import React from "react";
import { Panel } from "../UI/Panel";
import { Button } from "../UI/Button";
import { Bell, Check, CheckCheck, Settings, X } from "../UI/Icons";

const TYPE_ICONS = {
  driver_assigned: "🚚",
  driver_unassigned: "📤",
  order_status_change: "📦",
  delivery_problem: "⚠️",
};

const TYPE_LABELS = {
  driver_assigned: "Назначение водителя",
  driver_unassigned: "Снятие водителя",
  order_status_change: "Изменение статуса",
  delivery_problem: "Проблема доставки",
};

function formatTimeAgo(dateStr) {
  const date = new Date(dateStr);
  const now = new Date();
  const diffMs = now - date;
  const diffMin = Math.floor(diffMs / 60000);
  if (diffMin < 1) return "сейчас";
  if (diffMin < 60) return `${diffMin} мин`;
  const diffH = Math.floor(diffMin / 60);
  if (diffH < 24) return `${diffH} ч`;
  const diffD = Math.floor(diffH / 24);
  return `${diffD} д`;
}

export function NotificationBell({ notifications, unreadCount, onMarkAsRead, onMarkAllAsRead, onOpenSettings }) {
  const [isOpen, setIsOpen] = React.useState(false);
  const bellRef = React.useRef(null);

  React.useEffect(() => {
    if (!isOpen) return;
    const handleClickOutside = (e) => {
      if (bellRef.current && !bellRef.current.contains(e.target)) {
        setIsOpen(false);
      }
    };
    document.addEventListener("mousedown", handleClickOutside);
    return () => document.removeEventListener("mousedown", handleClickOutside);
  }, [isOpen]);

  return (
    <div className="relative" ref={bellRef}>
      <button
        className="relative flex h-9 w-9 items-center justify-center rounded-full transition hover:bg-[var(--color-surface-strong)]"
        onClick={() => setIsOpen(!isOpen)}
        aria-label={`Уведомления${unreadCount > 0 ? ` (${unreadCount})` : ""}`}
      >
        <Bell className="h-5 w-5" />
        {unreadCount > 0 && (
          <span className="absolute -right-0.5 -top-0.5 flex h-4 min-w-[16px] items-center justify-center rounded-full bg-red-500 px-1 text-[10px] font-bold text-white">
            {unreadCount > 99 ? "99+" : unreadCount}
          </span>
        )}
      </button>

      {isOpen && (
        <div className="absolute right-0 top-full z-50 mt-2 w-80 sm:w-96">
          <Panel className="max-h-[480px] overflow-hidden p-0 shadow-xl">
            <div className="flex items-center justify-between border-b border-[var(--color-border)] px-4 py-3">
              <h3 className="text-sm font-semibold">Уведомления</h3>
              <div className="flex items-center gap-1">
                {unreadCount > 0 && (
                  <button
                    className="rounded p-1 text-xs text-[var(--color-accent)] hover:bg-[var(--color-surface-strong)]"
                    onClick={onMarkAllAsRead}
                    title="Прочитать все"
                  >
                    <CheckCheck className="h-4 w-4" />
                  </button>
                )}
                {onOpenSettings && (
                  <button
                    className="rounded p-1 text-xs text-[var(--color-text-muted)] hover:bg-[var(--color-surface-strong)]"
                    onClick={() => { onOpenSettings(); setIsOpen(false); }}
                    title="Настройки"
                  >
                    <Settings className="h-4 w-4" />
                  </button>
                )}
                <button
                  className="rounded p-1 text-xs text-[var(--color-text-muted)] hover:bg-[var(--color-surface-strong)]"
                  onClick={() => setIsOpen(false)}
                >
                  <X className="h-4 w-4" />
                </button>
              </div>
            </div>

            <div className="overflow-y-auto" style={{ maxHeight: "400px" }}>
              {notifications.length === 0 ? (
                <div className="px-4 py-8 text-center text-sm text-[var(--color-text-muted)]">
                  Нет уведомлений
                </div>
              ) : (
                notifications.map((notif) => (
                  <div
                    key={notif.id}
                    className={`flex gap-3 border-b border-[var(--color-border)] px-4 py-3 transition hover:bg-[var(--color-surface-strong)] ${
                      !notif.read ? "bg-[var(--color-accent-soft)]/30" : ""
                    }`}
                    onClick={() => !notif.read && onMarkAsRead(notif.id)}
                  >
                    <span className="mt-0.5 text-base">
                      {TYPE_ICONS[notif.type] || "📦"}
                    </span>
                    <div className="min-w-0 flex-1">
                      <div className="flex items-start justify-between gap-2">
                        <p className={`text-sm ${!notif.read ? "font-semibold" : "font-normal"}`}>
                          {notif.title}
                        </p>
                        <span className="shrink-0 text-[10px] text-[var(--color-text-muted)]">
                          {formatTimeAgo(notif.created_at)}
                        </span>
                      </div>
                      {notif.body && (
                        <p className="mt-0.5 text-xs text-[var(--color-text-muted)] line-clamp-2">
                          {notif.body}
                        </p>
                      )}
                    </div>
                    {!notif.read && (
                      <div className="mt-1.5 h-2 w-2 shrink-0 rounded-full bg-[var(--color-accent)]" />
                    )}
                  </div>
                ))
              )}
            </div>
          </Panel>
        </div>
      )}
    </div>
  );
}