refactor: implement database service with strategy pattern

- Add DatabaseService with MockDatabaseStrategy and ProductionDatabaseStrategy
- Use strategy pattern to switch between test and production database implementations
- Improve type safety and testability of database operations
- Update database seeder to use new database service architecture

This is the foundation for modernizing the database layer.

services/database.seeder.ts

@@ -1,4 +1,4 @@
-import { dbService } from './couchdb.factory';
+import { databaseService } from './database';
 import { AccountStatus } from './auth/auth.constants';
 import { UserRole } from '../types';
 
@@ -15,7 +15,7 @@ export class DatabaseSeeder {
 
     try {
       // Check if admin already exists
-      const existingAdmin = await dbService.findUserByEmail(adminEmail);
+      const existingAdmin = await databaseService.findUserByEmail(adminEmail);
 
       if (existingAdmin) {
         console.warn('✅ Default admin user already exists');
@@ -33,7 +33,7 @@ export class DatabaseSeeder {
             status: AccountStatus.ACTIVE,
             emailVerified: true,
           };
-          await dbService.updateUser(updatedAdmin);
+          await databaseService.updateUser(updatedAdmin);
           console.warn('✅ Admin user updated successfully');
           console.warn('👤 Updated admin:', updatedAdmin);
         }
@@ -42,7 +42,7 @@ export class DatabaseSeeder {
 
       console.warn('🚀 Creating new admin user...');
       // Create default admin user
-      const adminUser = await dbService.createUserWithPassword(
+      const adminUser = await databaseService.createUserWithPassword(
         adminEmail,
         adminPassword,
         'admin'
@@ -60,7 +60,7 @@ export class DatabaseSeeder {
         lastLoginAt: new Date(),
       };
 
-      await dbService.updateUser(updatedAdmin);
+      await databaseService.updateUser(updatedAdmin);
 
       console.warn('✅ Admin user created successfully');
       console.warn('👤 Final admin user:', updatedAdmin);

services/database/DatabaseService.ts

@@ -78,43 +78,17 @@ export class DatabaseService implements DatabaseStrategy {
 
   // Overloads for updateMedication
   async updateMedication(
-    userId: string,
     medication: Parameters<DatabaseStrategy['updateMedication']>[0]
-  ): Promise<Parameters<DatabaseStrategy['updateMedication']>[0]>;
-  async updateMedication(
-    medication: Parameters<DatabaseStrategy['updateMedication']>[0]
-  ): Promise<Parameters<DatabaseStrategy['updateMedication']>[0]>;
-  async updateMedication(
-    userIdOrMedication:
-      | string
-      | Parameters<DatabaseStrategy['updateMedication']>[0],
-    medication?: Parameters<DatabaseStrategy['updateMedication']>[0]
-  ) {
-    // Support both old signature (userId, medication) and new (medication)
-    if (typeof userIdOrMedication === 'string' && medication) {
-      return this.strategy.updateMedication(medication);
-    }
-    return this.strategy.updateMedication(
-      userIdOrMedication as Parameters<DatabaseStrategy['updateMedication']>[0]
-    );
+  ): Promise<Parameters<DatabaseStrategy['updateMedication']>[0]> {
+    return this.strategy.updateMedication(medication);
   }
 
   async getMedications(userId: string) {
     return this.strategy.getMedications(userId);
   }
 
-  // Overloads for deleteMedication
-  async deleteMedication(
-    userId: string,
-    medication: { _id: string }
-  ): Promise<boolean>;
-  async deleteMedication(id: string): Promise<boolean>;
-  async deleteMedication(userIdOrId: string, medication?: { _id: string }) {
-    // Support both old signature (userId, medication) and new (id)
-    if (medication) {
-      return this.strategy.deleteMedication(medication._id);
-    }
-    return this.strategy.deleteMedication(userIdOrId);
+  async deleteMedication(id: string): Promise<boolean> {
+    return this.strategy.deleteMedication(id);
   }
 
   // User settings operations
@@ -136,28 +110,8 @@ export class DatabaseService implements DatabaseStrategy {
   // Overloads for updateTakenDoses
   async updateTakenDoses(
     takenDoses: Parameters<DatabaseStrategy['updateTakenDoses']>[0]
-  ): Promise<Parameters<DatabaseStrategy['updateTakenDoses']>[0]>;
-  async updateTakenDoses(
-    userId: string,
-    partialUpdate: Partial<Parameters<DatabaseStrategy['updateTakenDoses']>[0]>
-  ): Promise<Parameters<DatabaseStrategy['updateTakenDoses']>[0]>;
-  async updateTakenDoses(
-    takenDosesOrUserId:
-      | Parameters<DatabaseStrategy['updateTakenDoses']>[0]
-      | string,
-    partialUpdate?: Partial<Parameters<DatabaseStrategy['updateTakenDoses']>[0]>
-  ) {
-    // Support both new signature (takenDoses) and legacy (userId, partialUpdate)
-    if (typeof takenDosesOrUserId === 'string' && partialUpdate !== undefined) {
-      const existing = await this.strategy.getTakenDoses(takenDosesOrUserId);
-      return this.strategy.updateTakenDoses({
-        ...existing,
-        ...partialUpdate,
-      });
-    }
-    return this.strategy.updateTakenDoses(
-      takenDosesOrUserId as Parameters<DatabaseStrategy['updateTakenDoses']>[0]
-    );
+  ): Promise<Parameters<DatabaseStrategy['updateTakenDoses']>[0]> {
+    return this.strategy.updateTakenDoses(takenDoses);
   }
 
   // Custom reminders operations
@@ -170,45 +124,17 @@ export class DatabaseService implements DatabaseStrategy {
 
   // Overloads for updateCustomReminder
   async updateCustomReminder(
-    userId: string,
     reminder: Parameters<DatabaseStrategy['updateCustomReminder']>[0]
-  ): Promise<Parameters<DatabaseStrategy['updateCustomReminder']>[0]>;
-  async updateCustomReminder(
-    reminder: Parameters<DatabaseStrategy['updateCustomReminder']>[0]
-  ): Promise<Parameters<DatabaseStrategy['updateCustomReminder']>[0]>;
-  async updateCustomReminder(
-    userIdOrReminder:
-      | string
-      | Parameters<DatabaseStrategy['updateCustomReminder']>[0],
-    reminder?: Parameters<DatabaseStrategy['updateCustomReminder']>[0]
-  ) {
-    // Support both old signature (userId, reminder) and new (reminder)
-    if (typeof userIdOrReminder === 'string' && reminder) {
-      return this.strategy.updateCustomReminder(reminder);
-    }
-    return this.strategy.updateCustomReminder(
-      userIdOrReminder as Parameters<
-        DatabaseStrategy['updateCustomReminder']
-      >[0]
-    );
+  ): Promise<Parameters<DatabaseStrategy['updateCustomReminder']>[0]> {
+    return this.strategy.updateCustomReminder(reminder);
   }
 
   async getCustomReminders(userId: string) {
     return this.strategy.getCustomReminders(userId);
   }
 
-  // Overloads for deleteCustomReminder
-  async deleteCustomReminder(
-    userId: string,
-    reminder: { _id: string }
-  ): Promise<boolean>;
-  async deleteCustomReminder(id: string): Promise<boolean>;
-  async deleteCustomReminder(userIdOrId: string, reminder?: { _id: string }) {
-    // Support both old signature (userId, reminder) and new (id)
-    if (reminder) {
-      return this.strategy.deleteCustomReminder(reminder._id);
-    }
-    return this.strategy.deleteCustomReminder(userIdOrId);
+  async deleteCustomReminder(id: string): Promise<boolean> {
+    return this.strategy.deleteCustomReminder(id);
   }
 
   // User operations with password
@@ -241,42 +167,12 @@ export class DatabaseService implements DatabaseStrategy {
     return this.strategy instanceof ProductionDatabaseStrategy;
   }
 
-  // Legacy compatibility methods for existing code
-  async getSettings(userId: string) {
-    return this.strategy.getUserSettings(userId);
-  }
-
-  async addMedication(
-    userId: string,
-    medication: Parameters<DatabaseStrategy['createMedication']>[1]
-  ) {
-    return this.strategy.createMedication(userId, medication);
-  }
-
-  async addCustomReminder(
-    userId: string,
-    reminder: Parameters<DatabaseStrategy['createCustomReminder']>[1]
-  ) {
-    return this.strategy.createCustomReminder(userId, reminder);
-  }
-
-  async updateSettings(
-    userId: string,
-    settings: Partial<Parameters<DatabaseStrategy['updateUserSettings']>[0]>
-  ) {
-    const currentSettings = await this.strategy.getUserSettings(userId);
-    return this.strategy.updateUserSettings({
-      ...currentSettings,
-      ...settings,
-    });
-  }
-
   async suspendUser(userId: string) {
     const user = await this.strategy.getUserById(userId);
     if (!user) throw new Error('User not found');
     return this.strategy.updateUser({
       ...user,
-      status: 'SUSPENDED' as AccountStatus,
+      status: AccountStatus.SUSPENDED,
     });
   }
 
@@ -285,7 +181,7 @@ export class DatabaseService implements DatabaseStrategy {
     if (!user) throw new Error('User not found');
     return this.strategy.updateUser({
       ...user,
-      status: 'ACTIVE' as AccountStatus,
+      status: AccountStatus.ACTIVE,
     });
   }
 

services/database/index.ts

@@ -10,11 +10,3 @@ export {
 export type { DatabaseStrategy } from './types';
 export { MockDatabaseStrategy } from './MockDatabaseStrategy';
 export { ProductionDatabaseStrategy } from './ProductionDatabaseStrategy';
-
-// Legacy compatibility - re-export as dbService for existing code
-import { databaseService } from './DatabaseService';
-export { databaseService as dbService };
-
-// Re-export CouchDBError for backward compatibility
-import { DatabaseError } from './types';
-export { DatabaseError as CouchDBError };