import { describe, it, expect, vi, beforeEach } from 'vitest';
import {
  computeDiff,
  formatDiff,
  countChanges,
  formatEditDiff,
  confirmFileChange,
} from '../../../src/utils/diff.js';

// Mock readline
vi.mock('readline', () => ({
  createInterface: vi.fn(() => ({
    question: vi.fn(),
    close: vi.fn(),
  })),
}));

// Mock fs/promises
vi.mock('fs/promises', () => ({
  readFile: vi.fn(),
}));

// Mock chalk (保留原始功能以便测试输出格式)
vi.mock('chalk', () => ({
  default: {
    yellow: (s: string) => `[yellow]${s}[/yellow]`,
    cyan: (s: string) => `[cyan]${s}[/cyan]`,
    white: (s: string) => `[white]${s}[/white]`,
    gray: (s: string) => `[gray]${s}[/gray]`,
    red: (s: string) => `[red]${s}[/red]`,
    green: (s: string) => `[green]${s}[/green]`,
  },
}));

import * as readline from 'readline';
import * as fs from 'fs/promises';

describe('Diff - 差异比较扩展测试', () => {
  describe('computeDiff - 计算 diff', () => {
    it('新文件所有行都是添加', () => {
      const diff = computeDiff(null, 'line1\nline2\nline3');

      expect(diff.isNew).toBe(true);
      expect(diff.oldContent).toBeNull();
      expect(diff.hunks.length).toBe(1);
      expect(diff.hunks[0].lines.every(l => l.type === 'add')).toBe(true);
      expect(diff.hunks[0].newCount).toBe(3);
    });

    it('相同内容返回空 hunks', () => {
      const content = 'line1\nline2\nline3';
      const diff = computeDiff(content, content);

      expect(diff.isNew).toBe(false);
      // 相同内容可能没有实际变化的 hunks
      const hasChanges = diff.hunks.some(h =>
        h.lines.some(l => l.type === 'add' || l.type === 'remove')
      );
      expect(hasChanges).toBe(false);
    });

    it('检测添加的行', () => {
      const oldContent = 'line1\nline2';
      const newContent = 'line1\nline2\nline3';
      const diff = computeDiff(oldContent, newContent);

      expect(diff.isNew).toBe(false);
      const addedLines = diff.hunks.flatMap(h => h.lines.filter(l => l.type === 'add'));
      expect(addedLines.some(l => l.content === 'line3')).toBe(true);
    });

    it('检测删除的行', () => {
      const oldContent = 'line1\nline2\nline3';
      const newContent = 'line1\nline2';
      const diff = computeDiff(oldContent, newContent);

      const removedLines = diff.hunks.flatMap(h => h.lines.filter(l => l.type === 'remove'));
      expect(removedLines.some(l => l.content === 'line3')).toBe(true);
    });

    it('检测修改的行（删除+添加）', () => {
      const oldContent = 'line1\nold line\nline3';
      const newContent = 'line1\nnew line\nline3';
      const diff = computeDiff(oldContent, newContent);

      const removedLines = diff.hunks.flatMap(h => h.lines.filter(l => l.type === 'remove'));
      const addedLines = diff.hunks.flatMap(h => h.lines.filter(l => l.type === 'add'));

      expect(removedLines.some(l => l.content === 'old line')).toBe(true);
      expect(addedLines.some(l => l.content === 'new line')).toBe(true);
    });

    it('处理空文件', () => {
      const diff = computeDiff('', 'new content');

      expect(diff.isNew).toBe(false);
      // 空到有内容是添加
      const addedLines = diff.hunks.flatMap(h => h.lines.filter(l => l.type === 'add'));
      expect(addedLines.length).toBeGreaterThan(0);
    });

    it('处理多个不连续的变更', () => {
      const oldContent = 'line1\nkeep1\nold2\nkeep2\nold3\nline6';
      const newContent = 'line1\nkeep1\nnew2\nkeep2\nnew3\nline6';
      const diff = computeDiff(oldContent, newContent);

      // 应该有变更
      const changes = diff.hunks.flatMap(h =>
        h.lines.filter(l => l.type === 'add' || l.type === 'remove')
      );
      expect(changes.length).toBeGreaterThan(0);
    });

    it('处理完全不同的内容', () => {
      const oldContent = 'completely\ndifferent\ncontent';
      const newContent = 'totally\nnew\nstuff';
      const diff = computeDiff(oldContent, newContent);

      expect(diff.hunks.length).toBeGreaterThan(0);
    });
  });

  describe('formatDiff - 格式化 diff', () => {
    it('新文件显示 +++ 新文件标记', () => {
      const diff = computeDiff(null, 'new content');
      const formatted = formatDiff(diff, '/test/file.ts');

      expect(formatted).toContain('新文件');
      expect(formatted).toContain('/test/file.ts');
    });

    it('修改文件显示 --- 和 +++ 标记', () => {
      const diff = computeDiff('old', 'new');
      const formatted = formatDiff(diff, '/test/file.ts');

      expect(formatted).toContain('原文件');
      expect(formatted).toContain('修改后');
    });

    it('显示 hunk 头部 @@ 信息', () => {
      const diff = computeDiff('old', 'new');
      const formatted = formatDiff(diff, '/test/file.ts');

      expect(formatted).toContain('@@');
    });

    it('添加行使用 + 前缀', () => {
      const diff = computeDiff('', 'added line');
      const formatted = formatDiff(diff, '/test/file.ts');

      expect(formatted).toContain('+ added line');
    });

    it('删除行使用 - 前缀', () => {
      const diff = computeDiff('removed line', '');
      const formatted = formatDiff(diff, '/test/file.ts');

      expect(formatted).toContain('- removed line');
    });
  });

  describe('countChanges - 统计变更', () => {
    it('统计添加行数', () => {
      const diff = computeDiff(null, 'line1\nline2\nline3');
      const changes = countChanges(diff);

      expect(changes.additions).toBe(3);
      expect(changes.deletions).toBe(0);
    });

    it('统计删除行数', () => {
      const diff = computeDiff('line1\nline2\nline3', '');
      const changes = countChanges(diff);

      expect(changes.deletions).toBe(3);
    });

    it('统计混合变更', () => {
      const diff = computeDiff('old1\nold2', 'new1\nold2\nnew2');
      const changes = countChanges(diff);

      // 具体数字取决于 diff 算法实现
      expect(changes.additions).toBeGreaterThanOrEqual(0);
      expect(changes.deletions).toBeGreaterThanOrEqual(0);
    });

    it('无变更返回零', () => {
      const diff = computeDiff('same', 'same');
      const changes = countChanges(diff);

      expect(changes.additions + changes.deletions).toBe(0);
    });
  });

  describe('formatEditDiff - 编辑 diff 格式化', () => {
    it('显示删除和添加内容', () => {
      const formatted = formatEditDiff('old text', 'new text');

      expect(formatted).toContain('old text');
      expect(formatted).toContain('new text');
      expect(formatted).toContain('-');
      expect(formatted).toContain('+');
    });

    it('处理多行内容', () => {
      const formatted = formatEditDiff('old1\nold2', 'new1\nnew2');

      expect(formatted).toContain('old1');
      expect(formatted).toContain('old2');
      expect(formatted).toContain('new1');
      expect(formatted).toContain('new2');
    });

    it('包含变更内容标题', () => {
      const formatted = formatEditDiff('old', 'new');

      expect(formatted).toContain('变更内容');
    });
  });

  describe('confirmFileChange - 文件变更确认', () => {
    let consoleLogSpy: ReturnType<typeof vi.spyOn>;

    beforeEach(() => {
      vi.clearAllMocks();
      consoleLogSpy = vi.spyOn(console, 'log').mockImplementation(() => {});
    });

    it('内容相同直接返回确认', async () => {
      vi.mocked(fs.readFile).mockResolvedValue('same content');

      const result = await confirmFileChange('/test/file.ts', 'same content', 'write');

      expect(result.confirmed).toBe(true);
      expect(result.remember).toBe(false);
    });

    it('新文件（读取失败）显示 diff', async () => {
      vi.mocked(fs.readFile).mockRejectedValue(new Error('ENOENT'));

      const mockRl = {
        question: vi.fn((_, callback) => callback('y')),
        close: vi.fn(),
      };
      vi.mocked(readline.createInterface).mockReturnValue(mockRl as any);

      const result = await confirmFileChange('/test/file.ts', 'new content', 'write');

      expect(result.confirmed).toBe(true);
    });

    it('用户输入 y 确认写入', async () => {
      vi.mocked(fs.readFile).mockResolvedValue('old content');

      const mockRl = {
        question: vi.fn((_, callback) => callback('y')),
        close: vi.fn(),
      };
      vi.mocked(readline.createInterface).mockReturnValue(mockRl as any);

      const result = await confirmFileChange('/test/file.ts', 'new content', 'write');

      expect(result.confirmed).toBe(true);
      expect(result.remember).toBe(false);
    });

    it('用户输入 Y 确认并记住', async () => {
      vi.mocked(fs.readFile).mockResolvedValue('old content');

      const mockRl = {
        question: vi.fn((_, callback) => callback('Y')),
        close: vi.fn(),
      };
      vi.mocked(readline.createInterface).mockReturnValue(mockRl as any);

      const result = await confirmFileChange('/test/file.ts', 'new content', 'write');

      expect(result.confirmed).toBe(true);
      expect(result.remember).toBe(true);
    });

    it('用户输入 n 取消操作', async () => {
      vi.mocked(fs.readFile).mockResolvedValue('old content');

      const mockRl = {
        question: vi.fn((_, callback) => callback('n')),
        close: vi.fn(),
      };
      vi.mocked(readline.createInterface).mockReturnValue(mockRl as any);

      const result = await confirmFileChange('/test/file.ts', 'new content', 'write');

      expect(result.confirmed).toBe(false);
      expect(result.remember).toBe(false);
    });

    it('用户输入 N 取消并记住', async () => {
      vi.mocked(fs.readFile).mockResolvedValue('old content');

      const mockRl = {
        question: vi.fn((_, callback) => callback('N')),
        close: vi.fn(),
      };
      vi.mocked(readline.createInterface).mockReturnValue(mockRl as any);

      const result = await confirmFileChange('/test/file.ts', 'new content', 'write');

      expect(result.confirmed).toBe(false);
      expect(result.remember).toBe(true);
    });

    it('无效输入默认取消', async () => {
      vi.mocked(fs.readFile).mockResolvedValue('old content');

      const mockRl = {
        question: vi.fn((_, callback) => callback('invalid')),
        close: vi.fn(),
      };
      vi.mocked(readline.createInterface).mockReturnValue(mockRl as any);

      const result = await confirmFileChange('/test/file.ts', 'new content', 'write');

      expect(result.confirmed).toBe(false);
      expect(result.remember).toBe(false);
    });

    it('显示变更预览信息', async () => {
      vi.mocked(fs.readFile).mockResolvedValue('old content');

      const mockRl = {
        question: vi.fn((_, callback) => callback('y')),
        close: vi.fn(),
      };
      vi.mocked(readline.createInterface).mockReturnValue(mockRl as any);

      await confirmFileChange('/test/file.ts', 'new content', 'write');

      const output = consoleLogSpy.mock.calls.flat().join('\n');
      expect(output).toContain('文件变更预览');
      expect(output).toContain('写入文件');
      expect(output).toContain('/test/file.ts');
    });

    it('显示编辑操作类型', async () => {
      vi.mocked(fs.readFile).mockResolvedValue('old content');

      const mockRl = {
        question: vi.fn((_, callback) => callback('y')),
        close: vi.fn(),
      };
      vi.mocked(readline.createInterface).mockReturnValue(mockRl as any);

      await confirmFileChange('/test/file.ts', 'new content', 'edit');

      const output = consoleLogSpy.mock.calls.flat().join('\n');
      expect(output).toContain('编辑文件');
    });

    afterEach(() => {
      consoleLogSpy.mockRestore();
    });
  });
});