import { NextRequest, NextResponse } from 'next/server'
import { prisma } from '@/lib/prisma'
import { requireAuth, slugify, getCurrentUser } from '@/lib/auth'

export async function GET(
  request: NextRequest,
  { params }: { params: Promise<{ id: string }> }
) {
  try {
    const { id } = await params
    const user = await getCurrentUser()

    const playlist = await prisma.playlist.findUnique({
      where: { id },
      include: {
        user: {
          select: {
            id: true,
            username: true,
            displayName: true,
            avatarUrl: true,
          },
        },
        songs: {
          include: {
            song: {
              include: {
                artist: {
                  select: {
                    id: true,
                    name: true,
                    slug: true,
                    avatarUrl: true,
                    verified: true,
                  },
                },
                album: {
                  select: {
                    id: true,
                    title: true,
                    slug: true,
                    coverUrl: true,
                  },
                },
                genres: {
                  include: {
                    genre: true,
                  },
                },
              },
            },
          },
          orderBy: {
            position: 'asc',
          },
        },
      },
    })

    if (!playlist) {
      return NextResponse.json({ error: 'Playlist not found' }, { status: 404 })
    }

    // Only allow private playlists to be viewed by the owner
    if (!playlist.isPublic && (!user || user.id !== playlist.userId)) {
      return NextResponse.json({ error: 'Playlist not found' }, { status: 404 })
    }

    return NextResponse.json(playlist)
  } catch (error) {
    console.error('Error fetching playlist:', error)
    return NextResponse.json({ error: 'Failed to fetch playlist' }, { status: 500 })
  }
}

export async function PUT(
  request: NextRequest,
  { params }: { params: Promise<{ id: string }> }
) {
  try {
    const user = await requireAuth()
    const { id } = await params

    const existingPlaylist = await prisma.playlist.findUnique({
      where: { id },
    })

    if (!existingPlaylist) {
      return NextResponse.json({ error: 'Playlist not found' }, { status: 404 })
    }

    if (existingPlaylist.userId !== user.id) {
      return NextResponse.json({ error: 'Unauthorized' }, { status: 403 })
    }

    const body = await request.json()
    const { title, description, coverUrl, isPublic } = body

    const updateData: any = {}
    if (title !== undefined) {
      updateData.title = title
      updateData.slug = slugify(title)
    }
    if (description !== undefined) updateData.description = description
    if (coverUrl !== undefined) updateData.coverUrl = coverUrl
    if (isPublic !== undefined) updateData.isPublic = isPublic

    const updatedPlaylist = await prisma.playlist.update({
      where: { id },
      data: updateData,
      include: {
        _count: {
          select: {
            songs: true,
          },
        },
      },
    })

    return NextResponse.json(updatedPlaylist)
  } catch (error) {
    if (error instanceof Error && error.message === 'Unauthorized') {
      return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
    }
    console.error('Error updating playlist:', error)
    return NextResponse.json({ error: 'Failed to update playlist' }, { status: 500 })
  }
}

export async function DELETE(
  request: NextRequest,
  { params }: { params: Promise<{ id: string }> }
) {
  try {
    const user = await requireAuth()
    const { id } = await params

    const existingPlaylist = await prisma.playlist.findUnique({
      where: { id },
    })

    if (!existingPlaylist) {
      return NextResponse.json({ error: 'Playlist not found' }, { status: 404 })
    }

    if (existingPlaylist.userId !== user.id) {
      return NextResponse.json({ error: 'Unauthorized' }, { status: 403 })
    }

    await prisma.playlist.delete({
      where: { id },
    })

    return NextResponse.json({ message: 'Playlist deleted successfully' })
  } catch (error) {
    if (error instanceof Error && error.message === 'Unauthorized') {
      return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
    }
    console.error('Error deleting playlist:', error)
    return NextResponse.json({ error: 'Failed to delete playlist' }, { status: 500 })
  }
}