import { execFileSync } from "node:child_process";
import { chmod, readFile, rm, stat, symlink, unlink, writeFile } from "node:fs/promises";
import { join } from "node:path";
import { createTempTree, findCrossDeviceBase, type TempTree } from "@umt/testkit";
import { afterEach, describe, expect, it } from "vitest";
import {
  checkRoot,
  copyWithVerify,
  crossDeviceMove,
  diskUsage,
  FsError,
  ffprobe,
  moveSafe,
  scanIncremental,
  statSafe,
  sweepStalePartials,
} from "./index.ts";

const trees: TempTree[] = [];
async function tree(...a: Parameters<typeof createTempTree>) {
  const t = await createTempTree(...a);
  trees.push(t);
  return t;
}
afterEach(async () => {
  await Promise.all(trees.splice(0).map((t) => t.cleanup()));
});

const xdevBase = findCrossDeviceBase();
const isRoot = process.getuid?.() === 0;
const hasFfmpeg = (() => {
  try {
    execFileSync("ffmpeg", ["-version"], { stdio: "ignore" });
    return true;
  } catch {
    return false;
  }
})();

describe("copyWithVerify", () => {
  it.each(["size", "sha256", "sample"] as const)("%s 校验后原子提交,保留 mtime,无残留临时文件", async (hash) => {
    const t = await tree({ "src/a.mkv": 3 * 1024 * 1024 + 17, "dst/": null });
    const r = await copyWithVerify(t.path("src/a.mkv"), t.path("dst/a.mkv"), { hash, sampleChunkBytes: 4096 });
    expect(r.bytes).toBe(3 * 1024 * 1024 + 17);
    expect(r.verifiedBy).toBe(hash);
    if (hash === "sha256") expect(r.sha256).toMatch(/^[0-9a-f]{64}$/);
    expect((await readFile(t.path("dst/a.mkv"))).equals(await readFile(t.path("src/a.mkv")))).toBe(true);
    expect(Math.round((await stat(t.path("dst/a.mkv"))).mtimeMs)).toBe(
      Math.round((await stat(t.path("src/a.mkv"))).mtimeMs),
    );
    expect(await sweepStalePartials(t.path("dst"), -1)).toEqual([]);
  });

  it("目标已存在 → EEXIST,不覆盖", async () => {
    const t = await tree({ "a.mkv": "new", "b.mkv": "old" });
    const e = await copyWithVerify(t.path("a.mkv"), t.path("b.mkv")).catch((x) => x);
    expect(e).toBeInstanceOf(FsError);
    expect(e.code).toBe("EEXIST");
    expect(await readFile(t.path("b.mkv"), "utf8")).toBe("old");
  });

  it("父目录不存在默认不创建;中止信号清理临时文件", async () => {
    const t = await tree({ "a.mkv": 1024 * 1024 });
    expect((await copyWithVerify(t.path("a.mkv"), t.path("lib/x/a.mkv")).catch((e) => e)).code).toBe("ENOENT");
    const ac = new AbortController();
    ac.abort();
    await t.write("lib/.keep", "");
    const e = await copyWithVerify(t.path("a.mkv"), t.path("lib/a.mkv"), { signal: ac.signal }).catch((x) => x);
    expect(e.code).toBe("ABORTED");
    expect(await sweepStalePartials(t.path("lib"), -1)).toEqual([]);
    await expect(stat(t.path("lib/a.mkv"))).rejects.toThrow();
  });

  it("残留临时文件清理只删过期的 .uhd-partial", async () => {
    const t = await tree({ "lib/.x.mkv.1.abc.uhd-partial": "x", "lib/keep.mkv": "k" });
    const removed = await sweepStalePartials(t.path("lib"), -1);
    expect(removed).toEqual([t.path("lib/.x.mkv.1.abc.uhd-partial")]);
    expect(await sweepStalePartials(t.path("lib"), 60_000)).toEqual([]);
  });
});

describe("moveSafe / crossDeviceMove", () => {
  it("同设备移动;目标存在返回 exists 且不覆盖", async () => {
    const t = await tree({ "a.mkv": "A", "b.mkv": "B", "c.mkv": "C" });
    expect(await moveSafe(t.path("a.mkv"), t.path("moved.mkv"))).toEqual({ status: "moved" });
    await expect(stat(t.path("a.mkv"))).rejects.toThrow();
    expect(await moveSafe(t.path("b.mkv"), t.path("c.mkv"))).toEqual({ status: "exists" });
    expect(await readFile(t.path("c.mkv"), "utf8")).toBe("C");
    const e = await moveSafe(t.path("nope.mkv"), t.path("x.mkv")).catch((x) => x);
    expect(e.code).toBe("ENOENT");
  });

  it("link 成功但 unlink 前中断(同 inode)→ 续跑补完删除", async () => {
    const t = await tree({ "a.mkv": "A" });
    const { link } = await import("node:fs/promises");
    await link(t.path("a.mkv"), t.path("b.mkv"));
    expect(await moveSafe(t.path("a.mkv"), t.path("b.mkv"))).toEqual({ status: "moved" });
    await expect(stat(t.path("a.mkv"))).rejects.toThrow();
  });

  it.skipIf(!xdevBase)("跨设备:moveSafe 返回 exdev 不降级;crossDeviceMove 三步完成", async () => {
    // xdevBase 为 null 时跳过:本机找不到与 tmpdir 不同设备的可写目录
    const a = await tree({ "a.mkv": 256 * 1024 });
    const b = await tree({ "lib/": null }, { base: xdevBase! });
    expect(await moveSafe(a.path("a.mkv"), b.path("lib/a.mkv"))).toEqual({ status: "exdev" });
    await expect(stat(a.path("a.mkv"))).resolves.toBeTruthy();
    const r = await crossDeviceMove(a.path("a.mkv"), b.path("lib/a.mkv"), { hash: "sha256" });
    expect(r.status).toBe("completed");
    expect(r.steps.map((s) => `${s.step}:${s.status}`)).toEqual(["copy:done", "verify:done", "delete_source:done"]);
    await expect(stat(a.path("a.mkv"))).rejects.toThrow();
  });

  it("crossDeviceMove 可重入:目标已一致则跳过复制;源已删且上次已验证 → completed;目标不同 → failed 不删源", async () => {
    const t = await tree({ "src/a.mkv": "same", "dst/a.mkv": "same", "src/b.mkv": "bbbb", "dst/b.mkv": "cccc" });
    const r1 = await crossDeviceMove(t.path("src/a.mkv"), t.path("dst/a.mkv"), { hash: "sha256" });
    expect(r1.steps.map((s) => `${s.step}:${s.status}`)).toEqual(["copy:skipped", "verify:done", "delete_source:done"]);
    const r2 = await crossDeviceMove(t.path("src/a.mkv"), t.path("dst/a.mkv"), { previous: r1.steps });
    expect(r2.status).toBe("completed");
    const r3 = await crossDeviceMove(t.path("src/b.mkv"), t.path("dst/b.mkv"), { hash: "sha256" });
    expect(r3.status).toBe("failed");
    expect(await readFile(t.path("src/b.mkv"), "utf8")).toBe("bbbb");
    const r4 = await crossDeviceMove(t.path("src/none.mkv"), t.path("dst/b.mkv"));
    expect(r4.status).toBe("attention");
  });

  it.skipIf(isRoot)("删源失败 → attention(以 root 运行时跳过:root 无视目录权限)", async () => {
    const t = await tree({ "src/a.mkv": "A", "dst/": null });
    await chmod(t.path("src"), 0o555);
    try {
      const r = await crossDeviceMove(t.path("src/a.mkv"), t.path("dst/a.mkv"));
      expect(r.status).toBe("attention");
      expect(r.steps.at(-1)).toMatchObject({ step: "delete_source", status: "failed" });
    } finally {
      await chmod(t.path("src"), 0o755);
    }
  });
});

describe("statSafe / checkRoot / diskUsage", () => {
  it("区分正常、缺失、根离线", async () => {
    const t = await tree({ "movies/a.mkv": "A" }, { sentinel: true });
    const ok = await statSafe(t.path("movies/a.mkv"), { root: t.root });
    expect(ok.kind).toBe("ok");
    if (ok.kind === "ok") expect(ok.facts.size).toBe(1);
    expect((await statSafe(t.path("movies/b.mkv"), { root: t.root })).kind).toBe("missing");
    expect(await checkRoot(t.root)).toMatchObject({ kind: "online" });
    await unlink(t.path(".uhd-root"));
    expect(await statSafe(t.path("movies/b.mkv"), { root: t.root })).toMatchObject({
      kind: "root_offline",
      reason: "sentinel_missing",
    });
    expect(await checkRoot(join(t.root, "gone"))).toMatchObject({ kind: "offline", reason: "root_missing" });
  });

  it.skipIf(isRoot)("权限拒绝 → permission_denied(root 运行时跳过)", async () => {
    const t = await tree({ "locked/a.mkv": "A" });
    await chmod(t.path("locked"), 0o000);
    try {
      expect((await statSafe(t.path("locked/a.mkv"))).kind).toBe("permission_denied");
    } finally {
      await chmod(t.path("locked"), 0o755);
    }
  });

  it("磁盘用量:statfs 成功给出比例,路径不存在返回 unknown", async () => {
    const t = await tree();
    const u = await diskUsage(t.root);
    expect(u.status).toBe("ok");
    if (u.status === "ok") {
      expect(u.totalBytes).toBeGreaterThan(0);
      expect(u.usedRatio).toBeGreaterThanOrEqual(0);
      expect(u.usedRatio).toBeLessThanOrEqual(1);
    }
    expect(await diskUsage(join(t.root, "nope"))).toMatchObject({ status: "unknown", code: "ENOENT" });
  });
});

describe("scanIncremental", () => {
  it("按 I/O 上限分批,游标续扫覆盖全部且不重复", async () => {
    const spec: Record<string, string> = {};
    for (const d of ["A", "B", "C"]) for (let i = 0; i < 4; i++) spec[`${d}/s${i}/f${i}.mkv`] = `${d}${i}`;
    spec["B/.x.uhd-partial"] = "p";
    const t = await tree(spec, { sentinel: true });
    const seen: string[] = [];
    let cursor: string | null = null;
    let batches = 0;
    do {
      const r = await scanIncremental(t.root, { cursor, maxStats: 5 });
      expect(r.statCount).toBeLessThanOrEqual(5);
      seen.push(...r.entries.map((e) => e.relPath));
      cursor = r.cursor;
      batches++;
      if (r.status === "complete") break;
      expect(r.status).toBe("partial");
    } while (batches < 10);
    expect(batches).toBe(3);
    expect(seen).toEqual([...seen].sort());
    expect(new Set(seen).size).toBe(12);
    expect(seen).not.toContain("B/.x.uhd-partial");
  });

  it("标注 new/changed/unchanged;根离线不扫描;符号链接不跟随", async () => {
    const t = await tree({ "a.mkv": "A", "b.mkv": "B", "c.mkv": "C" }, { sentinel: true });
    await symlink(t.path("a.mkv"), t.path("d.mkv"));
    const first = await scanIncremental(t.root);
    const prev = new Map(first.entries.map((e) => [e.relPath, e]));
    await writeFile(t.path("b.mkv"), "BBBB");
    const second = await scanIncremental(t.root, { previous: (p) => prev.get(p) });
    const byPath = Object.fromEntries(second.entries.map((e) => [e.relPath, e]));
    expect(byPath["a.mkv"]!.change).toBe("unchanged");
    expect(byPath["b.mkv"]!.change).toBe("changed");
    expect(byPath["d.mkv"]!.isSymlink).toBe(true);
    await rm(t.path(".uhd-root"));
    const off = await scanIncremental(t.root);
    expect(off.status).toBe("root_offline");
    expect(off.entries).toEqual([]);
  });
});

describe("ffprobe", () => {
  it("可执行文件不存在 / 非媒体文件 → unknown,不抛", async () => {
    const t = await tree({ "a.txt": "hello" });
    expect(await ffprobe(t.path("a.txt"), { bin: "/nonexistent/ffprobe" })).toEqual({
      status: "unknown",
      reason: "ffprobe_unavailable",
    });
    const r = await ffprobe(t.path("a.txt"));
    expect(r.status).toBe("unknown");
  });

  it.skipIf(!hasFfmpeg)("真实小样片:读出分辨率与音轨(本机无 ffmpeg 时跳过)", async () => {
    const t = await tree();
    const out = t.path("s.mkv");
    execFileSync("ffmpeg", [
      "-v",
      "error",
      "-f",
      "lavfi",
      "-i",
      "testsrc=size=320x240:rate=5",
      "-f",
      "lavfi",
      "-i",
      "sine=frequency=440",
      "-t",
      "1",
      "-c:v",
      "mpeg4",
      "-c:a",
      "ac3",
      "-metadata:s:a:0",
      "language=jpn",
      out,
    ]);
    const r = await ffprobe(out);
    expect(r.status).toBe("ok");
    if (r.status === "ok") {
      expect(r.video[0]).toMatchObject({ codec: "mpeg4", width: 320, height: 240 });
      expect(r.video[0]!.hdr).toBeUndefined();
      expect(r.audio[0]).toMatchObject({ codec: "ac3", language: "jpn" });
    }
  });
});