import { spawn, exec, ChildProcess } from 'child_process';
import { app } from 'electron';
import path from 'path';
import log from 'electron-log';

const SDD_PORT = 9998;
const HEALTH_CHECK_INTERVAL = 10000;
const HEALTH_CHECK_TIMEOUT = 2000;

class SDDService {
  private process: ChildProcess | null = null;
  private processPid: number | null = null;
  private healthCheckTimer: NodeJS.Timeout | null = null;
  private _isRunning = false;
  private _isStarting = false;

  get port(): number {
    return SDD_PORT;
  }

  isRunning(): boolean {
    return this._isRunning;
  }

  getStatus(): { running: boolean; port: number } {
    return {
      running: this._isRunning,
      port: this.port,
    };
  }

  private getExePath(): string {
    const exeName = 'XCSDD.exe';
    const isPackaged = app.isPackaged;
    
    let basePath: string;
    if (isPackaged) {
      basePath = path.join(process.resourcesPath, 'app.asar.unpacked');
    } else {
      basePath = process.cwd();
    }

    return path.join(basePath, 'services', 'xcsdd', exeName);
  }

  private getExeArgs(): string[] {
    return ['--port', this.port.toString(), '--headless'];
  }

  private async checkHealth(): Promise<boolean> {
    try {
      const controller = new AbortController();
      const timeoutId = setTimeout(() => controller.abort(), HEALTH_CHECK_TIMEOUT);
      
      const response = await fetch(`http://127.0.0.1:${this.port}`, {
        signal: controller.signal,
      });
      
      clearTimeout(timeoutId);
      return response.ok || response.status === 401;
    } catch (error) {
      log.warn('[SDDService] Health check failed:', error);
      return false;
    }
  }

  private startHealthCheck(): void {
    if (this.healthCheckTimer) {
      clearInterval(this.healthCheckTimer);
    }

    this.healthCheckTimer = setInterval(async () => {
      const isHealthy = await this.checkHealth();
      if (!isHealthy && this._isRunning) {
        log.warn('[SDDService] Service not responding');
      }
    }, HEALTH_CHECK_INTERVAL);
  }

  async start(): Promise<{ success: boolean; error?: string }> {
    if (this._isRunning && this.process) {
      log.info('[SDDService] Already running');
      return { success: true };
    }

    if (this._isStarting) {
      log.info('[SDDService] Already starting');
      return { success: true };
    }

    this._isStarting = true;

    try {
      const exePath = this.getExePath();
      const exeArgs = this.getExeArgs();
      log.info(`[SDDService] Starting from: ${exePath} with args: ${exeArgs.join(' ')}`);

      this.process = spawn(exePath, exeArgs, {
        stdio: 'pipe',
      });

      this.processPid = this.process.pid ?? null;

      this.process.stdout?.on('data', (data) => {
        log.info(`[SDD] ${data}`);
      });

      this.process.stderr?.on('data', (data) => {
        log.error(`[SDD error] ${data}`);
      });

      this.process.on('error', (err) => {
        log.error('[SDDService] Process error:', err);
        this._isRunning = false;
        this._isStarting = false;
        this.process = null;
        this.processPid = null;
      });

      this.process.on('exit', (code) => {
        log.info(`[SDDService] Process exited with code ${code}`);
        this._isRunning = false;
        this._isStarting = false;
        this.process = null;
        this.processPid = null;
      });

      const maxWaitTime = 30000;
      const checkInterval = 500;
      const startTime = Date.now();

      while (Date.now() - startTime < maxWaitTime) {
        const isHealthy = await this.checkHealth();
        if (isHealthy) {
          break;
        }
        await new Promise<void>((resolve) => setTimeout(resolve, checkInterval));
      }

      const finalHealth = await this.checkHealth();
      if (!finalHealth) {
        log.warn('[SDDService] Health check failed after max wait time');
      }

      this._isRunning = true;
      this._isStarting = false;
      this.startHealthCheck();

      log.info(`[SDDService] Started successfully on port ${this.port}`);
      return { success: true };
    } catch (error: any) {
      log.error('[SDDService] Failed to start:', error);
      this._isRunning = false;
      this._isStarting = false;
      return { success: false, error: error.message };
    }
  }

  async stop(): Promise<{ success: boolean; error?: string }> {
    if (this.healthCheckTimer) {
      clearInterval(this.healthCheckTimer);
      this.healthCheckTimer = null;
    }

    if (!this.processPid) {
      log.info('[SDDService] Not running');
      return { success: true };
    }

    return new Promise((resolve) => {
      log.info(`[SDDService] Stopping process ${this.processPid}...`);

      exec(`taskkill /F /T /PID ${this.processPid}`, (error) => {
        this.process = null;
        this.processPid = null;
        this._isRunning = false;

        if (error) {
          log.error('[SDDService] Failed to stop:', error);
          resolve({ success: false, error: error.message });
        } else {
          log.info('[SDDService] Stopped');
          resolve({ success: true });
        }
      });
    });
  }
}

export const sddService = new SDDService();