import { computed, reactive, readonly, ref } from 'vue'

export interface QrCodePopupOptions {
  /**
   * Confirm callback for "Copy link" action.
   * Will be called when user clicks the primary button.
   */
  onCopyLink?: (link: string) => void
}

export interface QrCodePopupState {
  visible: boolean
  skillId: string
  skillName: string
  skillIcon: string
  price: number
  unit: string
  currencyAmount: number
  /** Generated QR code content/URL */
  qrcodeValue: string
  /** 当前激活的 tab：通用码 or 特定码 */
  activeTab: 'general' | 'specific'
  /** 特定码的内部状态：表单 or 预览二维码 */
  specificStep: 'form' | 'preview'
  /** 特定码 - 服务时长 */
  specificQty: number
}

const state = reactive<QrCodePopupState>({
  visible: false,
  skillId: '',
  skillName: '',
  skillIcon: '',
  price: 0,
  unit: '',
  currencyAmount: 0,
  qrcodeValue: '',
  activeTab: 'general',
  specificStep: 'form',
  specificQty: 1,
})

const copyHandler = ref<((link: string) => void) | null>(null)

const formattedPrice = computed(() => state.price.toLocaleString())
const currencyAmount = computed(() => state.currencyAmount.toLocaleString())

const isGeneralTab = computed(() => state.activeTab === 'general')
const isSpecificForm = computed(
  () => state.activeTab === 'specific' && state.specificStep === 'form',
)
const isSpecificPreview = computed(
  () => state.activeTab === 'specific' && state.specificStep === 'preview',
)

const open = (options: QrCodePopupOptions) => {
  state.qrcodeValue = '' // Reset on open

  // reset tab & specific state every time open
  state.activeTab = 'general'
  state.specificStep = 'form'
  state.specificQty = 1

  copyHandler.value = options.onCopyLink ?? null

  state.visible = true
}

const close = () => {
  state.visible = false
}

const switchTab = (tab: 'general' | 'specific') => {
  state.activeTab = tab

  // 切回通用码时，重置特定码到表单态
  if (tab === 'general') {
    state.specificStep = 'form'
  }
}

const resetSpecificStep = () => {
  state.specificStep = 'form'
}

const setSpecificQty = (value: number) => {
  const next = value || 1
  state.specificQty = next < 1 ? 1 : next
}

const generateSpecificQr = () => {
  state.specificStep = 'preview'
}

const updateQrcodeValue = (value: string) => {
  state.qrcodeValue = value
}

const updateCurrencyAmount = (value: number) => {
  state.currencyAmount = value
}

const updateSkillInfo = (info: { skillId: string, skillName: string, skillIcon: string, price: number, unit: string }) => {
  state.skillId = info.skillId
  state.skillName = info.skillName
  state.skillIcon = info.skillIcon
  state.price = info.price
  state.unit = info.unit
}

const handleCopyLink = () => {
  const handler = copyHandler.value
  if (handler) handler(state.qrcodeValue)
}

export const useQrCodePopup = () => {
  return {
    state: readonly(state),
    formattedPrice,
    currencyAmount,
    isGeneralTab,
    isSpecificForm,
    isSpecificPreview,
    open,
    close,
    switchTab,
    setSpecificQty,
    generateSpecificQr,
    handleCopyLink,
    updateQrcodeValue,
    updateCurrencyAmount,
    updateSkillInfo,
    resetSpecificStep,
  }
}