"use client";

import { useState, useEffect } from "react";
import { useRouter } from "next/navigation";
import { useSocket } from "@/components/socket-provider";
import { Card, CardContent, CardHeader, CardTitle } from "@/components/ui/card";
import { Button } from "@/components/ui/button";
import { Badge } from "@/components/ui/badge";
import { Separator } from "@/components/ui/separator";
import { Bell, CheckCheck, ArrowLeft } from "lucide-react";
import { useGetNotifications } from "@/features/notifications/api/use-get-notifications";
import { useMarkNotificationsRead } from "@/features/notifications/api/use-mark-notifications-read";
import { formatDistanceToNow } from "date-fns";
import { toast } from "sonner";

interface Notification {
  id: string;
  type: "MENTION" | "TASK_ASSIGNED" | "WORKSPACE_ADDED" | "COMMENT_REPLY";
  title: string;
  message: string;
  isRead: boolean;
  createdAt: string;
  task?: {
    id: string;
    name: string;
  };
  comment?: {
    id: string;
    content: string;
  };
  workspace: {
    id: string;
    name: string;
  };
  data?: any;
}

export default function NotificationsPage() {
  const router = useRouter();
  const [selectedIds, setSelectedIds] = useState<string[]>([]);
  const { socket } = useSocket();
  
  const { data: notifications = [], refetch } = useGetNotifications({});
  const { mutate: markAsRead, isPending } = useMarkNotificationsRead();

  const unreadNotifications = notifications.filter((n: Notification) => !n.isRead);
  const readNotifications = notifications.filter((n: Notification) => n.isRead);

  // Listen for real-time notifications
  useEffect(() => {
    if (socket) {
      const handleNewNotification = () => {
        refetch();
      };

      socket.on("notification", handleNewNotification);

      return () => {
        socket.off("notification", handleNewNotification);
      };
    }
  }, [socket, refetch]);

  const handleNotificationClick = (notification: Notification) => {
    // Mark as read if not already read
    if (!notification.isRead) {
      markAsRead(
        { json: { notificationIds: [notification.id] } },
        {
          onSuccess: () => {
            refetch();
          },
        }
      );
    }

    // Navigate to the relevant page
    if (notification.task) {
      if (notification.comment) {
        // Navigate to task and scroll to comment
        router.push(`/workspaces/${notification.workspace.id}/tasks/${notification.task.id}?comment=${notification.comment.id}`);
      } else {
        // Navigate to task
        router.push(`/workspaces/${notification.workspace.id}/tasks/${notification.task.id}`);
      }
    } else if (notification.type === "WORKSPACE_ADDED") {
      // Navigate to workspace
      router.push(`/workspaces/${notification.workspace.id}`);
    }
  };

  const handleMarkAllAsRead = () => {
    const unreadIds = unreadNotifications.map((n: Notification) => n.id);
    if (unreadIds.length === 0) {
      toast.info("No unread notifications");
      return;
    }

    markAsRead(
      { json: { notificationIds: unreadIds } },
      {
        onSuccess: () => {
          refetch();
          toast.success("All notifications marked as read");
        },
      }
    );
  };

  const getNotificationIcon = (type: string) => {
    switch (type) {
      case "MENTION":
        return "@";
      case "TASK_ASSIGNED":
        return "📋";
      case "COMMENT_REPLY":
        return "💬";
      case "WORKSPACE_ADDED":
        return "🏢";
      default:
        return "🔔";
    }
  };

  const getNotificationTypeColor = (type: string) => {
    switch (type) {
      case "MENTION":
        return "bg-blue-100 text-blue-800 dark:bg-blue-900 dark:text-blue-300";
      case "TASK_ASSIGNED":
        return "bg-green-100 text-green-800 dark:bg-green-900 dark:text-green-300";
      case "COMMENT_REPLY":
        return "bg-purple-100 text-purple-800 dark:bg-purple-900 dark:text-purple-300";
      case "WORKSPACE_ADDED":
        return "bg-orange-100 text-orange-800 dark:bg-orange-900 dark:text-orange-300";
      default:
        return "bg-gray-100 text-gray-800 dark:bg-gray-900 dark:text-gray-300";
    }
  };

  const renderNotification = (notification: Notification) => (
    <Card
      key={notification.id}
      className={`cursor-pointer transition-colors hover:bg-accent ${
        !notification.isRead ? "border-l-4 border-l-blue-500 bg-blue-50/50 dark:bg-blue-950/20" : ""
      }`}
      onClick={() => handleNotificationClick(notification)}
    >
      <CardContent className="p-4">
        <div className="flex items-start justify-between gap-3">
          <div className="flex items-start gap-3 flex-1">
            <div className="flex-shrink-0 w-8 h-8 rounded-full bg-muted flex items-center justify-center text-sm">
              {getNotificationIcon(notification.type)}
            </div>
            <div className="flex-1 min-w-0">
              <div className="flex items-center gap-2 mb-1">
                <h4 className="font-medium text-sm truncate">{notification.title}</h4>
                {!notification.isRead && (
                  <div className="w-2 h-2 bg-blue-500 rounded-full flex-shrink-0" />
                )}
              </div>
              <p className="text-sm text-muted-foreground mb-2">{notification.message}</p>
              <div className="flex items-center gap-2">
                <Badge variant="secondary" className={getNotificationTypeColor(notification.type)}>
                  {notification.type.replace("_", " ").toLowerCase()}
                </Badge>
                <span className="text-xs text-muted-foreground">
                  {formatDistanceToNow(new Date(notification.createdAt), { addSuffix: true })}
                </span>
              </div>
            </div>
          </div>
        </div>
      </CardContent>
    </Card>
  );

  return (
    <div className="container mx-auto p-6 max-w-4xl">
      <div className="flex items-center justify-between mb-6">
        <div className="flex items-center gap-3">
          <Button variant="outline" size="sm" onClick={() => router.back()}>
            <ArrowLeft className="h-4 w-4 mr-2" />
            Back
          </Button>
          <div className="flex items-center gap-2">
            <Bell className="h-6 w-6" />
            <h1 className="text-2xl font-semibold">All Notifications</h1>
            {unreadNotifications.length > 0 && (
              <Badge variant="destructive">{unreadNotifications.length}</Badge>
            )}
          </div>
        </div>
        
        {unreadNotifications.length > 0 && (
          <Button
            variant="outline"
            size="sm"
            onClick={handleMarkAllAsRead}
            disabled={isPending}
          >
            <CheckCheck className="h-4 w-4 mr-2" />
            Mark all as read
          </Button>
        )}
      </div>

      <div className="space-y-6">
        {unreadNotifications.length > 0 && (
          <div>
            <h2 className="text-lg font-medium mb-3 flex items-center gap-2">
              Unread ({unreadNotifications.length})
              <div className="w-2 h-2 bg-blue-500 rounded-full" />
            </h2>
            <div className="space-y-2">
              {unreadNotifications.map(renderNotification)}
            </div>
          </div>
        )}

        {unreadNotifications.length > 0 && readNotifications.length > 0 && (
          <Separator />
        )}

        {readNotifications.length > 0 && (
          <div>
            <h2 className="text-lg font-medium mb-3 text-muted-foreground">
              Read ({readNotifications.length})
            </h2>
            <div className="space-y-2">
              {readNotifications.map(renderNotification)}
            </div>
          </div>
        )}

        {notifications.length === 0 && (
          <Card>
            <CardContent className="p-8 text-center">
              <Bell className="h-12 w-12 mx-auto mb-4 text-muted-foreground" />
              <h3 className="text-lg font-medium mb-2">No notifications yet</h3>
              <p className="text-muted-foreground">
                You'll see notifications here when you're mentioned, assigned tasks, or added to workspaces.
              </p>
            </CardContent>
          </Card>
        )}
      </div>
    </div>
  );
}