import { randomUUID } from "node:crypto";
import { execFile } from "node:child_process";
import { mkdtemp, readFile, rm } from "node:fs/promises";
import { tmpdir } from "node:os";
import { join } from "node:path";
import { promisify } from "node:util";
import { uploadFile } from "@/lib/storage/service";
import { downloadCanvasMedia } from "./download-media";

const probe = promisify(execFile);
const pending = new Map<string, Promise<string>>();

export async function archiveCanvasVideo(url: string): Promise<string> {
  const existing = pending.get(url);
  if (existing) return existing;
  if (pending.size >= 2) throw new Error("视频保存繁忙，请稍后重试");
  const job = (async () => {
    const dir = await mkdtemp(join(tmpdir(), "canvas-video-archive-"));
    try {
      const input = join(dir, "video");
      await downloadCanvasMedia(url, input);
      const { stdout } = await probe("ffprobe", ["-v", "error", "-protocol_whitelist", "file", "-format_whitelist", "mov,matroska,webm", "-show_streams", "-show_format", "-of", "json", input], { timeout: 15000, maxBuffer: 1024 * 1024 });
      const media = JSON.parse(stdout);
      if (!media.streams?.some((stream: { codec_type: string }) => stream.codec_type === "video") || !(Number(media.format?.duration) > 0)) throw new Error("视频文件不完整");
      const extension = String(media.format.format_name).includes("mov") ? "mp4" : "webm";
      const data = await readFile(input);
      const uploaded = await uploadFile(`canvas-generated-${randomUUID()}.${extension}`, new Uint8Array(data).buffer);
      return uploaded.url;
    } finally {
      await rm(dir, { recursive: true, force: true });
    }
  })();
  pending.set(url, job);
  try { return await job; } finally { pending.delete(url); }
}