import { ContextManager } from '../context.js';
import { chat } from '../llm.js';
import { getTools } from '../tools/registry.js';
import { Tool } from '../types/index.js';
import { hooks } from '../hooks/index.js';

export interface AgentConfig {
  name: string;
  systemPrompt: string;
  /** 该 Agent 可用的工具列表，默认使用全局注册的所有工具 */
  tools?: Tool[];
}

export class Agent {
  public name: string;
  private context: ContextManager;
  private tools: Tool[];

  constructor(config: AgentConfig) {
    this.name = config.name;
    this.tools = config.tools ?? getTools();
    this.context = new ContextManager();
    this.context.add({ role: 'system', content: config.systemPrompt });
  }

  /**
   * 运行 Agent 循环：发送消息 → 处理 tool_calls → 返回最终回复
   */
  async run(userMessage: string): Promise<string> {
    this.context.add({ role: 'user', content: userMessage });

    const openaiTools = this.tools.length > 0
      ? this.tools.map((t) => ({
          type: 'function' as const,
          function: {
            name: t.name,
            description: t.description,
            parameters: t.parameters,
          },
        }))
      : undefined;

    let reply = await chat(this.context.getMessages(), openaiTools);

    // 工具调用循环
    while (reply.tool_calls && reply.tool_calls.length > 0) {
      this.context.add({
        role: 'assistant',
        content: '',
        tool_calls: reply.tool_calls,
      } as any);

      for (const tc of reply.tool_calls) {
        const tool = this.tools.find((t) => t.name === tc.function.name);
        if (!tool) {
          this.context.add({
            role: 'tool',
            tool_call_id: tc.id,
            content: `错误: 未知工具 ${tc.function.name}`,
          } as any);
          continue;
        }

        hooks.emit('tool:before', { toolCall: tc, agentName: this.name });

        try {
          const args = JSON.parse(tc.function.arguments);
          const result = await tool.execute(args);
          this.context.add({
            role: 'tool',
            tool_call_id: tc.id,
            content: result,
          } as any);
          hooks.emit('tool:after', { toolCall: tc, result, agentName: this.name });
        } catch (e: any) {
          this.context.add({
            role: 'tool',
            tool_call_id: tc.id,
            content: `工具执行错误: ${e.message}`,
          } as any);
          hooks.emit('tool:after', { toolCall: tc, result: `错误: ${e.message}`, agentName: this.name });
        }
      }

      reply = await chat(this.context.getMessages(), openaiTools);
    }

    const content = reply.content!;
    this.context.add({ role: 'assistant', content });
    return content;
  }
}