"use client"

import {useEffect, useState} from "react"
import {Button} from "@/components/ui/button"
import {Dialog, DialogContent, DialogDescription, DialogHeader, DialogTitle} from "@/components/ui/dialog"
import {Input} from "@/components/ui/input"
import {Label} from "@/components/ui/label"
import {Switch} from "@/components/ui/switch"
import {useAdminUsers} from "@/contexts/admin-users-context"
import {useAuth} from "@/components/providers/auth-provider"
import type {AdminUser} from "@/lib/services/admin"
import {
  AlertDialog,
  AlertDialogAction,
  AlertDialogCancel,
  AlertDialogContent,
  AlertDialogDescription,
  AlertDialogFooter,
  AlertDialogHeader,
  AlertDialogTitle
} from "@/components/ui/alert-dialog"
import {Loader2} from "lucide-react"

interface EditUserForm {
  nickname: string
  email: string
  is_admin: boolean
  password?: string
}

export function EditUserModal({
  isOpen,
  onClose,
  user,
}: {
  isOpen: boolean
  onClose: () => void
  user: AdminUser | null
}) {
  const { updateUser, deleteUser, getUserDetail } = useAdminUsers()
  const { user: currentUser } = useAuth()

  const isSelf = currentUser && user && currentUser.id.toString() === user.id.toString()

  const [form, setForm] = useState<EditUserForm>({
    nickname: "",
    email: "",
    is_admin: false,
    password: "",
  })
  const [saving, setSaving] = useState(false)
  const [errors, setErrors] = useState<Record<string, string>>({})
  const [showDeleteConfirm, setShowDeleteConfirm] = useState(false)

  useEffect(() => {
    let active = true
    if (isOpen && user) {
      setForm({
        nickname: user.nickname || "",
        email: user.email || "",
        is_admin: user.is_admin || false,
        password: "",
      })
      setErrors({})

      getUserDetail(user.id)
        .then((detail) => {
          if (active && detail) {
            setForm({
              nickname: detail.nickname || "",
              email: detail.email || "",
              is_admin: detail.is_admin || false,
              password: "",
            })
          }
        })
        .catch(() => {
          // ignore fetching error
        })
    } else {
      setSaving(false)
    }
    return () => {
      active = false
    }
  }, [isOpen, user, getUserDetail])

  const validate = () => {
    const newErrors: Record<string, string> = {}

    if (!form.email.trim()) {
      newErrors.email = "邮箱不能为空"
    } else if (!/^[^\s@]+@[^\s@]+\.[^\s@]+$/.test(form.email.trim())) {
      newErrors.email = "邮箱格式不正确"
    }

    if (form.password && form.password.length < 8) {
      newErrors.password = "密码长度不能少于 8 位"
    }

    setErrors(newErrors)
    return Object.keys(newErrors).length === 0
  }

  const handleSave = async (e: React.FormEvent) => {
    e.preventDefault()
    if (!user || !validate()) return

    setSaving(true)
    try {
      await updateUser(user.id, {
        nickname: form.nickname.trim() || undefined,
        email: form.email.trim(),
        is_admin: form.is_admin,
        password: form.password?.trim() || undefined,
      })
      onClose()
    } catch {
      // Errors are handled by context toast notifications
    } finally {
      setSaving(false)
    }
  }

  const handleDelete = async () => {
    if (!user) return
    setSaving(true)
    try {
      await deleteUser(user)
      onClose()
    } catch {
      // Errors are handled by context toast notifications
    } finally {
      setSaving(false)
      setShowDeleteConfirm(false)
    }
  }

  if (!user) return null

  return (
    <>
      <Dialog open={isOpen} onOpenChange={(open) => !open && onClose()}>
        <DialogContent className="max-w-md">
          <DialogHeader>
            <DialogTitle>编辑用户</DialogTitle>
            <DialogDescription>
              修改用户档案、授予/撤销管理权限或重置其密码。
            </DialogDescription>
          </DialogHeader>

          <form onSubmit={handleSave} className="space-y-4 pt-2">
            <div className="space-y-1.5">
              <Label htmlFor="username" className="text-xs text-muted-foreground">用户名 (不可修改)</Label>
              <Input
                id="username"
                value={user.username}
                disabled
                className="bg-muted/50 cursor-not-allowed select-none font-mono"
              />
            </div>

            <div className="space-y-1.5">
              <Label htmlFor="nickname">昵称 (选填)</Label>
              <Input
                id="nickname"
                value={form.nickname}
                onChange={(e) => setForm((prev) => ({ ...prev, nickname: e.target.value }))}
                placeholder="请输入昵称"
              />
            </div>

            <div className="space-y-1.5">
              <Label htmlFor="email">邮箱</Label>
              <Input
                id="email"
                type="email"
                value={form.email}
                onChange={(e) => setForm((prev) => ({ ...prev, email: e.target.value }))}
                placeholder="请输入邮箱地址"
              />
              {errors.email && (
                <p className="text-xs text-destructive">{errors.email}</p>
              )}
            </div>

            <div className="space-y-1.5">
              <Label htmlFor="password">重置密码 (选填)</Label>
              <Input
                id="password"
                type="password"
                value={form.password}
                onChange={(e) => setForm((prev) => ({ ...prev, password: e.target.value }))}
                placeholder="留空表示保持当前密码，输入则重置 (至少 8 位)"
              />
              {errors.password && (
                <p className="text-xs text-destructive">{errors.password}</p>
              )}
            </div>

            <div className="flex items-center justify-between rounded-lg border border-dashed p-3 bg-muted/10">
              <div>
                <div className="font-medium text-sm">管理员权限</div>
                <div className="text-xs text-muted-foreground">
                  {isSelf ? "不能撤销当前登录用户的管理员权限。" : "开启后此账号将拥有后台管理权限。"}
                </div>
              </div>
              <Switch
                checked={form.is_admin}
                disabled={!!isSelf || saving}
                onCheckedChange={async (checked) => {
                  setForm((prev) => ({ ...prev, is_admin: checked }))
                  setSaving(true)
                  try {
                    await updateUser(user.id, {
                      nickname: form.nickname.trim() || undefined,
                      email: form.email.trim(),
                      is_admin: checked,
                    })
                  } catch {
                    setForm((prev) => ({ ...prev, is_admin: !checked }))
                  } finally {
                    setSaving(false)
                  }
                }}
              />
            </div>

            <div className="flex justify-between items-center pt-2 border-t mt-2">
              <div>
                {!user.is_admin && (
                  <Button
                    type="button"
                    variant="destructive"
                    onClick={() => setShowDeleteConfirm(true)}
                    disabled={saving}
                  >
                    删除用户
                  </Button>
                )}
              </div>
              <div className="flex gap-2">
                <Button variant="outline" type="button" onClick={onClose} disabled={saving}>
                  取消
                </Button>
                <Button type="submit" disabled={saving} variant="secondary">
                  {saving ? "保存中..." : "保存"}
                </Button>
              </div>
            </div>
          </form>
        </DialogContent>
      </Dialog>

      <AlertDialog open={showDeleteConfirm} onOpenChange={setShowDeleteConfirm}>
        <AlertDialogContent>
          <AlertDialogHeader>
            <AlertDialogTitle>确认删除用户</AlertDialogTitle>
            <AlertDialogDescription>
              确定要删除用户 {user.nickname || user.username} 吗？该操作会移除用户账号，删除后无法撤销。
            </AlertDialogDescription>
          </AlertDialogHeader>
          <AlertDialogFooter>
            <AlertDialogCancel disabled={saving}>取消</AlertDialogCancel>
            <AlertDialogAction
              onClick={(e) => {
                e.preventDefault()
                handleDelete()
              }}
              disabled={saving}
            >
              {saving && <Loader2 className="size-3 animate-spin mr-1" />}
              确认删除
            </AlertDialogAction>
          </AlertDialogFooter>
        </AlertDialogContent>
      </AlertDialog>
    </>
  )
}