import { NextRequest, NextResponse } from 'next/server'
import connectDB from '@/lib/mongodb'
import TopicModel, { transformToTopic } from '@/models/topic'

export async function GET(
  request: NextRequest,
  { params }: { params: Promise<{ slug: string }> }
) {
  try {
    await connectDB()

    const { slug } = await params

    if (!slug) {
      return NextResponse.json(
        {
          success: false,
          error: {
            message: 'Topic slug is required',
            code: 'SLUG_REQUIRED',
          },
        },
        { status: 400 }
      )
    }

    // Find the topic post by slug (only published posts)
    const post = await TopicModel.findOne({ 
      slug, 
      isDraft: false 
    }).lean()

    if (!post) {
      return NextResponse.json(
        {
          success: false,
          error: {
            message: 'Topic post not found',
            code: 'POST_NOT_FOUND',
          },
        },
        { status: 404 }
      )
    }

    // Transform to proper format
    const transformedPost = transformToTopic(post)

    if (!transformedPost) {
      return NextResponse.json(
        {
          success: false,
          error: {
            message: 'Failed to process topic post',
            code: 'PROCESSING_ERROR',
          },
        },
        { status: 500 }
      )
    }

    return NextResponse.json({
      success: true,
      data: transformedPost,
    })
  } catch (error) {
    console.error('Error fetching topic post:', error)
    return NextResponse.json(
      {
        success: false,
        error: {
          message: 'Failed to fetch topic post',
          code: 'SERVER_ERROR',
        },
      },
      { status: 500 }
    )
  }
}