import { NextResponse } from 'next/server';
import { getServerSession } from 'next-auth';
import { authOptions } from "@/app/api/auth/options";
import { logger } from '@/lib/logger';

/**
 * Get RocketChat user token for WebSocket connection
 * This endpoint returns the user's auth token and userId for real-time connections
 */
export async function GET(request: Request) {
  try {
    const session = await getServerSession(authOptions);
    
    if (!session?.user?.email) {
      return NextResponse.json(
        { error: "Not authenticated" },
        { status: 401 }
      );
    }

    // Extract base URL, removing any paths like /channel, /_oauth/connect, etc.
    let baseUrl = process.env.NEXT_PUBLIC_IFRAME_PAROLE_URL;
    if (baseUrl) {
      // Remove /channel and everything after
      baseUrl = baseUrl.split('/channel')[0];
      // Remove /_oauth/connect and everything after
      baseUrl = baseUrl.split('/_oauth')[0];
      // Remove trailing slashes
      baseUrl = baseUrl.replace(/\/+$/, '');
    }
    if (!baseUrl) {
      logger.error('[ROCKET_CHAT_USER_TOKEN] Failed to get Rocket.Chat base URL');
      return NextResponse.json(
        { error: 'Server configuration error' },
        { status: 500 }
      );
    }

    logger.debug('[ROCKET_CHAT_USER_TOKEN] Using Rocket.Chat base URL', {
      baseUrl,
      hasToken: !!process.env.ROCKET_CHAT_TOKEN,
      hasUserId: !!process.env.ROCKET_CHAT_USER_ID,
      hasSecret: !!process.env.ROCKET_CHAT_CREATE_TOKEN_SECRET,
    });

    // Use admin token to authenticate
    const adminHeaders = {
      'X-Auth-Token': process.env.ROCKET_CHAT_TOKEN!,
      'X-User-Id': process.env.ROCKET_CHAT_USER_ID!,
      'Content-Type': 'application/json'
    };

    // Get username from email
    const username = session.user.email.split('@')[0];
    if (!username) {
      logger.error('[ROCKET_CHAT_USER_TOKEN] No username found in session email');
      return NextResponse.json(
        { error: 'Invalid user' },
        { status: 400 }
      );
    }

    // Get all users to find the current user
    let usersResponse;
    const usersListUrl = `${baseUrl}/api/v1/users.list`;
    try {
      logger.debug('[ROCKET_CHAT_USER_TOKEN] Fetching users list', { url: usersListUrl });
      
      usersResponse = await fetch(usersListUrl, {
        method: 'GET',
        headers: adminHeaders
      });
      
      logger.debug('[ROCKET_CHAT_USER_TOKEN] Users list response', {
        status: usersResponse.status,
        statusText: usersResponse.statusText,
        contentType: usersResponse.headers.get('content-type'),
      });
    } catch (error) {
      const errorMessage = error instanceof Error ? error.message : String(error);
      logger.error('[ROCKET_CHAT_USER_TOKEN] Error fetching users list', {
        error: errorMessage,
        baseUrl,
        url: usersListUrl,
      });
      return NextResponse.json(
        { error: 'Failed to connect to RocketChat' },
        { status: 500 }
      );
    }

    if (!usersResponse.ok) {
      const errorText = await usersResponse.text().catch(() => 'Unknown error');
      logger.error('[ROCKET_CHAT_USER_TOKEN] Failed to get users list', {
        status: usersResponse.status,
        statusText: usersResponse.statusText,
        errorPreview: errorText.substring(0, 200),
      });
      return NextResponse.json(
        { error: 'Failed to get user list from RocketChat' },
        { status: 500 }
      );
    }

    const contentType = usersResponse.headers.get('content-type') || '';
    if (!contentType.includes('application/json')) {
      const errorText = await usersResponse.text().catch(() => 'Unknown error');
      logger.error('[ROCKET_CHAT_USER_TOKEN] Expected JSON, got HTML', {
        contentType,
        errorPreview: errorText.substring(0, 200),
      });
      return NextResponse.json(
        { error: 'RocketChat returned invalid response format' },
        { status: 500 }
      );
    }

    let usersData;
    try {
      usersData = await usersResponse.json();
    } catch (error) {
      logger.error('[ROCKET_CHAT_USER_TOKEN] Failed to parse users list JSON', {
        error: error instanceof Error ? error.message : String(error),
      });
      return NextResponse.json(
        { error: 'Failed to parse RocketChat response' },
        { status: 500 }
      );
    }
    const currentUser = usersData.users?.find((u: any) => 
      u.username?.toLowerCase() === username.toLowerCase() ||
      u.emails?.some((e: any) => e.address?.toLowerCase() === session.user.email?.toLowerCase())
    );

    if (!currentUser) {
      logger.error('[ROCKET_CHAT_USER_TOKEN] User not found in RocketChat', { username });
      return NextResponse.json(
        { error: 'User not found' },
        { status: 404 }
      );
    }

    // Create user token
    const secret = process.env.ROCKET_CHAT_CREATE_TOKEN_SECRET;
    if (!secret) {
      logger.error('[ROCKET_CHAT_USER_TOKEN] ROCKET_CHAT_CREATE_TOKEN_SECRET not configured');
      return NextResponse.json(
        { error: 'Server configuration error' },
        { status: 500 }
      );
    }

    let createTokenResponse;
    try {
      createTokenResponse = await fetch(`${baseUrl}/api/v1/users.createToken`, {
      method: 'POST',
      headers: adminHeaders,
      body: JSON.stringify({
        userId: currentUser._id,
        secret: secret
      })
    });
    } catch (error) {
      logger.error('[ROCKET_CHAT_USER_TOKEN] Error creating token', {
        error: error instanceof Error ? error.message : String(error),
      });
      return NextResponse.json(
        { error: 'Failed to connect to RocketChat' },
        { status: 500 }
      );
    }

    if (!createTokenResponse.ok) {
      const errorText = await createTokenResponse.text().catch(() => 'Unknown error');
      logger.error('[ROCKET_CHAT_USER_TOKEN] Failed to create user token', {
        status: createTokenResponse.status,
        statusText: createTokenResponse.statusText,
        errorPreview: errorText.substring(0, 200),
      });
      return NextResponse.json(
        { error: 'Failed to create token' },
        { status: 500 }
      );
    }

    const tokenContentType = createTokenResponse.headers.get('content-type') || '';
    if (!tokenContentType.includes('application/json')) {
      const errorText = await createTokenResponse.text().catch(() => 'Unknown error');
      logger.error('[ROCKET_CHAT_USER_TOKEN] Expected JSON, got HTML', {
        contentType: tokenContentType,
        errorPreview: errorText.substring(0, 200),
      });
      return NextResponse.json(
        { error: 'RocketChat returned invalid response format' },
        { status: 500 }
      );
    }

    let tokenData;
    try {
      tokenData = await createTokenResponse.json();
    } catch (error) {
      logger.error('[ROCKET_CHAT_USER_TOKEN] Failed to parse token JSON', {
        error: error instanceof Error ? error.message : String(error),
      });
      return NextResponse.json(
        { error: 'Failed to parse RocketChat response' },
        { status: 500 }
      );
    }

    logger.debug('[ROCKET_CHAT_USER_TOKEN] Token created', {
      emailHash: Buffer.from(session.user.email.toLowerCase()).toString('base64').slice(0, 12),
      hasAuthToken: !!tokenData.data?.authToken,
      tokenLength: tokenData.data?.authToken?.length,
    });

    return NextResponse.json({
      userId: currentUser._id,
      authToken: tokenData.data.authToken,
      username: currentUser.username,
      // Also return the full token data for debugging
      tokenData: tokenData.data,
    });
  } catch (error: any) {
    logger.error('[ROCKET_CHAT_USER_TOKEN] Error', {
      error: error instanceof Error ? error.message : String(error),
    });
    return NextResponse.json(
      { error: "Internal server error", message: error.message },
      { status: 500 }
    );
  }
}