import assert from "node:assert/strict";
import { spawnSync } from "node:child_process";
import { mkdirSync, mkdtempSync, readFileSync, rmSync, statSync } from "node:fs";
import { tmpdir } from "node:os";
import { join } from "node:path";
import { after, test, type TestContext } from "node:test";
import { Runner } from "../src/runner/index.ts";
import type { ProcessResult, RunDefinition } from "../src/vocab/index.ts";

// 用真实 Docker 测（任务书 05 第五部分）：没有 Docker 时整个文件失败，不跳过。
// 镜像、容器名一律 inforsi-test- 开头的固定名字；本机还有别的项目在建删容器，只动自己前缀的。

const TASK_DIR = join(import.meta.dirname, "..", "tasks", "circle_packing");
const IMAGE_TAG = "inforsi-test-circle";
const MISSING_DIGEST = `sha256:${"0".repeat(64)}`;

const runner = new Runner(null);
const digest = await runner.buildImage(TASK_DIR, IMAGE_TAG);
after(() => docker(["rmi", IMAGE_TAG]));

function docker(args: string[]): { status: number | null; stdout: string; stderr: string } {
  return spawnSync("docker", args, { encoding: "utf8" });
}

/** 删掉测试自己的容器；不存在不算错，别的错误照样报。 */
function forceRemove(name: string): void {
  const removed = docker(["rm", "-f", name]);
  if (removed.status !== 0 && !removed.stderr.includes("No such container")) throw new Error(removed.stderr);
}

/** 一个测试用的容器名：先清掉上次没删干净的同名容器，测试结束后再删。 */
function containerName(t: TestContext, suffix: string): string {
  const name = `inforsi-test-${suffix}`;
  forceRemove(name);
  t.after(() => forceRemove(name));
  return name;
}

function dirs(t: TestContext): { runDir: string; logDir: string } {
  const root = mkdtempSync(join(tmpdir(), "inforsi-runner-"));
  t.after(() => rmSync(root, { recursive: true, force: true }));
  const runDir = join(root, "run");
  const logDir = join(root, "log");
  mkdirSync(runDir);
  mkdirSync(logDir);
  return { runDir, logDir };
}

function definition(command: string[], wallSeconds: number, image: string): RunDefinition {
  return {
    command,
    workdir: "/work",
    image: { digest: image, runtime: "runc" },
    wallSeconds,
    cores: 1,
    inheritEnv: false,
    env: {},
  };
}

const python = (code: string): string[] => ["python3", "-c", code];

/** 起一个容器并等它结束，交回结果和日志目录。 */
async function runToEnd(t: TestContext, suffix: string, command: string[], wallSeconds: number) {
  const name = containerName(t, suffix);
  const { runDir, logDir } = dirs(t);
  const outcome = await runner.start(name, definition(command, wallSeconds, digest), runDir);
  assert.deepEqual(outcome, { started: true });
  const result = await runner.wait(name, logDir);
  return { name, result, logDir };
}

function value(result: ProcessResult, key: "cpuSeconds" | "wallSeconds" | "peakMemoryBytes"): number {
  assert.notEqual(result.ending, "notStarted");
  if (result.ending === "notStarted") throw new Error("unreachable");
  const item = result[key];
  assert.equal(item.status, "measured", `${key} 应当测到`);
  if (item.status !== "measured") throw new Error("unreachable");
  return item.value;
}

test("建镜像命中参考项目的缓存；查镜像：有的答有，没有的答没有", async () => {
  assert.match(digest, /^sha256:7ed52793365c/);
  assert.equal(await runner.hasImage(digest), true);
  assert.equal(await runner.hasImage(MISSING_DIGEST), false);
});

test("正常退出：带退出码和三项资源用量，标准输出、标准错误存成两个文件", async (t) => {
  const code = "import sys; print('out'); print('err', file=sys.stderr); sys.exit(3)";
  const { result, logDir } = await runToEnd(t, "exit", python(code), 30);
  assert.equal(result.ending, "exited");
  assert.equal(result.ending === "exited" && result.exitCode, 3);
  assert.ok(value(result, "cpuSeconds") > 0);
  assert.ok(value(result, "wallSeconds") > 0 && value(result, "wallSeconds") < 30);
  assert.ok(value(result, "peakMemoryBytes") > 0);
  assert.equal(readFileSync(join(logDir, "stdout.log"), "utf8"), "out\n");
  assert.equal(readFileSync(join(logDir, "stderr.log"), "utf8"), "err\n");
});

test("超时：结局 timeout，CPU 秒接近时限，墙钟不短于时限", async (t) => {
  const { result } = await runToEnd(t, "timeout", python("while True: pass"), 2);
  assert.equal(result.ending, "timeout");
  const cpu = value(result, "cpuSeconds");
  assert.ok(cpu > 1.7 && cpu < 2.3, `CPU 秒 ${cpu}`);
  assert.ok(value(result, "wallSeconds") >= 2);
});

test("候选伪造计量结果再死循环：伪造不成，结局仍是 timeout，资源用量是真实测到的；写出的文件归当前用户", async (t) => {
  // 审阅时实测过的手法：先写一份假的 usage，再把目录改成只读，然后死循环到超时。
  const code = [
    "import os",
    "for attempt in (lambda: open('/inforsi-record/usage', 'w').write('exited 0 1 1 1\\n'), lambda: os.chmod('/inforsi-record', 0o555)):",
    "    try:",
    "        attempt()",
    "    except OSError as error:",
    "        print(type(error).__name__, flush=True)",
    "open('out.txt', 'w').write('x')",
    "while True: pass",
  ].join("\n");
  const name = containerName(t, "forge");
  const { runDir, logDir } = dirs(t);
  assert.deepEqual(await runner.start(name, definition(python(code), 2, digest), runDir), { started: true });
  const result = await runner.wait(name, logDir);
  assert.equal(readFileSync(join(logDir, "stdout.log"), "utf8"), "PermissionError\nPermissionError\n");
  assert.equal(result.ending, "timeout");
  const cpu = value(result, "cpuSeconds");
  t.diagnostic(`结局 ${result.ending}，CPU 秒 ${cpu}，墙钟秒 ${value(result, "wallSeconds")}`);
  assert.ok(cpu > 1.7 && cpu < 2.3, `CPU 秒 ${cpu}`);
  assert.ok(value(result, "wallSeconds") >= 2);
  assert.equal(statSync(join(runDir, "out.txt")).uid, process.getuid?.());
});

test("命令自己以 124 或 137 退出，不判成超时", async (t) => {
  const own124 = await runToEnd(t, "exit124", python("import sys; sys.exit(124)"), 30);
  assert.equal(own124.result.ending, "exited");
  assert.equal(own124.result.ending === "exited" && own124.result.exitCode, 124);
  const own137 = await runToEnd(t, "exit137", python("import os; os.kill(os.getpid(), 9)"), 30);
  assert.equal(own137.result.ending, "exited");
  assert.equal(own137.result.ending === "exited" && own137.result.exitCode, 137);
});

test("从外面 docker kill：结局 cancelled，三项资源都测不到并写明原因", async (t) => {
  const name = containerName(t, "killed");
  const { runDir, logDir } = dirs(t);
  const outcome = await runner.start(name, definition(python("import time; time.sleep(60)"), 120, digest), runDir);
  assert.deepEqual(outcome, { started: true });
  assert.equal(await runner.status(name), "running");
  const killed = docker(["kill", name]);
  assert.equal(killed.status, 0, killed.stderr);
  const result = await runner.wait(name, logDir);
  assert.equal(result.ending, "cancelled");
  if (result.ending !== "cancelled") return;
  for (const item of [result.cpuSeconds, result.wallSeconds, result.peakMemoryBytes]) {
    assert.equal(item.status, "unmeasured");
    assert.match(item.status === "unmeasured" ? item.reason : "", /从外面被结束/);
  }
});

test("镜像编号不存在：没启动，原因是 Docker 的报错原文，也没留下容器", async (t) => {
  const name = containerName(t, "noimage");
  const { runDir } = dirs(t);
  const outcome = await runner.start(name, definition(python("pass"), 30, MISSING_DIGEST), runDir);
  assert.equal(outcome.started, false);
  assert.match(outcome.started ? "" : outcome.reason, /No such image/);
  assert.equal(await runner.status(name), "absent");
});

test("断网：容器里连不上外网", async (t) => {
  const code = [
    "import socket, sys",
    "try:",
    "    socket.create_connection(('1.1.1.1', 53), timeout=3)",
    "except OSError as error:",
    "    print(type(error).__name__); sys.exit(0)",
    "sys.exit(1)",
  ].join("\n");
  const { result } = await runToEnd(t, "network", python(code), 30);
  assert.equal(result.ending === "exited" && result.exitCode, 0);
});

test("核数：容器里 os.cpu_count() 报 1", async (t) => {
  const { logDir } = await runToEnd(t, "cores", python("import os; print(os.cpu_count())"), 30);
  assert.equal(readFileSync(join(logDir, "stdout.log"), "utf8"), "1\n");
});

test("查状态：没有这个容器、建了没启动、在跑、已结束、问不到", async (t) => {
  assert.equal(await runner.status(containerName(t, "status-absent")), "absent");

  const created = containerName(t, "status-created");
  const create = docker(["create", "--name", created, digest, "true"]);
  assert.equal(create.status, 0, create.stderr);
  assert.equal(await runner.status(created), "created");

  const name = containerName(t, "status-running");
  const { runDir, logDir } = dirs(t);
  await runner.start(name, definition(python("import time; time.sleep(3)"), 30, digest), runDir);
  assert.equal(await runner.status(name), "running");
  await runner.wait(name, logDir);
  assert.equal(await runner.status(name), "exited");

  const nowhere = new Runner("unix:///nonexistent/docker.sock");
  assert.equal(await nowhere.status(name), "unreachable");

  await runner.remove(name);
  assert.equal(await runner.status(name), "absent");
});

test("等结束能接上另一个 Runner 实例启动的容器；已结束的容器再等一次，结果相同", async (t) => {
  const name = containerName(t, "resume");
  const { runDir, logDir } = dirs(t);
  const starter = new Runner(null);
  await starter.start(name, definition(python("import time; time.sleep(2); print('done')"), 30, digest), runDir);
  const resumed = new Runner(null);
  const first = await resumed.wait(name, logDir);
  assert.equal(first.ending === "exited" && first.exitCode, 0);
  assert.equal(readFileSync(join(logDir, "stdout.log"), "utf8"), "done\n");
  const again = await new Runner(null).wait(name, logDir);
  assert.deepEqual(again, first);
});

test("容器名不符合 Docker 的要求时报错", async () => {
  await assert.rejects(runner.status("inforsi test"), /不符合 Docker 的要求/);
  await assert.rejects(runner.status("-x"), /不符合 Docker 的要求/);
});