// The share link has to survive a chat client, a recipient whose saved settings
// differ from the sender's, and a version of the page older than the link.

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

import { buildFragment, readFragment, coerce } from './sharelink'

const DEFAULTS = {
  codetype: 'qr', errorcorrection: 'M', preset: 'zebra1x05',
  labelwidth: 1.0, labelheight: 0.5, dpi: 203, layout: 'side',
}

function state (extra = {}) {
  return { source: 'single', content: 'WJ-3204', ...DEFAULTS, ...extra }
}

describe('buildFragment', () => {
  it('carries what was typed', () => {
    const params = new URLSearchParams(buildFragment(state(), DEFAULTS).slice(1))
    expect(params.get('c')).toBe('WJ-3204')
    expect(params.get('s')).toBe('single')
  })

  it('leaves out layout values the sender never changed', () => {
    const fragment = buildFragment(state(), DEFAULTS)
    expect(fragment).not.toContain('labelwidth')
    expect(fragment).not.toContain('dpi')
  })

  it('carries a layout value the sender did change', () => {
    const fragment = buildFragment(state({ labelwidth: 2.0, dpi: 300 }), DEFAULTS)
    const params = new URLSearchParams(fragment.slice(1))
    expect(params.get('labelwidth')).toBe('2')
    expect(params.get('dpi')).toBe('300')
  })

  it('says nothing about one copy, which is what everybody has', () => {
    expect(buildFragment(state({ copies: 1 }), DEFAULTS)).not.toContain('n=')
    expect(buildFragment(state({ copies: 4 }), DEFAULTS)).toContain('n=4')
  })

  it('is empty when there is nothing to share', () => {
    // So the caller can disable its button rather than emit a bare '#'.
    expect(buildFragment({}, DEFAULTS)).toBe('')
  })

  it('never carries the picture', () => {
    // A data URL runs to megabytes; the link would not survive a chat box.
    const fragment = buildFragment(state({ pictureUrl: 'data:image/png;base64,AAAA' }), DEFAULTS)
    expect(fragment).not.toContain('data:image')
    expect(fragment).not.toContain('pictureUrl')
  })
})

describe('readFragment', () => {
  it('reads back what buildFragment wrote', () => {
    const sent = state({ content: 'Bay 310 / press 2', label: 'Press', copies: 3,
                         labelwidth: 2.0, layout: 'stack' })
    const back = readFragment(buildFragment(sent, DEFAULTS))
    expect(back.content).toBe('Bay 310 / press 2')
    expect(back.label).toBe('Press')
    expect(back.copies).toBe('3')
    expect(back.labelwidth).toBe('2')
    expect(back.layout).toBe('stack')
  })

  it('survives the characters people actually put in a label', () => {
    const awkward = 'CNC #4 & 5 - 50% duty, "spare"'
    const back = readFragment(buildFragment(state({ content: awkward }), DEFAULTS))
    expect(back.content).toBe(awkward)
  })

  it('ignores a key it does not know', () => {
    // A link made by a newer version must still open here, minus the parts
    // this version cannot use.
    const back = readFragment('#c=X&somethingnew=1')
    expect(back.content).toBe('X')
    expect(back.somethingnew).toBeUndefined()
  })

  it('is empty for an empty or absent fragment', () => {
    expect(readFragment('')).toEqual({})
    expect(readFragment('#')).toEqual({})
    expect(readFragment(undefined)).toEqual({})
  })
})

describe('coerce', () => {
  it('keeps a number a number', () => {
    // '0' + '2' is '02'; 0 + 2 is 2. The nudge fields are arithmetic.
    expect(coerce('2', 0)).toBe(2)
    expect(coerce('0.4286', 0.5)).toBeCloseTo(0.4286)
  })

  it('falls back to the current value when the link is nonsense', () => {
    expect(coerce('not-a-number', 203)).toBe(203)
  })

  it('reads a boolean back as a boolean', () => {
    expect(coerce('true', false)).toBe(true)
    expect(coerce('false', true)).toBe(false)
  })

  it('leaves a string alone', () => {
    expect(coerce('stack', 'side')).toBe('stack')
  })
})