/**
 * Tests for filename generation utilities
 */

import { describe, it, expect } from 'vitest';
import { generateScreenshotFilename, slugifyCaption } from './filename.js';

describe('generateScreenshotFilename', () => {
  it('formats UTC timestamp correctly', () => {
    const date = new Date('2026-01-15T14:30:45Z');
    expect(generateScreenshotFilename(date))
      .toBe('screenshot-2026-01-15-14-30-45-Z.jpg');
  });

  it('pads single digits with zeros', () => {
    const date = new Date('2026-01-05T08:09:03Z');
    expect(generateScreenshotFilename(date))
      .toBe('screenshot-2026-01-05-08-09-03-Z.jpg');
  });

  it('handles midnight correctly', () => {
    const date = new Date('2026-12-31T00:00:00Z');
    expect(generateScreenshotFilename(date))
      .toBe('screenshot-2026-12-31-00-00-00-Z.jpg');
  });

  it('includes slugified caption in filename', () => {
    const date = new Date('2026-01-15T14:30:45Z');
    expect(generateScreenshotFilename(date, 'Main Menu Screenshot'))
      .toBe('screenshot-2026-01-15-14-30-45-Z-main-menu-screenshot.jpg');
  });

  it('truncates long captions to 25 chars', () => {
    const date = new Date('2026-01-15T14:30:45Z');
    expect(generateScreenshotFilename(date, 'This is a very long caption that should be truncated'))
      .toBe('screenshot-2026-01-15-14-30-45-Z-this-is-a-very-long-capti.jpg');
  });

  it('omits slug when no caption provided', () => {
    const date = new Date('2026-01-15T14:30:45Z');
    expect(generateScreenshotFilename(date))
      .toBe('screenshot-2026-01-15-14-30-45-Z.jpg');
  });

  it('generates filename with current time when no date provided', () => {
    const filename = generateScreenshotFilename();

    // Verify format is correct
    expect(filename).toMatch(/^screenshot-\d{4}-\d{2}-\d{2}-\d{2}-\d{2}-\d{2}-Z\.jpg$/);

    // Extract timestamp from filename
    const match = filename.match(/^screenshot-(\d{4})-(\d{2})-(\d{2})-(\d{2})-(\d{2})-(\d{2})-Z\.jpg$/);
    expect(match).not.toBeNull();

    if (match) {
      const [, year, month, day, hours, minutes, seconds] = match;
      const filenameDate = new Date(Date.UTC(
        parseInt(year),
        parseInt(month) - 1,
        parseInt(day),
        parseInt(hours),
        parseInt(minutes),
        parseInt(seconds)
      ));

      // Verify the timestamp is reasonable (within last minute)
      const now = new Date();
      const diff = now.getTime() - filenameDate.getTime();
      expect(diff).toBeGreaterThanOrEqual(0);
      expect(diff).toBeLessThan(60000); // Within last 60 seconds
    }
  });
});

describe('slugifyCaption', () => {
  it('lowercases and replaces spaces with dashes', () => {
    expect(slugifyCaption('Main Menu')).toBe('main-menu');
  });

  it('replaces non-alphanumeric with dashes', () => {
    expect(slugifyCaption('Hello, World! #1')).toBe('hello-world-1');
  });

  it('collapses consecutive dashes', () => {
    expect(slugifyCaption('foo---bar')).toBe('foo-bar');
  });

  it('trims leading and trailing dashes', () => {
    expect(slugifyCaption('--hello--')).toBe('hello');
  });

  it('truncates to 25 chars without trailing dash', () => {
    expect(slugifyCaption('this is a very long caption that exceeds')).toBe('this-is-a-very-long-capti');
  });
});