import fs from "fs"
import path from "path"
import { get } from "./settings"

const COVERS_DIR = process.env.COVERS_DIR || path.join(process.cwd(), "data", "covers")

function ensureDir() {
  fs.mkdirSync(COVERS_DIR, { recursive: true })
}

function extFromContentType(ct: string | null): string {
  if (!ct) return ".jpg"
  const m = ct.match(/image\/(\w+)/)
  if (!m) return ".jpg"
  const exts: Record<string, string> = {
    jpeg: ".jpg",
    png: ".png",
    webp: ".webp",
    gif: ".gif",
  }
  return exts[m[1]] || ".jpg"
}

// Descarga la portada DIRECTAMENTE del upstream (API_BASE_URL), con la misma
// API key que usa el resto de la app. NO pasa por el proxy /api/proxy/* (que el
// middleware protege), evitando el redirect a /login que guardaba HTML como portada.
export async function cacheCover(gid: string): Promise<string | null> {
  ensureDir()
  try {
    const apiBase = get("API_BASE_URL", "http://127.0.0.1:8080/api/v1")
    const apiKey = get("API_KEY")
    const headers: Record<string, string> = {}
    if (apiKey) headers["X-API-Key"] = apiKey

    const res = await fetch(`${apiBase}/galleries/${gid}/cover`, {
      headers,
      signal: AbortSignal.timeout(15000),
    })
    if (!res.ok) return null

    const buffer = Buffer.from(await res.arrayBuffer())
    const ext = extFromContentType(res.headers.get("content-type"))
    const filePath = path.join(COVERS_DIR, `${gid}${ext}`)

    fs.writeFileSync(filePath, buffer)
    return filePath
  } catch {
    return null
  }
}

export function getCoverPath(gid: string): string | null {
  ensureDir()
  const files = fs.readdirSync(COVERS_DIR).filter((f) => f.startsWith(`${gid}.`))
  if (files.length === 0) return null
  return path.join(COVERS_DIR, files[0])
}

export function getCoverContentType(gid: string): string {
  const fp = getCoverPath(gid)
  if (!fp) return "image/jpeg"
  const ext = path.extname(fp).toLowerCase()
  const m: Record<string, string> = {
    ".jpg": "image/jpeg",
    ".jpeg": "image/jpeg",
    ".png": "image/png",
    ".webp": "image/webp",
    ".gif": "image/gif",
  }
  return m[ext] || "image/jpeg"
}

export function deleteCover(gid: string): void {
  const fp = getCoverPath(gid)
  if (fp) fs.unlinkSync(fp)
}