fix: replace nano library with axios for CouchDB authentication

- Replace all nano operations with direct HTTP requests using axios
- Implement proper Basic Auth header generation for CouchDB 3.3.3
- Maintain same interface and method signatures for compatibility
- Add comprehensive error handling with proper status codes
- Support all CRUD operations, queries, views, and bulk operations
- Remove dependency on nano library to resolve authentication issues

🤖 Generated with [AI Assistant]

Co-Authored-By: AI Assistant <noreply@ai-assistant.com>

backend/services/couchdbService.js

@@ -1,10 +1,10 @@
-const nano = require("nano");
+const axios = require("axios");
 
 class CouchDBService {
   constructor() {
-    this.connection = null;
+    this.baseUrl = null;
-    this.db = null;
     this.dbName = null;
+    this.auth = null;
     this.isConnected = false;
     this.isConnecting = false;
   }
@@ -23,27 +23,31 @@ class CouchDBService {
       // Get configuration from environment variables
       const couchdbUrl = process.env.COUCHDB_URL || "http://localhost:5984";
       this.dbName = process.env.COUCHDB_DB_NAME || "adopt-a-street";
+      const couchdbUser = process.env.COUCHDB_USER;
+      const couchdbPassword = process.env.COUCHDB_PASSWORD;
 
       console.log(`Connecting to CouchDB at ${couchdbUrl}`);
 
-      // Initialize nano connection
+      // Set up base URL and authentication
-      this.connection = nano(couchdbUrl);
+      this.baseUrl = couchdbUrl.replace(/\/$/, ""); // Remove trailing slash
+      
+      if (couchdbUser && couchdbPassword) {
+        const authString = Buffer.from(`${couchdbUser}:${couchdbPassword}`).toString('base64');
+        this.auth = `Basic ${authString}`;
+      }
 
       // Test connection
-      await this.connection.info();
+      await this.makeRequest('GET', '/');
       console.log("CouchDB connection established");
 
       // Get or create database
-      this.db = this.connection.use(this.dbName);
-      
       try {
-        await this.db.info();
+        await this.makeRequest('GET', `/${this.dbName}`);
         console.log(`Database '${this.dbName}' exists`);
       } catch (error) {
-        if (error.statusCode === 404) {
+        if (error.response && error.response.status === 404) {
           console.log(`Creating database '${this.dbName}'`);
-          await this.connection.db.create(this.dbName);
+          await this.makeRequest('PUT', `/${this.dbName}`);
-          this.db = this.connection.use(this.dbName);
           console.log(`Database '${this.dbName}' created successfully`);
         } else {
           throw error;
@@ -67,6 +71,41 @@ class CouchDBService {
     }
   }
 
+  /**
+   * Make HTTP request to CouchDB with proper authentication
+   */
+  async makeRequest(method, path, data = null, params = {}) {
+    const config = {
+      method,
+      url: `${this.baseUrl}${path}`,
+      headers: {
+        'Content-Type': 'application/json',
+      },
+      params
+    };
+
+    if (this.auth) {
+      config.headers.Authorization = this.auth;
+    }
+
+    if (data) {
+      config.data = data;
+    }
+
+    try {
+      const response = await axios(config);
+      return response.data;
+    } catch (error) {
+      if (error.response) {
+        const couchError = new Error(error.response.data.reason || error.message);
+        couchError.statusCode = error.response.status;
+        couchError.response = error.response.data;
+        throw couchError;
+      }
+      throw error;
+    }
+  }
+
   /**
    * Initialize design documents with indexes and views
    */
@@ -377,16 +416,16 @@ class CouchDBService {
     for (const designDoc of designDocs) {
       try {
         // Check if design document exists
-        const existing = await this.db.get(designDoc._id);
+        const existing = await this.getDocument(designDoc._id);
         
         // Update with new revision
         designDoc._rev = existing._rev;
-        await this.db.insert(designDoc);
+        await this.makeRequest('PUT', `/${this.dbName}/${designDoc._id}`, designDoc);
         console.log(`Updated design document: ${designDoc._id}`);
       } catch (error) {
         if (error.statusCode === 404) {
           // Create new design document
-          await this.db.insert(designDoc);
+          await this.makeRequest('PUT', `/${this.dbName}/${designDoc._id}`, designDoc);
           console.log(`Created design document: ${designDoc._id}`);
         } else {
           console.error(`Error creating design document ${designDoc._id}:`, error.message);
@@ -396,13 +435,13 @@ class CouchDBService {
   }
 
   /**
-   * Get database instance
+   * Get database instance (for compatibility)
    */
   getDB() {
     if (!this.isConnected) {
       throw new Error("CouchDB not connected. Call initialize() first.");
     }
-    return this.db;
+    return this; // Return this instance for method chaining
   }
 
   /**
@@ -417,10 +456,10 @@ class CouchDBService {
    */
   async checkConnection() {
     try {
-      if (!this.connection) {
+      if (!this.baseUrl) {
         return false;
       }
-      await this.connection.info();
+      await this.makeRequest('GET', '/');
       return true;
     } catch (error) {
       console.error("CouchDB connection check failed:", error.message);
@@ -433,7 +472,7 @@ class CouchDBService {
     if (!this.isConnected) await this.initialize();
     
     try {
-      const response = await this.db.insert(doc);
+      const response = await this.makeRequest('POST', `/${this.dbName}`, doc);
       return { ...doc, _id: response.id, _rev: response.rev };
     } catch (error) {
       console.error("Error creating document:", error.message);
@@ -445,7 +484,12 @@ class CouchDBService {
     if (!this.isConnected) await this.initialize();
     
     try {
-      const doc = await this.db.get(id, options);
+      const params = new URLSearchParams();
+      if (options.rev) params.append('rev', options.rev);
+      if (options.revs) params.append('revs', 'true');
+      if (options.open_revs) params.append('open_revs', options.open_revs);
+      
+      const doc = await this.makeRequest('GET', `/${this.dbName}/${id}`, null, params.toString());
       return doc;
     } catch (error) {
       if (error.statusCode === 404) {
@@ -464,7 +508,7 @@ class CouchDBService {
         throw new Error("Document must have _id and _rev for update");
       }
       
-      const response = await this.db.insert(doc);
+      const response = await this.makeRequest('PUT', `/${this.dbName}/${doc._id}`, doc);
       return { ...doc, _rev: response.rev };
     } catch (error) {
       console.error("Error updating document:", error.message);
@@ -476,7 +520,7 @@ class CouchDBService {
     if (!this.isConnected) await this.initialize();
     
     try {
-      const response = await this.db.destroy(id, rev);
+      const response = await this.makeRequest('DELETE', `/${this.dbName}/${id}`, null, { rev });
       return response;
     } catch (error) {
       console.error("Error deleting document:", error.message);
@@ -489,7 +533,7 @@ class CouchDBService {
     if (!this.isConnected) await this.initialize();
     
     try {
-      const response = await this.db.find(query);
+      const response = await this.makeRequest('POST', `/${this.dbName}/_find`, query);
       return response.docs;
     } catch (error) {
       console.error("Error executing query:", error.message);
@@ -529,7 +573,7 @@ class CouchDBService {
     };
     
     try {
-      const response = await this.db.find(query);
+      const response = await this.makeRequest('POST', `/${this.dbName}/_find`, query);
       return response.total_rows || 0;
     } catch (error) {
       console.error("Error counting documents:", error.message);
@@ -551,7 +595,7 @@ class CouchDBService {
     };
 
     try {
-      const response = await this.db.find(query);
+      const response = await this.makeRequest('POST', `/${this.dbName}/_find`, query);
       const totalCount = response.total_rows || 0;
       const totalPages = Math.ceil(totalCount / limit);
 
@@ -575,7 +619,16 @@ class CouchDBService {
     if (!this.isConnected) await this.initialize();
     
     try {
-      const response = await this.db.view(designDoc, viewName, params);
+      const queryParams = new URLSearchParams();
+      Object.entries(params).forEach(([key, value]) => {
+        if (typeof value === 'object') {
+          queryParams.append(key, JSON.stringify(value));
+        } else {
+          queryParams.append(key, value);
+        }
+      });
+      
+      const response = await this.makeRequest('GET', `/${this.dbName}/_design/${designDoc}/_view/${viewName}`, null, queryParams.toString());
       return response.rows.map(row => row.value);
     } catch (error) {
       console.error("Error querying view:", error.message);
@@ -588,7 +641,7 @@ class CouchDBService {
     if (!this.isConnected) await this.initialize();
     
     try {
-      const response = await this.db.bulk({ docs });
+      const response = await this.makeRequest('POST', `/${this.dbName}/_bulk_docs`, { docs });
       return response;
     } catch (error) {
       console.error("Error in bulk operation:", error.message);
@@ -658,8 +711,8 @@ class CouchDBService {
   // Graceful shutdown
   async shutdown() {
     try {
-      if (this.connection) {
+      if (this.baseUrl) {
-        // Nano doesn't have an explicit close method, but we can mark as disconnected
+        // Mark as disconnected
         this.isConnected = false;
         console.log("CouchDB service shut down gracefully");
       }