/**
 * OAuth API handlers
 * Public endpoints for OAuth/OIDC and LDAP authentication flows
 */

import type { IApiContext, IApiResponse } from '../router.ts';
import { AuthProvider, PlatformSettings } from '../../models/index.ts';
import { externalAuthService } from '../../services/external.auth.service.ts';

export class OAuthApi {
  /**
   * GET /api/v1/auth/providers
   * List active authentication providers (public info only)
   */
  public async listProviders(ctx: IApiContext): Promise<IApiResponse> {
    try {
      const settings = await PlatformSettings.get();
      const providers = await AuthProvider.getActiveProviders();

      return {
        status: 200,
        body: {
          providers: providers.map((p) => p.toPublicInfo()),
          localAuthEnabled: settings.auth.localAuthEnabled,
          defaultProviderId: settings.auth.defaultProviderId,
        },
      };
    } catch (error) {
      console.error('[OAuthApi] List providers error:', error);
      return {
        status: 500,
        body: { error: 'Failed to list providers' },
      };
    }
  }

  /**
   * GET /api/v1/auth/oauth/:id/authorize
   * Initiate OAuth flow - redirects to provider
   */
  public async authorize(ctx: IApiContext): Promise<IApiResponse> {
    try {
      const { id } = ctx.params;
      const returnUrl = ctx.url.searchParams.get('returnUrl') || undefined;

      const { authUrl } = await externalAuthService.initiateOAuth(id, returnUrl);

      // Return redirect response
      return {
        status: 302,
        headers: { Location: authUrl },
      };
    } catch (error) {
      console.error('[OAuthApi] Authorize error:', error);
      const errorMessage = error instanceof Error ? error.message : 'Authorization failed';
      return {
        status: 302,
        headers: {
          Location: `/login?error=${encodeURIComponent(errorMessage)}`,
        },
      };
    }
  }

  /**
   * GET /api/v1/auth/oauth/:id/callback
   * Handle OAuth callback from provider
   */
  public async callback(ctx: IApiContext): Promise<IApiResponse> {
    try {
      const code = ctx.url.searchParams.get('code');
      const state = ctx.url.searchParams.get('state');
      const error = ctx.url.searchParams.get('error');
      const errorDescription = ctx.url.searchParams.get('error_description');

      if (error) {
        return {
          status: 302,
          headers: {
            Location: `/login?error=${encodeURIComponent(errorDescription || error)}`,
          },
        };
      }

      if (!code || !state) {
        return {
          status: 302,
          headers: {
            Location: '/login?error=missing_parameters',
          },
        };
      }

      const result = await externalAuthService.handleOAuthCallback(
        { code, state },
        { ipAddress: ctx.ip, userAgent: ctx.userAgent }
      );

      if (!result.success) {
        return {
          status: 302,
          headers: {
            Location: `/login?error=${encodeURIComponent(result.errorCode || 'auth_failed')}`,
          },
        };
      }

      // Redirect to OAuth callback page with tokens
      const params = new URLSearchParams({
        accessToken: result.accessToken!,
        refreshToken: result.refreshToken!,
        sessionId: result.sessionId!,
      });

      return {
        status: 302,
        headers: {
          Location: `/oauth-callback?${params.toString()}`,
        },
      };
    } catch (error) {
      console.error('[OAuthApi] Callback error:', error);
      const errorMessage = error instanceof Error ? error.message : 'Callback failed';
      return {
        status: 302,
        headers: {
          Location: `/login?error=${encodeURIComponent(errorMessage)}`,
        },
      };
    }
  }

  /**
   * POST /api/v1/auth/ldap/:id/login
   * LDAP authentication with username/password
   */
  public async ldapLogin(ctx: IApiContext): Promise<IApiResponse> {
    try {
      const { id } = ctx.params;
      const body = await ctx.request.json();
      const { username, password } = body;

      if (!username || !password) {
        return {
          status: 400,
          body: { error: 'Username and password are required' },
        };
      }

      const result = await externalAuthService.authenticateLdap(id, username, password, {
        ipAddress: ctx.ip,
        userAgent: ctx.userAgent,
      });

      if (!result.success) {
        return {
          status: 401,
          body: {
            error: result.errorMessage,
            code: result.errorCode,
          },
        };
      }

      return {
        status: 200,
        body: {
          user: {
            id: result.user!.id,
            email: result.user!.email,
            username: result.user!.username,
            displayName: result.user!.displayName,
            isSystemAdmin: result.user!.isSystemAdmin,
          },
          accessToken: result.accessToken,
          refreshToken: result.refreshToken,
          sessionId: result.sessionId,
        },
      };
    } catch (error) {
      console.error('[OAuthApi] LDAP login error:', error);
      return {
        status: 500,
        body: { error: 'LDAP login failed' },
      };
    }
  }
}