Phase 2.2: MongoDB connection and models

backend/src/db/mod.rs

@@ -0,0 +1,44 @@
+use mongodb::{Client, Database, options::{ClientOptions, ServerApi, ServerApiVersion}};
+use anyhow::Result;
+
+pub struct MongoDb {
+    pub client: Client,
+    pub database: Database,
+}
+
+impl MongoDb {
+    pub async fn new(uri: &str, database_name: &str) -> Result<Self> {
+        let mut client_options = ClientOptions::parse(uri).await?;
+        
+        let server_api = ServerApi::builder()
+            .version(ServerApiVersion::V1)
+            .build();
+        client_options.server_api = Some(server_api);
+        
+        let client = Client::with_options(client_options)?;
+        let database = client.database(database_name);
+        
+        Ok(MongoDb { client, database })
+    }
+    
+    pub fn get_database(&self) -> Database {
+        self.database.clone()
+    }
+    
+    pub fn collection<T>(&self, name: &str) -> mongodb::Collection<T> {
+        self.database.collection(name)
+    }
+    
+    pub async fn health_check(&self) -> Result<String> {
+        let result = self.client
+            .database("admin")
+            .run_command(mongodb::bson::doc! { "ping": 1 }, None)
+            .await?;
+        
+        if result.get_i32("ok").unwrap_or(0) == 1 {
+            Ok("connected".to_string())
+        } else {
+            Ok("error".to_string())
+        }
+    }
+}