/**
 * SessionRecorder 测试（v0.7.2 覆盖补齐 —— 此前零测试）
 *
 * 锁定 TRACE 层录制契约（P1-6 重构的回归防线）：
 * 1. startRecording 建文件并写 session_start；stopRecording 同步 flush + session_end
 * 2. 多会话隔离（P1-6：每会话独立文件/seq，并发录制互不串扰）
 * 3. setEnabled(false) 总开关丢弃事件（F-8 接通契约）
 * 4. 缓冲上限（MAX_BUFFER_SIZE）强制同步落盘防 OOM
 * 5. 事件 seq 递增与 9 类事件的载荷形状
 */

import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
import { mkdtempSync, readFileSync, existsSync, rmSync, readdirSync } from 'fs';
import { join } from 'path';
import { tmpdir } from 'os';

vi.mock('electron-log', () => ({
  default: { info: vi.fn(), warn: vi.fn(), error: vi.fn(), debug: vi.fn() },
}));

import { SessionRecorder } from '../session-recorder.service';

let wsRoot: string;
let recorder: SessionRecorder;

beforeEach(() => {
  wsRoot = mkdtempSync(join(tmpdir(), 'metona-rec-'));
  recorder = new SessionRecorder(wsRoot);
});

afterEach(() => {
  try {
    rmSync(wsRoot, { recursive: true, force: true });
  } catch {
    /* ignore */
  }
});

function readLines(sessionId: string): Array<Record<string, unknown>> {
  const dir = join(wsRoot, 'logs');
  const files = readdirSync(dir) as string[];
  const target = files.filter((f) => f.includes(`session_${sessionId}_`));
  expect(target.length).toBeGreaterThan(0);
  const content = readFileSync(join(dir, target[0]), 'utf-8');
  return content
    .split('\n')
    .filter((l) => l.trim())
    .map((l) => JSON.parse(l) as Record<string, unknown>);
}

describe('SessionRecorder — 基本录制链路', () => {
  it('startRecording 会话开启后首条事件即 session_start（seq 0，经 flush 落盘）', () => {
    recorder.startRecording('s1');
    // 事件先进缓冲（100ms 定时 flush），stopRecording 的 flushSync 保证落盘后断言
    recorder.stopRecording('s1', {
      totalIterations: 0,
      totalTokens: 0,
      durationMs: 0,
      terminationReason: 'completed',
    });
    const lines = readLines('s1');
    expect(lines).toHaveLength(2); // session_start + session_end
    expect(lines[0]).toMatchObject({ event: 'session_start', sessionId: 's1' });
    expect(lines[0].ts).toBeDefined();
    expect(lines[0].seq).toBe(0);
    expect(lines[1].event).toBe('session_end');
  });

  it('stopRecording 同步 flush 全部缓冲并写 session_end（#35 契约）', () => {
    recorder.startRecording('s1');
    recorder.recordToolCall({
      sessionId: 's1',
      iteration: 1,
      toolName: 'read_file',
      args: { p: 'x' },
    });
    recorder.recordIterationStart('s1', 1);
    recorder.stopRecording('s1', {
      totalIterations: 1,
      totalTokens: 100,
      durationMs: 50,
      terminationReason: 'completed',
    });

    const lines = readLines('s1');
    const events = lines.map((l) => l.event);
    expect(events).toEqual(['session_start', 'tool_call', 'iteration_start', 'session_end']);
    const end = lines[lines.length - 1];
    expect(end).toMatchObject({
      totalIterations: 1,
      totalTokens: 100,
      terminationReason: 'completed',
    });
  });

  it('事件 seq 在会话内单调递增', () => {
    recorder.startRecording('s1');
    recorder.recordIterationStart('s1', 1);
    recorder.recordIterationStart('s1', 2);
    recorder.stopRecording('s1', {
      totalIterations: 2,
      totalTokens: 0,
      durationMs: 1,
      terminationReason: 'completed',
    });

    // session_start(0) + iteration_start×2(1,2) + session_end(3)
    const seqs = readLines('s1').map((l) => l.seq as number);
    expect(seqs).toEqual([0, 1, 2, 3]);
  });

  it('recordLLMResponse 载荷：content 截断 200 字符', () => {
    recorder.startRecording('s1');
    recorder.recordLLMResponse({
      sessionId: 's1',
      iteration: 1,
      content: 'y'.repeat(500),
      finishReason: 'stop',
      tokenUsage: { input: 10, output: 20, total: 30 },
    });
    recorder.stopRecording('s1', {
      totalIterations: 1,
      totalTokens: 30,
      durationMs: 1,
      terminationReason: 'completed',
    });

    const llm = readLines('s1').find((l) => l.event === 'llm_response') as Record<string, unknown>;
    expect((llm.contentPreview as string).length).toBe(200);
    expect(llm.tokenUsage).toEqual({ input: 10, output: 20, total: 30 });
  });

  it('recordToolResult 载荷：success/durationMs/resultPreview 截断 500/error', () => {
    recorder.startRecording('s1');
    recorder.recordToolResult({
      sessionId: 's1',
      iteration: 1,
      toolName: 'web_fetch',
      success: false,
      durationMs: 42,
      resultPreview: 'z'.repeat(800),
      error: 'HTTP 403',
    });
    recorder.stopRecording('s1', {
      totalIterations: 1,
      totalTokens: 0,
      durationMs: 1,
      terminationReason: 'error',
    });

    const tr = readLines('s1').find((l) => l.event === 'tool_result') as Record<string, unknown>;
    expect(tr.success).toBe(false);
    expect(tr.durationMs).toBe(42);
    expect((tr.resultPreview as string).length).toBe(500);
    expect(tr.error).toBe('HTTP 403');
  });
});

describe('SessionRecorder — 多会话隔离（P1-6）', () => {
  it('并发录制：每会话独立文件与独立 seq，互不串扰', () => {
    recorder.startRecording('s1');
    recorder.startRecording('s2');

    recorder.recordToolCall({ sessionId: 's1', iteration: 1, toolName: 'tool_a', args: {} });
    recorder.recordToolCall({ sessionId: 's2', iteration: 1, toolName: 'tool_b', args: {} });

    recorder.stopRecording('s1', {
      totalIterations: 1,
      totalTokens: 0,
      durationMs: 1,
      terminationReason: 'completed',
    });
    recorder.stopRecording('s2', {
      totalIterations: 1,
      totalTokens: 0,
      durationMs: 1,
      terminationReason: 'completed',
    });

    const s1Tools = readLines('s1').filter((l) => l.event === 'tool_call');
    const s2Tools = readLines('s2').filter((l) => l.event === 'tool_call');
    expect(s1Tools[0].tool).toBe('tool_a');
    expect(s2Tools[0].tool).toBe('tool_b');
    // seq 各自从 0 起算（s1: start=0, tool=1, end=2；s2 同构）
    expect(s1Tools[0].seq).toBe(1);
    expect(s2Tools[0].seq).toBe(1);
  });

  it('未 startRecording 的会话事件被静默丢弃', () => {
    recorder.recordToolCall({ sessionId: 'ghost', iteration: 1, toolName: 'x', args: {} });
    expect(recorder.getFilePath('ghost')).toBeNull();
  });

  it('stopRecording 幂等安全（未开始也会话状态不崩）', () => {
    expect(() =>
      recorder.stopRecording('ghost', {
        totalIterations: 0,
        totalTokens: 0,
        durationMs: 0,
        terminationReason: 'error',
      }),
    ).not.toThrow();
  });
});

describe('SessionRecorder — 总开关与缓冲上限', () => {
  it('setEnabled(false) 后事件全部丢弃（logging.traceEnabled 契约）', () => {
    recorder.setEnabled(false);
    recorder.startRecording('s1');
    recorder.recordToolCall({ sessionId: 's1', iteration: 1, toolName: 'x', args: {} });
    recorder.stopRecording('s1', {
      totalIterations: 1,
      totalTokens: 0,
      durationMs: 1,
      terminationReason: 'completed',
    });

    const dir = join(wsRoot, 'logs');
    const files = existsSync(dir) ? readdirSync(dir) : [];
    expect(files.filter((f) => f.startsWith('session_s1_'))).toEqual([]);
  });

  it('缓冲超过 MAX_BUFFER_SIZE 强制同步落盘（防 OOM）', () => {
    recorder.startRecording('s1');
    // MAX_BUFFER_SIZE = 1000 —— 写入超限触发 flushSync（文件应提前出现在磁盘）
    for (let i = 0; i < 1001; i++) {
      recorder.recordIterationStart('s1', i);
    }
    recorder.stopRecording('s1', {
      totalIterations: 1001,
      totalTokens: 0,
      durationMs: 1,
      terminationReason: 'completed',
    });

    const lines = readLines('s1');
    expect(lines.length).toBe(1003); // 1001 iterations + session_start + session_end
  });

  it('getFilePath 返回活动会话的录制文件路径；stop 后清除', () => {
    recorder.startRecording('s1');
    expect(recorder.getFilePath('s1')).toContain('session_s1_');
    recorder.stopRecording('s1', {
      totalIterations: 0,
      totalTokens: 0,
      durationMs: 0,
      terminationReason: 'completed',
    });
    expect(recorder.getFilePath('s1')).toBeNull();
  });
});

// ===== v0.7.3 P3-3: JSONL 录制文件生命周期（stats + prune） =====

describe('SessionRecorder — 录制文件统计与清理（P3-3）', () => {
  const writeRecording = async (name: string, ageHours: number): Promise<void> => {
    const fs = await import('node:fs');
    const logsDir = join(wsRoot, 'logs');
    if (!existsSync(logsDir)) fs.mkdirSync(logsDir, { recursive: true });
    const filePath = join(logsDir, name);
    fs.writeFileSync(filePath, '{"event":"session_start"}\n', 'utf-8');
    const mtime = new Date(Date.now() - ageHours * 3600_000);
    fs.utimesSync(filePath, mtime, mtime);
  };

  it('getRecordingStats：统计 count 与 totalBytes；目录不存在返回零值', async () => {
    expect(recorder.getRecordingStats()).toEqual({ count: 0, totalBytes: 0 });

    await writeRecording('session_s1_2026-01-01.jsonl', 1);
    await writeRecording('session_s2_2026-01-02.jsonl', 2);
    // 非 session_*.jsonl 命名的文件不受治理（用户自放文件）
    await writeRecording('user-notes.txt', 3);

    const stats = recorder.getRecordingStats();
    expect(stats.count).toBe(2);
    expect(stats.totalBytes).toBeGreaterThan(0);
  });

  it('pruneOldRecordings：按 mtime 保留最近 N 个，删除其余', async () => {
    for (let i = 0; i < 6; i++) {
      await writeRecording(`session_s${i}_f.jsonl`, i + 1); // s0 最旧
    }
    const deleted = recorder.pruneOldRecordings(3);
    expect(deleted).toBe(3);

    const remaining = (readdirSync(join(wsRoot, 'logs')) as string[]).filter((f) =>
      f.startsWith('session_'),
    );
    expect(remaining).toHaveLength(3);
    // 保留的应是最新的 3 个（s0/s1/s2 —— 年龄 1/2/3 小时，s0 最新）
    for (const keep of ['session_s0_f.jsonl', 'session_s1_f.jsonl', 'session_s2_f.jsonl']) {
      expect(remaining).toContain(keep);
    }
  });

  it('pruneOldRecordings：仅治理 session_*.jsonl 命名，用户文件不受影响', async () => {
    await writeRecording('session_a.jsonl', 100);
    await writeRecording('my-data.jsonl', 100);
    const deleted = recorder.pruneOldRecordings(0);
    expect(deleted).toBe(1);
    expect(existsSync(join(wsRoot, 'logs', 'my-data.jsonl'))).toBe(true);
  });

  it('pruneOldRecordings：未超限返回 0 且不删除任何文件', async () => {
    await writeRecording('session_x.jsonl', 1);
    expect(recorder.pruneOldRecordings(200)).toBe(0);
    expect(existsSync(join(wsRoot, 'logs', 'session_x.jsonl'))).toBe(true);
  });
});