/**
 * DiffViewerTool 单元测试（P1-14 测试基线）
 * 覆盖：LCS diff 计算（text 模式，不触文件系统）
 */

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

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

import { DiffViewerTool } from '../diff-viewer';
import type { ToolExecutionContext } from '../../../types/metona-tool';

const context: ToolExecutionContext = {
  sessionId: 'test',
  workspacePath: process.cwd(),
  iteration: 1,
  requestId: 'req_test',
};

interface DiffResult {
  success: boolean;
  error?: string;
  diff?: string;
  summary?: { lines_added: number; lines_removed: number; total_changes: number; similarity: number };
}

describe('DiffViewerTool（text 模式）', () => {
  const tool = new DiffViewerTool();

  it('两段文本生成统一 diff（成功）', async () => {
    const result = await tool.execute(
      { mode: 'text', text_a: 'line1\nline2\nline3', text_b: 'line1\nline2-changed\nline3' },
      context,
    ) as DiffResult;
    expect(result.success).toBe(true);
    expect(result.diff).toContain('-line2');
    expect(result.diff).toContain('+line2-changed');
    expect(result.summary?.total_changes).toBe(2);
  });

  it('相同文本返回无差异', async () => {
    const result = await tool.execute(
      { mode: 'text', text_a: 'same\nsame', text_b: 'same\nsame' },
      context,
    ) as DiffResult;
    expect(result.success).toBe(true);
    expect(result.summary?.total_changes).toBe(0);
    expect(result.summary?.similarity).toBe(1);
  });

  it('无效 mode 返回错误', async () => {
    const result = await tool.execute({ mode: 'invalid' }, context) as DiffResult;
    expect(result.success).toBe(false);
    expect(result.error).toContain('Invalid mode');
  });

  it('插入与删除均正确计算', async () => {
    const result = await tool.execute(
      { mode: 'text', text_a: 'a\nb\nc', text_b: 'a\nx\nb\nc\nd' },
      context,
    ) as DiffResult;
    expect(result.success).toBe(true);
    expect(result.diff).toContain('+x');
    expect(result.diff).toContain('+d');
    expect(result.summary?.lines_added).toBe(2);
  });
});