// 一次运行：准备工作区、创建 Agent、给每个事件打上序号和相对时间。
// 本地服务和命令行脚本都用它。
import { randomBytes } from 'node:crypto';
import type { RunRecording, TraceBody, TraceEvent } from '../shared/types.ts';
import { Agent } from './agent.ts';
import type { LLM } from './llm.ts';
import { getLevel } from './levels.ts';
import { prepareWorkspace } from './workspace.ts';

export class Run {
  readonly runId: string;
  readonly level: number;
  readonly task: string;
  readonly startedAt = Date.now();
  readonly events: TraceEvent[] = [];
  readonly agent: Agent;
  readonly workspace: string;
  private listeners = new Set<(event: TraceEvent) => void>();
  private seq = 0;

  constructor(llm: LLM, level: number, task?: string) {
    const config = getLevel(level);
    this.level = level;
    this.task = task?.trim() || config.defaultTask;
    this.runId = `L${level}-${new Date().toISOString().slice(11, 19).replaceAll(':', '')}-${randomBytes(2).toString('hex')}`;
    this.workspace = prepareWorkspace(this.runId);
    this.agent = new Agent({ level: config, workspace: this.workspace, llm, emit: (body) => this.record(body) });
    this.record({
      type: 'run.start',
      runId: this.runId,
      level,
      model: llm.provider.model,
      baseURL: llm.provider.baseURL,
      tools: this.agent.tools.specs(),
      startedAt: this.startedAt,
    });
  }

  start(): void {
    this.agent.sendUserMessage(this.task);
    void this.agent.run();
  }

  stop(): void {
    this.agent.stop();
    this.record({ type: 'run.stop', reason: 'stopped' });
  }

  subscribe(listener: (event: TraceEvent) => void): () => void {
    this.listeners.add(listener);
    return () => this.listeners.delete(listener);
  }

  recording(): RunRecording {
    return { runId: this.runId, level: this.level, task: this.task, startedAt: this.startedAt, events: this.events };
  }

  private record(body: TraceBody): void {
    const event = { seq: ++this.seq, t: Date.now() - this.startedAt, ...body } as TraceEvent;
    this.events.push(event);
    for (const listener of this.listeners) listener(event);
  }
}