import { describe, it, expect } from 'vitest'
import {
  generateOgImage,
  generateOgSvg,
  wrapText,
  escapeXml,
} from '../../../src/services/og-image.js'

// ===========================================================================
// escapeXml
// ===========================================================================

describe('escapeXml', () => {
  it('escapes ampersands', () => {
    expect(escapeXml('A & B')).toBe('A & B')
  })

  it('escapes angle brackets', () => {
    expect(escapeXml("<script>alert('xss')</script>")).toBe(
      '&lt;script&gt;alert(&apos;xss&apos;)&lt;/script&gt;'
    )
  })

  it('escapes quotes', () => {
    expect(escapeXml('He said "hello"')).toBe('He said &quot;hello&quot;')
  })

  it('returns empty string unchanged', () => {
    expect(escapeXml('')).toBe('')
  })

  it('returns plain text unchanged', () => {
    expect(escapeXml('Hello World')).toBe('Hello World')
  })
})

// ===========================================================================
// wrapText
// ===========================================================================

describe('wrapText', () => {
  it('returns single line when text fits', () => {
    const result = wrapText('Short title', 40, 3)
    expect(result).toEqual(['Short title'])
  })

  it('wraps text at word boundaries', () => {
    const result = wrapText('This is a longer title that should wrap', 20, 3)
    expect(result.length).toBeGreaterThan(1)
    // Each line should be at most 20 characters (approximately)
    for (const line of result) {
      // Allow some overflow for long words
      expect(line.length).toBeLessThanOrEqual(25)
    }
  })

  it('limits to maxLines', () => {
    const longText = 'word '.repeat(50).trim()
    const result = wrapText(longText, 20, 3)
    expect(result.length).toBeLessThanOrEqual(3)
  })

  it('adds ellipsis when text is truncated', () => {
    const longText = 'word '.repeat(50).trim()
    const result = wrapText(longText, 20, 2)
    const lastLine = result[result.length - 1]
    expect(lastLine).toContain('\u2026')
  })

  it('handles empty string', () => {
    const result = wrapText('', 40, 3)
    expect(result).toEqual([])
  })

  it('handles single long word', () => {
    const result = wrapText('Supercalifragilisticexpialidocious', 10, 3)
    expect(result.length).toBeGreaterThanOrEqual(1)
  })
})

// ===========================================================================
// generateOgSvg
// ===========================================================================

describe('generateOgSvg', () => {
  it('returns valid SVG string with correct dimensions', () => {
    const svg = generateOgSvg({
      title: 'My Topic',
      category: 'general',
      communityName: 'Test Community',
    })

    expect(svg).toContain('width="1200"')
    expect(svg).toContain('height="630"')
    expect(svg).toContain('xmlns=')
  })

  it('includes the topic title', () => {
    const svg = generateOgSvg({
      title: 'My Amazing Topic',
      category: 'general',
      communityName: 'Test Community',
    })

    expect(svg).toContain('My Amazing Topic')
  })

  it('includes the category name', () => {
    const svg = generateOgSvg({
      title: 'Topic',
      category: 'announcements',
      communityName: 'Test Community',
    })

    expect(svg).toContain('ANNOUNCEMENTS')
  })

  it('includes the community name', () => {
    const svg = generateOgSvg({
      title: 'Topic',
      category: 'general',
      communityName: 'My Forum',
    })

    expect(svg).toContain('My Forum')
  })

  it('includes Barazo branding', () => {
    const svg = generateOgSvg({
      title: 'Topic',
      category: 'general',
      communityName: 'Test Community',
    })

    expect(svg).toContain('barazo.forum')
  })

  it('escapes special characters in title', () => {
    const svg = generateOgSvg({
      title: 'Using <script> & "quotes"',
      category: 'general',
      communityName: 'Test Community',
    })

    expect(svg).not.toContain('<script>')
    expect(svg).toContain('&lt;script&gt;')
    expect(svg).toContain('&amp;')
  })

  it('escapes special characters in category', () => {
    const svg = generateOgSvg({
      title: 'Topic',
      category: 'Q&A',
      communityName: 'Test Community',
    })

    expect(svg).toContain('Q&amp;A')
  })

  it('wraps long titles across multiple lines', () => {
    const longTitle =
      'This is a very long topic title that should definitely wrap across multiple lines in the SVG'
    const svg = generateOgSvg({
      title: longTitle,
      category: 'general',
      communityName: 'Test Community',
    })

    // Multiple <text> elements for the title lines
    const titleTextMatches = svg.match(/<text[^>]*font-size="48"[^>]*>/g)
    expect(titleTextMatches).not.toBeNull()
    expect(titleTextMatches?.length).toBeGreaterThan(1)
  })
})

// ===========================================================================
// generateOgImage
// ===========================================================================

describe('generateOgImage', () => {
  it('returns a PNG buffer', async () => {
    const buffer = await generateOgImage({
      title: 'Test Topic',
      category: 'general',
      communityName: 'Test Community',
    })

    expect(buffer).toBeInstanceOf(Buffer)
    // PNG magic bytes: 0x89 0x50 0x4E 0x47
    expect(buffer[0]).toBe(0x89)
    expect(buffer[1]).toBe(0x50) // P
    expect(buffer[2]).toBe(0x4e) // N
    expect(buffer[3]).toBe(0x47) // G
  })

  it('produces an image under 1MB (Bluesky blob limit)', async () => {
    const buffer = await generateOgImage({
      title: 'A topic with a reasonably long title for testing size',
      category: 'discussions',
      communityName: 'A Community With a Long Name',
    })

    expect(buffer.length).toBeLessThan(1_000_000)
  })
})