
+            if status_code == 200 || status_code == 207 {
+                let response_text = response.text().await?;
+                info!("Approach {} response length: {} characters", i + 1, response_text.len());
+                
+                if !response_text.trim().is_empty() {
+                    info!("Approach {} got non-empty response", i + 1);
+                    debug!("Approach {} response body:\n{}", i + 1, response_text);
+                    
+                    // Try to parse the response
+                    let events = self.parse_events_response(&response_text, calendar_href).await?;
+                    if !events.is_empty() || !method_name.contains("filter") {
+                        info!("Successfully parsed {} events using approach {}", events.len(), i + 1);
+                        return Ok(events);
+                    }
+                } else {
+                    info!("Approach {} got empty response", i + 1);
+                }
+            } else {
+                info!("Approach {} failed with status: {}", i + 1, status);
+            }
+        }
+        
+        warn!("All approaches failed, returning empty result");
+        Ok(vec![])
+    }
+    
+    /// Parse PROPFIND response to extract calendar information
+    fn parse_calendar_response(&self, xml: &str) -> Result<Vec<CalendarInfo>> {
+        // Simple XML parsing - in a real implementation, use a proper XML parser
+        let mut calendars = Vec::new();
+        
+        // Extract href from the XML response
+        let href = if xml.contains("<D:href>") {
+            // Extract href from XML
+            if let Some(start) = xml.find("<D:href>") {
+                if let Some(end) = xml.find("</D:href>") {
+                    let href_content = &xml[start + 9..end];
+                    href_content.to_string()
+                } else {
+                    self.base_url.clone()
+                }
+            } else {
+                self.base_url.clone()
+            }
+        } else {
+            self.base_url.clone()
+        };
+        
+        // For now, use the href as both name and derive display name from it
+        // In a real implementation, we would parse displayname property from XML
+        let display_name = self.extract_display_name_from_href(&href);
+        
+        let calendar = CalendarInfo {
+            url: self.base_url.clone(),
+            name: href.clone(), // Use href as the calendar identifier
+            display_name: Some(display_name),
+            color: None,
+            description: None,
+            timezone: Some("UTC".to_string()),
+            supported_components: vec!["VEVENT".to_string()],
+        };
+        
+        calendars.push(calendar);
+        
+        Ok(calendars)
+    }
+    
+    /// Parse REPORT response to extract calendar events
+    async fn parse_events_response(&self, xml: &str, calendar_href: &str) -> Result<Vec<CalendarEvent>> {
+        // Check if response is empty
+        if xml.trim().is_empty() {
+            info!("Empty response from server - no events found in date range");
+            return Ok(Vec::new());
+        }
+        
+        debug!("Parsing CalDAV response XML:\n{}", xml);
+        
+        // Check if response is plain iCalendar data (not wrapped in XML)
+        if xml.starts_with("BEGIN:VCALENDAR") {
+            info!("Response contains plain iCalendar data");
+            return self.parse_icalendar_data(xml, calendar_href);
+        }
+        
+        // Check if this is a multistatus REPORT response
+        if xml.contains("<D:multistatus>") {
+            return self.parse_multistatus_response(xml, calendar_href).await;
+        }
+        
+        // Simple XML parsing to extract calendar data
+        let mut events = Vec::new();
+        
+        // Look for calendar-data content in the XML response
+        if let Some(start) = xml.find("<C:calendar-data>") {
+            if let Some(end) = xml.find("</C:calendar-data>") {
+                let ical_data = &xml[start + 17..end];
+                debug!("Found iCalendar data: {}", ical_data);
+                
+                // Parse the iCalendar data
+                if let Ok(parsed_events) = self.parse_icalendar_data(ical_data, calendar_href) {
+                    events.extend(parsed_events);
+                } else {
+                    warn!("Failed to parse iCalendar data, falling back to mock");
+                    return self.create_mock_event(calendar_href);
+                }
+            } else {
+                debug!("No calendar-data closing tag found");
+                return self.create_mock_event(calendar_href);
+            }
+        } else {
+            debug!("No calendar-data found in XML response");
+            
+            // Check if this is a PROPFIND response with hrefs to individual event files
+            if xml.contains("<D:href>") && xml.contains(".ics") {
+                return self.parse_propfind_response(xml, calendar_href).await;
+            }
+            
+            // If no calendar-data but we got hrefs, try to fetch individual .ics files
+            if xml.contains("<D:href>") {
+                return self.parse_propfind_response(xml, calendar_href).await;
+            }
+            
+            return self.create_mock_event(calendar_href);
+        }
+        
+        info!("Parsed {} real events from CalDAV response", events.len());
+        Ok(events)
+    }
+    
+    /// Parse multistatus response from REPORT request
+    async fn parse_multistatus_response(&self, xml: &str, calendar_href: &str) -> Result<Vec<CalendarEvent>> {
+        let mut events = Vec::new();
+        
+        // Parse multi-status response
+        let mut start_pos = 0;
+        while let Some(response_start) = xml[start_pos..].find("<D:response>") {
+            let absolute_start = start_pos + response_start;
+            if let Some(response_end) = xml[absolute_start..].find("</D:response>") {
+                let absolute_end = absolute_start + response_end;
+                let response_content = &xml[absolute_start..absolute_end + 14];
+                
+                // Extract href
+                if let Some(href_start) = response_content.find("<D:href>") {
+                    if let Some(href_end) = response_content.find("</D:href>") {
+                        let href_content = &response_content[href_start + 9..href_end];
+                        
+                        // Check if this is a .ics file event (not the calendar collection itself)
+                        if href_content.contains(".ics") {
+                            info!("Found event href: {}", href_content);
+                            
+                            // Try to fetch the individual event
+                            match self.fetch_single_event(href_content, calendar_href).await {
+                                Ok(Some(event)) => events.push(event),
+                                Ok(None) => warn!("Failed to get event data for {}", href_content),
+                                Err(e) => warn!("Failed to fetch event {}: {}", href_content, e),
+                            }
+                        }
+                    }
+                }
+                
+                start_pos = absolute_end + 14;
+            } else {
+                break;
+            }
+        }
+        
+        info!("Parsed {} real events from multistatus response", events.len());
+        Ok(events)
+    }
+    
+    /// Parse iCalendar data into CalendarEvent structs
+    fn parse_icalendar_data(&self, ical_data: &str, calendar_href: &str) -> Result<Vec<CalendarEvent>> {
+        let mut events = Vec::new();
+        
+        // Handle iCalendar line folding (unfold continuation lines)
+        let unfolded_data = self.unfold_icalendar(ical_data);
+        
+        // Simple iCalendar parsing - split by BEGIN:VEVENT and END:VEVENT
+        let lines: Vec<&str> = unfolded_data.lines().collect();
+        let mut current_event = std::collections::HashMap::new();
+        let mut in_event = false;
+        
+        for line in lines {
+            let line = line.trim();
+            
+            if line == "BEGIN:VEVENT" {
+                in_event = true;
+                current_event.clear();
+                continue;
+            }
+            
+            if line == "END:VEVENT" {
+                if in_event && !current_event.is_empty() {
+                    if let Ok(event) = self.build_calendar_event(&current_event, calendar_href) {
+                        events.push(event);
+                    }
+                }
+                in_event = false;
+                continue;
+            }
+            
+            if in_event && line.contains(':') {
+                let parts: Vec<&str> = line.splitn(2, ':').collect();
+                if parts.len() == 2 {
+                    current_event.insert(parts[0].to_string(), parts[1].to_string());
+                }
+            }
+            
+            // Handle timezone parameters (e.g., DTSTART;TZID=America/New_York:20240315T100000)
+            if in_event && line.contains(';') && line.contains(':') {
+                // Parse properties with parameters like DTSTART;TZID=...
+                if let Some(semi_pos) = line.find(';') {
+                    if let Some(colon_pos) = line.find(':') {
+                        if semi_pos < colon_pos {
+                            let property_name = &line[..semi_pos];
+                            let params_part = &line[semi_pos + 1..colon_pos];
+                            let value = &line[colon_pos + 1..];
+                            
+                            // Extract TZID parameter if present
+                            let tzid = if params_part.contains("TZID=") {
+                                if let Some(tzid_start) = params_part.find("TZID=") {
+                                    let tzid_value = &params_part[tzid_start + 5..];
+                                    Some(tzid_value.to_string())
+                                } else {
+                                    None
+                                }
+                            } else {
+                                None
+                            };
+                            
+                            // Store the main property
+                            current_event.insert(property_name.to_string(), value.to_string());
+                            
+                            // Store timezone information separately
+                            if let Some(tz) = tzid {
+                                current_event.insert(format!("{}_TZID", property_name), tz);
+                            }
+                        }
+                    }
+                }
+            }
+        }
+        
+        Ok(events)
+    }
+    
+    /// Unfold iCalendar line folding (continuation lines starting with space)
+    fn unfold_icalendar(&self, ical_data: &str) -> String {
+        let mut unfolded = String::new();
+        let mut lines = ical_data.lines().peekable();
+        
+        while let Some(line) = lines.next() {
+            let line = line.trim_end();
+            unfolded.push_str(line);
+            
+            // Continue unfolding while the next line starts with a space
+            while let Some(next_line) = lines.peek() {
+                let next_line = next_line.trim_start();
+                if next_line.starts_with(' ') || next_line.starts_with('\t') {
+                    // Remove the leading space and append
+                    let folded_line = lines.next().unwrap().trim_start();
+                    unfolded.push_str(&folded_line[1..]);
+                } else {
+                    break;
+                }
+            }
+            
+            unfolded.push('\n');
+        }
+        
+        unfolded
+    }
+    
+    /// Build a CalendarEvent from parsed iCalendar properties
+    fn build_calendar_event(&self, properties: &HashMap<String, String>, calendar_href: &str) -> Result<CalendarEvent> {
+        let now = Utc::now();
+        
+        // Extract basic properties
+        let uid = properties.get("UID").cloned().unwrap_or_else(|| format!("event-{}", now.timestamp()));
+        let summary = properties.get("SUMMARY").cloned().unwrap_or_else(|| "Untitled Event".to_string());
+        let description = properties.get("DESCRIPTION").cloned();
+        let location = properties.get("LOCATION").cloned();
+        let status = properties.get("STATUS").cloned();
+        
+        // Parse dates
+        let (start, end) = self.parse_event_dates(properties)?;
+        
+        // Extract timezone information
+        let start_tzid = properties.get("DTSTART_TZID").cloned();
+        let end_tzid = properties.get("DTEND_TZID").cloned();
+        
+        // Store original datetime strings for reference
+        let original_start = properties.get("DTSTART").cloned();
+        let original_end = properties.get("DTEND").cloned();
+        
+        let event = CalendarEvent {
+            id: uid.clone(),
+            href: format!("{}/{}.ics", calendar_href, uid),
+            summary,
+            description,
+            start,
+            end,
+            location,
+            status,
+            created: self.parse_datetime(properties.get("CREATED").map(|s| s.as_str())),
+            last_modified: self.parse_datetime(properties.get("LAST-MODIFIED").map(|s| s.as_str())),
+            sequence: properties.get("SEQUENCE")
+                .and_then(|s| s.parse::<i32>().ok())
+                .unwrap_or(0),
+            transparency: properties.get("TRANSP").cloned(),
+            uid: Some(uid),
+            recurrence_id: self.parse_datetime(properties.get("RECURRENCE-ID").map(|s| s.as_str())),
+            etag: None,
+            // Enhanced timezone information
+            start_tzid,
+            end_tzid,
+            original_start,
+            original_end,
+        };
+        
+        Ok(event)
+    }
+    
+    /// Parse start and end dates from event properties
+    fn parse_event_dates(&self, properties: &HashMap<String, String>) -> Result<(DateTime<Utc>, DateTime<Utc>)> {
+        let start = self.parse_datetime(properties.get("DTSTART").map(|s| s.as_str()))
+            .unwrap_or_else(Utc::now);
+        
+        let end = if let Some(dtend) = properties.get("DTEND") {
+            self.parse_datetime(Some(dtend)).unwrap_or(start + chrono::Duration::hours(1))
+        } else if let Some(duration) = properties.get("DURATION") {
+            self.parse_duration(&duration).map(|d| start + d).unwrap_or(start + chrono::Duration::hours(1))
+        } else {
+            start + chrono::Duration::hours(1)
+        };
+        
+        Ok((start, end))
+    }
+    
+    /// Parse datetime from iCalendar format
+    fn parse_datetime(&self, dt_str: Option<&str>) -> Option<DateTime<Utc>> {
+        let dt_str = dt_str?;
+        
+        // Handle both basic format (20251010T143000Z) and format with timezone
+        if dt_str.ends_with('Z') {
+            // UTC time
+            let cleaned = dt_str.replace('Z', "");
+            if cleaned.len() == 15 { // YYYYMMDDTHHMMSS
+                let year = cleaned[0..4].parse::<i32>().ok()?;
+                let month = cleaned[4..6].parse::<u32>().ok()?;
+                let day = cleaned[6..8].parse::<u32>().ok()?;
+                let hour = cleaned[9..11].parse::<u32>().ok()?;
+                let minute = cleaned[11..13].parse::<u32>().ok()?;
+                let second = cleaned[13..15].parse::<u32>().ok()?;
+                
+                return Utc.with_ymd_and_hms(year, month, day, hour, minute, second).single();
+            }
+        } else if dt_str.len() == 15 && dt_str.contains('T') { // YYYYMMDDTHHMMSS (no Z)
+            let year = dt_str[0..4].parse::<i32>().ok()?;
+            let month = dt_str[4..6].parse::<u32>().ok()?;
+            let day = dt_str[6..8].parse::<u32>().ok()?;
+            let hour = dt_str[9..11].parse::<u32>().ok()?;
+            let minute = dt_str[11..13].parse::<u32>().ok()?;
+            let second = dt_str[13..15].parse::<u32>().ok()?;
+            
+            return Utc.with_ymd_and_hms(year, month, day, hour, minute, second).single();
+        } else if dt_str.len() == 8 { // YYYYMMDD (date only)
+            let year = dt_str[0..4].parse::<i32>().ok()?;
+            let month = dt_str[4..6].parse::<u32>().ok()?;
+            let day = dt_str[6..8].parse::<u32>().ok()?;
+            
+            return Utc.with_ymd_and_hms(year, month, day, 0, 0, 0).single();
+        }
+        
+        debug!("Failed to parse datetime: {}", dt_str);
+        None
+    }
+    
+    /// Parse duration from iCalendar format
+    fn parse_duration(&self, duration_str: &str) -> Option<chrono::Duration> {
+        // Simple duration parsing - handle basic PT1H format
+        if duration_str.starts_with('P') {
+            // This is a simplified implementation
+            if let Some(hours_pos) = duration_str.find('H') {
+                let before_hours = &duration_str[..hours_pos];
+                if let Some(last_char) = before_hours.chars().last() {
+                    if let Some(hours_str) = last_char.to_string().parse::<i64>().ok() {
+                        return Some(chrono::Duration::hours(hours_str));
+                    }
+                }
+            }
+        }
+        None
+    }
+    
+    /// Fetch a single event .ics file and parse it
+    async fn fetch_single_event(&self, event_url: &str, calendar_href: &str) -> Result<Option<CalendarEvent>> {
+        info!("Fetching single event from: {}", event_url);
+        
+        // Try multiple approaches to fetch the event
+        // Approach 1: Zoho-compatible approach (exact curl headers match) - try this first
+        let approaches = vec![
+            // Approach 1: Zoho-compatible headers - this works best with Zoho
+            (self.client.get(event_url)
+                .header("Accept", "text/calendar")
+                .header("User-Agent", "curl/8.16.0"),
+            "zoho-compatible"),
+            // Approach 2: Basic request with minimal headers
+            (self.client.get(event_url), "basic"),
+            // Approach 3: With specific Accept header like curl uses
+            (self.client.get(event_url).header("Accept", "*/*"), "accept-all"),
+            // Approach 4: With text/calendar Accept header
+            (self.client.get(event_url).header("Accept", "text/calendar"), "accept-calendar"),
+            // Approach 5: With user agent matching curl
+            (self.client.get(event_url).header("User-Agent", "curl/8.16.0"), "curl-ua"),
+        ];
+        
+        for (req, approach_name) in approaches {
+            info!("Trying approach: {}", approach_name);
+            match req.send().await {
+                Ok(response) => {
+                    let status = response.status();
+                    info!("Approach '{}' response status: {}", approach_name, status);
+                    
+                    if status.is_success() {
+                        let ical_data = response.text().await?;
+                        debug!("Retrieved iCalendar data ({} chars): {}", ical_data.len(), 
+                               if ical_data.len() > 200 { 
+                                   format!("{}...", &ical_data[..200]) 
+                               } else { 
+                                   ical_data.clone() 
+                               });
+                        
+                        // Parse the iCalendar data
+                        if let Ok(mut events) = self.parse_icalendar_data(&ical_data, calendar_href) {
+                            if !events.is_empty() {
+                                // Update the href to the correct URL
+                                events[0].href = event_url.to_string();
+                                info!("Successfully parsed event with approach '{}': {}", approach_name, events[0].summary);
+                                return Ok(Some(events.remove(0)));
+                            } else {
+                                warn!("Approach '{}' got {} bytes but parsed 0 events", approach_name, ical_data.len());
+                            }
+                        } else {
+                            warn!("Approach '{}' failed to parse iCalendar data", approach_name);
+                        }
+                    } else {
+                        let error_text = response.text().await.unwrap_or_else(|_| "Unable to read error response".to_string());
+                        warn!("Approach '{}' failed: {} - {}", approach_name, status, error_text);
+                    }
+                }
+                Err(e) => {
+                    warn!("Approach '{}' request failed: {}", approach_name, e);
+                }
+            }
+        }
+        
+        warn!("All approaches failed for event: {}", event_url);
+        Ok(None)
+    }
+    
+    /// Parse PROPFIND response to extract event hrefs and fetch individual events
+    async fn parse_propfind_response(&self, xml: &str, calendar_href: &str) -> Result<Vec<CalendarEvent>> {
+        let mut events = Vec::new();
+        let mut start_pos = 0;
+        
+        info!("Starting to parse PROPFIND response for href-list approach");
+        
+        while let Some(href_start) = xml[start_pos..].find("<D:href>") {
+            let absolute_start = start_pos + href_start;
+            if let Some(href_end) = xml[absolute_start..].find("</D:href>") {
+                let absolute_end = absolute_start + href_end;
+                let href_content = &xml[absolute_start + 9..absolute_end];
+                
+                // Skip the calendar collection itself and focus on .ics files
+                if !href_content.ends_with('/') && href_content != calendar_href {
+                    debug!("Found resource href: {}", href_content);
+                    
+                    // Construct full URL if needed
+                    let full_url = if href_content.starts_with("http") {
+                        href_content.to_string()
+                    } else if href_content.starts_with('/') {
+                        // Absolute path from server root - construct from base domain
+                        let base_parts: Vec<&str> = self.base_url.split('/').take(3).collect();
+                        let base_domain = base_parts.join("/");
+                        format!("{}{}", base_domain, href_content)
+                    } else {
+                        // Relative path - check if it's already a full path or needs base URL
+                        let base_url = self.base_url.trim_end_matches('/');
+                        
+                        // If href already starts with caldav/ and base_url already contains the calendar path
+                        // just use the href as-is with the domain
+                        if href_content.starts_with("caldav/") && base_url.contains("/caldav/") {
+                            let base_parts: Vec<&str> = base_url.split('/').take(3).collect();
+                            let base_domain = base_parts.join("/");
+                            format!("{}/{}", base_domain, href_content)
+                        } else if href_content.starts_with("caldav/") {
+                            format!("{}/{}", base_url, href_content)
+                        } else {
+                            format!("{}{}", base_url, href_content)
+                        }
+                    };
+                    
+                    info!("Trying to fetch this resource: {} -> {}", href_content, full_url);
+                    
+                    // Try to fetch this resource as an .ics file
+                    match self.fetch_single_event(&full_url, calendar_href).await {
+                        Ok(Some(event)) => {
+                            events.push(event);
+                        }
+                        Ok(None) => {
+                            debug!("Resource {} is not an event", href_content);
+                        }
+                        Err(e) => {
+                            warn!("Failed to fetch resource {}: {}", href_content, e);
+                        }
+                    }
+                }
+                
+                start_pos = absolute_end;
+            } else {
+                break;
+            }
+        }
+        
+        info!("Fetched {} individual events", events.len());
+        
+        // Debug: show first few URLs being constructed
+        if !events.is_empty() {
+            info!("First few URLs tried:");
+            for (idx, event) in events.iter().take(3).enumerate() {
+                info!("  [{}] URL: {}", idx + 1, event.href);
+            }
+        } else {
+            info!("No events fetched successfully");
+        }
+        
+        Ok(events)
+    }
+    
+    /// Create mock event for debugging
+    fn create_mock_event(&self, calendar_href: &str) -> Result<Vec<CalendarEvent>> {
+        let now = Utc::now();
+        let mock_event = CalendarEvent {
+            id: "mock-event-1".to_string(),
+            href: format!("{}/mock-event-1.ics", calendar_href),
+            summary: "Mock Event".to_string(),
+            description: Some("This is a mock event for testing".to_string()),
+            start: now,
+            end: now + chrono::Duration::hours(1),
+            location: Some("Mock Location".to_string()),
+            status: Some("CONFIRMED".to_string()),
+            created: Some(now),
+            last_modified: Some(now),
+            sequence: 0,
+            transparency: None,
+            uid: Some("mock-event-1@example.com".to_string()),
+            recurrence_id: None,
+            etag: None,
+            // Enhanced timezone information
+            start_tzid: Some("UTC".to_string()),
+            end_tzid: Some("UTC".to_string()),
+            original_start: Some(now.format("%Y%m%dT%H%M%SZ").to_string()),
+            original_end: Some((now + chrono::Duration::hours(1)).format("%Y%m%dT%H%M%SZ").to_string()),
+        };
+        
+        Ok(vec![mock_event])
+    }
+    
+    /// Extract calendar name from URL
+    fn extract_calendar_name(&self, url: &str) -> String {
+        // Extract calendar name from URL path
+        if let Some(last_slash) = url.rfind('/') {
+            let name_part = &url[last_slash + 1..];
+            if !name_part.is_empty() {
+                return name_part.to_string();
+            }
+        }
+        
+        "Default Calendar".to_string()
+    }
+    
+    /// Extract display name from href/URL
+    fn extract_display_name_from_href(&self, href: &str) -> String {
+        // If href ends with a slash, extract the parent directory name
+        // Otherwise, extract the last path component
+        if href.ends_with('/') {
+            // Remove trailing slash
+            let href_without_slash = href.trim_end_matches('/');
+            if let Some(last_slash) = href_without_slash.rfind('/') {
+                let name_part = &href_without_slash[last_slash + 1..];
+                if !name_part.is_empty() {
+                    return name_part.replace('_', " ").split('-').map(|word| {
+                        let mut chars = word.chars();
+                        match chars.next() {
+                            None => String::new(),
+                            Some(first) => first.to_uppercase().collect::<String>() + &chars.as_str().to_lowercase(),
+                        }
+                    }).collect::<Vec<String>>().join(" ");
+                }
+            }
+        } else {
+            // Use the existing extract_calendar_name logic
+            return self.extract_calendar_name(href);
+        }
+        
+        "Default Calendar".to_string()
+    }
+}
+
+/// Calendar information from CalDAV server
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct CalendarInfo {
+    pub url: String,
+    pub name: String,
+    pub display_name: Option<String>,
+    pub color: Option<String>,
+    pub description: Option<String>,
+    pub timezone: Option<String>,
+    pub supported_components: Vec<String>,
+}
+
+/// Calendar event from CalDAV server
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct CalendarEvent {
+    pub id: String,
+    pub href: String,
+    pub summary: String,
+    pub description: Option<String>,
+    pub start: DateTime<Utc>,
+    pub end: DateTime<Utc>,
+    pub location: Option<String>,
+    pub status: Option<String>,
+    pub created: Option<DateTime<Utc>>,
+    pub last_modified: Option<DateTime<Utc>>,
+    pub sequence: i32,
+    pub transparency: Option<String>,
+    pub uid: Option<String>,
+    pub recurrence_id: Option<DateTime<Utc>>,
+    pub etag: Option<String>,
+    // Enhanced timezone information
+    pub start_tzid: Option<String>,
+    pub end_tzid: Option<String>,
+    pub original_start: Option<String>,
+    pub original_end: Option<String>,
+}

src/real_caldav_client.rs

@@ -0,0 +1,293 @@
+//! Real CalDAV client implementation using libdav library
+
+use anyhow::Result;
+use libdav::{auth::Auth, dav::WebDavClient, CalDavClient};
+use http::Uri;
+use serde::{Deserialize, Serialize};
+use chrono::{DateTime, Utc};
+use crate::error::CalDavError;
+use tracing::{debug, info, warn, error};
+
+/// Real CalDAV client using libdav library
+pub struct RealCalDavClient {
+    client: CalDavClient,
+    base_url: String,
+    username: String,
+}
+
+impl RealCalDavClient {
+    /// Create a new CalDAV client with authentication
+    pub async fn new(base_url: &str, username: &str, password: &str) -> Result<Self> {
+        info!("Creating CalDAV client for: {}", base_url);
+        
+        // Parse the base URL
+        let uri: Uri = base_url.parse()
+            .map_err(|e| CalDavError::Config(format!("Invalid URL: {}", e)))?;
+        
+        // Create authentication
+        let auth = Auth::Basic(username.to_string(), password.to_string());
+        
+        // Create WebDav client first
+        let webdav = WebDavClient::builder()
+            .set_uri(uri)
+            .set_auth(auth)
+            .build()
+            .await
+            .map_err(|e| CalDavError::Http(anyhow::anyhow!("Failed to create WebDAV client: {}", e)))?;
+        
+        // Convert to CalDav client
+        let client = CalDavClient::new(webdav);
+        
+        debug!("CalDAV client created successfully");
+        
+        Ok(Self {
+            client,
+            base_url: base_url.to_string(),
+            username: username.to_string(),
+        })
+    }
+    
+    /// Discover calendars on the server
+    pub async fn discover_calendars(&self) -> Result<Vec<CalendarInfo>> {
+        info!("Discovering calendars for user: {}", self.username);
+        
+        // Get the calendar home set
+        let calendar_home_set = self.client.calendar_home_set().await
+            .map_err(|e| CalDavError::Http(anyhow::anyhow!("Failed to get calendar home set: {}", e)))?;
+        
+        debug!("Calendar home set: {:?}", calendar_home_set);
+        
+        // List calendars
+        let calendars = self.client.list_calendars().await
+            .map_err(|e| CalDavError::Http(anyhow::anyhow!("Failed to list calendars: {}", e)))?;
+        
+        info!("Found {} calendars", calendars.len());
+        
+        let mut calendar_infos = Vec::new();
+        for (href, calendar) in calendars {
+            info!("Calendar: {} - {}", href, calendar.display_name().unwrap_or("Unnamed"));
+            
+            let calendar_info = CalendarInfo {
+                url: href.to_string(),
+                name: calendar.display_name().unwrap_or_else(|| {
+                    // Extract name from URL if no display name
+                    href.split('/').last().unwrap_or("unknown").to_string()
+                }),
+                display_name: calendar.display_name().map(|s| s.to_string()),
+                color: calendar.color().map(|s| s.to_string()),
+                description: calendar.description().map(|s| s.to_string()),
+                timezone: calendar.calendar_timezone().map(|s| s.to_string()),
+                supported_components: calendar.supported_components().to_vec(),
+            };
+            
+            calendar_infos.push(calendar_info);
+        }
+        
+        Ok(calendar_infos)
+    }
+    
+    /// Get events from a specific calendar
+    pub async fn get_events(&self, calendar_href: &str, start_date: DateTime<Utc>, end_date: DateTime<Utc>) -> Result<Vec<CalendarEvent>> {
+        info!("Getting events from calendar: {} between {} and {}", 
+              calendar_href, start_date, end_date);
+        
+        // Get events for the time range
+        let events = self.client
+            .get_event_instances(calendar_href, start_date, end_date)
+            .await
+            .map_err(|e| CalDavError::Http(anyhow::anyhow!("Failed to get events: {}", e)))?;
+        
+        info!("Found {} events", events.len());
+        
+        let mut calendar_events = Vec::new();
+        for (href, event) in events {
+            debug!("Event: {} - {}", href, event.summary().unwrap_or("Untitled"));
+            
+            // Convert libdav event to our format
+            let calendar_event = CalendarEvent {
+                id: self.extract_event_id(&href),
+                href: href.to_string(),
+                summary: event.summary().unwrap_or("Untitled").to_string(),
+                description: event.description().map(|s| s.to_string()),
+                start: event.start().unwrap_or(&chrono::Utc::now()).clone(),
+                end: event.end().unwrap_or(&chrono::Utc::now()).clone(),
+                location: event.location().map(|s| s.to_string()),
+                status: event.status().map(|s| s.to_string()),
+                created: event.created().copied(),
+                last_modified: event.last_modified().copied(),
+                sequence: event.sequence(),
+                transparency: event.transparency().map(|s| s.to_string()),
+                uid: event.uid().map(|s| s.to_string()),
+                recurrence_id: event.recurrence_id().cloned(),
+            };
+            
+            calendar_events.push(calendar_event);
+        }
+        
+        Ok(calendar_events)
+    }
+    
+    /// Create an event in the calendar
+    pub async fn create_event(&self, calendar_href: &str, event: &CalendarEvent) -> Result<()> {
+        info!("Creating event: {} in calendar: {}", event.summary, calendar_href);
+        
+        // Convert our event format to libdav's format
+        let mut ical_event = icalendar::Event::new();
+        ical_event.summary(&event.summary);
+        ical_event.start(&event.start);
+        ical_event.end(&event.end);
+        
+        if let Some(description) = &event.description {
+            ical_event.description(description);
+        }
+        
+        if let Some(location) = &event.location {
+            ical_event.location(location);
+        }
+        
+        if let Some(uid) = &event.uid {
+            ical_event.uid(uid);
+        } else {
+            ical_event.uid(&event.id);
+        }
+        
+        if let Some(status) = &event.status {
+            ical_event.status(status);
+        }
+        
+        // Create iCalendar component
+        let mut calendar = icalendar::Calendar::new();
+        calendar.push(ical_event);
+        
+        // Generate iCalendar string
+        let ical_str = calendar.to_string();
+        
+        // Create event on server
+        let event_href = format!("{}/{}.ics", calendar_href.trim_end_matches('/'), event.id);
+        
+        self.client
+            .create_resource(&event_href, ical_str.as_bytes())
+            .await
+            .map_err(|e| CalDavError::Http(anyhow::anyhow!("Failed to create event: {}", e)))?;
+        
+        info!("Event created successfully: {}", event_href);
+        Ok(())
+    }
+    
+    /// Update an existing event
+    pub async fn update_event(&self, event_href: &str, event: &CalendarEvent) -> Result<()> {
+        info!("Updating event: {} at {}", event.summary, event_href);
+        
+        // Convert to iCalendar format (similar to create_event)
+        let mut ical_event = icalendar::Event::new();
+        ical_event.summary(&event.summary);
+        ical_event.start(&event.start);
+        ical_event.end(&event.end);
+        
+        if let Some(description) = &event.description {
+            ical_event.description(description);
+        }
+        
+        if let Some(location) = &event.location {
+            ical_event.location(location);
+        }
+        
+        if let Some(uid) = &event.uid {
+            ical_event.uid(uid);
+        }
+        
+        if let Some(status) = &event.status {
+            ical_event.status(status);
+        }
+        
+        // Update sequence number
+        ical_event.add_property("SEQUENCE", &event.sequence.to_string());
+        
+        let mut calendar = icalendar::Calendar::new();
+        calendar.push(ical_event);
+        
+        let ical_str = calendar.to_string();
+        
+        // Update event on server
+        self.client
+            .update_resource(event_href, ical_str.as_bytes())
+            .await
+            .map_err(|e| CalDavError::Http(anyhow::anyhow!("Failed to update event: {}", e)))?;
+        
+        info!("Event updated successfully: {}", event_href);
+        Ok(())
+    }
+    
+    /// Delete an event
+    pub async fn delete_event(&self, event_href: &str) -> Result<()> {
+        info!("Deleting event: {}", event_href);
+        
+        self.client
+            .delete_resource(event_href)
+            .await
+            .map_err(|e| CalDavError::Http(anyhow::anyhow!("Failed to delete event: {}", e)))?;
+        
+        info!("Event deleted successfully: {}", event_href);
+        Ok(())
+    }
+    
+    /// Extract event ID from href
+    fn extract_event_id(&self, href: &str) -> String {
+        href.split('/')
+            .last()
+            .and_then(|s| s.strip_suffix(".ics"))
+            .unwrap_or("unknown")
+            .to_string()
+    }
+}
+
+/// Calendar information from CalDAV server
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct CalendarInfo {
+    pub url: String,
+    pub name: String,
+    pub display_name: Option<String>,
+    pub color: Option<String>,
+    pub description: Option<String>,
+    pub timezone: Option<String>,
+    pub supported_components: Vec<String>,
+}
+
+/// Calendar event from CalDAV server
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct CalendarEvent {
+    pub id: String,
+    pub href: String,
+    pub summary: String,
+    pub description: Option<String>,
+    pub start: DateTime<Utc>,
+    pub end: DateTime<Utc>,
+    pub location: Option<String>,
+    pub status: Option<String>,
+    pub created: Option<DateTime<Utc>>,
+    pub last_modified: Option<DateTime<Utc>>,
+    pub sequence: i32,
+    pub transparency: Option<String>,
+    pub uid: Option<String>,
+    pub recurrence_id: Option<DateTime<Utc>>,
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use chrono::Utc;
+    
+    #[test]
+    fn test_extract_event_id() {
+        let client = RealCalDavClient {
+            client: unsafe { std::mem::zeroed() }, // Not used in test
+            base_url: "https://example.com".to_string(),
+            username: "test".to_string(),
+        };
+        
+        assert_eq!(client.extract_event_id("/calendar/event123.ics"), "event123");
+        assert_eq!(client.extract_event_id("/calendar/path/event456.ics"), "event456");
+        assert_eq!(client.extract_event_id("event789.ics"), "event789");
+        assert_eq!(client.extract_event_id("no_extension"), "no_extension");
+    }
+}

src/real_sync.rs

@@ -0,0 +1,290 @@
+//! Synchronization engine for CalDAV calendars using real CalDAV implementation
+
+use crate::{config::Config, minicaldav_client::RealCalDavClient, error::CalDavResult};
+use chrono::{DateTime, Utc, Duration};
+use serde::{Deserialize, Serialize};
+use std::collections::HashMap;
+use tokio::time::sleep;
+use tracing::{info, warn, error, debug};
+
+/// Synchronization engine for managing calendar synchronization
+pub struct SyncEngine {
+    /// CalDAV client
+    pub client: RealCalDavClient,
+    /// Configuration
+    config: Config,
+    /// Local cache of events
+    local_events: HashMap<String, SyncEvent>,
+    /// Sync state
+    sync_state: SyncState,
+}
+
+/// Synchronization state
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct SyncState {
+    /// Last successful sync timestamp
+    pub last_sync: Option<DateTime<Utc>>,
+    /// Sync token for incremental syncs
+    pub sync_token: Option<String>,
+    /// Known event HREFs
+    pub known_events: HashMap<String, String>,
+    /// Sync statistics
+    pub stats: SyncStats,
+}
+
+/// Synchronization statistics
+#[derive(Debug, Clone, Serialize, Deserialize, Default)]
+pub struct SyncStats {
+    /// Total events synchronized
+    pub total_events: u64,
+    /// Events created
+    pub events_created: u64,
+    /// Events updated
+    pub events_updated: u64,
+    /// Events deleted
+    pub events_deleted: u64,
+    /// Errors encountered
+    pub errors: u64,
+    /// Last sync duration in milliseconds
+    pub sync_duration_ms: u64,
+}
+
+/// Event for synchronization
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct SyncEvent {
+    pub id: String,
+    pub href: String,
+    pub summary: String,
+    pub description: Option<String>,
+    pub start: DateTime<Utc>,
+    pub end: DateTime<Utc>,
+    pub location: Option<String>,
+    pub status: Option<String>,
+    pub last_modified: Option<DateTime<Utc>>,
+    pub source_calendar: String,
+    pub start_tzid: Option<String>,
+    pub end_tzid: Option<String>,
+}
+
+/// Synchronization result
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct SyncResult {
+    pub success: bool,
+    pub events_processed: u64,
+    pub duration_ms: u64,
+    pub error_message: Option<String>,
+    pub stats: SyncStats,
+}
+
+impl SyncEngine {
+    /// Create a new sync engine
+    pub async fn new(config: Config) -> CalDavResult<Self> {
+        info!("Creating sync engine for: {}", config.server.url);
+        
+        // Create CalDAV client
+        let client = RealCalDavClient::new(
+            &config.server.url,
+            &config.server.username,
+            &config.server.password,
+        ).await?;
+        
+        let sync_state = SyncState {
+            last_sync: None,
+            sync_token: None,
+            known_events: HashMap::new(),
+            stats: SyncStats::default(),
+        };
+        
+        Ok(Self {
+            client,
+            config,
+            local_events: HashMap::new(),
+            sync_state,
+        })
+    }
+    
+    /// Perform full synchronization
+    pub async fn sync_full(&mut self) -> CalDavResult<SyncResult> {
+        let start_time = Utc::now();
+        info!("Starting full calendar synchronization");
+        
+        let mut result = SyncResult {
+            success: true,
+            events_processed: 0,
+            duration_ms: 0,
+            error_message: None,
+            stats: SyncStats::default(),
+        };
+        
+        // Discover calendars
+        match self.discover_and_sync_calendars().await {
+            Ok(events_count) => {
+                result.events_processed = events_count;
+                result.stats.events_created = events_count;
+                info!("Full sync completed: {} events processed", events_count);
+            }
+            Err(e) => {
+                error!("Full sync failed: {}", e);
+                result.success = false;
+                result.error_message = Some(e.to_string());
+                result.stats.errors = 1;
+            }
+        }
+        
+        let duration = Utc::now() - start_time;
+        result.duration_ms = duration.num_milliseconds() as u64;
+        result.stats.sync_duration_ms = result.duration_ms;
+        
+        // Update sync state
+        self.sync_state.last_sync = Some(Utc::now());
+        self.sync_state.stats = result.stats.clone();
+        
+        Ok(result)
+    }
+    
+    /// Perform incremental synchronization
+    pub async fn sync_incremental(&mut self) -> CalDavResult<SyncResult> {
+        let _start_time = Utc::now();
+        info!("Starting incremental calendar synchronization");
+        
+        // For now, incremental sync is the same as full sync
+        // In a real implementation, we would use sync tokens or last modified timestamps
+        self.sync_full().await
+    }
+    
+    /// Force a full resynchronization
+    pub async fn force_full_resync(&mut self) -> CalDavResult<SyncResult> {
+        info!("Forcing full resynchronization");
+        
+        // Clear sync state
+        self.sync_state.sync_token = None;
+        self.sync_state.known_events.clear();
+        self.local_events.clear();
+        
+        self.sync_full().await
+    }
+    
+    /// Start automatic synchronization loop
+    pub async fn start_auto_sync(&mut self) -> CalDavResult<()> {
+        info!("Starting automatic synchronization loop");
+        
+        loop {
+            if let Err(e) = self.sync_incremental().await {
+                error!("Auto sync failed: {}", e);
+                // Wait before retrying
+                sleep(tokio::time::Duration::from_secs(60)).await;
+            }
+            
+            // Wait for next sync interval
+            let interval_secs = self.config.sync.interval;
+            debug!("Waiting {} seconds for next sync", interval_secs);
+            sleep(tokio::time::Duration::from_secs(interval_secs as u64)).await;
+        }
+    }
+    
+    /// Get local events
+    pub fn get_local_events(&self) -> Vec<SyncEvent> {
+        self.local_events.values().cloned().collect()
+    }
+    
+    /// Discover calendars and sync events
+    async fn discover_and_sync_calendars(&mut self) -> CalDavResult<u64> {
+        info!("Discovering calendars");
+        
+        // Get calendar list
+        let calendars = self.client.discover_calendars().await?;
+        let mut total_events = 0u64;
+        let mut found_matching_calendar = false;
+        
+        for calendar in calendars {
+            info!("Processing calendar: {}", calendar.name);
+            
+            // Find calendar matching our configured calendar name
+            if calendar.name == self.config.calendar.name || 
+               calendar.display_name.as_ref().map_or(false, |n| n == &self.config.calendar.name) {
+                
+                found_matching_calendar = true;
+                info!("Found matching calendar: {}", calendar.name);
+                
+                // Calculate date range based on configuration
+                let now = Utc::now();
+                let (start_date, end_date) = if self.config.sync.date_range.sync_all_events {
+                    // Sync all events regardless of date
+                    // Use a very wide date range
+                    let start_date = now - Duration::days(365 * 10); // 10 years ago
+                    let end_date = now + Duration::days(365 * 10);   // 10 years in future
+                    info!("Syncing all events (wide date range: {} to {})", 
+                          start_date.format("%Y-%m-%d"), end_date.format("%Y-%m-%d"));
+                    (start_date, end_date)
+                } else {
+                    // Use configured date range
+                    let days_back = self.config.sync.date_range.days_back;
+                    let days_ahead = self.config.sync.date_range.days_ahead;
+                    
+                    let start_date = now - Duration::days(days_back);
+                    let end_date = now + Duration::days(days_ahead);
+                    
+                    info!("Syncing events for date range: {} to {} ({} days back, {} days ahead)", 
+                          start_date.format("%Y-%m-%d"), 
+                          end_date.format("%Y-%m-%d"),
+                          days_back, days_ahead);
+                    (start_date, end_date)
+                };
+                
+                // Get events for this calendar
+                match self.client.get_events(&calendar.url, start_date, end_date).await {
+                    Ok(events) => {
+                        info!("Found {} events in calendar: {}", events.len(), calendar.name);
+                        
+                        // Process events
+                        for event in events {
+                            let sync_event = SyncEvent {
+                                id: event.id.clone(),
+                                href: event.href.clone(),
+                                summary: event.summary.clone(),
+                                description: event.description,
+                                start: event.start,
+                                end: event.end,
+                                location: event.location,
+                                status: event.status,
+                                last_modified: event.last_modified,
+                                source_calendar: calendar.name.clone(),
+                                start_tzid: event.start_tzid,
+                                end_tzid: event.end_tzid,
+                            };
+                            
+                            // Add to local cache
+                            self.local_events.insert(event.id.clone(), sync_event);
+                            total_events += 1;
+                        }
+                    }
+                    Err(e) => {
+                        warn!("Failed to get events from calendar {}: {}", calendar.name, e);
+                    }
+                }
+                
+                // For now, we only sync from one calendar as configured
+                break;
+            }
+        }
+        
+        if !found_matching_calendar {
+            warn!("No calendars found matching: {}", self.config.calendar.name);
+        } else if total_events == 0 {
+            info!("No events found in matching calendar for the specified date range");
+        }
+        
+        Ok(total_events)
+    }
+}
+
+impl Default for SyncState {
+    fn default() -> Self {
+        Self {
+            last_sync: None,
+            sync_token: None,
+            known_events: HashMap::new(),
+            stats: SyncStats::default(),
+        }
+    }
+}