import { computed } from 'nanostores'

import { getAttackResult, isValidAttack } from '#lobo/attack.ts'
import type { WolfOrPlayer } from '#lobo/player.ts'

import {
  $library,
  $playerHand,
  $playerRoundScores,
  $selectedPlayerCardIds,
  $selectedWolfCardIds,
  $winningScore,
  $wolfHand,
  $wolfRoundScores,
} from './state'

export const $wolfScore = computed([$wolfRoundScores], (rounds) =>
  rounds.reduce((total, round) => total + round, 0),
)
export const $playerScore = computed([$playerRoundScores], (rounds) =>
  rounds.reduce((total, round) => total + round, 0),
)

export const $selectedWolfCards = computed([$wolfHand, $selectedWolfCardIds], (hand, ids) =>
  hand.filter((c) => ids.includes(c.id)),
)
export const $selectedPlayerCards = computed([$playerHand, $selectedPlayerCardIds], (hand, ids) =>
  hand.filter((c) => ids.includes(c.id)),
)

export const $isValidAttack = computed(
  [$selectedWolfCards, $selectedPlayerCards, $library],
  (wolfCards, playerCards, library) => {
    if (!library || !isValidAttack(wolfCards, playerCards)) {
      return false
    }

    // Only allow attacks if there are enough cards left to draw
    const result = getAttackResult(wolfCards, playerCards)
    return result.drawCount <= library.size
  },
)

export const $winner = computed(
  [$wolfScore, $playerScore, $winningScore],
  (wolfScore, playerScore, WINNING_SCORE): WolfOrPlayer | null => {
    if (wolfScore >= WINNING_SCORE) {
      return 'wolf'
    } else if (playerScore >= WINNING_SCORE) {
      return 'player'
    } else {
      return null
    }
  },
)

export const $hasGameEnded = computed($winner, (winner) => winner !== null)