import { EventEmitter } from 'events';
import { createHash, randomBytes } from 'crypto';

/**
 * Global Edge Computing Manager for ZAI Platform
 * Edge AI processing, distributed computing mesh, and real-time synchronization
 */
export class EdgeComputingManager extends EventEmitter {
  constructor() {
    super();
    
    this.edgeNodes = new Map();
    this.computingMesh = new Map();
    this.synchronizationChannels = new Map();
    this.edgeAIModels = new Map();
    this.distributedTasks = new Map();
    
    // Edge computing configuration
    this.edgeConfig = {
      maxLatency: 50, // milliseconds
      minBandwidth: 100, // Mbps
      replicationFactor: 3,
      syncInterval: 5000, // 5 seconds
      loadBalanceThreshold: 0.8,
      failoverTimeout: 10000, // 10 seconds
      edgeAIEnabled: true
    };
    
    // Global edge node locations
    this.edgeLocations = [
      { id: 'edge-us-east', region: 'us-east-1', city: 'New York', lat: 40.7128, lng: -74.0060 },
      { id: 'edge-us-west', region: 'us-west-1', city: 'San Francisco', lat: 37.7749, lng: -122.4194 },
      { id: 'edge-eu-west', region: 'eu-west-1', city: 'London', lat: 51.5074, lng: -0.1278 },
      { id: 'edge-eu-central', region: 'eu-central-1', city: 'Frankfurt', lat: 50.1109, lng: 8.6821 },
      { id: 'edge-ap-southeast', region: 'ap-southeast-1', city: 'Singapore', lat: 1.3521, lng: 103.8198 },
      { id: 'edge-ap-northeast', region: 'ap-northeast-1', city: 'Tokyo', lat: 35.6762, lng: 139.6503 },
      { id: 'edge-ap-south', region: 'ap-south-1', city: 'Mumbai', lat: 19.0760, lng: 72.8777 },
      { id: 'edge-sa-east', region: 'sa-east-1', city: 'São Paulo', lat: -23.5505, lng: -46.6333 }
    ];
    
    this.initializeEdgeNodes();
    this.startEdgeMonitoring();
    this.deployEdgeAI();
    
    console.log('🌐 Global Edge Computing Manager initialized');
  }

  /**
   * Initialize edge nodes worldwide
   */
  initializeEdgeNodes() {
    for (const location of this.edgeLocations) {
      const edgeNode = {
        ...location,
        status: 'ACTIVE',
        capacity: {
          cpu: 16, // cores
          memory: 64, // GB
          storage: 1000, // GB
          bandwidth: 1000 // Mbps
        },
        utilization: {
          cpu: 0.2 + Math.random() * 0.3,
          memory: 0.3 + Math.random() * 0.2,
          storage: 0.1 + Math.random() * 0.4,
          bandwidth: 0.2 + Math.random() * 0.3
        },
        performance: {
          latency: 10 + Math.random() * 40,
          throughput: 800 + Math.random() * 200,
          availability: 0.999,
          lastHealthCheck: Date.now()
        },
        aiModels: new Map(),
        activeTasks: new Map(),
        connections: new Set(),
        syncStatus: 'SYNCHRONIZED'
      };
      
      this.edgeNodes.set(location.id, edgeNode);
    }
    
    console.log(`🌐 ${this.edgeLocations.length} edge nodes initialized globally`);
  }

  /**
   * Deploy AI models to edge nodes
   */
  async deployEdgeAI() {
    const aiModels = [
      {
        id: 'edge-sentiment-analyzer',
        type: 'SENTIMENT_ANALYSIS',
        size: 50, // MB
        latency: 5, // ms
        accuracy: 0.92
      },
      {
        id: 'edge-conversation-classifier',
        type: 'CONVERSATION_CLASSIFICATION',
        size: 75, // MB
        latency: 8, // ms
        accuracy: 0.89
      },
      {
        id: 'edge-anomaly-detector',
        type: 'ANOMALY_DETECTION',
        size: 30, // MB
        latency: 3, // ms
        accuracy: 0.85
      },
      {
        id: 'edge-user-intent-predictor',
        type: 'INTENT_PREDICTION',
        size: 40, // MB
        latency: 6, // ms
        accuracy: 0.87
      }
    ];
    
    const deploymentResults = [];
    
    for (const model of aiModels) {
      const deployment = await this.deployModelToEdge(model);
      deploymentResults.push(deployment);
      this.edgeAIModels.set(model.id, model);
    }
    
    console.log(`🤖 ${aiModels.length} AI models deployed to edge nodes`);
    this.emit('edgeAIDeployed', deploymentResults);
    
    return deploymentResults;
  }

  /**
   * Deploy AI model to optimal edge nodes
   */
  async deployModelToEdge(model) {
    const deployment = {
      modelId: model.id,
      timestamp: Date.now(),
      targetNodes: [],
      deployedNodes: [],
      failedNodes: [],
      replicationFactor: this.edgeConfig.replicationFactor
    };
    
    // Select optimal nodes for deployment
    const optimalNodes = this.selectOptimalNodes(model, this.edgeConfig.replicationFactor);
    deployment.targetNodes = optimalNodes.map(node => node.id);
    
    // Deploy to each selected node
    for (const node of optimalNodes) {
      try {
        const deployResult = await this.deployToNode(model, node);
        
        if (deployResult.success) {
          deployment.deployedNodes.push(node.id);
          node.aiModels.set(model.id, {
            ...model,
            deployedAt: Date.now(),
            status: 'ACTIVE',
            requests: 0,
            averageLatency: model.latency
          });
        } else {
          deployment.failedNodes.push({
            nodeId: node.id,
            error: deployResult.error
          });
        }
      } catch (error) {
        deployment.failedNodes.push({
          nodeId: node.id,
          error: error.message
        });
      }
    }
    
    console.log(`🤖 Model ${model.id} deployed to ${deployment.deployedNodes.length}/${deployment.targetNodes.length} nodes`);
    
    return deployment;
  }

  /**
   * Process AI request at edge
   */
  async processEdgeAIRequest(request) {
    const {
      modelType,
      data,
      clientLocation,
      priority = 'NORMAL',
      maxLatency = this.edgeConfig.maxLatency
    } = request;
    
    const processingResult = {
      requestId: this.generateRequestId(),
      timestamp: Date.now(),
      modelType,
      clientLocation,
      selectedNode: null,
      processingTime: 0,
      result: null,
      fallbackUsed: false,
      error: null
    };
    
    try {
      // Find optimal edge node for processing
      const optimalNode = await this.findOptimalEdgeNode(modelType, clientLocation, maxLatency);
      
      if (!optimalNode) {
        // Fallback to cloud processing
        processingResult.fallbackUsed = true;
        processingResult.result = await this.processInCloud(modelType, data);
        processingResult.processingTime = 200; // Simulated cloud latency
      } else {
        processingResult.selectedNode = optimalNode.id;
        
        const startTime = Date.now();
        processingResult.result = await this.processAtEdgeNode(optimalNode, modelType, data);
        processingResult.processingTime = Date.now() - startTime;
        
        // Update node statistics
        this.updateNodeStatistics(optimalNode, processingResult);
      }
      
      this.emit('edgeAIRequestProcessed', processingResult);
      
    } catch (error) {
      processingResult.error = error.message;
      console.error('❌ Edge AI processing failed:', error.message);
    }
    
    return processingResult;
  }

  /**
   * Create distributed computing mesh
   */
  async createComputingMesh(taskDefinition) {
    const meshId = this.generateMeshId();
    
    const computingMesh = {
      id: meshId,
      taskDefinition,
      createdAt: Date.now(),
      status: 'INITIALIZING',
      participatingNodes: new Set(),
      taskDistribution: new Map(),
      results: new Map(),
      synchronization: {
        lastSync: Date.now(),
        syncErrors: 0,
        consistency: 'STRONG'
      }
    };
    
    try {
      // Select nodes for the computing mesh
      const selectedNodes = await this.selectMeshNodes(taskDefinition);
      
      // Distribute tasks across nodes
      const taskDistribution = await this.distributeTasks(taskDefinition, selectedNodes);
      
      for (const [nodeId, tasks] of taskDistribution.entries()) {
        computingMesh.participatingNodes.add(nodeId);
        computingMesh.taskDistribution.set(nodeId, tasks);
        
        // Start task execution on node
        await this.startTasksOnNode(nodeId, tasks, meshId);
      }
      
      computingMesh.status = 'ACTIVE';
      this.computingMesh.set(meshId, computingMesh);
      
      // Start mesh synchronization
      this.startMeshSynchronization(meshId);
      
      console.log(`🕸️ Computing mesh created: ${meshId} with ${selectedNodes.length} nodes`);
      this.emit('computingMeshCreated', computingMesh);
      
    } catch (error) {
      computingMesh.status = 'FAILED';
      computingMesh.error = error.message;
      console.error('❌ Computing mesh creation failed:', error.message);
    }
    
    return computingMesh;
  }

  /**
   * Real-time synchronization across edge nodes
   */
  async synchronizeEdgeNodes() {
    const syncReport = {
      timestamp: Date.now(),
      totalNodes: this.edgeNodes.size,
      syncedNodes: 0,
      failedNodes: [],
      dataConsistency: 'STRONG',
      syncLatency: 0
    };
    
    const syncStartTime = Date.now();
    
    // Create synchronization channels between nodes
    const syncChannels = await this.createSyncChannels();
    
    // Synchronize data across all nodes
    for (const [nodeId, node] of this.edgeNodes.entries()) {
      try {
        const syncResult = await this.syncNodeData(node, syncChannels);
        
        if (syncResult.success) {
          syncReport.syncedNodes++;
          node.syncStatus = 'SYNCHRONIZED';
          node.lastSync = Date.now();
        } else {
          syncReport.failedNodes.push({
            nodeId,
            error: syncResult.error
          });
          node.syncStatus = 'SYNC_FAILED';
        }
      } catch (error) {
        syncReport.failedNodes.push({
          nodeId,
          error: error.message
        });
        node.syncStatus = 'SYNC_ERROR';
      }
    }
    
    syncReport.syncLatency = Date.now() - syncStartTime;
    
    // Determine data consistency level
    if (syncReport.failedNodes.length === 0) {
      syncReport.dataConsistency = 'STRONG';
    } else if (syncReport.failedNodes.length <= 2) {
      syncReport.dataConsistency = 'EVENTUAL';
    } else {
      syncReport.dataConsistency = 'WEAK';
    }
    
    console.log(`🔄 Edge synchronization: ${syncReport.syncedNodes}/${syncReport.totalNodes} nodes (${syncReport.syncLatency}ms)`);
    this.emit('edgeSynchronizationCompleted', syncReport);
    
    return syncReport;
  }

  /**
   * Start edge monitoring
   */
  startEdgeMonitoring() {
    // Monitor edge nodes every 30 seconds
    setInterval(() => {
      this.monitorEdgeNodes();
    }, 30000);
    
    // Synchronize edge nodes every 5 seconds
    setInterval(() => {
      this.synchronizeEdgeNodes();
    }, this.edgeConfig.syncInterval);
    
    // Optimize edge placement every 5 minutes
    setInterval(() => {
      this.optimizeEdgePlacement();
    }, 300000);
    
    console.log('🌐 Edge monitoring started');
  }

  /**
   * Utility methods
   */
  selectOptimalNodes(model, count) {
    const availableNodes = Array.from(this.edgeNodes.values())
      .filter(node => node.status === 'ACTIVE')
      .filter(node => this.hasCapacityForModel(node, model))
      .sort((a, b) => this.calculateNodeScore(b, model) - this.calculateNodeScore(a, model));
    
    return availableNodes.slice(0, count);
  }
  
  hasCapacityForModel(node, model) {
    const availableStorage = node.capacity.storage * (1 - node.utilization.storage);
    return availableStorage >= model.size;
  }
  
  calculateNodeScore(node, model) {
    const latencyScore = (100 - node.performance.latency) / 100;
    const utilizationScore = (1 - node.utilization.cpu) * 0.5 + (1 - node.utilization.memory) * 0.3 + (1 - node.utilization.bandwidth) * 0.2;
    const availabilityScore = node.performance.availability;
    
    return (latencyScore * 0.4) + (utilizationScore * 0.4) + (availabilityScore * 0.2);
  }
  
  async deployToNode(model, node) {
    // Simulate model deployment
    const deploymentTime = 1000 + Math.random() * 2000;
    
    await new Promise(resolve => setTimeout(resolve, deploymentTime));
    
    const success = Math.random() > 0.1; // 90% success rate
    
    return {
      success,
      deploymentTime,
      error: success ? null : 'Deployment failed'
    };
  }
  
  async findOptimalEdgeNode(modelType, clientLocation, maxLatency) {
    const availableNodes = Array.from(this.edgeNodes.values())
      .filter(node => node.status === 'ACTIVE')
      .filter(node => node.aiModels.has(this.getModelIdByType(modelType)))
      .filter(node => node.performance.latency <= maxLatency);
    
    if (availableNodes.length === 0) {
      return null;
    }
    
    // Calculate distance-based scores
    const scoredNodes = availableNodes.map(node => ({
      node,
      score: this.calculateLocationScore(node, clientLocation)
    }));
    
    scoredNodes.sort((a, b) => b.score - a.score);
    
    return scoredNodes[0].node;
  }
  
  getModelIdByType(modelType) {
    const typeMapping = {
      'SENTIMENT_ANALYSIS': 'edge-sentiment-analyzer',
      'CONVERSATION_CLASSIFICATION': 'edge-conversation-classifier',
      'ANOMALY_DETECTION': 'edge-anomaly-detector',
      'INTENT_PREDICTION': 'edge-user-intent-predictor'
    };
    
    return typeMapping[modelType];
  }
  
  calculateLocationScore(node, clientLocation) {
    if (!clientLocation || !clientLocation.lat || !clientLocation.lng) {
      return 0.5; // Default score for unknown location
    }
    
    const distance = this.calculateDistance(
      node.lat, node.lng,
      clientLocation.lat, clientLocation.lng
    );
    
    // Closer nodes get higher scores
    const distanceScore = Math.max(0, 1 - (distance / 20000)); // Normalize to 20,000 km max
    const utilizationScore = 1 - node.utilization.cpu;
    
    return (distanceScore * 0.7) + (utilizationScore * 0.3);
  }
  
  calculateDistance(lat1, lng1, lat2, lng2) {
    const R = 6371; // Earth's radius in km
    const dLat = (lat2 - lat1) * Math.PI / 180;
    const dLng = (lng2 - lng1) * Math.PI / 180;
    const a = Math.sin(dLat/2) * Math.sin(dLat/2) +
              Math.cos(lat1 * Math.PI / 180) * Math.cos(lat2 * Math.PI / 180) *
              Math.sin(dLng/2) * Math.sin(dLng/2);
    const c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a));
    return R * c;
  }
  
  async processInCloud(modelType, data) {
    // Simulate cloud processing
    await new Promise(resolve => setTimeout(resolve, 150 + Math.random() * 100));
    
    return {
      result: `Cloud processed ${modelType}`,
      confidence: 0.85,
      processingLocation: 'CLOUD'
    };
  }
  
  async processAtEdgeNode(node, modelType, data) {
    const model = node.aiModels.get(this.getModelIdByType(modelType));
    
    if (!model) {
      throw new Error(`Model ${modelType} not available on node ${node.id}`);
    }
    
    // Simulate edge processing
    await new Promise(resolve => setTimeout(resolve, model.latency + Math.random() * 5));
    
    return {
      result: `Edge processed ${modelType}`,
      confidence: model.accuracy,
      processingLocation: 'EDGE',
      nodeId: node.id
    };
  }
  
  updateNodeStatistics(node, processingResult) {
    const modelId = this.getModelIdByType(processingResult.modelType);
    const model = node.aiModels.get(modelId);
    
    if (model) {
      model.requests++;
      model.averageLatency = (model.averageLatency + processingResult.processingTime) / 2;
    }
    
    // Update node utilization
    node.utilization.cpu = Math.min(0.95, node.utilization.cpu + 0.01);
  }
  
  async selectMeshNodes(taskDefinition) {
    const requiredNodes = taskDefinition.parallelism || 3;
    
    return Array.from(this.edgeNodes.values())
      .filter(node => node.status === 'ACTIVE')
      .sort((a, b) => this.calculateNodeScore(b, {}) - this.calculateNodeScore(a, {}))
      .slice(0, requiredNodes);
  }
  
  async distributeTasks(taskDefinition, nodes) {
    const taskDistribution = new Map();
    const tasksPerNode = Math.ceil(taskDefinition.totalTasks / nodes.length);
    
    nodes.forEach((node, index) => {
      const startTask = index * tasksPerNode;
      const endTask = Math.min(startTask + tasksPerNode, taskDefinition.totalTasks);
      
      const tasks = [];
      for (let i = startTask; i < endTask; i++) {
        tasks.push({
          taskId: `task_${i}`,
          data: taskDefinition.taskData[i] || {},
          priority: 'NORMAL'
        });
      }
      
      taskDistribution.set(node.id, tasks);
    });
    
    return taskDistribution;
  }
  
  async startTasksOnNode(nodeId, tasks, meshId) {
    const node = this.edgeNodes.get(nodeId);
    
    if (!node) {
      throw new Error(`Node ${nodeId} not found`);
    }
    
    for (const task of tasks) {
      node.activeTasks.set(task.taskId, {
        ...task,
        meshId,
        startedAt: Date.now(),
        status: 'RUNNING'
      });
    }
    
    console.log(`🕸️ Started ${tasks.length} tasks on node ${nodeId}`);
  }
  
  startMeshSynchronization(meshId) {
    const syncInterval = setInterval(async () => {
      try {
        await this.synchronizeMesh(meshId);
      } catch (error) {
        console.error(`❌ Mesh synchronization failed for ${meshId}:`, error.message);
      }
    }, this.edgeConfig.syncInterval);
    
    // Store interval reference for cleanup
    const mesh = this.computingMesh.get(meshId);
    if (mesh) {
      mesh.syncInterval = syncInterval;
    }
  }
  
  async synchronizeMesh(meshId) {
    const mesh = this.computingMesh.get(meshId);
    
    if (!mesh || mesh.status !== 'ACTIVE') {
      return;
    }
    
    // Collect results from all participating nodes
    for (const nodeId of mesh.participatingNodes) {
      const node = this.edgeNodes.get(nodeId);
      
      if (node) {
        // Sync task results
        for (const [taskId, task] of node.activeTasks.entries()) {
          if (task.meshId === meshId && task.status === 'COMPLETED') {
            mesh.results.set(taskId, task.result);
          }
        }
      }
    }
    
    mesh.synchronization.lastSync = Date.now();
  }
  
  async createSyncChannels() {
    const channels = new Map();
    
    for (const [nodeId, node] of this.edgeNodes.entries()) {
      channels.set(nodeId, {
        nodeId,
        status: 'ACTIVE',
        bandwidth: node.capacity.bandwidth,
        latency: node.performance.latency
      });
    }
    
    return channels;
  }
  
  async syncNodeData(node, syncChannels) {
    // Simulate data synchronization
    const syncTime = 50 + Math.random() * 100;
    
    await new Promise(resolve => setTimeout(resolve, syncTime));
    
    const success = Math.random() > 0.05; // 95% success rate
    
    return {
      success,
      syncTime,
      error: success ? null : 'Sync failed'
    };
  }
  
  async monitorEdgeNodes() {
    for (const [nodeId, node] of this.edgeNodes.entries()) {
      // Update node performance metrics
      node.performance.latency = 10 + Math.random() * 40;
      node.performance.throughput = 800 + Math.random() * 200;
      node.performance.lastHealthCheck = Date.now();
      
      // Update utilization
      node.utilization.cpu = Math.max(0.1, node.utilization.cpu + (Math.random() - 0.5) * 0.1);
      node.utilization.memory = Math.max(0.1, node.utilization.memory + (Math.random() - 0.5) * 0.05);
      node.utilization.bandwidth = Math.max(0.1, node.utilization.bandwidth + (Math.random() - 0.5) * 0.1);
      
      // Check for overloaded nodes
      if (node.utilization.cpu > this.edgeConfig.loadBalanceThreshold) {
        this.emit('edgeNodeOverloaded', { nodeId, utilization: node.utilization });
      }
    }
  }
  
  async optimizeEdgePlacement() {
    console.log('🔧 Optimizing edge placement...');
    
    // Analyze traffic patterns and optimize model placement
    const optimizations = [];
    
    for (const [modelId, model] of this.edgeAIModels.entries()) {
      const currentPlacements = this.getCurrentModelPlacements(modelId);
      const optimalPlacements = await this.calculateOptimalPlacements(model);
      
      if (this.shouldRebalance(currentPlacements, optimalPlacements)) {
        optimizations.push({
          modelId,
          action: 'REBALANCE',
          from: currentPlacements,
          to: optimalPlacements
        });
      }
    }
    
    if (optimizations.length > 0) {
      console.log(`🔧 ${optimizations.length} edge optimizations identified`);
      this.emit('edgeOptimizationsIdentified', optimizations);
    }
  }
  
  getCurrentModelPlacements(modelId) {
    const placements = [];
    
    for (const [nodeId, node] of this.edgeNodes.entries()) {
      if (node.aiModels.has(modelId)) {
        placements.push(nodeId);
      }
    }
    
    return placements;
  }
  
  async calculateOptimalPlacements(model) {
    // Simplified optimal placement calculation
    return this.selectOptimalNodes(model, this.edgeConfig.replicationFactor)
      .map(node => node.id);
  }
  
  shouldRebalance(current, optimal) {
    // Simple rebalancing logic
    const overlap = current.filter(nodeId => optimal.includes(nodeId));
    return overlap.length < Math.ceil(current.length * 0.7);
  }
  
  generateRequestId() {
    return 'REQ_' + Date.now() + '_' + randomBytes(4).toString('hex').toUpperCase();
  }
  
  generateMeshId() {
    return 'MESH_' + Date.now() + '_' + randomBytes(4).toString('hex').toUpperCase();
  }
  
  /**
   * Get edge computing statistics
   */
  getEdgeComputingStats() {
    const activeNodes = Array.from(this.edgeNodes.values()).filter(n => n.status === 'ACTIVE');
    const totalModels = Array.from(this.edgeNodes.values())
      .reduce((sum, node) => sum + node.aiModels.size, 0);
    
    return {
      nodes: {
        total: this.edgeNodes.size,
        active: activeNodes.length,
        averageLatency: activeNodes.reduce((sum, n) => sum + n.performance.latency, 0) / activeNodes.length,
        averageUtilization: activeNodes.reduce((sum, n) => sum + n.utilization.cpu, 0) / activeNodes.length
      },
      aiModels: {
        total: this.edgeAIModels.size,
        deployed: totalModels,
        averageAccuracy: Array.from(this.edgeAIModels.values())
          .reduce((sum, m) => sum + m.accuracy, 0) / this.edgeAIModels.size
      },
      computingMesh: {
        activeMeshes: Array.from(this.computingMesh.values()).filter(m => m.status === 'ACTIVE').length,
        totalTasks: Array.from(this.distributedTasks.values()).length
      },
      synchronization: {
        syncedNodes: Array.from(this.edgeNodes.values()).filter(n => n.syncStatus === 'SYNCHRONIZED').length,
        lastSyncLatency: 75 // Average sync latency
      }
    };
  }
}
