// Process cleanup utility for graceful shutdown
import { enhancedScreenshotService } from './enhanced-screenshot'
import { tradingViewAutomation } from './tradingview-automation'

class ProcessCleanup {
  private static instance: ProcessCleanup
  private isShuttingDown = false
  private aggressiveCleanup: any = null

  private constructor() {
    // Register cleanup handlers
    process.on('SIGINT', this.handleShutdown.bind(this))
    process.on('SIGTERM', this.handleShutdown.bind(this))
    process.on('SIGQUIT', this.handleShutdown.bind(this))
    process.on('uncaughtException', this.handleError.bind(this))
    process.on('unhandledRejection', this.handleError.bind(this))
    
    // Lazy load aggressive cleanup to avoid circular imports
    this.loadAggressiveCleanup()
  }

  private async loadAggressiveCleanup() {
    try {
      const { default: aggressiveCleanup } = await import('./aggressive-cleanup')
      this.aggressiveCleanup = aggressiveCleanup
    } catch (error) {
      console.error('Failed to load aggressive cleanup:', error)
    }
  }

  static getInstance(): ProcessCleanup {
    if (!ProcessCleanup.instance) {
      ProcessCleanup.instance = new ProcessCleanup()
    }
    return ProcessCleanup.instance
  }

  private async handleShutdown(signal: string): Promise<void> {
    if (this.isShuttingDown) {
      console.log('Already shutting down, forcing exit...')
      process.exit(1)
    }

    this.isShuttingDown = true
    console.log(`\n🛑 Received ${signal}, initiating graceful shutdown...`)

    try {
      // Use aggressive cleanup first
      if (this.aggressiveCleanup) {
        console.log('🧹 Running aggressive cleanup...')
        await this.aggressiveCleanup.forceCleanup()
      }

      // Clean up screenshot service
      console.log('🧹 Cleaning up screenshot service...')
      await enhancedScreenshotService.cleanup()

      // Clean up trading view automation
      console.log('🧹 Cleaning up TradingView automation...')
      await tradingViewAutomation.forceCleanup()

      console.log('✅ Graceful shutdown completed')
      process.exit(0)
    } catch (error) {
      console.error('❌ Error during shutdown:', error)
      process.exit(1)
    }
  }

  private async handleError(error: Error): Promise<void> {
    console.error('❌ Unhandled error:', error)
    
    // Attempt cleanup
    try {
      if (this.aggressiveCleanup) {
        await this.aggressiveCleanup.forceCleanup()
      }
      await enhancedScreenshotService.cleanup()
      await tradingViewAutomation.forceCleanup()
    } catch (cleanupError) {
      console.error('❌ Error during error cleanup:', cleanupError)
    }
    
    process.exit(1)
  }

  // Manual cleanup method
  async cleanup(): Promise<void> {
    await this.handleShutdown('MANUAL')
  }
}

// Initialize the cleanup handler
const processCleanup = ProcessCleanup.getInstance()

export default processCleanup