import { describe, expect, it } from 'vitest'
import { FALLBACK_TERMINAL_FONT, parseMonospaceFont } from '../src/main/desktop'

describe('parseMonospaceFont', () => {
  it('splits a family from its size', () => {
    expect(parseMonospaceFont("'Ubuntu Mono 13'")).toEqual({
      family: '"Ubuntu Mono"',
      sizePx: 17.33,
    })
  })

  it('converts points to pixels', () => {
    // Pango reports points and CSS wants pixels: 1pt = 1/72in, 1px = 1/96in.
    // Getting this wrong makes the terminal a third too small, which reads as
    // "the font is wrong" rather than "the size is wrong".
    expect(parseMonospaceFont("'Monospace 12'")?.sizePx).toBe(16)
    expect(parseMonospaceFont("'Monospace 9'")?.sizePx).toBe(12)
    expect(parseMonospaceFont("'Monospace 10.5'")?.sizePx).toBe(14)
  })

  it('keeps multi-word families intact', () => {
    // The failure this guards against is the family being read as a font stack:
    // "Noto Sans Mono" is one family, not three.
    expect(parseMonospaceFont("'Noto Sans Mono 12'")?.family).toBe('"Noto Sans Mono"')
  })

  it('treats the trailing number as the size, not the first one', () => {
    // Families legitimately contain digits.
    expect(parseMonospaceFont("'Fira Code 2 12'")).toEqual({
      family: '"Fira Code 2"',
      sizePx: 16,
    })
  })

  it('accepts an unquoted description', () => {
    expect(parseMonospaceFont('Ubuntu Mono 13')).toEqual({
      family: '"Ubuntu Mono"',
      sizePx: 17.33,
    })
  })

  it('accepts a bare family name, sizing it with the default', () => {
    // Some desktops report only the family. Dropping it would be worse than
    // using a sensible size.
    expect(parseMonospaceFont("'Ubuntu Mono'")).toEqual({
      family: '"Ubuntu Mono"',
      sizePx: 13,
    })
  })

  it('strips quotes that would otherwise end up inside the CSS value', () => {
    expect(parseMonospaceFont(`"Ubuntu Mono 13"`)?.family).toBe('"Ubuntu Mono"')
  })

  it('rejects nonsense rather than producing a broken font string', () => {
    for (const bad of ['', '   ', "''", '0', 'DejaVu 0', 'DejaVu -3']) {
      const parsed = parseMonospaceFont(bad)
      // Either null, or a usable family — never a zero or negative size, which
      // xterm would take and render as nothing.
      if (parsed) expect(parsed.sizePx).toBeGreaterThan(0)
    }
    expect(parseMonospaceFont('')).toBeNull()
    expect(parseMonospaceFont('   ')).toBeNull()
  })

  it('never returns an empty family', () => {
    for (const input of ["'Ubuntu Mono 13'", 'Ubuntu Mono 13', "'X'", 'X 12']) {
      expect(parseMonospaceFont(input)?.family.length ?? 0).toBeGreaterThan(0)
    }
  })
})

describe('FALLBACK_TERMINAL_FONT', () => {
  it('asks the engine for the system monospace face', () => {
    // The same intent as the GSettings lookup, resolved one layer down — so a
    // desktop that will not answer still gets a sensible font.
    expect(FALLBACK_TERMINAL_FONT.family).toContain('ui-monospace')
    expect(FALLBACK_TERMINAL_FONT.family).toContain('monospace')
    expect(FALLBACK_TERMINAL_FONT.sizePx).toBeGreaterThan(0)
  })
})