import { NextResponse } from 'next/server'

const IPTV_ORG_URL = 'https://iptv-org.github.io/api/channels.json'

interface IptvChannel {
  id: string
  name: string
  country: string
  categories: string[]
  is_nsfw: boolean
  is_closed: boolean
}

interface SlimChannel {
  id: string
  name: string
  country: string
  categories: string[]
}

let cache: { data: SlimChannel[]; fetchedAt: number } | null = null
const CACHE_TTL = 60 * 60 * 1000 // 1 hour

export async function GET() {
  try {
    if (cache && Date.now() - cache.fetchedAt < CACHE_TTL) {
      return NextResponse.json(cache.data)
    }

    const res = await fetch(IPTV_ORG_URL, { next: { revalidate: 3600 } })
    if (!res.ok) {
      throw new Error(`iptv-org API returned ${res.status}`)
    }

    const channels: IptvChannel[] = await res.json()

    const filtered: SlimChannel[] = channels
      .filter((ch) => !ch.is_nsfw && !ch.is_closed)
      .map(({ id, name, country, categories }) => ({ id, name, country, categories }))

    cache = { data: filtered, fetchedAt: Date.now() }

    return NextResponse.json(filtered)
  } catch (error) {
    console.error('Failed to fetch channels:', error)
    // Return cached data even if stale on error
    if (cache) {
      return NextResponse.json(cache.data)
    }
    return NextResponse.json(
      { error: 'Failed to load channel list' },
      { status: 502 }
    )
  }
}