import { execFile } from 'child_process';
import * as crypto from 'crypto';
import * as fs from 'fs';

import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
import * as cacheModule from '../../src/cache';
import {
  getFileHashes,
  parseScriptParts,
  ScriptCompletionProvider,
} from '../../src/providers/scriptCompletion';
import type { MockedFunction } from 'vitest';

vi.mock('child_process', async (importOriginal) => {
  return {
    ...(await importOriginal()),
    execFile: vi.fn(),
  };
});
vi.mock('../../src/cache', async () => {
  const actual = await vi.importActual<typeof import('../../src/cache')>('../../src/cache');
  return {
    ...actual,
    getCache: vi.fn(),
    isCacheEnabled: vi.fn(),
  };
});
vi.mock('fs', async () => {
  const actual = await vi.importActual<typeof import('fs')>('fs');
  const existsSync = vi.fn();
  const statSync = vi.fn();
  const readFileSync = vi.fn();
  return {
    ...actual,
    existsSync,
    statSync,
    readFileSync,
    default: { ...actual, existsSync, statSync, readFileSync },
  };
});

vi.mock('crypto', async () => {
  const actual = await vi.importActual<typeof import('crypto')>('crypto');
  const createHash = vi.fn();
  return {
    ...actual,
    createHash,
    default: { ...actual, createHash },
  };
});

let existsSyncMock: MockedFunction<typeof fs.existsSync>;
let statSyncMock: MockedFunction<typeof fs.statSync>;
let readFileSyncMock: MockedFunction<typeof fs.readFileSync>;
let createHashMock: MockedFunction<typeof crypto.createHash>;

function normalizeFsPath(path: fs.PathOrFileDescriptor): string {
  if (path instanceof URL) {
    return path.pathname;
  }

  return String(path);
}

afterEach(() => {
  vi.restoreAllMocks();
});

describe('parseScriptParts', () => {
  it('should parse script parts correctly', () => {
    const scriptPath = `node script.js "arg with 'spaces'" 'another arg' simple_arg`;
    const result = parseScriptParts(scriptPath);
    expect(result).toEqual(['node', 'script.js', "arg with 'spaces'", 'another arg', 'simple_arg']);
  });

  it('should handle script path with no arguments', () => {
    const scriptPath = '/bin/bash script.sh';
    const result = parseScriptParts(scriptPath);
    expect(result).toEqual(['/bin/bash', 'script.sh']);
  });
});

describe('getFileHashes', () => {
  beforeEach(() => {
    vi.clearAllMocks();
    existsSyncMock = vi.mocked(fs.existsSync);
    statSyncMock = vi.mocked(fs.statSync);
    readFileSyncMock = vi.mocked(fs.readFileSync);
    createHashMock = vi.mocked(crypto.createHash);
  });

  it('should return file hashes for existing files', () => {
    const scriptParts = ['file1.js', 'file2.js', 'nonexistent.js'];
    const mockFileContent1 = 'content1';
    const mockFileContent2 = 'content2';
    const mockHash1 = 'hash1';
    const mockHash2 = 'hash2';

    existsSyncMock.mockImplementation(function (path: fs.PathLike) {
      return normalizeFsPath(path) !== 'nonexistent.js';
    });
    statSyncMock.mockReturnValue({
      isFile: () => true,
      isDirectory: () => false,
      isBlockDevice: () => false,
      isCharacterDevice: () => false,
      isSymbolicLink: () => false,
      isFIFO: () => false,
      isSocket: () => false,
    } as fs.Stats);
    readFileSyncMock.mockImplementation(function (path: fs.PathOrFileDescriptor) {
      const normalizedPath = normalizeFsPath(path);
      if (normalizedPath === 'file1.js') {
        return mockFileContent1;
      }
      if (normalizedPath === 'file2.js') {
        return mockFileContent2;
      }
      throw new Error('File not found');
    });

    const mockHashUpdate = {
      update: vi.fn().mockReturnThis(),
      digest: vi.fn(),
    } as unknown as crypto.Hash;
    vi.mocked(mockHashUpdate.digest)
      .mockImplementationOnce(function () {
        return mockHash1;
      })
      .mockReturnValueOnce(mockHash2);
    createHashMock.mockReturnValue(mockHashUpdate);

    const result = getFileHashes(scriptParts);

    expect(result).toEqual([mockHash1, mockHash2]);
    expect(existsSyncMock).toHaveBeenCalledTimes(3);
    expect(readFileSyncMock).toHaveBeenCalledTimes(2);
    expect(createHashMock).toHaveBeenCalledTimes(2);
  });

  it('should return an empty array for non-existent files', () => {
    const scriptParts = ['nonexistent1.js', 'nonexistent2.js'];
    existsSyncMock.mockReturnValue(false);

    const result = getFileHashes(scriptParts);

    expect(result).toEqual([]);
    expect(existsSyncMock).toHaveBeenCalledTimes(2);
    expect(readFileSyncMock).not.toHaveBeenCalled();
    expect(createHashMock).not.toHaveBeenCalled();
  });
});

describe('ScriptCompletionProvider', () => {
  let provider: ScriptCompletionProvider;

  beforeEach(() => {
    provider = new ScriptCompletionProvider('node script.js');
    vi.clearAllMocks();
    vi.mocked(cacheModule.getCache).mockReset();
    vi.mocked(cacheModule.isCacheEnabled).mockReset();
    existsSyncMock = vi.mocked(fs.existsSync);
    statSyncMock = vi.mocked(fs.statSync);
    readFileSyncMock = vi.mocked(fs.readFileSync);
    createHashMock = vi.mocked(crypto.createHash);

    // Set up default file system mocks for all tests
    existsSyncMock.mockReturnValue(true);
    statSyncMock.mockReturnValue({
      isFile: () => true,
      isDirectory: () => false,
      isBlockDevice: () => false,
      isCharacterDevice: () => false,
      isSymbolicLink: () => false,
      isFIFO: () => false,
      isSocket: () => false,
    } as fs.Stats);
    readFileSyncMock.mockReturnValue('default file content');

    // Set up default crypto mock
    const mockHashUpdate = {
      update: vi.fn().mockReturnThis(),
      digest: vi.fn().mockReturnValue('default-hash'),
    } as unknown as crypto.Hash;
    createHashMock.mockReturnValue(mockHashUpdate);
  });

  it('should return the correct id', () => {
    expect(provider.id()).toBe('exec:node script.js');
  });

  it('should close stdin on the child process to prevent hanging', async () => {
    const stdinEnd = vi.fn();
    vi.mocked(execFile).mockImplementation(function (_cmd, _args, _options, callback) {
      (callback as (error: Error | null, stdout: string | Buffer, stderr: string | Buffer) => void)(
        null,
        Buffer.from('ok'),
        '',
      );
      return { stdin: { end: stdinEnd } } as any;
    });

    await provider.callApi('test prompt');
    expect(stdinEnd).toHaveBeenCalledOnce();
  });

  it('should handle child process with no stdin gracefully', async () => {
    vi.mocked(execFile).mockImplementation(function (_cmd, _args, _options, callback) {
      (callback as (error: Error | null, stdout: string | Buffer, stderr: string | Buffer) => void)(
        null,
        Buffer.from('ok'),
        '',
      );
      return { stdin: null } as any;
    });

    const result = await provider.callApi('test prompt');
    expect(result.output).toBe('ok');
  });

  it('should close stdin before the exec callback rejects on script execution errors', async () => {
    const stdinEnd = vi.fn();
    const errorMessage = 'Script execution failed';
    let stdinClosedBeforeCallback = false;
    vi.mocked(execFile).mockImplementation(function (_cmd, _args, _options, callback) {
      const childProcess = { stdin: { end: stdinEnd } } as any;
      queueMicrotask(() => {
        stdinClosedBeforeCallback = stdinEnd.mock.calls.length > 0;
        if (typeof callback === 'function') {
          callback(new Error(errorMessage), '', '');
        }
      });
      return childProcess;
    });

    await expect(provider.callApi('test prompt')).rejects.toThrow(errorMessage);
    expect(stdinEnd).toHaveBeenCalledOnce();
    expect(stdinClosedBeforeCallback).toBe(true);
  });

  it('should handle UTF-8 characters in script output', async () => {
    const utf8Output = 'Hello, 世界!';
    vi.mocked(execFile).mockImplementation(function (_cmd, _args, _options, callback) {
      (callback as (error: Error | null, stdout: string | Buffer, stderr: string | Buffer) => void)(
        null,
        Buffer.from(utf8Output),
        '',
      );
      return {} as any;
    });

    const result = await provider.callApi('test prompt');
    expect(result.output).toBe(utf8Output);
  });

  it('should handle UTF-8 characters in error output', async () => {
    const utf8Error = 'エラー発生';
    vi.mocked(execFile).mockImplementation(function (_cmd, _args, _options, callback) {
      if (typeof callback === 'function') {
        callback(null, '', Buffer.from(utf8Error));
      }
      return {} as any;
    });

    await expect(provider.callApi('test prompt')).rejects.toThrow(utf8Error);
  });

  it('should use cache when available', async () => {
    const cachedResult = { output: 'cached result' };
    const mockCache = {
      get: vi.fn().mockResolvedValue(JSON.stringify(cachedResult)),
      set: vi.fn(),
    };
    vi.spyOn(cacheModule, 'getCache').mockResolvedValue(mockCache as never);
    vi.spyOn(cacheModule, 'isCacheEnabled').mockReturnValue(true);

    // Mock fs.existsSync to return true for at least one file
    existsSyncMock.mockReturnValue(true);
    statSyncMock.mockReturnValue({ isFile: () => true } as fs.Stats);
    readFileSyncMock.mockReturnValue('file content');

    const mockHashUpdate = {
      update: vi.fn().mockReturnThis(),
      digest: vi.fn().mockReturnValue('mock hash'),
    } as unknown as crypto.Hash;
    vi.mocked(crypto.createHash).mockImplementation(function () {
      return mockHashUpdate;
    });

    const result = await provider.callApi('test prompt');
    expect(result.cached).toBe(true);
    expect(result).toEqual({ ...cachedResult, cached: true });
    expect(mockCache.get).toHaveBeenCalledWith(
      'exec:node script.js:mock hash:mock hash:test prompt:undefined',
    );
    expect(execFile).not.toHaveBeenCalled();
  });

  it('should handle script execution errors', async () => {
    const errorMessage = 'Script execution failed';
    vi.mocked(execFile).mockImplementation(function (_cmd, _args, _options, callback) {
      if (typeof callback === 'function') {
        callback(new Error(errorMessage), '', '');
      }
      return {} as any;
    });

    await expect(provider.callApi('test prompt')).rejects.toThrow(errorMessage);
  });

  it('should handle empty standard output with error output', async () => {
    const errorOutput = 'Warning: Something went wrong';
    vi.mocked(execFile).mockImplementation(function (_cmd, _args, _options, callback) {
      if (typeof callback === 'function') {
        callback(null, '', Buffer.from(errorOutput));
      }
      return {} as any;
    });

    await expect(provider.callApi('test prompt')).rejects.toThrow(errorOutput);
  });

  it('should strip ANSI escape codes from output', async () => {
    const ansiOutput = '\x1b[31mColored\x1b[0m \x1b[1mBold\x1b[0m';
    const strippedOutput = 'Colored Bold';
    vi.mocked(execFile).mockImplementation(function (_cmd, _args, _options, callback) {
      if (typeof callback === 'function') {
        callback(null, Buffer.from(ansiOutput), '');
      }
      return {} as any;
    });

    const result = await provider.callApi('test prompt');
    expect(result.output).toBe(strippedOutput);
  });
});