import { DomainEventBus } from '../runtime/DomainEventBus';

// 数据源配置
export interface DataSourceConfig {
  id: string;
  name: string;
  type: 'database' | 'api' | 'file' | 'stream';
  connectionString: string;
  credentials?: Record<string, string>;
  options?: Record<string, any>;
  status: 'active' | 'inactive' | 'error';
  createdAt: Date;
  lastUpdated: Date;
}

// 数据转换规则
export interface DataTransformationRule {
  id: string;
  name: string;
  sourceField: string;
  targetField: string;
  transformation: string; // 转换表达式
  conditions?: string; // 条件表达式
  createdAt: Date;
  lastUpdated: Date;
}

// 数据集成任务
export interface IntegrationTask {
  id: string;
  name: string;
  sourceDataSourceId: string;
  targetDataSourceId: string;
  transformationRules: string[]; // 规则ID列表
  schedule: string; // cron表达式
  status: 'pending' | 'running' | 'success' | 'failed';
  lastRun: Date | null;
  nextRun: Date | null;
  createdAt: Date;
  lastUpdated: Date;
}

// 集成任务执行日志
export interface IntegrationLog {
  id: string;
  taskId: string;
  status: 'success' | 'failed';
  startTime: Date;
  endTime: Date;
  recordsProcessed: number;
  recordsFailed: number;
  errorMessage?: string;
  metadata?: Record<string, any>;
}

// 数据集成平台
export class DataIntegrationPlatform {
  private static instance: DataIntegrationPlatform;
  private dataSources: Map<string, DataSourceConfig> = new Map();
  private transformationRules: Map<string, DataTransformationRule> = new Map();
  private integrationTasks: Map<string, IntegrationTask> = new Map();
  private integrationLogs: Map<string, IntegrationLog> = new Map();
  private eventBus: DomainEventBus;

  private constructor() {
    this.eventBus = DomainEventBus.getInstance();
  }

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

  // 注册数据源
  async registerDataSource(dataSource: Omit<DataSourceConfig, 'id' | 'status' | 'createdAt' | 'lastUpdated'>): Promise<DataSourceConfig> {
    const id = `ds_${Date.now()}_${Math.random().toString(36).substr(2, 9)}`;
    
    const newDataSource: DataSourceConfig = {
      ...dataSource,
      id,
      status: 'inactive',
      createdAt: new Date(),
      lastUpdated: new Date()
    };

    this.dataSources.set(id, newDataSource);
    this.eventBus.publish('datasource.registered', newDataSource);
    return newDataSource;
  }

  // 获取数据源信息
  getDataSource(dataSourceId: string): DataSourceConfig | undefined {
    return this.dataSources.get(dataSourceId);
  }

  // 获取所有数据源
  getAllDataSources(filters?: {
    type?: string;
    status?: string;
  }): DataSourceConfig[] {
    let result = Array.from(this.dataSources.values());

    if (filters) {
      if (filters.type) {
        result = result.filter(ds => ds.type === filters.type);
      }

      if (filters.status) {
        result = result.filter(ds => ds.status === filters.status);
      }
    }

    return result;
  }

  // 更新数据源
  async updateDataSource(dataSourceId: string, updates: Partial<DataSourceConfig>): Promise<DataSourceConfig | null> {
    const dataSource = this.dataSources.get(dataSourceId);
    if (!dataSource) {
      return null;
    }

    const updatedDataSource = {
      ...dataSource,
      ...updates,
      lastUpdated: new Date()
    };

    this.dataSources.set(dataSourceId, updatedDataSource);
    this.eventBus.publish('datasource.updated', updatedDataSource);
    return updatedDataSource;
  }

  // 测试数据源连接
  async testDataSourceConnection(dataSourceId: string): Promise<{ success: boolean; message: string }> {
    const dataSource = this.dataSources.get(dataSourceId);
    if (!dataSource) {
      return { success: false, message: 'DataSource not found' };
    }

    try {
      // 这里应该有实际的连接测试逻辑
      // 暂时模拟测试
      await new Promise(resolve => setTimeout(resolve, 1000));
      const success = Math.random() > 0.1; // 90% 成功率
      
      if (success) {
        dataSource.status = 'active';
        this.dataSources.set(dataSourceId, dataSource);
        return { success: true, message: 'Connection successful' };
      } else {
        dataSource.status = 'error';
        this.dataSources.set(dataSourceId, dataSource);
        return { success: false, message: 'Connection failed' };
      }
    } catch (error) {
      dataSource.status = 'error';
      this.dataSources.set(dataSourceId, dataSource);
      return { success: false, message: error instanceof Error ? error.message : 'Unknown error' };
    }
  }

  // 创建数据转换规则
  async createTransformationRule(rule: Omit<DataTransformationRule, 'id' | 'createdAt' | 'lastUpdated'>): Promise<DataTransformationRule> {
    const id = `rule_${Date.now()}_${Math.random().toString(36).substr(2, 9)}`;
    
    const newRule: DataTransformationRule = {
      ...rule,
      id,
      createdAt: new Date(),
      lastUpdated: new Date()
    };

    this.transformationRules.set(id, newRule);
    this.eventBus.publish('transformation.rule.created', newRule);
    return newRule;
  }

  // 获取转换规则
  getTransformationRule(ruleId: string): DataTransformationRule | undefined {
    return this.transformationRules.get(ruleId);
  }

  // 获取所有转换规则
  getAllTransformationRules(): DataTransformationRule[] {
    return Array.from(this.transformationRules.values());
  }

  // 更新转换规则
  async updateTransformationRule(ruleId: string, updates: Partial<DataTransformationRule>): Promise<DataTransformationRule | null> {
    const rule = this.transformationRules.get(ruleId);
    if (!rule) {
      return null;
    }

    const updatedRule = {
      ...rule,
      ...updates,
      lastUpdated: new Date()
    };

    this.transformationRules.set(ruleId, updatedRule);
    this.eventBus.publish('transformation.rule.updated', updatedRule);
    return updatedRule;
  }

  // 创建集成任务
  async createIntegrationTask(task: Omit<IntegrationTask, 'id' | 'status' | 'lastRun' | 'nextRun' | 'createdAt' | 'lastUpdated'>): Promise<IntegrationTask> {
    const id = `task_${Date.now()}_${Math.random().toString(36).substr(2, 9)}`;
    
    const newTask: IntegrationTask = {
      ...task,
      id,
      status: 'pending',
      lastRun: null,
      nextRun: this.calculateNextRun(task.schedule),
      createdAt: new Date(),
      lastUpdated: new Date()
    };

    this.integrationTasks.set(id, newTask);
    this.eventBus.publish('integration.task.created', newTask);
    return newTask;
  }

  // 获取集成任务
  getIntegrationTask(taskId: string): IntegrationTask | undefined {
    return this.integrationTasks.get(taskId);
  }

  // 获取所有集成任务
  getAllIntegrationTasks(filters?: {
    status?: string;
    sourceDataSourceId?: string;
    targetDataSourceId?: string;
  }): IntegrationTask[] {
    let result = Array.from(this.integrationTasks.values());

    if (filters) {
      if (filters.status) {
        result = result.filter(t => t.status === filters.status);
      }

      if (filters.sourceDataSourceId) {
        result = result.filter(t => t.sourceDataSourceId === filters.sourceDataSourceId);
      }

      if (filters.targetDataSourceId) {
        result = result.filter(t => t.targetDataSourceId === filters.targetDataSourceId);
      }
    }

    return result;
  }

  // 更新集成任务
  async updateIntegrationTask(taskId: string, updates: Partial<IntegrationTask>): Promise<IntegrationTask | null> {
    const task = this.integrationTasks.get(taskId);
    if (!task) {
      return null;
    }

    const updatedTask = {
      ...task,
      ...updates,
      lastUpdated: new Date()
    };

    if (updates.schedule) {
      updatedTask.nextRun = this.calculateNextRun(updates.schedule);
    }

    this.integrationTasks.set(taskId, updatedTask);
    this.eventBus.publish('integration.task.updated', updatedTask);
    return updatedTask;
  }

  // 执行集成任务
  async executeIntegrationTask(taskId: string): Promise<IntegrationLog> {
    const task = this.integrationTasks.get(taskId);
    if (!task) {
      throw new Error('Task not found');
    }

    task.status = 'running';
    this.integrationTasks.set(taskId, task);
    this.eventBus.publish('integration.task.started', task);

    const startTime = new Date();
    let recordsProcessed = 0;
    let recordsFailed = 0;
    let errorMessage: string | undefined;

    try {
      // 这里应该有实际的任务执行逻辑
      // 暂时模拟执行
      await new Promise(resolve => setTimeout(resolve, 3000));
      
      recordsProcessed = Math.floor(Math.random() * 1000) + 100;
      recordsFailed = Math.floor(Math.random() * 10);
      
      if (recordsFailed > 5) {
        throw new Error('Integration failed');
      }

      task.status = 'success';
      task.lastRun = new Date();
      task.nextRun = this.calculateNextRun(task.schedule);
    } catch (error) {
      task.status = 'failed';
      errorMessage = error instanceof Error ? error.message : 'Unknown error';
    }

    this.integrationTasks.set(taskId, task);
    
    const endTime = new Date();
    const log: IntegrationLog = {
      id: `log_${Date.now()}_${Math.random().toString(36).substr(2, 9)}`,
      taskId,
      status: task.status === 'success' ? 'success' : 'failed',
      startTime,
      endTime,
      recordsProcessed,
      recordsFailed,
      errorMessage
    };

    this.integrationLogs.set(log.id, log);
    this.eventBus.publish('integration.task.completed', { task, log });
    return log;
  }

  // 获取任务执行日志
  getIntegrationLog(logId: string): IntegrationLog | undefined {
    return this.integrationLogs.get(logId);
  }

  // 获取任务的执行日志
  getTaskLogs(taskId: string): IntegrationLog[] {
    return Array.from(this.integrationLogs.values()).filter(log => log.taskId === taskId);
  }

  // 计算下次执行时间
  private calculateNextRun(cronExpression: string): Date {
    // 这里应该有实际的cron表达式解析逻辑
    // 暂时返回当前时间后1小时
    const nextRun = new Date();
    nextRun.setHours(nextRun.getHours() + 1);
    return nextRun;
  }

  // 启动所有定时任务
  async startScheduledTasks(): Promise<void> {
    // 这里应该有实际的定时任务启动逻辑
    // 暂时模拟启动
    this.eventBus.publish('integration.tasks.started', { timestamp: new Date() });
  }

  // 停止所有定时任务
  async stopScheduledTasks(): Promise<void> {
    // 这里应该有实际的定时任务停止逻辑
    // 暂时模拟停止
    this.eventBus.publish('integration.tasks.stopped', { timestamp: new Date() });
  }

  // 获取平台状态
  getPlatformStatus(): {
    totalDataSources: number;
    activeDataSources: number;
    totalTasks: number;
    runningTasks: number;
    successTasks: number;
    failedTasks: number;
    totalLogs: number;
  } {
    const dataSources = Array.from(this.dataSources.values());
    const tasks = Array.from(this.integrationTasks.values());
    const logs = Array.from(this.integrationLogs.values());

    return {
      totalDataSources: dataSources.length,
      activeDataSources: dataSources.filter(ds => ds.status === 'active').length,
      totalTasks: tasks.length,
      runningTasks: tasks.filter(t => t.status === 'running').length,
      successTasks: tasks.filter(t => t.status === 'success').length,
      failedTasks: tasks.filter(t => t.status === 'failed').length,
      totalLogs: logs.length
    };
  }
}
