import { NextRequest, NextResponse } from 'next/server';
import { db } from '@/lib/db';
import { requireAuth } from '@/lib/auth';
import { getErrorMessage } from '@/lib/errors';

// Get messages for a conversation
export async function GET(
  request: NextRequest,
  { params }: { params: Promise<{ id: string }> }
) {
  try {
    const user = await requireAuth();
    if (!user) {
      return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });
    }

    const { id } = await params;

    // Verify user is participant
    const { rows: participants } = await db.query(
      'SELECT * FROM conversation_participants WHERE conversation_id = $1 AND user_id = $2',
      [id, user.id]
    );

    if (participants.length === 0) {
      return NextResponse.json({ error: 'Not authorized for this conversation' }, { status: 403 });
    }

    // Get all messages with sender info
    const { rows: messages } = await db.query(`
      SELECT 
        dm.id,
        dm.content,
        dm.created_at,
        u.id as sender_id,
        u.username,
        u.first_name,
        u.last_name,
        u.role
      FROM direct_messages dm
      JOIN users u ON dm.sender_id = u.id
      WHERE dm.conversation_id = $1
      ORDER BY dm.created_at ASC
    `, [id]);

    // Get conversation details with participants
    const { rows: convRows } = await db.query(`
      SELECT 
        c.id,
        c.subject,
        c.created_at,
        c.updated_at
      FROM conversations c
      WHERE c.id = $1
    `, [id]);

    const { rows: participantRows } = await db.query(`
      SELECT u.id, u.username, u.first_name, u.last_name, u.role
      FROM conversation_participants cp
      JOIN users u ON cp.user_id = u.id
      WHERE cp.conversation_id = $1
    `, [id]);

    return NextResponse.json({
      conversation: convRows[0],
      participants: participantRows,
      messages
    });
  } catch (error) {
    console.error('Get messages error:', error);
    return NextResponse.json(
      { error: getErrorMessage(error, 'Failed to get messages') },
      { status: 500 }
    );
  }
}