const { v4: uuidv4 } = require('uuid')
const logger = require('../utils/logger')
const redis = require('../models/redis')

class AccountGroupService {
  constructor() {
    this.GROUPS_KEY = 'account_groups'
    this.GROUP_PREFIX = 'account_group:'
    this.GROUP_MEMBERS_PREFIX = 'account_group_members:'
    this.REVERSE_INDEX_PREFIX = 'account_groups_reverse:'
    this.REVERSE_INDEX_MIGRATED_KEY = 'account_groups_reverse:migrated'
  }

  /**
   * 确保反向索引存在（启动时自动调用）
   * 检查是否已迁移，如果没有则自动回填
   */
  async ensureReverseIndexes() {
    try {
      const client = redis.getClientSafe()
      if (!client) {
        return
      }

      // 检查是否已迁移
      const migrated = await client.get(this.REVERSE_INDEX_MIGRATED_KEY)
      if (migrated === 'true') {
        logger.debug('📁 账户分组反向索引已存在，跳过回填')
        return
      }

      logger.info('📁 开始回填账户分组反向索引...')

      const allGroupIds = await client.smembers(this.GROUPS_KEY)
      if (allGroupIds.length === 0) {
        await client.set(this.REVERSE_INDEX_MIGRATED_KEY, 'true')
        return
      }

      let totalOperations = 0

      for (const groupId of allGroupIds) {
        const group = await client.hgetall(`${this.GROUP_PREFIX}${groupId}`)
        if (!group || !group.platform) {
          continue
        }

        const members = await client.smembers(`${this.GROUP_MEMBERS_PREFIX}${groupId}`)
        if (members.length === 0) {
          continue
        }

        const pipeline = client.pipeline()
        for (const accountId of members) {
          pipeline.sadd(`${this.REVERSE_INDEX_PREFIX}${group.platform}:${accountId}`, groupId)
        }
        await pipeline.exec()
        totalOperations += members.length
      }

      await client.set(this.REVERSE_INDEX_MIGRATED_KEY, 'true')
      logger.success(`📁 账户分组反向索引回填完成，共 ${totalOperations} 条`)
    } catch (error) {
      logger.error('❌ 账户分组反向索引回填失败:', error)
    }
  }

  /**
   * 创建账户分组
   * @param {Object} groupData - 分组数据
   * @param {string} groupData.name - 分组名称
   * @param {string} groupData.platform - 平台类型 (claude/gemini/openai)
   * @param {string} groupData.description - 分组描述
   * @returns {Object} 创建的分组
   */
  async createGroup(groupData) {
    try {
      const { name, platform, description = '' } = groupData

      // 验证必填字段
      if (!name || !platform) {
        throw new Error('分组名称和平台类型为必填项')
      }

      // 验证平台类型
      if (!['claude', 'gemini', 'openai', 'droid'].includes(platform)) {
        throw new Error('平台类型必须是 claude、gemini、openai 或 droid')
      }

      const client = redis.getClientSafe()
      const groupId = uuidv4()
      const now = new Date().toISOString()

      const group = {
        id: groupId,
        name,
        platform,
        description,
        createdAt: now,
        updatedAt: now
      }

      // 保存分组数据
      await client.hmset(`${this.GROUP_PREFIX}${groupId}`, group)

      // 添加到分组集合
      await client.sadd(this.GROUPS_KEY, groupId)

      logger.success(`创建账户分组成功: ${name} (${platform})`)

      return group
    } catch (error) {
      logger.error('❌ 创建账户分组失败:', error)
      throw error
    }
  }

  /**
   * 更新分组信息
   * @param {string} groupId - 分组ID
   * @param {Object} updates - 更新的字段
   * @returns {Object} 更新后的分组
   */
  async updateGroup(groupId, updates) {
    try {
      const client = redis.getClientSafe()
      const groupKey = `${this.GROUP_PREFIX}${groupId}`

      // 检查分组是否存在
      const exists = await client.exists(groupKey)
      if (!exists) {
        throw new Error('分组不存在')
      }

      // 获取现有分组数据
      const existingGroup = await client.hgetall(groupKey)

      // 不允许修改平台类型
      if (updates.platform && updates.platform !== existingGroup.platform) {
        throw new Error('不能修改分组的平台类型')
      }

      // 准备更新数据
      const updateData = {
        ...updates,
        updatedAt: new Date().toISOString()
      }

      // 移除不允许修改的字段
      delete updateData.id
      delete updateData.platform
      delete updateData.createdAt

      // 更新分组
      await client.hmset(groupKey, updateData)

      // 返回更新后的完整数据
      const updatedGroup = await client.hgetall(groupKey)

      logger.success(`更新账户分组成功: ${updatedGroup.name}`)

      return updatedGroup
    } catch (error) {
      logger.error('❌ 更新账户分组失败:', error)
      throw error
    }
  }

  /**
   * 删除分组
   * @param {string} groupId - 分组ID
   */
  async deleteGroup(groupId) {
    try {
      const client = redis.getClientSafe()

      // 检查分组是否存在
      const group = await this.getGroup(groupId)
      if (!group) {
        throw new Error('分组不存在')
      }

      // 检查分组是否为空
      const members = await this.getGroupMembers(groupId)
      if (members.length > 0) {
        throw new Error('分组内还有账户，无法删除')
      }

      // 检查是否有API Key绑定此分组
      const boundApiKeys = await this.getApiKeysUsingGroup(groupId)
      if (boundApiKeys.length > 0) {
        throw new Error('还有API Key使用此分组，无法删除')
      }

      // 删除分组数据
      await client.del(`${this.GROUP_PREFIX}${groupId}`)
      await client.del(`${this.GROUP_MEMBERS_PREFIX}${groupId}`)

      // 从分组集合中移除
      await client.srem(this.GROUPS_KEY, groupId)

      logger.success(`删除账户分组成功: ${group.name}`)
    } catch (error) {
      logger.error('❌ 删除账户分组失败:', error)
      throw error
    }
  }

  /**
   * 获取分组详情
   * @param {string} groupId - 分组ID
   * @returns {Object|null} 分组信息
   */
  async getGroup(groupId) {
    try {
      const client = redis.getClientSafe()
      const groupData = await client.hgetall(`${this.GROUP_PREFIX}${groupId}`)

      if (!groupData || Object.keys(groupData).length === 0) {
        return null
      }

      // 获取成员数量
      const memberCount = await client.scard(`${this.GROUP_MEMBERS_PREFIX}${groupId}`)

      return {
        ...groupData,
        memberCount: memberCount || 0
      }
    } catch (error) {
      logger.error('❌ 获取分组详情失败:', error)
      throw error
    }
  }

  /**
   * 获取所有分组
   * @param {string} platform - 平台筛选 (可选)
   * @returns {Array} 分组列表
   */
  async getAllGroups(platform = null) {
    try {
      const client = redis.getClientSafe()
      const groupIds = await client.smembers(this.GROUPS_KEY)

      const groups = []
      for (const groupId of groupIds) {
        const group = await this.getGroup(groupId)
        if (group) {
          // 如果指定了平台，进行筛选
          if (!platform || group.platform === platform) {
            groups.push(group)
          }
        }
      }

      // 按创建时间倒序排序
      groups.sort((a, b) => new Date(b.createdAt) - new Date(a.createdAt))

      return groups
    } catch (error) {
      logger.error('❌ 获取分组列表失败:', error)
      throw error
    }
  }

  /**
   * 添加账户到分组
   * @param {string} accountId - 账户ID
   * @param {string} groupId - 分组ID
   * @param {string} accountPlatform - 账户平台
   */
  async addAccountToGroup(accountId, groupId, accountPlatform) {
    try {
      const client = redis.getClientSafe()

      // 获取分组信息
      const group = await this.getGroup(groupId)
      if (!group) {
        throw new Error('分组不存在')
      }

      // 验证平台一致性 (Claude和Claude Console视为同一平台)
      const normalizedAccountPlatform =
        accountPlatform === 'claude-console' ? 'claude' : accountPlatform
      if (normalizedAccountPlatform !== group.platform) {
        throw new Error('账户平台与分组平台不匹配')
      }

      // 添加到分组成员集合
      await client.sadd(`${this.GROUP_MEMBERS_PREFIX}${groupId}`, accountId)

      // 维护反向索引
      await client.sadd(`account_groups_reverse:${group.platform}:${accountId}`, groupId)

      logger.success(`添加账户到分组成功: ${accountId} -> ${group.name}`)
    } catch (error) {
      logger.error('❌ 添加账户到分组失败:', error)
      throw error
    }
  }

  /**
   * 从分组移除账户
   * @param {string} accountId - 账户ID
   * @param {string} groupId - 分组ID
   * @param {string} platform - 平台（可选，如果不传则从分组获取）
   */
  async removeAccountFromGroup(accountId, groupId, platform = null) {
    try {
      const client = redis.getClientSafe()

      // 从分组成员集合中移除
      await client.srem(`${this.GROUP_MEMBERS_PREFIX}${groupId}`, accountId)

      // 维护反向索引
      let groupPlatform = platform
      if (!groupPlatform) {
        const group = await this.getGroup(groupId)
        groupPlatform = group?.platform
      }
      if (groupPlatform) {
        await client.srem(`account_groups_reverse:${groupPlatform}:${accountId}`, groupId)
      }

      logger.success(`从分组移除账户成功: ${accountId}`)
    } catch (error) {
      logger.error('❌ 从分组移除账户失败:', error)
      throw error
    }
  }

  /**
   * 获取分组成员
   * @param {string} groupId - 分组ID
   * @returns {Array} 成员ID列表
   */
  async getGroupMembers(groupId) {
    try {
      const client = redis.getClientSafe()
      const members = await client.smembers(`${this.GROUP_MEMBERS_PREFIX}${groupId}`)
      return members || []
    } catch (error) {
      logger.error('❌ 获取分组成员失败:', error)
      throw error
    }
  }

  /**
   * 检查分组是否为空
   * @param {string} groupId - 分组ID
   * @returns {boolean} 是否为空
   */
  async isGroupEmpty(groupId) {
    try {
      const members = await this.getGroupMembers(groupId)
      return members.length === 0
    } catch (error) {
      logger.error('❌ 检查分组是否为空失败:', error)
      throw error
    }
  }

  /**
   * 获取使用指定分组的API Key列表
   * @param {string} groupId - 分组ID
   * @returns {Array} API Key列表
   */
  async getApiKeysUsingGroup(groupId) {
    try {
      const client = redis.getClientSafe()
      const groupKey = `group:${groupId}`

      // 获取所有API Key
      const apiKeyIds = await client.smembers('api_keys')
      const boundApiKeys = []

      for (const keyId of apiKeyIds) {
        const keyData = await client.hgetall(`api_key:${keyId}`)
        if (
          keyData &&
          (keyData.claudeAccountId === groupKey ||
            keyData.geminiAccountId === groupKey ||
            keyData.openaiAccountId === groupKey ||
            keyData.droidAccountId === groupKey)
        ) {
          boundApiKeys.push({
            id: keyId,
            name: keyData.name
          })
        }
      }

      return boundApiKeys
    } catch (error) {
      logger.error('❌ 获取使用分组的API Key失败:', error)
      throw error
    }
  }

  /**
   * 根据账户ID获取其所属的分组（兼容性方法，返回单个分组）
   * @param {string} accountId - 账户ID
   * @returns {Object|null} 分组信息
   */
  async getAccountGroup(accountId) {
    try {
      const client = redis.getClientSafe()
      const allGroupIds = await client.smembers(this.GROUPS_KEY)

      for (const groupId of allGroupIds) {
        const isMember = await client.sismember(`${this.GROUP_MEMBERS_PREFIX}${groupId}`, accountId)
        if (isMember) {
          return await this.getGroup(groupId)
        }
      }

      return null
    } catch (error) {
      logger.error('❌ 获取账户所属分组失败:', error)
      throw error
    }
  }

  /**
   * 根据账户ID获取其所属的所有分组
   * @param {string} accountId - 账户ID
   * @returns {Array} 分组信息数组
   */
  async getAccountGroups(accountId) {
    try {
      const client = redis.getClientSafe()
      const allGroupIds = await client.smembers(this.GROUPS_KEY)
      const memberGroups = []

      for (const groupId of allGroupIds) {
        const isMember = await client.sismember(`${this.GROUP_MEMBERS_PREFIX}${groupId}`, accountId)
        if (isMember) {
          const group = await this.getGroup(groupId)
          if (group) {
            memberGroups.push(group)
          }
        }
      }

      // 按创建时间倒序排序
      memberGroups.sort((a, b) => new Date(b.createdAt) - new Date(a.createdAt))

      return memberGroups
    } catch (error) {
      logger.error('❌ 获取账户所属分组列表失败:', error)
      throw error
    }
  }

  /**
   * 批量设置账户的分组
   * @param {string} accountId - 账户ID
   * @param {Array} groupIds - 分组ID数组
   * @param {string} accountPlatform - 账户平台
   */
  async setAccountGroups(accountId, groupIds, accountPlatform) {
    try {
      // 首先移除账户的所有现有分组
      await this.removeAccountFromAllGroups(accountId)

      // 然后添加到新的分组中
      for (const groupId of groupIds) {
        await this.addAccountToGroup(accountId, groupId, accountPlatform)
      }

      logger.success(`批量设置账户分组成功: ${accountId} -> [${groupIds.join(', ')}]`)
    } catch (error) {
      logger.error('❌ 批量设置账户分组失败:', error)
      throw error
    }
  }

  /**
   * 从所有分组中移除账户
   * @param {string} accountId - 账户ID
   * @param {string} platform - 平台（可选，用于清理反向索引）
   */
  async removeAccountFromAllGroups(accountId, platform = null) {
    try {
      const client = redis.getClientSafe()
      const allGroupIds = await client.smembers(this.GROUPS_KEY)

      for (const groupId of allGroupIds) {
        await client.srem(`${this.GROUP_MEMBERS_PREFIX}${groupId}`, accountId)
      }

      // 清理反向索引
      if (platform) {
        await client.del(`account_groups_reverse:${platform}:${accountId}`)
      } else {
        // 如果没有指定平台，清理所有可能的平台
        const platforms = ['claude', 'gemini', 'openai', 'droid']
        const pipeline = client.pipeline()
        for (const p of platforms) {
          pipeline.del(`account_groups_reverse:${p}:${accountId}`)
        }
        await pipeline.exec()
      }

      logger.success(`从所有分组移除账户成功: ${accountId}`)
    } catch (error) {
      logger.error('❌ 从所有分组移除账户失败:', error)
      throw error
    }
  }

  /**
   * 批量获取多个账户的分组信息（性能优化版本，使用反向索引）
   * @param {Array<string>} accountIds - 账户ID数组
   * @param {string} platform - 平台类型
   * @param {Object} options - 选项
   * @param {boolean} options.skipMemberCount - 是否跳过 memberCount（默认 true）
   * @returns {Map<string, Array>} accountId -> 分组信息数组的映射
   */
  async batchGetAccountGroupsByIndex(accountIds, platform, options = {}) {
    const { skipMemberCount = true } = options

    if (!accountIds || accountIds.length === 0) {
      return new Map()
    }

    try {
      const client = redis.getClientSafe()

      // Pipeline 批量获取所有账户的分组ID
      const pipeline = client.pipeline()
      for (const accountId of accountIds) {
        pipeline.smembers(`${this.REVERSE_INDEX_PREFIX}${platform}:${accountId}`)
      }
      const groupIdResults = await pipeline.exec()

      // 收集所有需要的分组ID
      const uniqueGroupIds = new Set()
      const accountGroupIdsMap = new Map()
      let hasAnyGroups = false
      accountIds.forEach((accountId, i) => {
        const [err, groupIds] = groupIdResults[i]
        const ids = err ? [] : groupIds || []
        accountGroupIdsMap.set(accountId, ids)
        ids.forEach((id) => {
          uniqueGroupIds.add(id)
          hasAnyGroups = true
        })
      })

      // 如果反向索引全空，回退到原方法（兼容未迁移的数据）
      if (!hasAnyGroups) {
        const migrated = await client.get(this.REVERSE_INDEX_MIGRATED_KEY)
        if (migrated !== 'true') {
          logger.debug('📁 Reverse index not migrated, falling back to getAccountGroups')
          const result = new Map()
          for (const accountId of accountIds) {
            try {
              const groups = await this.getAccountGroups(accountId)
              result.set(accountId, groups)
            } catch {
              result.set(accountId, [])
            }
          }
          return result
        }
      }

      // 对于反向索引为空的账户，单独查询并补建索引（处理部分缺失情况）
      const emptyIndexAccountIds = []
      for (const accountId of accountIds) {
        const ids = accountGroupIdsMap.get(accountId) || []
        if (ids.length === 0) {
          emptyIndexAccountIds.push(accountId)
        }
      }
      if (emptyIndexAccountIds.length > 0 && emptyIndexAccountIds.length < accountIds.length) {
        // 部分账户索引缺失，逐个查询并补建
        for (const accountId of emptyIndexAccountIds) {
          try {
            const groups = await this.getAccountGroups(accountId)
            if (groups.length > 0) {
              const groupIds = groups.map((g) => g.id)
              accountGroupIdsMap.set(accountId, groupIds)
              groupIds.forEach((id) => uniqueGroupIds.add(id))
              // 异步补建反向索引
              client
                .sadd(`${this.REVERSE_INDEX_PREFIX}${platform}:${accountId}`, ...groupIds)
                .catch(() => {})
            }
          } catch {
            // 忽略错误，保持空数组
          }
        }
      }

      // 批量获取分组详情
      const groupDetailsMap = new Map()
      if (uniqueGroupIds.size > 0) {
        const detailPipeline = client.pipeline()
        const groupIdArray = Array.from(uniqueGroupIds)
        for (const groupId of groupIdArray) {
          detailPipeline.hgetall(`${this.GROUP_PREFIX}${groupId}`)
          if (!skipMemberCount) {
            detailPipeline.scard(`${this.GROUP_MEMBERS_PREFIX}${groupId}`)
          }
        }
        const detailResults = await detailPipeline.exec()

        const step = skipMemberCount ? 1 : 2
        for (let i = 0; i < groupIdArray.length; i++) {
          const groupId = groupIdArray[i]
          const [err1, groupData] = detailResults[i * step]
          if (!err1 && groupData && Object.keys(groupData).length > 0) {
            const group = { ...groupData }
            if (!skipMemberCount) {
              const [err2, memberCount] = detailResults[i * step + 1]
              group.memberCount = err2 ? 0 : memberCount || 0
            }
            groupDetailsMap.set(groupId, group)
          }
        }
      }

      // 构建最终结果
      const result = new Map()
      for (const [accountId, groupIds] of accountGroupIdsMap) {
        const groups = groupIds
          .map((gid) => groupDetailsMap.get(gid))
          .filter(Boolean)
          .sort((a, b) => new Date(b.createdAt) - new Date(a.createdAt))
        result.set(accountId, groups)
      }

      return result
    } catch (error) {
      logger.error('❌ 批量获取账户分组失败:', error)
      return new Map(accountIds.map((id) => [id, []]))
    }
  }
}

module.exports = new AccountGroupService()