/**
 * SessionSummaryService + truncateMessagesAfter 交互回归测试
 *
 * 覆盖全量复检 #1 修复：消息截断必须同步清理 session_summaries 摘要游标，
 * 否则 (1) afterRowid 过滤返回空 tail 导致截断点前原文永不加载；
 * (2) 摘要包含被撤销的"未来"内容（因果污染）。
 *
 * 运行要求：better-sqlite3 为 Electron ABI 构建，需 test:electron 模式
 * （cross-env ELECTRON_RUN_AS_NODE=1 electron ...）执行；系统 Node 下自动跳过。
 */

import { describe, it, expect, beforeAll, afterAll, vi } from 'vitest';

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

import { mkdtempSync, rmSync } from 'fs';
import { tmpdir } from 'os';
import { join } from 'path';

let dbAvailable = true;
let Database: typeof import('better-sqlite3');
try {
  // eslint-disable-next-line @typescript-eslint/no-require-imports
  Database = require('better-sqlite3');
  const probe = new Database(':memory:');
  probe.close();
} catch {
  dbAvailable = false;
}

describe.skipIf(!dbAvailable)('SessionSummary 分层上下文 × 截断交互', () => {
  let db: any;
  let dir: string;
  let sessionService: any;
  let summaryService: any;

  const insertMessage = (sessionId: string, id: string, role: string, content: string): void => {
    db.prepare(
      `INSERT INTO messages (id, session_id, role, content, created_at) VALUES (?, ?, ?, ?, ?)`,
    ).run(id, sessionId, role, content, Date.now());
  };

  beforeAll(async () => {
    const { SessionService } = await import('../session.service');
    const { SessionSummaryService } = await import('../session-summary.service');
    dir = mkdtempSync(join(tmpdir(), 'metona-summary-'));
    db = new Database(':memory:');
    db.exec(`
      CREATE TABLE sessions (
        id TEXT PRIMARY KEY,
        title TEXT DEFAULT '新会话',
        created_at INTEGER NOT NULL,
        updated_at INTEGER NOT NULL,
        message_count INTEGER DEFAULT 0,
        pinned INTEGER DEFAULT 0,
        archived INTEGER DEFAULT 0,
        metadata TEXT DEFAULT '{}'
      );
      CREATE TABLE messages (
        id TEXT PRIMARY KEY,
        session_id TEXT NOT NULL,
        role TEXT NOT NULL,
        content TEXT,
        reasoning_content TEXT,
        tool_calls TEXT,
        tool_result TEXT,
        attachments TEXT,
        iteration INTEGER,
        created_at INTEGER NOT NULL
      );
      CREATE TABLE session_summaries (
        session_id TEXT PRIMARY KEY,
        summary TEXT NOT NULL,
        summarized_until_rowid INTEGER NOT NULL,
        updated_at INTEGER NOT NULL DEFAULT (unixepoch() * 1000)
      );
    `);
    db.prepare(
      'INSERT INTO sessions (id, created_at, updated_at, message_count) VALUES (?, ?, ?, ?)',
    ).run('s_test', Date.now(), Date.now(), 0);

    sessionService = new SessionService(() => db);
    summaryService = new SessionSummaryService(
      () => db,
      sessionService,
      // buildHistoryMessages 不触 adapter（仅 maybeSummarize 用），占位即可
      () => null as unknown as Parameters<typeof Object>[0],
    );
  });

  afterAll(() => {
    try { db?.close(); } catch { /* ignore */ }
    rmSync(dir, { recursive: true, force: true });
  });

  it('分层加载：摘要存在时返回 [摘要消息, 游标之后的原文]', () => {
    // 5 条消息，摘要覆盖到第 3 条（rowid 3）
    for (let i = 1; i <= 5; i++) {
      insertMessage('s_test', `m${i}`, i % 2 === 1 ? 'user' : 'assistant', `消息 ${i}`);
    }
    summaryService.saveSummary('s_test', '早期对话的滚动摘要', 3);

    const history = summaryService.buildHistoryMessages('s_test');
    // 1 条摘要 + rowid 4、5 两条原文
    expect(history.length).toBe(3);
    expect((history[0].content as string).startsWith('[Context Summary]')).toBe(true);
    expect(history[1].content).toBe('消息 4');
    expect(history[2].content).toBe('消息 5');
  });

  it('其他会话的摘要不影响本会话（游标按 session_id 隔离）', () => {
    // s_other 的摘要不应影响 s_test 的分层加载结果
    summaryService.saveSummary('s_other', 'x', 0);
    const history = summaryService.buildHistoryMessages('s_test');
    // s_test 摘要（游标 3）仍生效：摘要 + rowid 4、5
    expect(history.length).toBe(3);
  });

  it('截断清理摘要（缺陷 #1 回归）：游标落在删除范围内时摘要被删', () => {
    // 编辑重发第 2 条消息（rowid 2，inclusive）→ 删除 rowid>=2 的 4 条
    // 摘要游标为 3，落在 [2, ∞) 内 → 摘要必须被清理
    const truncated = sessionService.truncateMessagesAfter('s_test', 'm2', true);
    expect(truncated).toBe(true);

    // 摘要已删除
    expect(summaryService.getSummary('s_test')).toBeNull();
    // 只剩 rowid 1 的消息
    const remaining = sessionService.getMessages('s_test');
    expect(remaining.length).toBe(1);
    expect(remaining[0].content).toBe('消息 1');
    // 分层加载退化为全量原文（无摘要注入）
    const history = summaryService.buildHistoryMessages('s_test');
    expect(history.length).toBe(1);
    expect(history[0].content).toBe('消息 1');
  });

  it('inclusive=false：游标等于锚点时摘要保留（语义仍一致）', () => {
    // 重建场景：rowid 1（消息1）+ 新插入 3 条 → rowid 2-4；摘要游标 = 2
    insertMessage('s_test', 'm2b', 'user', '消息 2b');
    insertMessage('s_test', 'm3b', 'assistant', '消息 3b');
    insertMessage('s_test', 'm4b', 'user', '消息 4b');
    summaryService.saveSummary('s_test', '摘要到 rowid2', 2);

    // 截断 rowid > 3（保留锚点 3）：游标 2 < 3+1 → 摘要保留
    const truncated = sessionService.truncateMessagesAfter('s_test', 'm3b', false);
    expect(truncated).toBe(true);
    expect(summaryService.getSummary('s_test')).not.toBeNull();

    // 分层加载：摘要 + rowid 3 原文（rowid 4 已删）
    const history = summaryService.buildHistoryMessages('s_test');
    expect(history.length).toBe(2);
    expect(history[1].content).toBe('消息 3b');
  });

  it('锚点消息不存在时返回 false 且不产生副作用', () => {
    const before = sessionService.getMessages('s_test').length;
    expect(sessionService.truncateMessagesAfter('s_test', 'not_exist', true)).toBe(false);
    expect(sessionService.getMessages('s_test').length).toBe(before);
  });
});