import { spawn, ChildProcess } from 'child_process';
import { join } from 'path';

export interface WebsiteServerHarnessOptions {
  port?: number;
  env?: Record<string, string>;
  cwd?: string;
}

export class WebsiteServerHarness {
  private process: ChildProcess | null = null;
  private logs: string[] = [];
  private port: number;

  constructor(options: WebsiteServerHarnessOptions = {}) {
    this.port = options.port || 3000;
  }

  async start(): Promise<void> {
    return new Promise((resolve, reject) => {
      const cwd = join(process.cwd(), 'apps/website');
      
      // Use 'npm run dev' or 'npm run start' depending on environment
      // For integration tests, 'dev' is often easier if we don't want to build first,
      // but 'start' is more realistic for SSR.
      // Assuming 'npm run dev' for now as it's faster for local tests.
      this.process = spawn('npm', ['run', 'dev', '--', '-p', this.port.toString()], {
        cwd,
        env: {
          ...process.env,
          PORT: this.port.toString(),
          ...((this.process as unknown as { env: Record<string, string> })?.env || {}),
        },
        shell: true,
      });

      this.process.stdout?.on('data', (data) => {
        const str = data.toString();
        this.logs.push(str);
        if (str.includes('ready') || str.includes('started') || str.includes('Local:')) {
          resolve();
        }
      });

      this.process.stderr?.on('data', (data) => {
        const str = data.toString();
        this.logs.push(str);
        console.error(`[Website Server Error] ${str}`);
      });

      this.process.on('error', (err) => {
        reject(err);
      });

      this.process.on('exit', (code) => {
        if (code !== 0 && code !== null) {
          console.error(`Website server exited with code ${code}`);
        }
      });

      // Timeout after 30 seconds
      setTimeout(() => {
        reject(new Error('Website server failed to start within 30s'));
      }, 30000);
    });
  }

  async stop(): Promise<void> {
    if (this.process) {
      this.process.kill();
      this.process = null;
    }
  }

  getLogs(): string[] {
    return this.logs;
  }

  getLogTail(lines: number = 60): string {
    return this.logs.slice(-lines).join('');
  }

  hasErrorPatterns(): boolean {
    const errorPatterns = [
      'uncaughtException',
      'unhandledRejection',
      'Error: ',
    ];
    return this.logs.some(log => errorPatterns.some(pattern => log.includes(pattern)));
  }
}