import { useState } from "react"
import { useQuery, useMutation, useQueryClient } from "@tanstack/react-query"
import {
  notificationList,
  notificationMarkRead,
  notificationMarkAllRead,
} from "@/client/api"
import type { NotificationResponse } from "@/client/model"
import { Bell, CheckCheck, Mail, MailOpen, Loader2 } from "lucide-react"
import { Badge } from "@/components/ui/badge"
import { Button } from "@/components/ui/button"
import { Card, CardContent } from "@/components/ui/card"
import {
  Empty,
  EmptyDescription,
  EmptyHeader,
  EmptyMedia,
  EmptyTitle,
} from "@/components/ui/empty"

const NOTIFICATION_TYPE_LABELS: Record<string, string> = {
  mention: "Mention",
  invitation: "Invitation",
  role_change: "Role Change",
  room_created: "Room Created",
  room_deleted: "Room Deleted",
  system_announcement: "Announcement",
  project_invitation: "Project Invitation",
}

function NotificationItem({
  notification,
}: {
  notification: NotificationResponse
}) {
  const queryClient = useQueryClient()
  const markReadMutation = useMutation({
    mutationFn: () => notificationMarkRead(notification.id),
    onSuccess: () => {
      queryClient.invalidateQueries({ queryKey: ["notificationList"] })
    },
  })

  return (
    <button
      type="button"
      className="w-full rounded-2xl border text-left transition-all hover:-translate-y-0.5"
      style={{
        backgroundColor: notification.is_read
          ? "var(--surface-secondary)"
          : "var(--surface-elevated)",
        borderColor: "var(--border-subtle)",
        opacity: notification.is_read ? 0.85 : 1,
      }}
      onClick={() => {
        if (!notification.is_read) markReadMutation.mutate()
      }}
    >
      <div className="p-4">
        <div className="flex items-start gap-3">
          <div
            className="flex size-8 shrink-0 items-center justify-center rounded-xl"
            style={{
              backgroundColor: notification.is_read
                ? "var(--surface-ground)"
                : "var(--accent)",
            }}
          >
            {notification.is_read ? (
              <MailOpen
                className="size-4"
                style={{ color: "var(--text-muted)" }}
              />
            ) : (
              <Mail className="size-4 text-white" />
            )}
          </div>
          <div className="min-w-0 flex-1">
            <div className="flex flex-wrap items-center gap-2">
              <span
                className="text-[12px] font-medium"
                style={{ color: "var(--text-primary)" }}
              >
                {NOTIFICATION_TYPE_LABELS[notification.notification_type] ||
                  notification.notification_type}
              </span>
              {!notification.is_read && (
                <span
                  className="size-1.5 rounded-full"
                  style={{ backgroundColor: "var(--accent)" }}
                />
              )}
              <span
                className="ml-auto text-[11px]"
                style={{ color: "var(--text-tertiary)" }}
              >
                {new Date(notification.created_at).toLocaleString()}
              </span>
            </div>
            <p
              className="mt-1 truncate text-[13px] font-medium"
              style={{ color: "var(--text-primary)" }}
            >
              {notification.title}
            </p>
            {notification.content && (
              <p
                className="mt-1 line-clamp-2 text-[12px]"
                style={{ color: "var(--text-secondary)" }}
              >
                {notification.content}
              </p>
            )}
            {(notification.room || notification.project) && (
              <div className="mt-3 flex flex-wrap gap-2">
                {notification.project && (
                  <Badge variant="outline">{`Project: ${notification.project}`}</Badge>
                )}
                {notification.room && (
                  <Badge variant="outline">{`Room: ${notification.room}`}</Badge>
                )}
              </div>
            )}
          </div>
        </div>
      </div>
    </button>
  )
}

export function NotificationList() {
  const queryClient = useQueryClient()
  const [onlyUnread, setOnlyUnread] = useState(false)

  const { data, isLoading, isError } = useQuery({
    queryKey: ["notificationList", onlyUnread],
    queryFn: () =>
      notificationList({ only_unread: onlyUnread || undefined, limit: 50 }),
  })

  const markAllReadMutation = useMutation({
    mutationFn: () => notificationMarkAllRead(),
    onSuccess: () => {
      queryClient.invalidateQueries({ queryKey: ["notificationList"] })
    },
  })

  if (isLoading) {
    return (
      <div className="flex justify-center py-12">
        <Loader2
          className="size-6 animate-spin"
          style={{ color: "var(--accent)" }}
        />
      </div>
    )
  }

  if (isError) {
    return (
      <Empty className="border-[var(--border-subtle)] bg-[var(--surface-secondary)]">
        <EmptyHeader>
          <EmptyMedia variant="icon">
            <Bell />
          </EmptyMedia>
          <EmptyTitle>通知加载失败</EmptyTitle>
          <EmptyDescription>请刷新页面或检查网络连接。</EmptyDescription>
        </EmptyHeader>
      </Empty>
    )
  }

  const notifications = data?.data?.data?.notifications ?? []
  const unreadCount = data?.data?.data?.unread_count ?? 0

  return (
    <div className="space-y-4">
      <Card>
        <CardContent className="flex flex-wrap items-center justify-between gap-3 pt-4">
          <div className="flex items-center gap-2">
            <Bell
              className="size-4"
              style={{ color: "var(--text-tertiary)" }}
            />
            <span
              className="text-[13px]"
              style={{ color: "var(--text-secondary)" }}
            >
              {unreadCount > 0 ? `${unreadCount} unread` : "All read"}
            </span>
          </div>
          <div className="flex items-center gap-2">
            <button
              type="button"
              className="rounded-full px-3 py-1.5 text-[12px] transition-colors"
              style={{
                color: onlyUnread ? "var(--accent)" : "var(--text-secondary)",
                backgroundColor: onlyUnread
                  ? "color-mix(in srgb, var(--accent) 10%, transparent)"
                  : "transparent",
              }}
              onClick={() => setOnlyUnread(!onlyUnread)}
            >
              Unread only
            </button>
            {unreadCount > 0 && (
              <Button
                variant="outline"
                size="sm"
                className="h-7 gap-1.5 rounded-full text-[12px]"
                onClick={() => markAllReadMutation.mutate()}
                disabled={markAllReadMutation.isPending}
              >
                <CheckCheck className="size-3.5" />
                Mark all read
              </Button>
            )}
          </div>
        </CardContent>
      </Card>

      {notifications.length === 0 ? (
        <Empty className="border-[var(--border-subtle)] bg-[var(--surface-secondary)] py-14">
          <EmptyHeader>
            <EmptyMedia variant="icon">
              <Bell />
            </EmptyMedia>
            <EmptyTitle>暂无通知</EmptyTitle>
            <EmptyDescription>
              {onlyUnread ? "没有未读通知" : "你已经查看完了"}
            </EmptyDescription>
          </EmptyHeader>
        </Empty>
      ) : (
        <div className="space-y-2">
          {notifications.map((n) => (
            <NotificationItem key={n.id} notification={n} />
          ))}
        </div>
      )}
    </div>
  )
}