import { Observable, Subject, BehaviorSubject } from 'rxjs'

// AG-UI Protocol Event Types
export interface AGUIEvent {
  type: 'message' | 'progress' | 'state' | 'tool_call' | 'error' | 'complete' | 'thinking' | 'action'
  id: string
  timestamp: Date
  data: any
  metadata?: {
    agent_id?: string
    session_id?: string
    correlation_id?: string
  }
}

export interface AGUIMessage {
  role: 'user' | 'assistant' | 'system'
  content: string
  timestamp: Date
  metadata?: any
}

export interface AGUIState {
  connected: boolean
  processing: boolean
  currentAgent?: string
  sessionId?: string
  error?: string
}

export interface AGUIAgentConfig {
  id: string
  name: string
  description: string
  capabilities: string[]
  endpoint?: string
}

export class AGUIService {
  private eventSubject = new Subject<AGUIEvent>()
  private stateSubject = new BehaviorSubject<AGUIState>({
    connected: false,
    processing: false
  })
  
  private sessionId: string
  private agents: Map<string, AGUIAgentConfig> = new Map()

  constructor() {
    this.sessionId = this.generateSessionId()
    this.initializeDefaultAgents()
  }

  private generateSessionId(): string {
    return `session_${Date.now()}_${Math.random().toString(36).substring(2, 11)}`
  }

  private initializeDefaultAgents() {
    const videoCreationAgent: AGUIAgentConfig = {
      id: 'video_creator',
      name: 'Video Creation Agent',
      description: '专业的视频创作智能体，擅长生成高质量的产品展示视频',
      capabilities: [
        'video_generation',
        'script_writing',
        'model_selection',
        'scene_composition',
        'quality_optimization'
      ]
    }

    const contentOptimizationAgent: AGUIAgentConfig = {
      id: 'content_optimizer',
      name: 'Content Optimization Agent', 
      description: '内容优化专家，专注于提升视频内容的吸引力和转化率',
      capabilities: [
        'content_analysis',
        'audience_targeting',
        'engagement_optimization',
        'a_b_testing',
        'performance_metrics'
      ]
    }

    this.agents.set(videoCreationAgent.id, videoCreationAgent)
    this.agents.set(contentOptimizationAgent.id, contentOptimizationAgent)
  }

  // 连接到AG-UI智能体
  async connect(agentId?: string): Promise<void> {
    try {
      this.updateState({ connected: true, currentAgent: agentId })
      
      // 发送连接事件
      this.emitEvent({
        type: 'state',
        id: this.generateEventId(),
        timestamp: new Date(),
        data: { 
          status: 'connected',
          agent_id: agentId,
          session_id: this.sessionId
        },
        metadata: {
          agent_id: agentId,
          session_id: this.sessionId
        }
      })

      // 模拟连接延迟
      await new Promise(resolve => setTimeout(resolve, 1000))
      
    } catch (error) {
      this.updateState({ 
        connected: false, 
        error: error instanceof Error ? error.message : 'Connection failed' 
      })
      throw error
    }
  }

  // 断开连接
  async disconnect(): Promise<void> {
    this.updateState({ connected: false, processing: false, currentAgent: undefined })
    
    this.emitEvent({
      type: 'state',
      id: this.generateEventId(),
      timestamp: new Date(),
      data: { 
        status: 'disconnected',
        session_id: this.sessionId
      }
    })
  }

  // 发送消息到智能体
  async sendMessage(message: string, context?: any): Promise<void> {
    if (!this.stateSubject.value.connected) {
      throw new Error('Not connected to agent')
    }

    this.updateState({ processing: true })

    try {
      // 发送用户消息事件
      this.emitEvent({
        type: 'message',
        id: this.generateEventId(),
        timestamp: new Date(),
        data: {
          role: 'user',
          content: message,
          context
        },
        metadata: {
          session_id: this.sessionId,
          correlation_id: this.generateEventId()
        }
      })

      // 模拟智能体处理
      await this.simulateAgentProcessing(message, context)

    } catch (error) {
      this.emitEvent({
        type: 'error',
        id: this.generateEventId(),
        timestamp: new Date(),
        data: {
          error: error instanceof Error ? error.message : 'Unknown error',
          original_message: message
        }
      })
      throw error
    } finally {
      this.updateState({ processing: false })
    }
  }

  // 模拟智能体处理过程
  private async simulateAgentProcessing(message: string, context?: any): Promise<void> {
    const correlationId = this.generateEventId()
    
    // 1. 思考阶段
    this.emitEvent({
      type: 'thinking',
      id: this.generateEventId(),
      timestamp: new Date(),
      data: {
        message: '正在分析您的需求...',
        stage: 'analysis'
      },
      metadata: { correlation_id: correlationId }
    })

    await this.delay(800)

    // 2. 进度更新
    const progressSteps = [
      { progress: 20, message: '理解需求内容' },
      { progress: 40, message: '选择最佳策略' },
      { progress: 60, message: '生成创作方案' },
      { progress: 80, message: '优化输出质量' }
    ]

    for (const step of progressSteps) {
      this.emitEvent({
        type: 'progress',
        id: this.generateEventId(),
        timestamp: new Date(),
        data: step,
        metadata: { correlation_id: correlationId }
      })
      await this.delay(600)
    }

    // 3. 工具调用
    this.emitEvent({
      type: 'tool_call',
      id: this.generateEventId(),
      timestamp: new Date(),
      data: {
        tool: 'video_generator',
        parameters: {
          prompt: message,
          context: context,
          quality: 'high',
          format: 'mp4'
        }
      },
      metadata: { correlation_id: correlationId }
    })

    await this.delay(1000)

    // 4. 智能体响应
    const response = this.generateAgentResponse(message, context)
    this.emitEvent({
      type: 'message',
      id: this.generateEventId(),
      timestamp: new Date(),
      data: {
        role: 'assistant',
        content: response,
        confidence: 0.95
      },
      metadata: { correlation_id: correlationId }
    })

    await this.delay(500)

    // 5. 完成
    this.emitEvent({
      type: 'complete',
      id: this.generateEventId(),
      timestamp: new Date(),
      data: {
        success: true,
        duration: Date.now() - new Date().getTime(),
        tokens_used: Math.floor(Math.random() * 1000) + 500
      },
      metadata: { correlation_id: correlationId }
    })
  }

  private generateAgentResponse(message: string, context?: any): string {
    const productName = context?.project?.product_name || '您的产品'
    
    const responses = [
      `我理解您想要为"${productName}"创作视频内容。基于您的描述，我建议采用以下创作策略：

🎯 **核心亮点**
• 突出产品的独特价值
• 展示真实使用场景
• 强调用户体验

📹 **视觉风格**
• 现代简约的设计风格
• 温暖自然的色调
• 动态流畅的镜头运动

🎭 **内容结构**
1. 吸引注意的开场
2. 产品核心功能展示
3. 用户使用场景
4. 强有力的行动召唤

您希望我开始创作吗？或者您想调整某些方面？`,

      `很好的创意！让我为"${productName}"设计一个专业的视频方案：

✨ **创作思路**
基于您的需求，我推荐制作一个既有情感共鸣又具有说服力的产品视频。

🎬 **制作建议**
• 时长：30-60秒最佳
• 风格：现代商业风格
• 重点：产品价值传递

📊 **预期效果**
• 提升品牌认知度
• 增强用户信任感
• 促进转化行动

我现在可以开始为您生成具体的视频内容，您觉得这个方向如何？`
    ]

    return responses[Math.floor(Math.random() * responses.length)]
  }

  // 获取事件流
  getEventStream(): Observable<AGUIEvent> {
    return this.eventSubject.asObservable()
  }

  // 获取状态流
  getStateStream(): Observable<AGUIState> {
    return this.stateSubject.asObservable()
  }

  // 获取可用智能体
  getAvailableAgents(): AGUIAgentConfig[] {
    return Array.from(this.agents.values())
  }

  // 私有辅助方法
  private emitEvent(event: AGUIEvent): void {
    this.eventSubject.next(event)
  }

  private updateState(updates: Partial<AGUIState>): void {
    const currentState = this.stateSubject.value
    this.stateSubject.next({ ...currentState, ...updates })
  }

  private generateEventId(): string {
    return `event_${Date.now()}_${Math.random().toString(36).substring(2, 11)}`
  }

  private delay(ms: number): Promise<void> {
    return new Promise(resolve => setTimeout(resolve, ms))
  }

  // 清理资源
  dispose(): void {
    this.eventSubject.complete()
    this.stateSubject.complete()
  }
}

// 单例实例
export const aguiService = new AGUIService()
