import { getEnvVar, isTest } from '../../utils/env';
import { MockDatabaseStrategy } from './MockDatabaseStrategy';
import { ProductionDatabaseStrategy } from './ProductionDatabaseStrategy';
import { DatabaseStrategy } from './types';
import { AccountStatus } from '../auth/auth.constants';

/**
 * Consolidated Database Service
 * Uses strategy pattern to switch between mock and production implementations
 */
export class DatabaseService implements DatabaseStrategy {
  private strategy: DatabaseStrategy;

  constructor() {
    this.strategy = this.createStrategy();
  }

  private createStrategy(): DatabaseStrategy {
    // Always use mock service in test environment
    if (isTest()) {
      return new MockDatabaseStrategy();
    }

    // Check if we're in a Docker environment or if CouchDB URL is configured
    const couchdbUrl =
      getEnvVar('VITE_COUCHDB_URL') || getEnvVar('COUCHDB_URL');
    const useProduction = !!couchdbUrl && couchdbUrl !== 'mock';

    if (useProduction) {
      try {
        return new ProductionDatabaseStrategy();
      } catch (error) {
        console.warn(
          'Production CouchDB service not available, falling back to mock:',
          error
        );
        return new MockDatabaseStrategy();
      }
    } else {
      return new MockDatabaseStrategy();
    }
  }

  // Delegate all methods to the strategy

  // User operations
  async createUser(user: Parameters<DatabaseStrategy['createUser']>[0]) {
    return this.strategy.createUser(user);
  }

  async updateUser(user: Parameters<DatabaseStrategy['updateUser']>[0]) {
    return this.strategy.updateUser(user);
  }

  async getUserById(id: string) {
    return this.strategy.getUserById(id);
  }

  async findUserByEmail(email: string) {
    return this.strategy.findUserByEmail(email);
  }

  async deleteUser(id: string) {
    return this.strategy.deleteUser(id);
  }

  async getAllUsers() {
    return this.strategy.getAllUsers();
  }

  // Medication operations
  async createMedication(
    userId: string,
    medication: Parameters<DatabaseStrategy['createMedication']>[1]
  ) {
    return this.strategy.createMedication(userId, medication);
  }

  // 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]
    );
  }

  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);
  }

  // User settings operations
  async getUserSettings(userId: string) {
    return this.strategy.getUserSettings(userId);
  }

  async updateUserSettings(
    settings: Parameters<DatabaseStrategy['updateUserSettings']>[0]
  ) {
    return this.strategy.updateUserSettings(settings);
  }

  // Taken doses operations
  async getTakenDoses(userId: string) {
    return this.strategy.getTakenDoses(userId);
  }

  // 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]
    );
  }

  // Custom reminders operations
  async createCustomReminder(
    userId: string,
    reminder: Parameters<DatabaseStrategy['createCustomReminder']>[1]
  ) {
    return this.strategy.createCustomReminder(userId, reminder);
  }

  // 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]
    );
  }

  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);
  }

  // User operations with password
  async createUserWithPassword(
    email: string,
    hashedPassword: string,
    username?: string
  ) {
    return this.strategy.createUserWithPassword(
      email,
      hashedPassword,
      username
    );
  }

  async createUserFromOAuth(email: string, username: string, provider: string) {
    return this.strategy.createUserFromOAuth(email, username, provider);
  }

  // Utility methods
  getStrategyType(): string {
    return this.strategy.constructor.name;
  }

  isUsingMockStrategy(): boolean {
    return this.strategy instanceof MockDatabaseStrategy;
  }

  isUsingProductionStrategy(): boolean {
    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,
    });
  }

  async activateUser(userId: string) {
    const user = await this.strategy.getUserById(userId);
    if (!user) throw new Error('User not found');
    return this.strategy.updateUser({
      ...user,
      status: 'ACTIVE' as AccountStatus,
    });
  }

  async changeUserPassword(userId: string, newPassword: string) {
    const user = await this.strategy.getUserById(userId);
    if (!user) throw new Error('User not found');
    return this.strategy.updateUser({
      ...user,
      password: newPassword,
    });
  }

  async deleteAllUserData(userId: string) {
    // Delete user's medications
    const medications = await this.strategy.getMedications(userId);
    for (const med of medications) {
      await this.strategy.deleteMedication(med._id);
    }

    // Delete user's reminders
    const reminders = await this.strategy.getCustomReminders(userId);
    for (const reminder of reminders) {
      await this.strategy.deleteCustomReminder(reminder._id);
    }

    // Delete user
    return this.strategy.deleteUser(userId);
  }
}

// Export singleton instance
export const databaseService = new DatabaseService();

// Re-export types and errors
export { DatabaseError } from './types';
export type { DatabaseStrategy } from './types';