import { NextResponse } from "next/server"
import { createSupabaseServerClient } from "@/lib/supabase/server"
import { rateLimit } from "@/lib/rate-limit"

export async function GET() {
  const supabaseClient = await createSupabaseServerClient()
  const {
    data: { user },
  } = await supabaseClient.auth.getUser()

  if (!user) {
    return NextResponse.json({ error: "not authenticated" }, { status: 401 })
  }

  const rateLimitResult = await rateLimit(`export:${user.id}`, 5, 3_600_000)
  if (!rateLimitResult.success) {
    return NextResponse.json({ error: "too many requests" }, { status: 429 })
  }

  const { data: profile } = await supabaseClient
    .from("user_profiles")
    .select("tier")
    .eq("id", user.id)
    .single()

  const tier = profile?.tier ?? "free"

  const { data: savedEntries } = await supabaseClient
    .from("user_entry_states")
    .select(
      "entries(id, title, url, author, summary, published_at, feeds(title, url))"
    )
    .eq("user_id", user.id)
    .eq("saved", true)

  const exportData: Record<string, unknown> = {
    exportedAt: new Date().toISOString(),
    tier,
    savedEntries:
      (savedEntries ?? []).map((row) => (row as Record<string, unknown>).entries) ?? [],
  }

  if (tier === "pro" || tier === "developer") {
    const [subscriptionsResult, foldersResult, mutedKeywordsResult] =
      await Promise.all([
        supabaseClient
          .from("subscriptions")
          .select("id, feed_id, folder_id, custom_title, feeds(title, url)")
          .eq("user_id", user.id),
        supabaseClient
          .from("folders")
          .select("id, name, position")
          .eq("user_id", user.id),
        supabaseClient
          .from("muted_keywords")
          .select("id, keyword")
          .eq("user_id", user.id),
      ])

    exportData.subscriptions = subscriptionsResult.data ?? []
    exportData.folders = foldersResult.data ?? []
    exportData.mutedKeywords = mutedKeywordsResult.data ?? []
  }

  const jsonString = JSON.stringify(exportData, null, 2)

  return new Response(jsonString, {
    headers: {
      "Content-Type": "application/json",
      "Content-Disposition": `attachment; filename="asa-news-export-${new Date().toISOString().slice(0, 10)}.json"`,
    },
  })
}