import { execFile } from "node:child_process";
import { promisify } from "node:util";
import { mkdtemp, readFile, rm } from "node:fs/promises";
import { tmpdir } from "node:os";
import { join } from "node:path";
import { uploadFile } from "@/lib/storage/service";
import { probeVideoMetadata } from "./video-probe";
export type VideoMediaOperation = "extract-frame" | "trim" | "crop" | "extract-audio" | "mute";
export type VideoMediaInput = {
  operation: VideoMediaOperation;
  url: string;
  time?: number;
  end?: number;
  frame?: "first" | "last" | "time";
  x?: number;
  y?: number;
  width?: number;
  height?: number;
};
const execute = promisify(execFile);
export async function processVideoMedia(input: VideoMediaInput, upload = uploadFile) {
  if (!/^https?:\/\//i.test(input.url)) throw new Error("视频缺少已保存的远程链接");
  const metadata = await probeVideoMetadata(input.url);
  if (metadata.duration > 120)
    throw new Error("当前 Agent 媒体工具单次支持不超过 120 秒的视频，请先选择短片段");
  const directory = await mkdtemp(join(tmpdir(), "canvas-agent-media-"));
  const type: "image" | "audio" | "video" =
    input.operation === "extract-frame"
      ? "image"
      : input.operation === "extract-audio"
        ? "audio"
        : "video";
  const extension = type === "image" ? "png" : type === "audio" ? "m4a" : "mp4";
  const path = join(directory, `result.${extension}`);
  try {
    const args = ["-v", "error", "-nostdin", "-threads", "2"];
    let seek = Math.max(0, input.time || 0);
    if (input.operation === "extract-frame" && input.frame === "last")
      seek = Math.max(0, metadata.duration - 0.1);
    if (input.operation === "extract-frame" && input.frame === "first") seek = 0;
    if (seek >= metadata.duration) throw new Error("截取时间超出真实视频时长");
    if (input.operation === "extract-frame" || input.operation === "trim")
      args.push("-ss", String(seek));
    args.push("-protocol_whitelist", "http,https,tcp,tls,crypto", "-i", input.url);
    if (input.operation === "extract-frame") args.push("-frames:v", "1", "-update", "1");
    else if (input.operation === "extract-audio") args.push("-vn", "-c:a", "aac");
    else {
      if (input.operation === "trim") {
        const end = Math.min(metadata.duration, input.end ?? metadata.duration);
        if (end <= seek) throw new Error("剪辑结束时间必须大于开始时间");
        args.push("-t", String(end - seek));
      }
      if (input.operation === "crop") {
        const rect = [input.x, input.y, input.width, input.height];
        if (
          !rect.every((value) => typeof value === "number" && Number.isInteger(value)) ||
          input.x! < 0 ||
          input.y! < 0 ||
          input.width! < 2 ||
          input.height! < 2 ||
          input.x! + input.width! > metadata.width ||
          input.y! + input.height! > metadata.height
        )
          throw new Error("裁剪坐标超出真实视频尺寸");
        args.push("-vf", `crop=${input.width}:${input.height}:${input.x}:${input.y}`);
      }
      if (input.operation === "mute") args.push("-an");
      args.push(
        "-c:v",
        "libx264",
        "-preset",
        "veryfast",
        "-pix_fmt",
        "yuv420p",
        "-movflags",
        "+faststart",
      );
    }
    args.push("-y", path);
    await execute("ffmpeg", args, { timeout: 180_000, maxBuffer: 1024 * 1024 });
    const bytes = await readFile(path);
    if (!bytes.length) throw new Error("媒体处理未产生文件");
    const uploaded = await upload(
      `video-agent-${crypto.randomUUID()}.${extension}`,
      new Uint8Array(bytes).buffer,
    );
    return {
      url: uploaded.url,
      type,
      duration:
        input.operation === "trim"
          ? Math.min(metadata.duration, input.end ?? metadata.duration) - seek
          : metadata.duration,
    };
  } finally {
    await rm(directory, { recursive: true, force: true });
  }
}