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

export async function GET() {
  try {
    const session = await getServerSession(authOptions);
    if (!session) {
      console.error('No session found');
      return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
    }

    console.log('Session data:', {
      hasToken: !!session.rocketChatToken,
      hasUserId: !!session.rocketChatUserId,
      tokenLength: session.rocketChatToken?.length,
      userIdLength: session.rocketChatUserId?.length
    });

    // Get the user's Rocket.Chat token from their session
    const rocketChatToken = session.rocketChatToken;
    const rocketChatUserId = session.rocketChatUserId;

    if (!rocketChatToken || !rocketChatUserId) {
      console.error('Missing Rocket.Chat credentials in session:', {
        hasToken: !!rocketChatToken,
        hasUserId: !!rocketChatUserId,
        session: session
      });
      return NextResponse.json({ error: "User not authenticated with Rocket.Chat" }, { status: 401 });
    }

    // 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': rocketChatToken,
          'X-User-Id': rocketChatUserId,
          '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': rocketChatToken,
                'X-User-Id': rocketChatUserId,
                '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];
            
            // For direct messages, check if the room ID contains the user's ID
            if (subscription.t === 'd') {
              // Extract the other user's ID from the room ID
              const roomIdParts = subscription.rid.split(rocketChatUserId);
              const otherUserId = roomIdParts[0] || roomIdParts[1];
              
              // Only include messages where the user is either the sender or the recipient
              if (message.u._id === rocketChatUserId || message.u._id === otherUserId) {
                return {
                  ...message,
                  roomName: subscription.fname || subscription.name || 'Direct Message',
                  roomType: subscription.t,
                };
              }
            } else {
              // For channels and groups, only include messages where the user is the sender
              if (message.u._id === rocketChatUserId) {
                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 }
    );
  }
}