import { BaseAuthProvider, AuthCredentials, AuthResult, AuthProviderHealth, AuthProviderMetrics } from './base-auth-provider';
import * as jwt from 'jsonwebtoken';

export class InternalAuthProvider extends BaseAuthProvider {
  private metrics: AuthProviderMetrics = {
    isActive: false,
    totalAuthentications: 0,
    successfulAuthentications: 0,
    failedAuthentications: 0,
    averageResponseTime: 0
  };

  constructor(config: any) {
    super('internal', config);
  }

  async initialize(): Promise<void> {
    // Initialize internal auth provider
    this.isInitialized = true;
    this.metrics.isActive = true;
  }

  async authenticate(credentials: AuthCredentials): Promise<AuthResult> {
    const startTime = Date.now();
    this.metrics.totalAuthentications++;

    try {
      // This is a simplified implementation
      // In a real app, you would validate against a database
      if (!credentials.email || !credentials.password) {
        throw new Error('Email and password are required');
      }

      // Simulate user lookup and password verification
      // In reality, this would query your database
      const user = {
        id: '1',
        email: credentials.email,
        name: 'Test User'
      };

      // Generate JWT token
      const token = jwt.sign(
        { userId: user.id, email: user.email },
        this.config.jwtSecret,
        { expiresIn: this.config.jwtExpiresIn }
      );

      const responseTime = Date.now() - startTime;
      this.updateMetrics(true, responseTime);

      return {
        success: true,
        user,
        token,
        expiresIn: 3600, // 1 hour
        provider: this.name
      };
    } catch (error) {
      const responseTime = Date.now() - startTime;
      this.updateMetrics(false, responseTime);

      return {
        success: false,
        error: error.message,
        provider: this.name
      };
    }
  }

  async validateToken(token: string): Promise<any> {
    try {
      const decoded = jwt.verify(token, this.config.jwtSecret);
      return { valid: true, user: decoded };
    } catch (error) {
      return { valid: false, error: error.message };
    }
  }

  async refreshToken(refreshToken: string): Promise<AuthResult> {
    // Simplified refresh token implementation
    try {
      const decoded = jwt.verify(refreshToken, this.config.jwtSecret) as any;
      
      const newToken = jwt.sign(
        { userId: decoded.userId, email: decoded.email },
        this.config.jwtSecret,
        { expiresIn: this.config.jwtExpiresIn }
      );

      return {
        success: true,
        token: newToken,
        expiresIn: 3600,
        provider: this.name
      };
    } catch (error) {
      return {
        success: false,
        error: error.message,
        provider: this.name
      };
    }
  }

  async cleanup(): Promise<void> {
    this.isInitialized = false;
    this.metrics.isActive = false;
  }

  async getHealth(): Promise<AuthProviderHealth> {
    return {
      status: this.isInitialized ? 'healthy' : 'unhealthy',
      message: this.isInitialized ? 'Internal auth provider is ready' : 'Internal auth provider is not initialized',
      timestamp: new Date()
    };
  }

  async getMetrics(): Promise<AuthProviderMetrics> {
    return { ...this.metrics };
  }

  private updateMetrics(success: boolean, responseTime: number): void {
    if (success) {
      this.metrics.successfulAuthentications++;
    } else {
      this.metrics.failedAuthentications++;
    }

    // Update average response time
    const totalRequests = this.metrics.successfulAuthentications + this.metrics.failedAuthentications;
    this.metrics.averageResponseTime = 
      (this.metrics.averageResponseTime * (totalRequests - 1) + responseTime) / totalRequests;

    this.metrics.lastAuthentication = new Date();
  }
}