import { i18n, SUPPORTED_LOCALES } from '../i18n'

type MatomoWindow = Window & { _paq?: unknown[][] }
type EventCategory = '欢迎页' | '页面导航' | '时间轴' | '系统设置' | '属性面板' | '使用说明'
type EventAction = '点击按钮' | '点击开关' | '调整数值' | '点击下载'
type MessageTree = Record<string, unknown>

let chineseLabels: Map<string, string> | null = null

function flattenMessages(value: unknown, prefix = '', output: Record<string, string> = {}) {
  if (!value || typeof value !== 'object') return output
  for (const [key, child] of Object.entries(value as MessageTree)) {
    const path = prefix ? `${prefix}.${key}` : key
    if (typeof child === 'string') output[path] = child
    else flattenMessages(child, path, output)
  }
  return output
}

function localizedToChinese(value: string | null | undefined) {
  const label = value?.replace(/\s+/g, ' ').trim()
  if (!label) return ''
  if (!chineseLabels) {
    chineseLabels = new Map()
    const chinese = flattenMessages(i18n.global.getLocaleMessage('zh-CN'))
    for (const locale of SUPPORTED_LOCALES) {
      const messages = flattenMessages(i18n.global.getLocaleMessage(locale.code))
      for (const [key, text] of Object.entries(messages)) {
        const translated = chinese[key]
        if (translated) chineseLabels.set(text.replace(/\s+/g, ' ').trim(), translated)
      }
    }
  }
  return chineseLabels.get(label) || ''
}

function categoryFor(element: Element): EventCategory {
  const section = element.closest<HTMLElement>('[data-matomo-section]')?.dataset.matomoSection
  if (section === 'welcome') return '欢迎页'
  if (section === 'timeline') return '时间轴'
  if (section === 'settings') return '系统设置'
  return '属性面板'
}

function controlName(control: Element, fallback: string) {
  const candidates = [
    (control as HTMLElement).dataset.matomoName,
    control.closest<HTMLElement>('[data-matomo-name]')?.dataset.matomoName,
    control.getAttribute('aria-label'),
    control.getAttribute('title'),
    control.textContent,
    control.closest('label')?.textContent,
    control.parentElement?.querySelector('.ns-label, .pac-label')?.textContent,
  ]
  for (const candidate of candidates) {
    const chinese = localizedToChinese(candidate)
    if (chinese) return chinese
  }
  return fallback
}

function buttonName(button: HTMLButtonElement) {
  const section = button.closest('[data-matomo-section]') || document
  const className = [...button.classList]
    .filter((name) => !['active', 'collapsed', 'danger', 'ghost', 'off', 'on', 'primary', 'selected'].includes(name))
    .sort()
    .join('-') || button.type || 'button'
  const peers = [...section.querySelectorAll<HTMLButtonElement>('button')]
    .filter((peer) => ([...peer.classList]
      .filter((name) => !['active', 'collapsed', 'danger', 'ghost', 'off', 'on', 'primary', 'selected'].includes(name))
      .sort()
      .join('-') || peer.type || 'button') === className)
  return controlName(button, `按钮${Math.max(1, peers.indexOf(button) + 1)}`)
}

export function trackMatomoEvent(category: EventCategory, action: EventAction, name: string) {
  if (!import.meta.env.PROD) return
  const target = window as MatomoWindow
  ;(target._paq ||= []).push(['trackEvent', category, action, name])
}

export function trackMatomoPageView() {
  if (!import.meta.env.PROD) return
  const target = window as MatomoWindow
  ;(target._paq ||= []).push(
    ['setCustomUrl', window.location.href],
    ['setDocumentTitle', document.title],
    ['trackPageView'],
  )
}

export function installMatomoEventTracking() {
  if (!import.meta.env.PROD) return
  document.addEventListener('click', (event) => {
    const target = event.target
    if (!(target instanceof Element)) return
    const download = target.closest<HTMLAnchorElement>('a[data-matomo-category][data-matomo-action][data-matomo-name]')
    if (download) {
      trackMatomoEvent(
        download.dataset.matomoCategory as EventCategory,
        download.dataset.matomoAction as EventAction,
        download.dataset.matomoName || '',
      )
      return
    }
    const tracked = target.closest<HTMLElement>('[data-matomo-event]')
    if (tracked) {
      const category = tracked.dataset.matomoCategory as EventCategory | undefined
      const action = tracked.dataset.matomoAction as EventAction | undefined
      trackMatomoEvent(category || categoryFor(tracked), action || '点击按钮', tracked.dataset.matomoEvent || '')
      return
    }
    const button = target.closest<HTMLButtonElement>('button')
    if (!button) return
    trackMatomoEvent(categoryFor(button), '点击按钮', buttonName(button))
  }, true)

  document.addEventListener('change', (event) => {
    const target = event.target
    if (!(target instanceof HTMLInputElement)) return
    if (target.type === 'checkbox') {
      const name = controlName(target, '开关')
      trackMatomoEvent(categoryFor(target), '点击开关', `${name}=${target.checked ? '开启' : '关闭'}`)
      return
    }
    if (target.type !== 'range' && target.type !== 'number') return
    const pairedRange = target.type === 'range'
      || !!target.parentElement?.querySelector('input[type="range"]')
    if (!pairedRange) return
    const name = controlName(target, '数值')
    trackMatomoEvent(categoryFor(target), '调整数值', `${name}=${target.value}`)
  }, true)
}