import { useState, useEffect, useCallback } from 'react'
import type { User, Role, PaginatedResponse } from '@/types'
import { usersApi, type UserQueryParams, type UserDetail as UserDetailType } from '@/api'
import { Card, CardContent, CardDescription, CardHeader, CardTitle } from '@/components/ui/card'
import { Button } from '@/components/ui/button'
import { Input } from '@/components/ui/input'
import { Badge } from '@/components/ui/badge'
import { Avatar, AvatarFallback, AvatarImage } from '@/components/ui/avatar'
import {
  Table,
  TableBody,
  TableCell,
  TableHead,
  TableHeader,
  TableRow,
} from '@/components/ui/table'
import {
  Select,
  SelectContent,
  SelectItem,
  SelectTrigger,
  SelectValue,
} from '@/components/ui/select'
import {
  Dialog,
  DialogContent,
  DialogDescription,
  DialogHeader,
  DialogTitle,
} from '@/components/ui/dialog'
import { PaginationNavigator } from '@/components/ui/pagination'
import UserDetail from '@/components/UserDetail'
import UserRoleDialog from '@/components/UserRoleDialog'
import { Search, RefreshCw, Eye, UserPlus, Ban, Unlock, Loader2 } from 'lucide-react'

// 状态颜色映射
const statusColors: Record<string, string> = {
  active: 'bg-green-500',
  banned: 'bg-red-500',
  deleted: 'bg-gray-500',
}

// 状态文本映射
const statusText: Record<string, string> = {
  active: '正常',
  banned: '已封禁',
  deleted: '已删除',
}

// 角色颜色映射
const roleColors: Record<string, string> = {
  admin: 'bg-red-500',
  moderator: 'bg-orange-500',
  user: 'bg-blue-500',
  super_admin: 'bg-purple-500',
}

export default function Users() {
  // 状态
  const [users, setUsers] = useState<User[]>([])
  const [loading, setLoading] = useState(true)
  const [total, setTotal] = useState(0)
  const [page, setPage] = useState(1)
  const pageSize = 10
  const [keyword, setKeyword] = useState('')
  const [statusFilter, setStatusFilter] = useState<string>('all')
  
  // 详情对话框
  const [detailOpen, setDetailOpen] = useState(false)
  const [selectedUser, setSelectedUser] = useState<UserDetailType | null>(null)
  const [detailLoading, setDetailLoading] = useState(false)
  
  // 角色对话框
  const [roleDialogOpen, setRoleDialogOpen] = useState(false)
  const [roleDialogUser, setRoleDialogUser] = useState<User | null>(null)
  const [allRoles, setAllRoles] = useState<Role[]>([])

  // 加载用户列表
  const loadUsers = useCallback(async () => {
    setLoading(true)
    try {
      const params: UserQueryParams = {
        page,
        page_size: pageSize,
        keyword: keyword || undefined,
        status: statusFilter !== 'all' ? statusFilter : undefined,
      }
      const response = await usersApi.getUsers(params)
      const data = response.data.data as PaginatedResponse<User>
      setUsers(data.list || [])
      setTotal(data.total || 0)
    } catch (error) {
      console.error('Failed to load users:', error)
      setUsers([])
      setTotal(0)
    } finally {
      setLoading(false)
    }
  }, [page, pageSize, keyword, statusFilter])

  // 加载所有角色
  const loadAllRoles = useCallback(async () => {
    try {
      const { rolesApi } = await import('@/api')
      const response = await rolesApi.getRoles()
      const roles = response.data.data || []
      setAllRoles(roles.map(r => ({
        id: r.name, // 使用 name 作为 id
        name: r.name,
        description: r.description,
        created_at: '', // 后端列表接口不返回这些字段
        updated_at: '',
      })))
    } catch (error) {
      console.error('Failed to load roles:', error)
    }
  }, [])

  // 初始加载
  useEffect(() => {
    loadUsers()
  }, [loadUsers])

  // 加载角色列表（仅一次）
  useEffect(() => {
    loadAllRoles()
  }, [loadAllRoles])

  // 查看用户详情
  const handleViewDetail = async (user: User) => {
    setDetailLoading(true)
    setDetailOpen(true)
    try {
      const response = await usersApi.getUserById(user.id)
      setSelectedUser(response.data.data)
    } catch (error) {
      console.error('Failed to load user detail:', error)
      setSelectedUser(null)
    } finally {
      setDetailLoading(false)
    }
  }

  // 打开角色分配对话框
  const handleOpenRoleDialog = (user: User) => {
    setRoleDialogUser(user)
    setRoleDialogOpen(true)
  }

  // 分配角色
  const handleAssignRole = async (userId: string, role: string) => {
    await usersApi.assignRole(userId, role)
    // 刷新用户列表
    loadUsers()
    // 如果详情对话框打开，也刷新详情
    if (selectedUser?.id === userId) {
      const response = await usersApi.getUserById(userId)
      setSelectedUser(response.data.data)
    }
  }

  // 移除角色
  const handleRemoveRole = async (userId: string, role: string) => {
    await usersApi.removeRole(userId, role)
    // 刷新用户列表
    loadUsers()
    // 如果详情对话框打开，也刷新详情
    if (selectedUser?.id === userId) {
      const response = await usersApi.getUserById(userId)
      setSelectedUser(response.data.data)
    }
  }

  // 切换用户状态
  const handleToggleStatus = async (user: User) => {
    const newStatus = user.status === 'active' ? 'banned' : 'active'
    try {
      await usersApi.updateUserStatus(user.id, newStatus)
      // 刷新用户列表
      loadUsers()
      // 如果详情对话框打开，也刷新详情
      if (selectedUser?.id === user.id) {
        const response = await usersApi.getUserById(user.id)
        setSelectedUser(response.data.data)
      }
    } catch (error) {
      console.error('Failed to update user status:', error)
    }
  }

  // 搜索
  const handleSearch = () => {
    setPage(1)
    loadUsers()
  }

  // 刷新
  const handleRefresh = () => {
    loadUsers()
  }

  // 分页变化
  const handlePageChange = (newPage: number) => {
    setPage(newPage)
  }

  // 计算总页数
  const totalPages = Math.ceil(total / pageSize)

  // 获取头像fallback文字
  const getInitials = (name: string) => {
    return name.slice(0, 2).toUpperCase()
  }

  // 格式化日期
  const formatDate = (dateString: string) => {
    return new Date(dateString).toLocaleDateString('zh-CN', {
      year: 'numeric',
      month: '2-digit',
      day: '2-digit',
    })
  }

  return (
    <div className="space-y-6">
      <div className="flex items-center justify-between">
        <div>
          <h1 className="text-3xl font-bold">用户管理</h1>
          <p className="text-muted-foreground">管理系统用户账户</p>
        </div>
        <Button onClick={handleRefresh} disabled={loading}>
          {loading ? <Loader2 className="h-4 w-4 animate-spin" /> : <RefreshCw className="h-4 w-4" />}
          刷新
        </Button>
      </div>
      
      {/* 筛选栏 */}
      <Card>
        <CardHeader>
          <CardTitle>筛选条件</CardTitle>
          <CardDescription>根据条件筛选用户</CardDescription>
        </CardHeader>
        <CardContent>
          <div className="flex flex-wrap gap-4">
            <div className="flex gap-2 flex-1 min-w-[300px]">
              <Input
                placeholder="搜索用户名或邮箱..."
                value={keyword}
                onChange={(e) => setKeyword(e.target.value)}
                onKeyDown={(e) => e.key === 'Enter' && handleSearch()}
                className="max-w-sm"
              />
              <Button variant="outline" onClick={handleSearch}>
                <Search className="h-4 w-4 mr-2" />
                搜索
              </Button>
            </div>
            <Select value={statusFilter} onValueChange={setStatusFilter}>
              <SelectTrigger className="w-[150px]">
                <SelectValue placeholder="状态筛选" />
              </SelectTrigger>
              <SelectContent>
                <SelectItem value="all">全部状态</SelectItem>
                <SelectItem value="active">正常</SelectItem>
                <SelectItem value="banned">已封禁</SelectItem>
                <SelectItem value="deleted">已删除</SelectItem>
              </SelectContent>
            </Select>
          </div>
        </CardContent>
      </Card>
      
      {/* 用户表格 */}
      <Card>
        <CardHeader>
          <CardTitle>用户列表</CardTitle>
          <CardDescription>
            共 {total} 个用户
          </CardDescription>
        </CardHeader>
        <CardContent>
          <Table>
            <TableHeader>
              <TableRow>
                <TableHead className="w-[60px]">ID</TableHead>
                <TableHead className="w-[60px]">头像</TableHead>
                <TableHead>用户名</TableHead>
                <TableHead>邮箱</TableHead>
                <TableHead>状态</TableHead>
                <TableHead>角色</TableHead>
                <TableHead>注册时间</TableHead>
                <TableHead className="w-[200px]">操作</TableHead>
              </TableRow>
            </TableHeader>
            <TableBody>
              {loading ? (
                <TableRow>
                  <TableCell colSpan={8} className="text-center py-8">
                    <Loader2 className="h-6 w-6 animate-spin mx-auto text-muted-foreground" />
                    <p className="text-muted-foreground mt-2">加载中...</p>
                  </TableCell>
                </TableRow>
              ) : users.length === 0 ? (
                <TableRow>
                  <TableCell colSpan={8} className="text-center py-8 text-muted-foreground">
                    暂无数据
                  </TableCell>
                </TableRow>
              ) : (
                users.map((user) => (
                  <TableRow
                    key={user.id}
                    className="cursor-pointer hover:bg-muted/50"
                    onClick={() => handleViewDetail(user)}
                  >
                    <TableCell>{user.id}</TableCell>
                    <TableCell>
                      <Avatar className="h-8 w-8">
                        <AvatarImage src={user.avatar} alt={user.nickname || user.username} />
                        <AvatarFallback>{getInitials(user.nickname || user.username)}</AvatarFallback>
                      </Avatar>
                    </TableCell>
                    <TableCell>
                      <div>
                        <p className="font-medium">{user.nickname || user.username}</p>
                        <p className="text-xs text-muted-foreground">@{user.username}</p>
                      </div>
                    </TableCell>
                    <TableCell>{user.email}</TableCell>
                    <TableCell>
                      <Badge className={statusColors[user.status] || 'bg-gray-500'}>
                        {statusText[user.status] || user.status}
                      </Badge>
                    </TableCell>
                    <TableCell>
                      <div className="flex flex-wrap gap-1">
                        {user.roles?.slice(0, 2).map((role: Role) => (
                          <Badge key={role.id} className={roleColors[role.name] || 'bg-gray-500'} variant="secondary">
                            {role.name}
                          </Badge>
                        ))}
                        {user.roles && user.roles.length > 2 && (
                          <Badge variant="outline">+{user.roles.length - 2}</Badge>
                        )}
                      </div>
                    </TableCell>
                    <TableCell>{formatDate(user.created_at)}</TableCell>
                    <TableCell onClick={(e) => e.stopPropagation()}>
                      <div className="flex gap-1">
                        <Button
                          variant="ghost"
                          size="sm"
                          onClick={() => handleViewDetail(user)}
                          title="查看详情"
                        >
                          <Eye className="h-4 w-4" />
                        </Button>
                        <Button
                          variant="ghost"
                          size="sm"
                          onClick={() => handleOpenRoleDialog(user)}
                          title="分配角色"
                        >
                          <UserPlus className="h-4 w-4" />
                        </Button>
                        {user.status === 'active' ? (
                          <Button
                            variant="ghost"
                            size="sm"
                            onClick={() => handleToggleStatus(user)}
                            title="封禁用户"
                          >
                            <Ban className="h-4 w-4 text-red-500" />
                          </Button>
                        ) : user.status === 'banned' ? (
                          <Button
                            variant="ghost"
                            size="sm"
                            onClick={() => handleToggleStatus(user)}
                            title="解除封禁"
                          >
                            <Unlock className="h-4 w-4 text-green-500" />
                          </Button>
                        ) : null}
                      </div>
                    </TableCell>
                  </TableRow>
                ))
              )}
            </TableBody>
          </Table>
          
          {/* 分页 */}
          {totalPages > 1 && (
            <div className="mt-4 flex justify-center">
              <PaginationNavigator
                currentPage={page}
                totalPages={totalPages}
                onPageChange={handlePageChange}
              />
            </div>
          )}
        </CardContent>
      </Card>

      {/* 用户详情对话框 */}
      <Dialog open={detailOpen} onOpenChange={setDetailOpen}>
        <DialogContent className="max-w-lg max-h-[90vh] overflow-y-auto">
          <DialogHeader>
            <DialogTitle>用户详情</DialogTitle>
            <DialogDescription>查看用户详细信息</DialogDescription>
          </DialogHeader>
          {detailLoading ? (
            <div className="flex items-center justify-center py-8">
              <Loader2 className="h-8 w-8 animate-spin text-muted-foreground" />
            </div>
          ) : selectedUser ? (
            <UserDetail
              user={selectedUser}
              onAssignRole={() => {
                setDetailOpen(false)
                setRoleDialogUser({
                  id: selectedUser.id,
                  username: selectedUser.username,
                  nickname: selectedUser.nickname,
                  email: selectedUser.email,
                  avatar: selectedUser.avatar,
                  status: selectedUser.status,
                  roles: selectedUser.roles,
                  created_at: selectedUser.created_at,
                  updated_at: selectedUser.updated_at,
                })
                setRoleDialogOpen(true)
              }}
              onToggleStatus={() => handleToggleStatus(selectedUser)}
            />
          ) : (
            <p className="text-center text-muted-foreground py-8">加载失败</p>
          )}
        </DialogContent>
      </Dialog>

      {/* 角色分配对话框 */}
      {roleDialogUser && (
        <UserRoleDialog
          open={roleDialogOpen}
          onOpenChange={setRoleDialogOpen}
          userId={roleDialogUser.id}
          username={roleDialogUser.nickname || roleDialogUser.username}
          currentRoles={roleDialogUser.roles || []}
          allRoles={allRoles}
          onAssignRole={handleAssignRole}
          onRemoveRole={handleRemoveRole}
        />
      )}
    </div>
  )
}