import type { SearchResponse, SearchResultItem, SearchSort } from "@/lib/search/types"
import type { Player, PlayerService, Shop } from "@/lib/types"

export interface SearchCatalogParams {
  q?: string
  selectedGames?: string[]
  min?: string
  max?: string
  onlyOnline?: boolean
  minRating?: string
  sort?: SearchSort
  limit?: number
  offset?: number
}

export interface SearchCatalogData {
  players: Player[]
  shops: Shop[]
  services: PlayerService[]
}

type InternalResultItem = SearchResultItem & { __index: number }

function minPriceFromServices(services: PlayerService[]) {
  return services.length === 0 ? 0 : Math.min(...services.map((s) => s.price))
}

function unitFromCheapestService(services: PlayerService[]): PlayerService["unit"] {
  if (services.length === 0) return "局"
  return services.reduce((prev, curr) => (prev.price < curr.price ? prev : curr)).unit
}

export function searchCatalog(
  params: SearchCatalogParams,
  data: SearchCatalogData,
): SearchResponse {
  const q = params.q ?? ""
  const query = q ? q.toLowerCase() : ""
  const selectedGames = params.selectedGames ?? []

  const min = params.min ?? ""
  const max = params.max ?? ""
  const minP = min ? Number(min) : 0
  const maxP = max ? Number(max) : Infinity

  const onlyOnline = params.onlyOnline ?? false
  const minRating = Number(params.minRating ?? "0")
  const sort = params.sort ?? "composite"

  const offset = Math.max(0, params.offset ?? 0)
  const limit = Math.max(0, params.limit ?? 12)

  const shopDerivedById = new Map<
    string,
    {
      minPrice: number
      unit: PlayerService["unit"]
      games: string[]
      hasAvailable: boolean
    }
  >()

  for (const shop of data.shops) {
    const shopPlayers = data.players.filter((player) => player.shopId === shop.id)
    const playerIds = new Set(shopPlayers.map((player) => player.id))
    const shopServices = data.services.filter((service) => playerIds.has(service.playerId))
    const shopMinPrice = shopServices.length > 0 ? Math.min(...shopServices.map((s) => s.price)) : 0
    const shopUnit = shopServices.length > 0 ? unitFromCheapestService(shopServices) : "局"
    const shopGames = [...new Set(shopServices.map((service) => service.gameName))]
    const hasAvailable = shopPlayers.some((player) => player.status === "available")

    shopDerivedById.set(shop.id, {
      minPrice: shopMinPrice,
      unit: shopUnit,
      games: shopGames,
      hasAvailable,
    })
  }

  let nextIndex = 0
  const results: InternalResultItem[] = []

  for (const player of data.players) {
    results.push({
      __index: nextIndex++,
      type: "player",
      player,
      rating: player.rating,
      orders: player.totalOrders,
      minPrice: minPriceFromServices(player.services),
      unit: unitFromCheapestService(player.services),
    })
  }

  for (const shop of data.shops) {
    const derived = shopDerivedById.get(shop.id)
    if (!derived) continue

    results.push({
      __index: nextIndex++,
      type: "shop",
      shop,
      rating: Number(shop.rating),
      orders: shop.totalOrders,
      minPrice: derived.minPrice,
      unit: derived.unit,
      games: derived.games,
      hasAvailable: derived.hasAvailable,
    })
  }

  const filtered = results.filter((item) => {
    if (query) {
      if (item.type === "player") {
        const matchName = item.player.user.nickname.toLowerCase().includes(query)
        const matchTags = item.player.tags.some((tag) => tag.toLowerCase().includes(query))
        const matchGames = item.player.games.some((game) => game.toLowerCase().includes(query))
        if (!matchName && !matchTags && !matchGames) return false
      } else {
        const matchName = item.shop.name.toLowerCase().includes(query)
        const matchDescription = item.shop.description.toLowerCase().includes(query)
        const matchGames = item.games.some((game) => game.toLowerCase().includes(query))
        if (!matchName && !matchDescription && !matchGames) return false
      }
    }

    if (selectedGames.length > 0) {
      if (item.type === "player") {
        const hasGame = item.player.games.some((game) => selectedGames.includes(game))
        if (!hasGame) return false
      } else {
        const hasGame = item.games.some((game) => selectedGames.includes(game))
        if (!hasGame) return false
      }
    }

    if (item.minPrice < minP) return false
    if (max && item.minPrice > maxP) return false

    if (onlyOnline) {
      if (item.type === "player") {
        if (item.player.status !== "available") return false
      } else {
        if (!item.hasAvailable) return false
      }
    }

    if (item.type === "player") {
      if (item.player.rating < minRating) return false
    } else {
      if (Number(item.shop.rating) < minRating) return false
    }

    return true
  })

  filtered.sort((a, b) => {
    let diff = 0
    switch (sort) {
      case "rating":
        diff = b.rating - a.rating
        break
      case "price_asc":
        diff = a.minPrice - b.minPrice
        break
      case "price_desc":
        diff = b.minPrice - a.minPrice
        break
      case "orders":
        diff = b.orders - a.orders
        break
      case "composite": {
        const scoreA = a.rating * Math.log10(a.orders + 1)
        const scoreB = b.rating * Math.log10(b.orders + 1)
        diff = scoreB - scoreA
        break
      }
      default:
        diff = 0
    }

    if (diff !== 0) return diff
    return a.__index - b.__index
  })

  const total = filtered.length
  const items = filtered.slice(offset, offset + limit).map(({ __index, ...item }) => item)
  return { items, meta: { total, offset, limit } }
}