/**
 * 物品系统 - 使用/装备/品质计算
 * Phase 6 核心系统实现
 */

import { ITEM_CONFIG } from '@/config/items.js'
import { GAME_CONSTANTS } from '@/config/constants.js'
import { SKILL_CONFIG } from '@/config/skills.js'

/**
 * 计算装备品质后的属性
 * 使用数学模型中的公式：品质倍率 = 1 + (品质 - 100) * 0.01
 * @param {String} itemId - 物品ID
 * @param {Number} quality - 品质值 (0-250)
 * @param {Number} itemLevel - 物品等级（影响属性）
 * @returns {Object|null} 计算后的属性
 */
export function calculateItemStats(itemId, quality = 100, itemLevel = 1) {
  const config = ITEM_CONFIG[itemId]
  if (!config) {
    return null
  }

  const qualityLevel = getQualityLevel(quality)

  // 品质倍率：1 + (品质 - 100) * 0.01
  // 品质100 = 1.0倍，品质150 = 1.5倍，品质50 = 0.5倍
  const qualityMultiplier = 1 + (quality - 100) * GAME_CONSTANTS.QUALITY.BASE_MULTIPLIER

  // 等级倍率：每级 +2%
  const levelMultiplier = 1 + (itemLevel - 1) * 0.02

  // 综合倍率
  const totalMultiplier = qualityMultiplier * levelMultiplier

  const stats = {
    id: itemId,
    name: config.name,
    type: config.type,
    subtype: config.subtype,
    description: config.description,
    icon: config.icon,
    quality: quality,
    itemLevel: itemLevel,
    qualityLevel: qualityLevel.level,
    qualityName: qualityLevel.name,
    qualityColor: qualityLevel.color
  }

  // 应用品质倍率到基础属性
  if (config.baseDamage) {
    stats.baseDamage = config.baseDamage
    stats.finalDamage = Math.max(1, Math.floor(config.baseDamage * totalMultiplier))
  }

  if (config.baseDefense) {
    stats.baseDefense = config.baseDefense
    stats.finalDefense = Math.max(1, Math.floor(config.baseDefense * totalMultiplier))
  }

  if (config.baseShield) {
    stats.baseShield = config.baseShield
    stats.finalShield = Math.floor(config.baseShield * totalMultiplier)
  }

  if (config.attackSpeed) {
    stats.attackSpeed = config.attackSpeed
  }

  // 计算价值（品质影响）
  stats.baseValue = config.baseValue || 0
  stats.finalValue = Math.floor(config.baseValue * totalMultiplier)

  // 消耗品效果
  if (config.effect) {
    stats.effect = { ...config.effect }
  }

  // 书籍信息
  if (config.type === 'book') {
    stats.readingTime = config.readingTime
    stats.expReward = { ...config.expReward }
    stats.completionBonus = config.completionBonus
  }

  // 解锁技能
  if (config.unlockSkill) {
    stats.unlockSkill = config.unlockSkill
  }

  // 额外属性（来自物品配置）
  if (config.stats) {
    stats.stats = { ...config.stats }
  }

  // 堆叠信息
  if (config.stackable !== undefined) {
    stats.stackable = config.stackable
    stats.maxStack = config.maxStack || 99
  }

  return stats
}

/**
 * 获取品质等级
 * @param {Number} quality - 品质值
 * @returns {Object} 品质等级信息
 */
export function getQualityLevel(quality) {
  // 确保品质在有效范围内
  const clampedQuality = Math.max(0, Math.min(250, quality))

  for (const [level, data] of Object.entries(GAME_CONSTANTS.QUALITY_LEVELS)) {
    if (clampedQuality >= data.range[0] && clampedQuality <= data.range[1]) {
      return {
        level: parseInt(level),
        ...data
      }
    }
  }

  // 默认返回垃圾品质
  return GAME_CONSTANTS.QUALITY_LEVELS[1]
}

/**
 * 生成随机品质
 * @param {Number} luck - 运气值 (0-100)，影响高品质概率
 * @returns {Number} 品质值
 */
export function generateRandomQuality(luck = 0) {
  // 单次随机判定
  const roll = Math.random()

  // 运气加成：每1点运气增加对应品质概率的 0.1%
  const luckBonus = luck * 0.001

  // 传说品质：0.1% + 运气加成
  if (roll < 0.001 + luckBonus) {
    return 200 + Math.floor(Math.random() * 51)  // 200-250
  }
  // 史诗品质：1% + 运气加成
  if (roll < 0.01 + luckBonus * 2) {
    return 170 + Math.floor(Math.random() * 30)  // 170-199
  }
  // 稀有品质：5% + 运气加成
  if (roll < 0.05 + luckBonus * 3) {
    return 140 + Math.floor(Math.random() * 30)  // 140-169
  }
  // 优秀品质：15% + 运气加成
  if (roll < 0.15 + luckBonus * 4) {
    return 100 + Math.floor(Math.random() * 40)  // 100-139
  }
  // 普通品质：剩余大部分
  if (roll < 0.85) {
    return 50 + Math.floor(Math.random() * 50)  // 50-99
  }
  // 垃圾品质：15%
  return Math.floor(Math.random() * 50)  // 0-49
}

/**
 * 使用物品
 * @param {Object} playerStore - 玩家Store
 * @param {Object} gameStore - 游戏Store
 * @param {String} itemId - 物品ID
 * @param {Number} count - 使用数量
 * @returns {Object} { success: boolean, message: string, effects: Object }
 */
export function useItem(playerStore, gameStore, itemId, count = 1) {
  const config = ITEM_CONFIG[itemId]
  if (!config) {
    return { success: false, message: '物品不存在' }
  }

  // 查找背包中的物品
  const itemIndex = playerStore.inventory.findIndex(i => i.id === itemId)
  if (itemIndex === -1) {
    return { success: false, message: '背包中没有该物品' }
  }

  const inventoryItem = playerStore.inventory[itemIndex]

  // 检查数量
  if (inventoryItem.count < count) {
    return { success: false, message: '物品数量不足' }
  }

  // 根据物品类型处理
  if (config.type === 'consumable') {
    return useConsumable(playerStore, gameStore, config, inventoryItem, count, itemIndex)
  }

  if (config.type === 'book') {
    return useBook(playerStore, gameStore, config, inventoryItem)
  }

  return { success: false, message: '该物品无法使用' }
}

/**
 * 使用消耗品
 */
function useConsumable(playerStore, gameStore, config, inventoryItem, count, itemIndex) {
  const effects = {}
  const appliedEffects = []

  // 应用效果
  if (config.effect) {
    if (config.effect.health) {
      const oldHealth = playerStore.currentStats.health
      playerStore.currentStats.health = Math.min(
        playerStore.currentStats.maxHealth,
        playerStore.currentStats.health + config.effect.health * count
      )
      effects.health = playerStore.currentStats.health - oldHealth
      if (effects.health > 0) appliedEffects.push(`恢复${effects.health}生命`)
    }

    if (config.effect.stamina) {
      const oldStamina = playerStore.currentStats.stamina
      playerStore.currentStats.stamina = Math.min(
        playerStore.currentStats.maxStamina,
        playerStore.currentStats.stamina + config.effect.stamina * count
      )
      effects.stamina = playerStore.currentStats.stamina - oldStamina
      if (effects.stamina > 0) appliedEffects.push(`恢复${effects.stamina}耐力`)
    }

    if (config.effect.sanity) {
      const oldSanity = playerStore.currentStats.sanity
      playerStore.currentStats.sanity = Math.min(
        playerStore.currentStats.maxSanity,
        playerStore.currentStats.sanity + config.effect.sanity * count
      )
      effects.sanity = playerStore.currentStats.sanity - oldSanity
      if (effects.sanity > 0) appliedEffects.push(`恢复${effects.sanity}精神`)
    }
  }

  // 消耗物品
  inventoryItem.count -= count
  if (inventoryItem.count <= 0) {
    playerStore.inventory.splice(itemIndex, 1)
  }

  // 记录日志
  const effectText = appliedEffects.length > 0 ? appliedEffects.join('、') : '使用'
  if (gameStore.addLog) {
    gameStore.addLog(`使用了 ${config.name} x${count}，${effectText}`, 'info')
  }

  return {
    success: true,
    message: effectText,
    effects
  }
}

/**
 * 使用书籍（阅读）
 */
function useBook(playerStore, gameStore, config, inventoryItem) {
  // 书籍不消耗，返回阅读任务信息
  return {
    success: true,
    message: '开始阅读',
    readingTask: {
      itemId: config.id,
      bookName: config.name,
      readingTime: config.readingTime,
      expReward: config.expReward,
      completionBonus: config.completionBonus
    }
  }
}

/**
 * 装备物品
 * @param {Object} playerStore - 玩家Store
 * @param {Object} gameStore - 游戏Store
 * @param {String} uniqueId - 物品唯一ID（背包中的物品）
 * @returns {Object} { success: boolean, message: string }
 */
export function equipItem(playerStore, gameStore, uniqueId) {
  const inventoryItem = playerStore.inventory.find(i => i.uniqueId === uniqueId)
  if (!inventoryItem) {
    return { success: false, message: '物品不存在' }
  }

  const config = ITEM_CONFIG[inventoryItem.id]
  if (!config) {
    return { success: false, message: '物品配置不存在' }
  }

  // 确定装备槽位
  let slot = config.type
  if (config.subtype === 'one_handed' || config.subtype === 'two_handed') {
    slot = 'weapon'
  } else if (config.type === 'armor') {
    slot = 'armor'
  } else if (config.type === 'shield') {
    slot = 'shield'
  } else if (config.type === 'accessory') {
    slot = 'accessory'
  }

  if (!slot || !playerStore.equipment.hasOwnProperty(slot)) {
    return { success: false, message: '无法装备该物品' }
  }

  // 如果已有装备，先卸下
  const currentlyEquipped = playerStore.equipment[slot]
  if (currentlyEquipped) {
    unequipItemBySlot(playerStore, gameStore, slot)
  }

  // 装备新物品
  playerStore.equipment[slot] = inventoryItem
  inventoryItem.equipped = true

  // 应用装备属性
  applyEquipmentStats(playerStore, slot, inventoryItem)

  // 记录日志
  if (gameStore.addLog) {
    gameStore.addLog(`装备了 ${inventoryItem.name}`, 'info')
  }

  return { success: true, message: '装备成功' }
}

/**
 * 卸下装备
 * @param {Object} playerStore - 玩家Store
 * @param {Object} gameStore - 游戏Store
 * @param {String} slot - 装备槽位
 * @returns {Object} { success: boolean, message: string }
 */
export function unequipItemBySlot(playerStore, gameStore, slot) {
  const equipped = playerStore.equipment[slot]
  if (!equipped) {
    return { success: false, message: '该槽位没有装备' }
  }

  // 移除装备属性
  removeEquipmentStats(playerStore, slot)

  // 标记为未装备
  equipped.equipped = false

  // 清空槽位
  playerStore.equipment[slot] = null

  // 记录日志
  if (gameStore.addLog) {
    gameStore.addLog(`卸下了 ${equipped.name}`, 'info')
  }

  return { success: true, message: '卸下成功' }
}

/**
 * 应用装备属性到玩家
 */
function applyEquipmentStats(playerStore, slot, item) {
  if (!playerStore.equipmentStats) {
    playerStore.equipmentStats = {
      attack: 0,
      defense: 0,
      shield: 0,
      critRate: 0,
      attackSpeed: 1
    }
  }

  if (item.finalDamage) {
    playerStore.equipmentStats.attack += item.finalDamage
  }

  if (item.finalDefense) {
    playerStore.equipmentStats.defense += item.finalDefense
  }

  if (item.finalShield) {
    playerStore.equipmentStats.shield += item.finalShield
  }

  if (item.attackSpeed) {
    playerStore.equipmentStats.attackSpeed *= item.attackSpeed
  }
}

/**
 * 移除装备属性
 */
function removeEquipmentStats(playerStore, slot) {
  const equipped = playerStore.equipment[slot]
  if (!equipped || !playerStore.equipmentStats) {
    return
  }

  if (equipped.finalDamage) {
    playerStore.equipmentStats.attack -= equipped.finalDamage
  }

  if (equipped.finalDefense) {
    playerStore.equipmentStats.defense -= equipped.finalDefense
  }

  if (equipped.finalShield) {
    playerStore.equipmentStats.shield -= equipped.finalShield
  }
}

/**
 * 添加物品到背包
 * @param {Object} playerStore - 玩家Store
 * @param {String} itemId - 物品ID
 * @param {Number} count - 数量
 * @param {Number} quality - 品质值（装备用，0-250）
 * @returns {Object} { success: boolean, item: Object }
 */
export function addItemToInventory(playerStore, itemId, count = 1, quality = null) {
  const config = ITEM_CONFIG[itemId]
  if (!config) {
    return { success: false, message: '物品不存在' }
  }

  // 素材和关键道具不需要品质，使用固定值
  // 装备类物品才需要随机品质
  const needsQuality = config.type === 'weapon' || config.type === 'armor' ||
                       config.type === 'shield' || config.type === 'accessory'
  const itemQuality = quality !== null ? quality
    : (needsQuality ? generateRandomQuality(playerStore.baseStats?.intuition || 0) : 100)

  // 计算物品属性（包含品质等级）
  const itemStats = calculateItemStats(itemId, itemQuality)

  // 素材类物品 - 只按ID堆叠
  if (config.stackable) {
    const existingItem = playerStore.inventory.find(i => i.id === itemId)
    if (existingItem) {
      existingItem.count += count
      return { success: true, item: existingItem }
    }
  }

  // 装备类物品 - 不堆叠，每个装备都有独立的唯一ID
  // 这样可以正确跟踪每个装备的装备状态
  if (needsQuality) {
    // 检查是否有完全相同品质的装备（用于显示堆叠数量，但各自独立）
    // 注意：装备不再真正堆叠，每个都是独立实例
    // 生成唯一ID：itemId + quality + 时间戳 + 随机数
    const uniqueId = `${itemId}_q${itemQuality}_${Date.now()}_${Math.random().toString(36).substring(2, 9)}`

    const newItem = {
      ...itemStats,
      uniqueId,
      count: 1, // 装备始终为1
      equipped: false,
      obtainedAt: Date.now()
    }

    playerStore.inventory.push(newItem)
    return { success: true, item: newItem }
  }

  // 创建新物品（非装备类）
  const uniqueId = `${itemId}_${Date.now()}_${Math.random().toString(36).substring(2, 11)}`

  const newItem = {
    ...itemStats,
    uniqueId,
    count,
    equipped: false,
    obtainedAt: Date.now()
  }

  playerStore.inventory.push(newItem)

  return { success: true, item: newItem }
}

/**
 * 从背包移除物品
 * @param {Object} playerStore - 玩家Store
 * @param {String} uniqueId - 物品唯一ID
 * @param {Number} count - 移除数量
 * @returns {Object} { success: boolean, message: string }
 */
export function removeItemFromInventory(playerStore, uniqueId, count = 1) {
  const itemIndex = playerStore.inventory.findIndex(i => i.uniqueId === uniqueId)
  if (itemIndex === -1) {
    return { success: false, message: '物品不存在' }
  }

  const item = playerStore.inventory[itemIndex]

  if (item.count < count) {
    return { success: false, message: '物品数量不足' }
  }

  item.count -= count

  if (item.count <= 0) {
    // 如果已装备，先卸下
    if (item.equipped) {
      for (const [slot, equipped] of Object.entries(playerStore.equipment)) {
        if (equipped && equipped.uniqueId === uniqueId) {
          playerStore.equipment[slot] = null
          break
        }
      }
    }
    playerStore.inventory.splice(itemIndex, 1)
  }

  return { success: true, message: '移除成功' }
}

/**
 * 检查是否拥有物品
 * @param {Object} playerStore - 玩家Store
 * @param {String} itemId - 物品ID
 * @returns {Boolean}
 */
export function hasItem(playerStore, itemId) {
  return playerStore.inventory.some(i => i.id === itemId && i.count > 0)
}

/**
 * 获取物品数量
 * @param {Object} playerStore - 玩家Store
 * @param {String} itemId - 物品ID
 * @returns {Number}
 */
export function getItemCount(playerStore, itemId) {
  const item = playerStore.inventory.find(i => i.id === itemId)
  return item ? item.count : 0
}

// Note: checkSkillUnlock, calculateSellPrice, calculateBuyPrice,
// getQualityColor, getQualityName are now test-only utilities
// and are not exported for production use