import fs from 'fs';
import path from 'path';
import yaml from 'js-yaml';
import { fileURLToPath } from 'url';

const __filename = fileURLToPath(import.meta.url);
const __dirname = path.dirname(__filename);

// 智能体配置接口
export interface AgentConfig {
  id: string;
  name: string;
  nameEn: string;
  description: string;
  category: string;
  icon: string;
  enabled: boolean;
  systemPromptFile: string;
  userPromptTemplateFile: string;
  models: {
    [modelName: string]: {
      temperature: number;
      maxTokens: number;
      topP?: number;
    };
  };
  ragEnabled: boolean;
  requiresProject: boolean;
  outputFormat: 'text' | 'structured' | 'document';
  tags: string[];
}

// 配置文件根结构
interface AgentsConfigFile {
  agents: AgentConfig[];
}

class AgentService {
  private agents: Map<string, AgentConfig> = new Map();
  private prompts: Map<string, string> = new Map();
  private configPath: string;
  private promptsPath: string;

  constructor() {
    // 配置文件路径
    this.configPath = path.resolve(__dirname, '../../config/agents.yaml');
    this.promptsPath = path.resolve(__dirname, '../../prompts');
    
    // 初始化加载配置
    this.loadAgents();
  }

  // 加载智能体配置
  private loadAgents() {
    try {
      const fileContents = fs.readFileSync(this.configPath, 'utf8');
      const config = yaml.load(fileContents) as AgentsConfigFile;
      
      if (!config || !config.agents) {
        throw new Error('Invalid agents configuration file');
      }

      // 存储到Map中
      config.agents.forEach((agent) => {
        this.agents.set(agent.id, agent);
      });

      console.log(`✅ Loaded ${this.agents.size} agent configurations`);
    } catch (error) {
      console.error('❌ Failed to load agent configurations:', error);
      throw error;
    }
  }

  // 加载Prompt模板
  private loadPrompt(filename: string): string {
    const cacheKey = filename;
    
    // 检查缓存
    if (this.prompts.has(cacheKey)) {
      return this.prompts.get(cacheKey)!;
    }

    try {
      const promptPath = path.join(this.promptsPath, filename);
      const content = fs.readFileSync(promptPath, 'utf8');
      
      // 缓存到内存
      this.prompts.set(cacheKey, content);
      
      return content;
    } catch (error) {
      console.error(`❌ Failed to load prompt file: ${filename}`, error);
      throw new Error(`Prompt file not found: ${filename}`);
    }
  }

  // 获取所有智能体列表
  getAllAgents(): AgentConfig[] {
    return Array.from(this.agents.values());
  }

  // 获取启用的智能体列表
  getEnabledAgents(): AgentConfig[] {
    return Array.from(this.agents.values()).filter((agent) => agent.enabled);
  }

  // 根据ID获取智能体配置
  getAgentById(agentId: string): AgentConfig | null {
    return this.agents.get(agentId) || null;
  }

  // 根据分类获取智能体列表
  getAgentsByCategory(category: string): AgentConfig[] {
    return Array.from(this.agents.values()).filter(
      (agent) => agent.category === category
    );
  }

  // 获取智能体的系统Prompt
  getSystemPrompt(agentId: string): string {
    const agent = this.getAgentById(agentId);
    if (!agent) {
      throw new Error(`Agent not found: ${agentId}`);
    }

    return this.loadPrompt(agent.systemPromptFile);
  }

  // 获取智能体的用户Prompt模板
  getUserPromptTemplate(agentId: string): string {
    const agent = this.getAgentById(agentId);
    if (!agent) {
      throw new Error(`Agent not found: ${agentId}`);
    }

    return this.loadPrompt(agent.userPromptTemplateFile);
  }

  // 渲染用户Prompt（替换模板变量）
  renderUserPrompt(
    agentId: string,
    variables: {
      projectBackground?: string;
      userInput: string;
      knowledgeBaseContext?: string;
    }
  ): string {
    const template = this.getUserPromptTemplate(agentId);
    
    let rendered = template;
    
    // 替换变量
    rendered = rendered.replace(/\{\{projectBackground\}\}/g, variables.projectBackground || '未提供项目背景');
    rendered = rendered.replace(/\{\{userInput\}\}/g, variables.userInput);
    
    // 处理条件块（知识库上下文）
    if (variables.knowledgeBaseContext) {
      rendered = rendered.replace(
        /\{\{#if knowledgeBaseContext\}\}([\s\S]*?)\{\{\/if\}\}/g,
        '$1'
      );
      rendered = rendered.replace(/\{\{knowledgeBaseContext\}\}/g, variables.knowledgeBaseContext);
    } else {
      // 移除条件块
      rendered = rendered.replace(
        /\{\{#if knowledgeBaseContext\}\}[\s\S]*?\{\{\/if\}\}/g,
        ''
      );
    }
    
    return rendered.trim();
  }

  // 检查智能体是否存在
  agentExists(agentId: string): boolean {
    return this.agents.has(agentId);
  }

  // 检查智能体是否启用
  isAgentEnabled(agentId: string): boolean {
    const agent = this.getAgentById(agentId);
    return agent ? agent.enabled : false;
  }

  // 获取智能体的模型配置
  getModelConfig(agentId: string, modelName: string) {
    const agent = this.getAgentById(agentId);
    if (!agent) {
      throw new Error(`Agent not found: ${agentId}`);
    }

    const modelConfig = agent.models[modelName];
    if (!modelConfig) {
      throw new Error(`Model ${modelName} not configured for agent ${agentId}`);
    }

    return modelConfig;
  }

  // 重新加载配置（热更新）
  reloadConfig() {
    this.agents.clear();
    this.prompts.clear();
    this.loadAgents();
    console.log('✅ Agent configurations reloaded');
  }
}

// 导出单例
export const agentService = new AgentService();