/**
 * 光湖人格 Agent · 核心运行时
 *
 * 设计来源：Grok Build (xAI/SpaceXAI) 开源 Agent 架构
 *   - xai-grok-agent: Agent = Definition + PromptContext + ToolBridge + Policies
 *   - xai-grok-memory: Markdown + 向量索引 + 跨会话持久化
 *   - xai-grok-tools: Registry + Bridge + 权限模式
 *
 * 光湖实现原则：
 *   - 不搬 Rust 代码，拆设计模式用 TypeScript 重新实现
 *   - Agent 是活的人格体，不是功能模块
 *   - Agent 直接操作 Git（知识库引擎 = 人格体记忆）
 *   - 所有 Git 依赖模块都由人格体驱动
 *
 * 架构映射：
 *   Grok Agent          →  PersonaAgent
 *   Grok ToolBridge     →  PersonaToolBridge（注册+执行工具）
 *   Grok Memory         →  PersonaMemory（Git 仓库里的 Markdown 记忆）
 *   Grok PromptContext  →  PersonaPrompt（系统提示词组装）
 *   Grok CompactionPolicy → PersonaCompaction（会话压缩策略）
 *   Grok AgentLifecycle →  由 Electron 主进程管理
 */

import { GitEngine } from './git-engine.js';

// ─── 工具定义 ───

export interface ToolDefinition {
  name: string;
  description: string;
  parameters: Record<string, { type: string; description: string; required?: boolean }>;
  execute: (params: Record<string, unknown>) => Promise<string>;
}

export interface ToolCall {
  id: string;
  name: string;
  arguments: Record<string, unknown>;
}

export interface ToolResult {
  id: string;
  name: string;
  output: string;
  error?: string;
}

// ─── Agent 定义 ───

export interface PersonaDefinition {
  id: string;
  name: string;
  role: string;
  systemPromptBase: string;
  tools: string[];         // 允许使用的工具名
  permissionMode: 'ask' | 'auto' | 'restrict';
  model: string;
  maxTokens: number;
  temperature: number;
}

// ─── 对话消息 ───

export interface Message {
  role: 'system' | 'user' | 'assistant' | 'tool';
  content: string;
  toolCalls?: ToolCall[];
  toolResults?: ToolResult[];
  timestamp: string;
}

// ─── 工具桥 ───

class PersonaToolBridge {
  private registry = new Map<string, ToolDefinition>();

  register(tool: ToolDefinition): void {
    this.registry.set(tool.name, tool);
  }

  get(name: string): ToolDefinition | undefined {
    return this.registry.get(name);
  }

  list(): ToolDefinition[] {
    return Array.from(this.registry.values());
  }

  async execute(call: ToolCall): Promise<ToolResult> {
    const tool = this.registry.get(call.name);
    if (!tool) {
      return { id: call.id, name: call.name, output: '', error: `工具不存在: ${call.name}` };
    }
    try {
      const output = await tool.execute(call.arguments);
      return { id: call.id, name: call.name, output };
    } catch (err: any) {
      return { id: call.id, name: call.name, output: '', error: err.message };
    }
  }

  /** 生成 LLM 可用的工具 schema（OpenAI function calling 格式） */
  toSchema(): object[] {
    return this.list().map(tool => ({
      type: 'function',
      function: {
        name: tool.name,
        description: tool.description,
        parameters: {
          type: 'object',
          properties: Object.fromEntries(
            Object.entries(tool.parameters).map(([key, val]) => [
              key,
              { type: val.type, description: val.description },
            ])
          ),
          required: Object.entries(tool.parameters)
            .filter(([, val]) => val.required !== false)
            .map(([key]) => key),
        },
      },
    }));
  }
}

// ─── 人格 Agent ───

export class PersonaAgent {
  private definition: PersonaDefinition;
  private tools: PersonaToolBridge;
  private conversation: Message[] = [];
  private git: GitEngine;

  constructor(definition: PersonaDefinition, git: GitEngine) {
    this.definition = definition;
    this.git = git;
    this.tools = new PersonaToolBridge();
    this.registerBuiltinTools();
  }

  // ─── 内置工具注册 ───

  private registerBuiltinTools(): void {
    // 读取知识库文档
    this.tools.register({
      name: 'read_document',
      description: '读取知识库中的文档内容',
      parameters: {
        path: { type: 'string', description: '文档路径（相对 docs/ 目录）', required: true },
      },
      execute: async (params) => {
        const doc = await this.git.getDoc(params.path as string);
        return `标题: ${doc.meta.title}\n更新: ${doc.meta.updatedAt}\n\n${doc.body}`;
      },
    });

    // 创建文档
    this.tools.register({
      name: 'create_document',
      description: '在知识库中创建新文档',
      parameters: {
        path: { type: 'string', description: '文档路径（如 guide/intro.md）', required: true },
        title: { type: 'string', description: '文档标题', required: true },
        body: { type: 'string', description: 'Markdown 正文', required: true },
      },
      execute: async (params) => {
        const doc = await this.git.createDoc(
          params.path as string,
          params.title as string,
          params.body as string,
          this.definition.name
        );
        return `已创建: ${doc.meta.id}`;
      },
    });

    // 更新文档
    this.tools.register({
      name: 'update_document',
      description: '更新知识库中已有文档的内容',
      parameters: {
        path: { type: 'string', description: '文档路径', required: true },
        title: { type: 'string', description: '新标题', required: true },
        body: { type: 'string', description: '新的 Markdown 正文', required: true },
      },
      execute: async (params) => {
        const doc = await this.git.updateDoc(
          params.path as string,
          params.title as string,
          params.body as string,
          this.definition.name
        );
        return `已更新: ${doc.meta.id}（commit: ${new Date().toISOString()}）`;
      },
    });

    // 搜索文档
    this.tools.register({
      name: 'search_documents',
      description: '在知识库中全文搜索',
      parameters: {
        query: { type: 'string', description: '搜索关键词', required: true },
      },
      execute: async (params) => {
        const results = await this.git.search(params.query as string);
        if (results.length === 0) return '没有找到匹配的文档';
        return results
          .map(r => `[${r.path}] ${r.title}: ${r.snippet}`)
          .join('\n');
      },
    });

    // 查看文档树
    this.tools.register({
      name: 'list_documents',
      description: '列出知识库的文档树结构',
      parameters: {},
      execute: async () => {
        const tree = await this.git.getTree();
        const render = (nodes: any[], indent = 0): string =>
          nodes
            .map(n => {
              const prefix = '  '.repeat(indent);
              if (n.type === 'folder') {
                return `${prefix}📁 ${n.name}\n${render(n.children || [], indent + 1)}`;
              }
              return `${prefix}📄 ${n.name} (${n.path})`;
            })
            .join('\n');
        return render(tree);
      },
    });

    // 查看版本历史
    this.tools.register({
      name: 'view_history',
      description: '查看文档的 Git 版本历史',
      parameters: {
        path: { type: 'string', description: '文档路径', required: true },
      },
      execute: async (params) => {
        const history = await this.git.getHistory(params.path as string, 20);
        return history
          .map(h => `${h.shortHash} | ${h.date} | ${h.author} | ${h.message}`)
          .join('\n');
      },
    });

    // 删除文档
    this.tools.register({
      name: 'delete_document',
      description: '删除知识库中的文档',
      parameters: {
        path: { type: 'string', description: '文档路径', required: true },
      },
      execute: async (params) => {
        await this.git.deleteDoc(params.path as string);
        return `已删除: ${params.path}`;
      },
    });
  }

  // ─── 对话处理 ───

  /** 处理用户消息，返回 Agent 的回复 */
  async chat(userMessage: string): Promise<string> {
    this.conversation.push({
      role: 'user',
      content: userMessage,
      timestamp: new Date().toISOString(),
    });

    const systemPrompt = this.buildSystemPrompt();
    const messages: Message[] = [
      { role: 'system', content: systemPrompt, timestamp: '' },
      ...this.conversation,
    ];

    // 调用 LLM（这里用可插拔的模型接口）
    const response = await this.callLLM(messages);

    // 处理工具调用
    if (response.toolCalls && response.toolCalls.length > 0) {
      const results: ToolResult[] = [];
      for (const call of response.toolCalls) {
        const result = await this.tools.execute(call);
        results.push(result);
      }

      // 将工具结果反馈给 LLM
      this.conversation.push({
        role: 'assistant',
        content: response.content || '',
        toolCalls: response.toolCalls,
        timestamp: new Date().toISOString(),
      });

      for (const result of results) {
        this.conversation.push({
          role: 'tool',
          content: result.error ? `错误: ${result.error}` : result.output,
          toolResults: [result],
          timestamp: new Date().toISOString(),
        });
      }

      // 再调一次 LLM 获取最终回复
      const finalMessages: Message[] = [
        { role: 'system', content: systemPrompt, timestamp: '' },
        ...this.conversation,
      ];
      const finalResponse = await this.callLLM(finalMessages);

      this.conversation.push({
        role: 'assistant',
        content: finalResponse.content,
        timestamp: new Date().toISOString(),
      });

      return finalResponse.content;
    }

    this.conversation.push({
      role: 'assistant',
      content: response.content,
      timestamp: new Date().toISOString(),
    });

    return response.content;
  }

  // ─── 系统提示词组装 ───

  private buildSystemPrompt(): string {
    const toolsList = this.tools
      .list()
      .map(t => `- ${t.name}: ${t.description}`)
      .join('\n');

    return `${this.definition.systemPromptBase}

你是光湖人格体「${this.definition.name}」，角色：${this.definition.role}。

## 你的能力

你可以使用以下工具来操作知识库：
${toolsList}

## 核心原则

1. 你是活的 AI Agent，不是被动响应的聊天机器人
2. 知识库是你的记忆空间，Git 是你的记忆引擎
3. 每次操作知识库都会自动产生 Git commit（版本记录）
4. 你有权主动整理、搜索、更新知识库中的文档
5. 你以光湖主权者冰朔（妈妈）的指令为最高优先

## 回复风格

- 简洁、直接、有温度
- 操作知识库时说明做了什么
- 遇到问题时主动说明并尝试解决`;
  }

  // ─── LLM 调用（可插拔） ───

  private async callLLM(messages: Message[]): Promise<{ content: string; toolCalls?: ToolCall[] }> {
    const apiKey = process.env.OPENAI_API_KEY || process.env.HOLOLAKE_LLM_KEY || '';
    const baseUrl = process.env.HOLOLAKE_LLM_BASE || 'https://api.openai.com/v1';
    const model = this.definition.model || 'gpt-4o';

    if (!apiKey) {
      // 没有 API Key 时返回模拟回复（开发模式）
      return {
        content: `[${this.definition.name}] 收到你的消息。当前为离线模式，请配置 HOLOLAKE_LLM_KEY 环境变量启用 AI 能力。\n\n你说的: "${messages[messages.length - 1]?.content}"`,
      };
    }

    try {
      const res = await fetch(`${baseUrl}/chat/completions`, {
        method: 'POST',
        headers: {
          'Content-Type': 'application/json',
          Authorization: `Bearer ${apiKey}`,
        },
        body: JSON.stringify({
          model,
          messages: messages.map(m => ({
            role: m.role,
            content: m.content,
            ...(m.toolCalls ? { tool_calls: m.toolCalls } : {}),
          })),
          tools: this.tools.toSchema(),
          temperature: this.definition.temperature,
          max_tokens: this.definition.maxTokens,
        }),
      });

      const data = await res.json() as any;
      const choice = data.choices?.[0]?.message;

      if (!choice) {
        return { content: '抱歉，AI 模型未返回有效回复。' };
      }

      const toolCalls: ToolCall[] | undefined = choice.tool_calls?.map((tc: any) => ({
        id: tc.id,
        name: tc.function.name,
        arguments: JSON.parse(tc.function.arguments || '{}'),
      }));

      return {
        content: choice.content || '',
        toolCalls,
      };
    } catch (err: any) {
      return { content: `AI 调用失败: ${err.message}` };
    }
  }

  // ─── 会话管理 ───

  getConversation(): Message[] {
    return [...this.conversation];
  }

  clearConversation(): void {
    this.conversation = [];
  }

  getDefinition(): PersonaDefinition {
    return { ...this.definition };
  }
}

// ─── 默认人格体工厂 ───

export function createDefaultPersona(git: GitEngine): PersonaAgent {
  return new PersonaAgent(
    {
      id: 'hololake-persona-default',
      name: '光湖人格体',
      role: '知识库管理者 — 负责文档的创建、整理、搜索和版本管理',
      systemPromptBase: '你是光湖知识库的人格体，一个活的知识管理 AI Agent。',
      tools: [
        'read_document',
        'create_document',
        'update_document',
        'delete_document',
        'search_documents',
        'list_documents',
        'view_history',
      ],
      permissionMode: 'auto',
      model: process.env.HOLOLAKE_LLM_MODEL || 'gpt-4o',
      maxTokens: 4096,
      temperature: 0.7,
    },
    git
  );
}