import {createServer} from 'node:net';
import {mkdtempSync, readFileSync, rmSync} from 'node:fs';
import {tmpdir} from 'node:os';
import {join} from 'node:path';
import {describe, expect, it} from 'vitest';
import {
  findAvailablePort,
  mapDevPortsToPortRange,
  parsePortRangeSpec,
  reserveLinuxDevPortRange,
  resolveDevStackPorts,
} from './dev-stack-port-utils.mjs';

function reservePort(port) {
  return new Promise((resolve, reject) => {
    const server = createServer();

    server.once('error', reject);
    server.listen(port, '127.0.0.1', () => {
      server.off('error', reject);
      resolve(server);
    });
  });
}

describe('dev stack port utils', () => {
  it('解析端口段并映射到四个 dev 端口', () => {
    expect(parsePortRangeSpec('10000-10099')).toEqual({
      start: 10000,
      end: 10099,
      label: '10000-10099',
    });
    expect(mapDevPortsToPortRange('10000-10099')).toMatchObject({
      webPort: 10000,
      apiPort: 10001,
      spacetimePort: 10002,
      adminWebPort: 10003,
    });
  });

  it('使用端口可用性检查为被占用端口寻找后续可用端口', async () => {
    const firstServer = await reservePort(0);
    const firstPort = firstServer.address().port;
    const secondServer = await reservePort(firstPort + 1);

    try {
      const availablePort = await findAvailablePort({
        host: '127.0.0.1',
        preferredPort: firstPort,
      });

      expect(availablePort).toBeGreaterThan(firstPort + 1);
    } finally {
      await Promise.all([
        new Promise((resolve) => firstServer.close(resolve)),
        new Promise((resolve) => secondServer.close(resolve)),
      ]);
    }
  });

  it('端口查找不会越过 Linux 用户端口段', async () => {
    await expect(
      findAvailablePort({
        host: '127.0.0.1',
        preferredPort: 9999,
        portRange: {start: 10000, end: 10099, label: '10000-10099'},
      }),
    ).rejects.toThrow('不在允许端口段');
  });

  it('为 npm run dev 的所有后续流程解析互不冲突的端口', async () => {
    const resolvedPorts = await resolveDevStackPorts({
      spacetime: {host: '127.0.0.1', preferredPort: 0},
      api: {host: '127.0.0.1', preferredPort: 0},
      web: {host: '127.0.0.1', preferredPort: 0},
      adminWeb: {host: '127.0.0.1', preferredPort: 0},
    });

    expect(new Set(Object.values(resolvedPorts)).size).toBe(4);
  });

  it('端口段内会一直漂移到段尾，不会被默认 200 次尝试截断', async () => {
    const rangeStart = 10000;
    const rangeEnd = 10300;
    const reservedPorts = new Set(
      Array.from({length: 201}, (_, index) => rangeStart + index),
    );

    const availablePort = await findAvailablePort({
      host: '127.0.0.1',
      preferredPort: rangeStart,
      reservedPorts,
      portRange: {start: rangeStart, end: rangeEnd, label: `${rangeStart}-${rangeEnd}`},
    });

    expect(availablePort).toBeGreaterThan(rangeStart + 200);
    expect(availablePort).toBeLessThanOrEqual(rangeEnd);
  });

  const linuxIt = process.platform === 'linux' ? it : it.skip;

  linuxIt('Linux 未手动指定端口段时从 10000 开始按 100 端口块自动分配', async () => {
    const tempRoot = mkdtempSync(join(tmpdir(), 'genarrative-port-range-'));
    const registryPath = join(tempRoot, 'registry.json');
    const lockPath = join(tempRoot, 'registry.lock');

    try {
      const aliceAllocation = await reserveLinuxDevPortRange({
        env: {
          USER: 'alice',
          LOGNAME: 'alice',
          GENARRATIVE_DEV_PORT_RANGE_REGISTRY_DIR: tempRoot,
        },
        username: 'alice',
        requestedRange: null,
        registryPath,
        lockPath,
      });
      const bobAllocation = await reserveLinuxDevPortRange({
        env: {
          USER: 'bob',
          LOGNAME: 'bob',
          GENARRATIVE_DEV_PORT_RANGE_REGISTRY_DIR: tempRoot,
        },
        username: 'bob',
        requestedRange: null,
        registryPath,
        lockPath,
      });

      expect(aliceAllocation.range.label).toBe('10000-10099');
      expect(aliceAllocation.source).toBe('auto');
      expect(bobAllocation.range.label).toBe('10100-10199');
      expect(bobAllocation.source).toBe('auto');
    } finally {
      rmSync(tempRoot, {recursive: true, force: true});
    }
  });

  linuxIt('Linux 系统级端口段记录会阻止两个用户拿到同一段', async () => {
    const tempRoot = mkdtempSync(join(tmpdir(), 'genarrative-port-range-'));
    const registryPath = join(tempRoot, 'registry.json');
    const lockPath = join(tempRoot, 'registry.lock');

    try {
      const baseEnv = {
        USER: 'alice',
        LOGNAME: 'alice',
        GENARRATIVE_DEV_PORT_RANGE_REGISTRY_DIR: tempRoot,
        GENARRATIVE_DEV_PORT_RANGE: '10000-10099',
      };

      const aliceAllocation = await reserveLinuxDevPortRange({
        env: baseEnv,
        username: 'alice',
        registryPath,
        lockPath,
      });

      expect(aliceAllocation.range.label).toBe('10000-10099');

      const registryAfterAlice = JSON.parse(readFileSync(registryPath, 'utf8'));
      expect(registryAfterAlice.allocations.alice.range.label).toBe('10000-10099');

      await expect(
        reserveLinuxDevPortRange({
          env: {
            ...baseEnv,
            USER: 'bob',
            LOGNAME: 'bob',
          },
          username: 'bob',
          requestedRange: '10000-10099',
          registryPath,
          lockPath,
        }),
      ).rejects.toThrow('已被用户 alice 占用');

      const aliceReuse = await reserveLinuxDevPortRange({
        env: {
          ...baseEnv,
          USER: 'alice',
          LOGNAME: 'alice',
        },
        username: 'alice',
        registryPath,
        lockPath,
      });

      expect(aliceReuse.range.label).toBe('10000-10099');
      expect(aliceReuse.source).toBe('manual');
      expect(
        (
          await reserveLinuxDevPortRange({
            env: {
              ...baseEnv,
              USER: 'alice',
              LOGNAME: 'alice',
              GENARRATIVE_DEV_PORT_RANGE: '10100-10199',
            },
            username: 'alice',
            requestedRange: '10100-10199',
            registryPath,
            lockPath,
          })
        ).range.label,
      ).toBe('10000-10099');

      const registryAfterReuse = JSON.parse(readFileSync(registryPath, 'utf8'));
      expect(registryAfterReuse.allocations.alice.range.label).toBe('10000-10099');

      const bobAllocation = await reserveLinuxDevPortRange({
        env: {
          ...baseEnv,
          USER: 'bob',
          LOGNAME: 'bob',
          GENARRATIVE_DEV_PORT_RANGE: '10100-10199',
        },
        username: 'bob',
        requestedRange: '10100-10199',
        registryPath,
        lockPath,
      });

      expect(bobAllocation.range.label).toBe('10100-10199');
    } finally {
      rmSync(tempRoot, {recursive: true, force: true});
    }
  });

  linuxIt('Linux 同一用户第二个 dev 会话会复用同一用户段并继续在段内漂移', async () => {
    const tempRoot = mkdtempSync(join(tmpdir(), 'genarrative-port-range-'));
    const registryPath = join(tempRoot, 'registry.json');
    const lockPath = join(tempRoot, 'registry.lock');

    try {
      const baseEnv = {
        USER: 'alice',
        LOGNAME: 'alice',
        GENARRATIVE_DEV_PORT_RANGE_REGISTRY_DIR: tempRoot,
        GENARRATIVE_DEV_PORT_RANGE: '10000-10099',
      };

      const first = await reserveLinuxDevPortRange({
        env: baseEnv,
        username: 'alice',
        registryPath,
        lockPath,
      });

      const second = await reserveLinuxDevPortRange({
        env: baseEnv,
        username: 'alice',
        registryPath,
        lockPath,
      });

      expect(first.range.label).toBe('10000-10099');
      expect(second.range.label).toBe('10000-10099');
      expect(second.username).toBe('alice');
      expect(JSON.parse(readFileSync(registryPath, 'utf8')).allocations.alice.range.label).toBe(
        '10000-10099',
      );
    } finally {
      rmSync(tempRoot, {recursive: true, force: true});
    }
  });
});