'use client';

import { useEffect, useState } from 'react';
import { useForm } from 'react-hook-form';
import { zodResolver } from '@hookform/resolvers/zod';
import * as z from 'zod';
import { Card, CardContent, CardHeader, CardTitle } from '@/components/ui/card';
import { Button } from '@/components/ui/button';
import { Input } from '@/components/ui/input';
import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from '@/components/ui/select';
import { Form, FormControl, FormField, FormItem, FormLabel, FormMessage } from '@/components/ui/form';
import { Dialog, DialogContent, DialogHeader, DialogTitle, DialogTrigger } from '@/components/ui/dialog';
import { Table, TableBody, TableCell, TableHead, TableHeader, TableRow } from '@/components/ui/table';
import { Avatar, AvatarFallback } from '@/components/ui/avatar';
import { useUser } from '@/components/user-context';
import { ROLE_LABELS } from '@/lib/constants';
import type { User } from '@/types/database';
import { toast } from 'sonner';
import { getErrorMessage } from '@/lib/error-utils';
import { Plus, Pencil, Trash2, Users, Loader2, Crown, Briefcase, User as UserIcon } from 'lucide-react';
import {
  AlertDialog,
  AlertDialogAction,
  AlertDialogCancel,
  AlertDialogContent,
  AlertDialogDescription,
  AlertDialogFooter,
  AlertDialogHeader,
  AlertDialogTitle,
} from '@/components/ui/alert-dialog';
import { fetchApi } from '@/lib/api-client';

const userSchema = z.object({
  name: z.string().min(1, '名称不能为空'),
  role: z.enum(['owner', 'pm', 'member']),
  username: z.string().min(1, '账号不能为空'),
  password: z.string().optional(),
});

type UserFormValues = z.infer<typeof userSchema>;

const roleIcons = {
  owner: Crown,
  pm: Briefcase,
  member: UserIcon,
};

export default function AdminUsersPage() {
  const { currentUser, users, refreshUsers } = useUser();
  const [isLoading, setIsLoading] = useState(false);
  const [isDialogOpen, setIsDialogOpen] = useState(false);
  const [editingUser, setEditingUser] = useState<User | null>(null);
  const [isSubmitting, setIsSubmitting] = useState(false);
  const [deleteUserId, setDeleteUserId] = useState<string | null>(null);
  const [isDeleteOpen, setIsDeleteOpen] = useState(false);
  const [isDeleting, setIsDeleting] = useState(false);

  const form = useForm<UserFormValues>({
    resolver: zodResolver(userSchema),
    defaultValues: {
      name: '',
      role: 'member',
      username: '',
      password: '',
    },
  });

  const onSubmit = async (values: UserFormValues) => {
    setIsSubmitting(true);
    try {
      if (!editingUser && !values.password) {
        throw new Error('请设置初始密码');
      }

      const url = editingUser ? `/api/users/${editingUser.id}` : '/api/users';
      const method = editingUser ? 'PATCH' : 'POST';

      const payload = {
        name: values.name,
        role: values.role,
        username: values.username,
        password: values.password ? values.password : undefined,
      };

      const res = await fetchApi(url, {
        method,
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify(payload),
      });

      if (!res.ok) {
        const data = await res.json();
        throw new Error(data.error || '操作失败');
      }

      toast.success(editingUser ? '用户已更新' : '用户已创建');
      setIsDialogOpen(false);
      setEditingUser(null);
      form.reset();
      refreshUsers();
    } catch (error) {
      toast.error(error instanceof Error ? error.message : '操作失败');
    } finally {
      setIsSubmitting(false);
    }
  };

  const handleEdit = (user: User) => {
    setEditingUser(user);
    form.reset({
      name: user.name,
      role: user.role,
      username: user.username || '',
      password: '',
    });
    setIsDialogOpen(true);
  };

  const requestDelete = (userId: string) => {
    setDeleteUserId(userId);
    setIsDeleteOpen(true);
  };

  const confirmDelete = async () => {
    if (!deleteUserId) return;
    setIsDeleting(true);
    try {
      const res = await fetchApi(`/api/users/${deleteUserId}`, { method: 'DELETE' });
      const data = await res.json().catch(() => ({}));
      if (!res.ok) throw new Error(data?.error || '删除失败');

      toast.success('用户已删除');
      refreshUsers();
    } catch (error) {
      toast.error(getErrorMessage(error));
    } finally {
      setIsDeleting(false);
      setIsDeleteOpen(false);
      setDeleteUserId(null);
    }
  };

  const handleDialogClose = () => {
    setIsDialogOpen(false);
    setEditingUser(null);
    form.reset();
  };

  if (currentUser?.role !== 'owner') {
    return (
      <div className="max-w-4xl mx-auto px-4 py-8 text-center">
        <p className="text-muted-foreground">仅老板可访问此页面</p>
      </div>
    );
  }

  return (
    <div className="max-w-4xl mx-auto px-4 py-8">
      <div className="flex items-center justify-between mb-8">
        <div>
          <h1 className="text-2xl font-bold text-slate-800 flex items-center gap-2">
            <Users className="h-6 w-6 text-teal-600" />
            用户管理
          </h1>
          <p className="text-muted-foreground mt-1">管理系统用户</p>
        </div>

        <Dialog open={isDialogOpen} onOpenChange={setIsDialogOpen}>
          <DialogTrigger asChild>
            <Button className="bg-teal-600 hover:bg-teal-700">
              <Plus className="h-4 w-4 mr-2" />
              新建用户
            </Button>
          </DialogTrigger>
          <DialogContent>
            <DialogHeader>
              <DialogTitle>{editingUser ? '编辑用户' : '新建用户'}</DialogTitle>
            </DialogHeader>
            <Form {...form}>
              <form onSubmit={form.handleSubmit(onSubmit)} className="space-y-4">
                <FormField
                  control={form.control}
                  name="name"
                  render={({ field }) => (
                    <FormItem>
                      <FormLabel>名称 *</FormLabel>
                      <FormControl>
                        <Input placeholder="输入用户名称" {...field} />
                      </FormControl>
                      <FormMessage />
                    </FormItem>
                  )}
                />

                <FormField
                  control={form.control}
                  name="username"
                  render={({ field }) => (
                    <FormItem>
                      <FormLabel>账号 *</FormLabel>
                      <FormControl>
                        <Input placeholder="输入登录账号" {...field} />
                      </FormControl>
                      <FormMessage />
                    </FormItem>
                  )}
                />

                <FormField
                  control={form.control}
                  name="password"
                  render={({ field }) => (
                    <FormItem>
                      <FormLabel>{editingUser ? '重置密码' : '密码 *'}</FormLabel>
                      <FormControl>
                        <Input type="password" placeholder={editingUser ? '留空则不修改' : '输入初始密码'} {...field} />
                      </FormControl>
                      <FormMessage />
                    </FormItem>
                  )}
                />

                <FormField
                  control={form.control}
                  name="role"
                  render={({ field }) => (
                    <FormItem>
                      <FormLabel>角色 *</FormLabel>
                      <Select onValueChange={field.onChange} defaultValue={field.value}>
                        <FormControl>
                          <SelectTrigger>
                            <SelectValue />
                          </SelectTrigger>
                        </FormControl>
                        <SelectContent>
                          {Object.entries(ROLE_LABELS).map(([key, label]) => (
                            <SelectItem key={key} value={key}>
                              {label}
                            </SelectItem>
                          ))}
                        </SelectContent>
                      </Select>
                      <FormMessage />
                    </FormItem>
                  )}
                />

                <div className="flex gap-2 pt-4">
                  <Button type="submit" disabled={isSubmitting} className="bg-teal-600 hover:bg-teal-700">
                    {isSubmitting && <Loader2 className="h-4 w-4 mr-2 animate-spin" />}
                    {editingUser ? '保存' : '创建'}
                  </Button>
                  <Button type="button" variant="outline" onClick={handleDialogClose}>
                    取消
                  </Button>
                </div>
              </form>
            </Form>
          </DialogContent>
        </Dialog>
      </div>

      <Card>
        <CardContent className="p-0">
          <Table>
            <TableHeader>
              <TableRow>
                <TableHead>用户</TableHead>
                <TableHead>账号</TableHead>
                <TableHead>角色</TableHead>
                <TableHead>创建时间</TableHead>
                <TableHead className="text-right">操作</TableHead>
              </TableRow>
            </TableHeader>
            <TableBody>
              {users.map(user => {
                const RoleIcon = roleIcons[user.role];
                return (
                  <TableRow key={user.id}>
                    <TableCell>
                      <div className="flex items-center gap-3">
                        <Avatar className="h-8 w-8">
                          <AvatarFallback className="bg-slate-100">
                            {user.name.charAt(0)}
                          </AvatarFallback>
                        </Avatar>
                        <span className="font-medium">{user.name}</span>
                      </div>
                    </TableCell>
                    <TableCell className="text-muted-foreground">
                      {user.username || '-'}
                    </TableCell>
                    <TableCell>
                      <div className="flex items-center gap-2">
                        <RoleIcon className="h-4 w-4 text-muted-foreground" />
                        {ROLE_LABELS[user.role]}
                      </div>
                    </TableCell>
                    <TableCell className="text-muted-foreground">
                      {new Date(user.created_at).toLocaleDateString('zh-CN')}
                    </TableCell>
                    <TableCell className="text-right">
                      <Button variant="ghost" size="sm" onClick={() => handleEdit(user)}>
                        <Pencil className="h-4 w-4" />
                      </Button>
                      <Button
                        variant="ghost"
                        size="sm"
                        onClick={() => requestDelete(user.id)}
                        disabled={user.role === 'owner'}
                      >
                        <Trash2 className="h-4 w-4 text-rose-500" />
                      </Button>
                    </TableCell>
                  </TableRow>
                );
              })}
            </TableBody>
          </Table>
        </CardContent>
      </Card>

      <AlertDialog open={isDeleteOpen} onOpenChange={setIsDeleteOpen}>
        <AlertDialogContent>
          <AlertDialogHeader>
            <AlertDialogTitle>确认删除用户？</AlertDialogTitle>
            <AlertDialogDescription>
              删除后无法恢复。
            </AlertDialogDescription>
          </AlertDialogHeader>
          <AlertDialogFooter>
            <AlertDialogCancel disabled={isDeleting}>取消</AlertDialogCancel>
            <AlertDialogAction
              className="bg-rose-600 hover:bg-rose-700"
              onClick={confirmDelete}
              disabled={isDeleting}
            >
              {isDeleting ? '删除中...' : '确认删除'}
            </AlertDialogAction>
          </AlertDialogFooter>
        </AlertDialogContent>
      </AlertDialog>
    </div>
  );
}