import { EventEmitter } from 'node:events';
import { existsSync, mkdtempSync, rmSync } from 'node:fs';
import { tmpdir } from 'node:os';
import { join } from 'node:path';

import { describe, expect, test, vi } from 'vitest';

import {
  isProcessGroupAlive,
  spawnChild,
  terminateChildTree,
} from '../scripts/start-dev-stack.mjs';
import {
  buildTauriArguments,
  runTauriDev as runTauriDevImpl,
} from '../scripts/start-tauri-dev.mjs';

const testEndpoint = {
  host: '127.0.0.1',
  port: 10005,
  url: 'http://127.0.0.1:10005/',
  markerUrl: 'http://127.0.0.1:10005/__agc_dev_server.json',
  portRange: { start: 10000, end: 10099, label: '10000-10099' },
};
const resolveTestEndpoint = async () => testEndpoint;
const runTauriDev = (
  argv: string[],
  options: Parameters<typeof runTauriDevImpl>[1],
) => runTauriDevImpl(argv, { prepareFrontend: async () => {}, ...options });

async function waitForFile(path: string, timeoutMs = 5000) {
  const deadline = Date.now() + timeoutMs;
  while (Date.now() < deadline) {
    if (existsSync(path)) {
      return;
    }
    await new Promise((resolveWait) => setTimeout(resolveWait, 25));
  }
  throw new Error(`等待测试进程标记超时: ${path}`);
}

describe('AI 游戏创作 Tauri dev 启动参数', () => {
  test('普通 dev 参数原样交给 Tauri CLI', () => {
    expect(buildTauriArguments(['--no-watch'], testEndpoint.url)).toEqual([
      'dev',
      '--no-watch',
      '--config',
      '{"build":{"devUrl":"http://127.0.0.1:10005/","beforeDevCommand":""}}',
    ]);
  });

  test('动态 devUrl 配置位于用户 Tauri 配置之后且不越过参数分隔符', () => {
    expect(
      buildTauriArguments(
        ['--config', 'custom.json', '--', '--', '--example-app-arg'],
        testEndpoint.url,
      ),
    ).toEqual([
      'dev',
      '--config',
      'custom.json',
      '--config',
      '{"build":{"devUrl":"http://127.0.0.1:10005/","beforeDevCommand":""}}',
      '--',
      '--',
      '--example-app-arg',
    ]);
  });

  test('单个启动器分隔符后的参数进入应用而不是 Cargo', () => {
    expect(
      buildTauriArguments(
        ['--', '--config-dir', 'C:\\temp\\agc-dev-config'],
        testEndpoint.url,
      ),
    ).toEqual([
      'dev',
      '--config',
      '{"build":{"devUrl":"http://127.0.0.1:10005/","beforeDevCommand":""}}',
      '--',
      '--',
      '--config-dir',
      'C:\\temp\\agc-dev-config',
    ]);
  });
});

describe('AI 游戏创作 Tauri dev 生命周期', () => {
  test('前端就绪前不启动 Tauri，准备失败时清理自有服务', async () => {
    const spawnCli = vi.fn();
    const frontend = { pid: 1234 };
    const terminateTree = vi.fn(async () => ({ stopped: true }));
    await expect(
      runTauriDev([], {
        resolveDevEndpoint: resolveTestEndpoint,
        preflight: async () => {},
        prepareFrontend: async (_, { onChild }) => {
          onChild(frontend);
          expect(spawnCli).not.toHaveBeenCalled();
          throw new Error('backend failed');
        },
        spawnCli,
        terminateTree,
      }),
    ).rejects.toThrow('backend failed');
    expect(spawnCli).not.toHaveBeenCalled();
    expect(terminateTree).toHaveBeenCalledWith(frontend);
  });
  test('动态端口预检失败时不启动 Tauri CLI', async () => {
    const spawnCli = vi.fn();

    await expect(
      runTauriDev([], {
        resolveDevEndpoint: resolveTestEndpoint,
        preflight: async () => {
          throw new Error('stale AGC Vite');
        },
        spawnCli,
      }),
    ).rejects.toThrow('stale AGC Vite');

    expect(spawnCli).not.toHaveBeenCalled();
  });

  test('预检先于 CLI 启动且 CLI 退出后始终清理进程树', async () => {
    const order: string[] = [];
    const child = Object.assign(new EventEmitter(), {
      pid: 1234,
      exitCode: 1,
      signalCode: null,
      kill: vi.fn(),
    });
    const result = await runTauriDev([], {
      resolveDevEndpoint: resolveTestEndpoint,
      preflight: async () => {
        order.push('preflight');
      },
      prepareFrontend: async () => {
        order.push('frontend-ready');
      },
      spawnCli: () => {
        order.push('spawn');
        return child;
      },
      waitForCli: async () => {
        order.push('exit');
        return { type: 'exit', code: 1, signal: null };
      },
      terminateTree: async (receivedChild) => {
        expect(receivedChild).toBe(child);
        order.push('cleanup');
        return { stopped: true, forced: false };
      },
    });

    expect(result).toBe(1);
    expect(order).toEqual([
      'preflight',
      'frontend-ready',
      'spawn',
      'exit',
      'cleanup',
    ]);
  });

  const posixTest = process.platform === 'win32' ? test.skip : test;

  posixTest('Tauri CLI leader 先退出后仍收束同 PGID 的客户端后代', async () => {
    const tempDir = mkdtempSync(join(tmpdir(), 'agc-tauri-tree-'));
    const readyPath = join(tempDir, 'client-ready');
    const stoppedPath = join(tempDir, 'client-stopped');
    const descendantSource = `
      const { writeFileSync } = require('node:fs');
      const [readyPath, stoppedPath] = process.argv.slice(1);
      process.on('SIGTERM', () => {
        writeFileSync(stoppedPath, 'stopped');
        process.exit(0);
      });
      writeFileSync(readyPath, 'ready');
      setInterval(() => {}, 1000);
    `;
    const leaderSource = `
      const { existsSync } = require('node:fs');
      const { spawn } = require('node:child_process');
      const [readyPath, stoppedPath, descendantSource] = process.argv.slice(1);
      const descendant = spawn(
        process.execPath,
        ['-e', descendantSource, readyPath, stoppedPath],
        { stdio: 'ignore' },
      );
      descendant.unref();
      const timer = setInterval(() => {
        if (existsSync(readyPath)) {
          clearInterval(timer);
          process.exit(42);
        }
      }, 10);
    `;
    let cliChild;
    try {
      const result = await runTauriDev([], {
        resolveDevEndpoint: resolveTestEndpoint,
        preflight: async () => {},
        spawnCli: () => {
          cliChild = spawnChild(
            process.execPath,
            ['-e', leaderSource, readyPath, stoppedPath, descendantSource],
            { cwd: process.cwd() },
          );
          return cliChild;
        },
      });

      expect(result).toBe(42);
      await waitForFile(stoppedPath);
    } finally {
      if (Number.isInteger(cliChild?.pid)) {
        try {
          process.kill(-cliChild.pid, 'SIGKILL');
        } catch {
          // 进程组已经由启动器收束。
        }
      }
      rmSync(tempDir, { recursive: true, force: true });
    }
  });

  posixTest('客户端后代忽略 TERM 时在有界宽限后升级 KILL', async () => {
    const tempDir = mkdtempSync(join(tmpdir(), 'agc-tauri-force-tree-'));
    const readyPath = join(tempDir, 'client-ready');
    const descendantSource = `
      const { writeFileSync } = require('node:fs');
      const [readyPath] = process.argv.slice(1);
      process.on('SIGTERM', () => {});
      writeFileSync(readyPath, 'ready');
      setInterval(() => {}, 1000);
    `;
    const leaderSource = `
      const { existsSync } = require('node:fs');
      const { spawn } = require('node:child_process');
      const [readyPath, descendantSource] = process.argv.slice(1);
      const descendant = spawn(
        process.execPath,
        ['-e', descendantSource, readyPath],
        { stdio: 'ignore' },
      );
      descendant.unref();
      const timer = setInterval(() => {
        if (existsSync(readyPath)) {
          clearInterval(timer);
          process.exit(42);
        }
      }, 10);
    `;
    let cliChild;
    try {
      const result = await runTauriDev([], {
        resolveDevEndpoint: resolveTestEndpoint,
        preflight: async () => {},
        spawnCli: () => {
          cliChild = spawnChild(
            process.execPath,
            ['-e', leaderSource, readyPath, descendantSource],
            { cwd: process.cwd() },
          );
          return cliChild;
        },
        terminateTree: (child) =>
          terminateChildTree(child, {
            gracefulTimeoutMs: 50,
            forceTimeoutMs: 2000,
          }),
      });

      expect(result).toBe(42);
      expect(isProcessGroupAlive(cliChild.pid)).toBe(false);
    } finally {
      if (Number.isInteger(cliChild?.pid)) {
        try {
          process.kill(-cliChild.pid, 'SIGKILL');
        } catch {
          // 进程组已经由启动器强制收束。
        }
      }
      rmSync(tempDir, { recursive: true, force: true });
    }
  });
});