import { getServerSession } from "next-auth";
import { authOptions } from "@/app/api/auth/[...nextauth]/route";
import { NextResponse } from "next/server";

if (!process.env.ROCKET_CHAT_TOKEN || !process.env.ROCKET_CHAT_USER_ID) {
  console.error('Missing Rocket.Chat credentials in environment variables');
}

export async function GET() {
  try {
    const session = await getServerSession(authOptions);
    if (!session) {
      return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
    }

    // Debug log to see all session data
    console.log('Session data:', {
      user: session.user,
      accessToken: session.accessToken ? 'present' : 'missing'
    });

    if (!session.accessToken) {
      return NextResponse.json({ error: "No access token found" }, { status: 401 });
    }

    // First get the username from Keycloak
    const keycloakResponse = await fetch(
      `${process.env.KEYCLOAK_BASE_URL}/realms/${process.env.KEYCLOAK_REALM}/protocol/openid-connect/userinfo`,
      {
        headers: {
          'Authorization': `Bearer ${session.accessToken}`
        }
      }
    );

    if (!keycloakResponse.ok) {
      console.error('Failed to get Keycloak user info:', {
        status: keycloakResponse.status,
        statusText: keycloakResponse.statusText,
        response: await keycloakResponse.text().catch(() => 'Could not get response text')
      });
      return NextResponse.json(
        { error: "Failed to get user info from Keycloak" },
        { status: keycloakResponse.status }
      );
    }

    const keycloakUser = await keycloakResponse.json();
    const username = keycloakUser.preferred_username;

    console.log('Keycloak user info:', {
      username,
      sub: keycloakUser.sub
    });

    if (!username) {
      return NextResponse.json(
        { error: "No username found in Keycloak user info" },
        { status: 400 }
      );
    }

    // Get user info using personal access token
    const userInfoResponse = await fetch(
      `https://parole.slm-lab.net/api/v1/users.info?username=${username}`,
      {
        headers: {
          'X-Auth-Token': process.env.ROCKET_CHAT_TOKEN!,
          'X-User-Id': process.env.ROCKET_CHAT_USER_ID!,
          'Content-Type': 'application/json'
        }
      }
    );

    if (!userInfoResponse.ok) {
      console.error('Failed to get user info:', {
        status: userInfoResponse.status,
        statusText: userInfoResponse.statusText,
        headers: userInfoResponse.headers,
        response: await userInfoResponse.text().catch(() => 'Could not get response text')
      });
      return NextResponse.json(
        { error: "Failed to get user info" },
        { status: userInfoResponse.status }
      );
    }

    const userInfo = await userInfoResponse.json();
    console.log('User info success:', {
      userId: userInfo.user._id,
      username: userInfo.user.username
    });

    // Get the user's subscriptions (rooms they are in)
    const subscriptionsResponse = await fetch(
      'https://parole.slm-lab.net/api/v1/subscriptions.get',
      {
        headers: {
          'X-Auth-Token': process.env.ROCKET_CHAT_TOKEN!,
          'X-User-Id': userInfo.user._id,
          'Content-Type': 'application/json'
        }
      }
    );

    if (!subscriptionsResponse.ok) {
      console.error('Rocket.Chat subscriptions error:', {
        status: subscriptionsResponse.status,
        statusText: subscriptionsResponse.statusText,
        response: await subscriptionsResponse.text().catch(() => 'Could not get response text')
      });
      return NextResponse.json(
        { error: "Failed to fetch subscriptions" },
        { status: subscriptionsResponse.status }
      );
    }

    const subscriptions = await subscriptionsResponse.json();
    console.log('Subscriptions response:', subscriptions);

    if (!subscriptions.update || subscriptions.update.length === 0) {
      console.log('No subscriptions found');
      return NextResponse.json({ messages: [] });
    }

    // Get the last message from each room
    const messages = await Promise.all(
      subscriptions.update.map(async (subscription: any) => {
        try {
          if (!subscription.rid) {
            console.log('No room ID found for subscription:', subscription);
            return null;
          }

          // Choose the appropriate endpoint based on room type
          const endpoint = subscription.t === 'd' 
            ? 'im.messages' 
            : subscription.t === 'c' 
              ? 'channels.messages' 
              : 'groups.messages';

          console.log(`Fetching messages for room ${subscription.name} using endpoint ${endpoint}`);

          // Get the most recent messages from the room
          const messagesResponse = await fetch(
            `https://parole.slm-lab.net/api/v1/${endpoint}?roomId=${subscription.rid}&count=1`,
            {
              headers: {
                'X-Auth-Token': process.env.ROCKET_CHAT_TOKEN!,
                'X-User-Id': process.env.ROCKET_CHAT_USER_ID!,
                'Content-Type': 'application/json'
              }
            }
          );

          if (!messagesResponse.ok) {
            console.error('Failed to fetch messages:', {
              roomId: subscription.rid,
              endpoint,
              status: messagesResponse.status,
              response: await messagesResponse.text().catch(() => 'Could not get response text')
            });
            return null;
          }

          const messagesData = await messagesResponse.json();
          console.log(`Messages response for ${subscription.name}:`, {
            count: messagesData.messages?.length,
            success: messagesData.success
          });
          
          if (messagesData.messages && messagesData.messages.length > 0) {
            const message = messagesData.messages[0];
            return {
              ...message,
              roomName: subscription.fname || subscription.name || 'Direct Message',
              roomType: subscription.t,
            };
          }
          
          console.log('No messages found for room:', subscription.rid);
          return null;
        } catch (error) {
          console.error('Error processing room:', subscription.rid, error);
          return null;
        }
      })
    );

    // Filter out any null messages and sort by timestamp
    const validMessages = messages
      .filter((msg): msg is NonNullable<typeof msg> => msg !== null)
      .sort((a, b) => new Date(b.ts).getTime() - new Date(a.ts).getTime());

    console.log('Found messages:', validMessages.length);
    return NextResponse.json({ messages: validMessages });
  } catch (error) {
    console.error('Error fetching messages:', error);
    return NextResponse.json(
      { error: "Internal server error" },
      { status: 500 }
    );
  }
}