import { onUnmounted, reactive, readonly, watch } from 'vue'
import { useBaseConstsStore } from '~/stores/baseConsts'
import type { BaseConstsConfig } from '~/types/api'

export interface FindPartnerTag {
  id: string
  /**
   * i18n key for the tag label
   */
  labelKey: string
}

export interface FindPartnerSection {
  id: 'gender' | 'age' | 'region' | 'rating' | 'price'
  /**
   * i18n key for the section title
   */
  titleKey: string
  tags: FindPartnerTag[]
}

export interface FindPartnerPopupState {
  visible: boolean
  sections: FindPartnerSection[]
  /** 每个 section 当前选中的 tag id，未选中则为 undefined */
  selected: Record<FindPartnerSection['id'], string | undefined>
}

export interface FindPartnerFilterPayload {
  /** 后端 gender 参数 */
  gender: number
  /** 后端 ageRange 参数 */
  ageRange: number
  /** 后端 areCode 参数 */
  areCode: string
  /** 后端 priceRange 参数 */
  priceRange: number
  /** 后端 sortByStar 参数（结合弹窗与外部排序） */
  sortByStar: number
}

const initialSelected: FindPartnerPopupState['selected'] = {
  gender: 'unlimited',
  age: 'unlimited',
  region: '',
  rating: 'unlimited',
  price: 'unlimited',
}

const state = reactive<FindPartnerPopupState>({
  visible: false,
  sections: [
    {
      id: 'gender',
      titleKey: 'home.findPartner.sections.gender.title',
      tags: [
        {
          id: 'unlimited',
          labelKey: 'home.findPartner.sections.gender.tags.unlimited',
        },
        {
          id: 'male',
          labelKey: 'home.findPartner.sections.gender.tags.male',
        },
        {
          id: 'female',
          labelKey: 'home.findPartner.sections.gender.tags.female',
        },
      ],
    },
    {
      id: 'age',
      titleKey: 'home.findPartner.sections.age.title',
      tags: [
        {
          id: 'unlimited',
          labelKey: 'home.findPartner.sections.age.tags.unlimited',
        },
        {
          id: '15-25',
          labelKey: 'home.findPartner.sections.age.tags.range_15_25',
        },
        {
          id: '25-35',
          labelKey: 'home.findPartner.sections.age.tags.range_25_35',
        },
        {
          id: '35+',
          labelKey: 'home.findPartner.sections.age.tags.range_35_plus',
        },
      ],
    },
    {
      id: 'region',
      titleKey: 'home.findPartner.sections.region.title',
      tags: [],
    },
    {
      id: 'rating',
      titleKey: 'home.findPartner.sections.rating.title',
      tags: [
        {
          id: 'unlimited',
          labelKey: 'home.findPartner.sections.rating.tags.unlimited',
        },
        {
          id: 'high-to-low',
          labelKey: 'home.findPartner.sections.rating.tags.highToLow',
        },
        {
          id: 'low-to-high',
          labelKey: 'home.findPartner.sections.rating.tags.lowToHigh',
        },
      ],
    },
    {
      id: 'price',
      titleKey: 'home.findPartner.sections.price.title',
      tags: [
        {
          id: 'unlimited',
          labelKey: 'home.findPartner.sections.price.tags.unlimited',
        },
        {
          id: '0-10',
          labelKey: 'home.findPartner.sections.price.tags.range_0_10',
        },
        {
          id: '10-15',
          labelKey: 'home.findPartner.sections.price.tags.range_10_15',
        },
        {
          id: '15-25',
          labelKey: 'home.findPartner.sections.price.tags.range_15_25',
        },
        {
          id: '25-50',
          labelKey: 'home.findPartner.sections.price.tags.range_25_50',
        },
        {
          id: 'over50',
          labelKey: 'home.findPartner.sections.price.tags.range_over50',
        },
      ],
    },
  ],
  selected: { ...initialSelected },
})

const open = () => {
  state.visible = true
}

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

const toggleTag = (sectionId: FindPartnerSection['id'], tagId: string) => {
  const current = state.selected[sectionId]
  state.selected[sectionId] = current === tagId ? undefined : tagId
}

const resetFilters = () => {
  state.selected = {
    ...initialSelected,
  }
}

// ===== 弹窗选项 -> 列表接口参数映射 =====
const mapGenderToBackend = (id?: string): number => {
  // 性别：-1:无限制,0:未知，1:男，2:女
  if (!id || id === 'unlimited')
    return -1
  if (id === 'male')
    return 1
  if (id === 'female')
    return 2
  return -1
}

const mapAgeToBackend = (id?: string): number => {
  // 年龄，-1:不限制，0:15-25，1:25-35，2:35以上
  if (!id || id === 'unlimited')
    return -1
  if (id === '15-25')
    return 0
  if (id === '25-35')
    return 1
  if (id === '35+')
    return 2
  return -1
}

const mapRegionToBackend = (id?: string): string => {
  // 区域编码，暂无“不限”选项；未选择时传空字符串
  if (!id)
    return ''
  return id
}

const mapPriceToBackend = (id?: string): number => {
  // 价格区间：-1:无限制，0:[0,10]，1:(10,15]，2:(15,25]，3:(25,50]，4:over50
  if (!id || id === 'unlimited')
    return -1
  if (id === '0-10')
    return 0
  if (id === '10-15')
    return 1
  if (id === '15-25')
    return 2
  if (id === '25-50')
    return 3
  if (id === 'over50')
    return 4
  return -1
}

const mapRatingToSortByStar = (id: string | undefined, currentSortByStar: number): number => {
  // 评分排序，-1:默认排序，0:升序，1:降序
  if (!id || id === 'unlimited')
    return currentSortByStar
  if (id === 'high-to-low')
    return 1
  if (id === 'low-to-high')
    return 0
  return currentSortByStar
}

const getFilters = (currentSortByStar: number): FindPartnerFilterPayload => {
  const gender = mapGenderToBackend(state.selected.gender)
  const ageRange = mapAgeToBackend(state.selected.age)
  const areCode = mapRegionToBackend(state.selected.region)
  const priceRange = mapPriceToBackend(state.selected.price)
  const sortByStar = mapRatingToSortByStar(state.selected.rating, currentSortByStar)

  return {
    gender,
    ageRange,
    areCode,
    priceRange,
    sortByStar,
  }
}

type ApplyListener = () => void

const applyListeners = new Set<ApplyListener>()

const onApply = (listener: ApplyListener) => {
  applyListeners.add(listener)

  onUnmounted(() => {
    applyListeners.delete(listener)
  })
}

const applyFilters = () => {
  applyListeners.forEach(listener => listener())
}

const regionTagsInitializedFromBaseConsts = ref(false)

const setupRegionTagsFromBaseConsts = () => {
  if (regionTagsInitializedFromBaseConsts.value)
    return

  const baseConstsStore = useBaseConstsStore()

  const updateRegionTags = (config: BaseConstsConfig | null) => {
    const regionSection = state.sections.find(section => section.id === 'region')
    if (!regionSection)
      return

    const list = config?.commonAreaConsts

    if (!Array.isArray(list) || list.length === 0)
      return

    regionSection.tags = list
      .filter(item => item && item.code)
      .map(item => ({
        // areCode 直接取后端提供的区域 code
        id: String(item.code),
        // 这里直接使用后端下发的 name，i18n 未配置时会直接展示该文案
        labelKey: String(item.name),
      }))

    regionTagsInitializedFromBaseConsts.value = true
  }

  watch(
    () => baseConstsStore.config,
    (config) => {
      updateRegionTags(config)
    },
    {
      immediate: true,
    },
  )
}

export const useFindPartnerPopup = () => {
  setupRegionTagsFromBaseConsts()

  return {
    state: readonly(state),
    open,
    close,
    toggleTag,
    resetFilters,
    getFilters,
    onApply,
    applyFilters,
  }
}