import { describe, expect, it } from 'vitest'
import {
  ean13CheckDigit, isValidEan13,
  parseScaleBarcode, type ScaleBarcodeProfile,
  parseEntry,
  WedgeDetector,
} from '@sims/scanning'

describe('EAN-13', () => {
  it('computes and validates check digits', () => {
    expect(ean13CheckDigit('400638133393')).toBe(1)
    expect(isValidEan13('4006381333931')).toBe(true)
    expect(isValidEan13('4006381333932')).toBe(false)
    expect(isValidEan13('123')).toBe(false)
  })
})

describe('label-scale barcodes (2x prefix)', () => {
  const profile: ScaleBarcodeProfile = {
    prefixes: ['21'],
    pluLength: 5,
    valueKind: 'weight',
    valueDivisor: 1000,
  }
  const body = '210004201250' // prefix 21 · PLU 00042 · 1250 g
  const code = body + String(ean13CheckDigit(body))

  it('extracts PLU and weight as quantity', () => {
    expect(parseScaleBarcode(code, profile)).toEqual({ kind: 'scale-weight', plu: '00042', qty: 1.25 })
  })
  it('rejects a corrupted check digit instead of guessing a weight', () => {
    const bad = body + String((ean13CheckDigit(body) + 1) % 10)
    expect(parseScaleBarcode(bad, profile)).toEqual({ kind: 'invalid', reason: 'check-digit' })
  })
  it('passes non-scale codes through untouched', () => {
    expect(parseScaleBarcode('4006381333931', profile)).toEqual({ kind: 'not-scale' })
  })
  it('supports price-embedded profiles', () => {
    const priceProfile: ScaleBarcodeProfile = { ...profile, valueKind: 'price', valueDivisor: 1 }
    expect(parseScaleBarcode(code, priceProfile)).toEqual({
      kind: 'scale-price',
      plu: '00042',
      pricePaise: 1250,
    })
  })
})

describe('scan-box entry grammar', () => {
  it('parses the four grammars without modes', () => {
    expect(parseEntry('')).toEqual({ kind: 'empty' })
    expect(parseEntry('3*')).toEqual({ kind: 'multiplier', qty: 3, rest: '' })
    expect(parseEntry('1.5*atta')).toEqual({ kind: 'multiplier', qty: 1.5, rest: 'atta' })
    expect(parseEntry('4006381333931')).toEqual({ kind: 'barcode', code: '4006381333931' })
    expect(parseEntry('42')).toEqual({ kind: 'code', code: '42' })
    expect(parseEntry('chawal')).toEqual({ kind: 'search', text: 'chawal' })
  })
})

describe('wedge detector — scanner vs human, by timing', () => {
  it('classifies a fast burst as a scan', () => {
    const d = new WedgeDetector()
    '4006381333931'.split('').forEach((c, i) => d.feed(c, i * 10))
    expect(d.terminate()).toEqual({ type: 'scan', code: '4006381333931' })
  })
  it('classifies human-speed typing as typed input', () => {
    const d = new WedgeDetector()
    '400638'.split('').forEach((c, i) => d.feed(c, i * 120))
    expect(d.terminate()).toEqual({ type: 'typed', text: '400638' })
  })
  it('treats short fast bursts as typed (quick-key PLUs)', () => {
    const d = new WedgeDetector()
    '42'.split('').forEach((c, i) => d.feed(c, i * 5))
    expect(d.terminate()).toEqual({ type: 'typed', text: '42' })
  })
  it('resets cleanly between bursts', () => {
    const d = new WedgeDetector()
    d.feed('9', 0)
    d.terminate()
    '4006381333931'.split('').forEach((c, i) => d.feed(c, 1000 + i * 10))
    expect(d.terminate().type).toBe('scan')
  })
})