/**
 * Import ChatGPT conversations using OpenAI's Conversations API
 */

import { NextResponse } from 'next/server';
import { getAdminAuth, getAdminDb } from '@/lib/firebase/admin';

const OPENAI_API_URL = 'https://api.openai.com/v1/conversations';

export async function POST(request: Request) {
  try {
    // Authenticate user
    const authHeader = request.headers.get('Authorization');
    if (!authHeader?.startsWith('Bearer ')) {
      return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });
    }

    const idToken = authHeader.split('Bearer ')[1];
    const adminAuth = getAdminAuth();
    const adminDb = getAdminDb();
    
    let userId: string;
    try {
      const decodedToken = await adminAuth.verifyIdToken(idToken);
      userId = decodedToken.uid;
    } catch (error) {
      return NextResponse.json({ error: 'Invalid token' }, { status: 401 });
    }

    const { conversationId, openaiApiKey, projectId } = await request.json();

    if (!conversationId) {
      return NextResponse.json({ error: 'Conversation ID is required' }, { status: 400 });
    }

    if (!openaiApiKey) {
      return NextResponse.json({ error: 'OpenAI API key is required' }, { status: 400 });
    }

    // Fetch conversation from OpenAI
    console.log(`[ChatGPT Import] Fetching conversation: ${conversationId}`);
    
    const openaiResponse = await fetch(`${OPENAI_API_URL}/${conversationId}`, {
      method: 'GET',
      headers: {
        'Authorization': `Bearer ${openaiApiKey}`,
        'Content-Type': 'application/json',
      },
    });

    if (!openaiResponse.ok) {
      const errorText = await openaiResponse.text();
      console.error('[ChatGPT Import] OpenAI API error:', openaiResponse.status, errorText);
      return NextResponse.json(
        { 
          error: 'Failed to fetch conversation from OpenAI',
          details: errorText,
          status: openaiResponse.status,
        },
        { status: openaiResponse.status }
      );
    }

    const conversationData = await openaiResponse.json();
    console.log('[ChatGPT Import] Conversation fetched successfully');

    // Extract relevant information
    const messages = conversationData.messages || [];
    const title = conversationData.title || 'Untitled Conversation';
    const createdAt = conversationData.created_at || new Date().toISOString();

    // Store in Firestore
    const chatGPTImportRef = adminDb.collection('chatgptImports').doc();
    
    await chatGPTImportRef.set({
      userId,
      projectId: projectId || null,
      conversationId,
      title,
      createdAt,
      importedAt: new Date().toISOString(),
      messageCount: messages.length,
      messages: messages.map((msg: any) => ({
        role: msg.role || msg.author?.role || 'unknown',
        content: msg.content?.parts?.join('\n') || msg.content || '',
        timestamp: msg.create_time || msg.timestamp || null,
      })),
      rawData: conversationData, // Store full response for future reference
    });

    // If projectId provided, update project with ChatGPT reference
    if (projectId) {
      const projectRef = adminDb.collection('projects').doc(projectId);
      await projectRef.update({
        chatgptConversationId: conversationId,
        chatgptTitle: title,
        chatgptImportedAt: new Date().toISOString(),
      });
      console.log(`[ChatGPT Import] Updated project ${projectId} with conversation reference`);
    }

    return NextResponse.json({
      success: true,
      importId: chatGPTImportRef.id,
      conversationId,
      title,
      messageCount: messages.length,
      messages: messages.slice(0, 5).map((msg: any) => ({
        role: msg.role || msg.author?.role || 'unknown',
        preview: (msg.content?.parts?.join('\n') || msg.content || '').substring(0, 200) + '...',
      })),
    });
  } catch (error) {
    console.error('[ChatGPT Import] Error:', error);
    return NextResponse.json(
      {
        error: 'Failed to import ChatGPT conversation',
        details: error instanceof Error ? error.message : String(error),
      },
      { status: 500 }
    );
  }
}

// GET endpoint to list imported conversations
export async function GET(request: Request) {
  try {
    const authHeader = request.headers.get('Authorization');
    if (!authHeader?.startsWith('Bearer ')) {
      return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });
    }

    const idToken = authHeader.split('Bearer ')[1];
    const adminAuth = getAdminAuth();
    const adminDb = getAdminDb();
    
    let userId: string;
    try {
      const decodedToken = await adminAuth.verifyIdToken(idToken);
      userId = decodedToken.uid;
    } catch (error) {
      return NextResponse.json({ error: 'Invalid token' }, { status: 401 });
    }

    // Get projectId from query params if provided
    const url = new URL(request.url);
    const projectId = url.searchParams.get('projectId');

    let query = adminDb
      .collection('chatgptImports')
      .where('userId', '==', userId);

    if (projectId) {
      query = query.where('projectId', '==', projectId) as any;
    }

    const snapshot = await query.orderBy('importedAt', 'desc').limit(50).get();

    const imports = snapshot.docs.map(doc => ({
      id: doc.id,
      ...doc.data(),
      // Don't send full rawData in list view
      rawData: undefined,
    }));

    return NextResponse.json({ imports });
  } catch (error) {
    console.error('[ChatGPT Import] List error:', error);
    return NextResponse.json(
      {
        error: 'Failed to list imports',
        details: error instanceof Error ? error.message : String(error),
      },
      { status: 500 }
    );
  }
}