import { useState, useRef, useEffect } from 'react';
import { FontAwesomeIcon } from '@fortawesome/react-fontawesome';
import { faBell, faTriangleExclamation, faXmark, faCheck } from '@fortawesome/pro-duotone-svg-icons';
import { Badge } from '@/components/base/badges/badges';
import { usePerformanceAlerts } from '@/hooks/use-performance-alerts';
import { cx } from '@/utils/cx';

export const NotificationBell = () => {
    const { alerts, dismiss, dismissAll } = usePerformanceAlerts();
    const [open, setOpen] = useState(false);
    const panelRef = useRef<HTMLDivElement>(null);

    // Close on outside click
    useEffect(() => {
        if (!open) return;
        const handler = (e: MouseEvent) => {
            if (panelRef.current && !panelRef.current.contains(e.target as Node)) {
                setOpen(false);
            }
        };
        document.addEventListener('mousedown', handler);
        return () => document.removeEventListener('mousedown', handler);
    }, [open]);

    return (
        <div className="relative" ref={panelRef}>
            <button
                onClick={() => setOpen(!open)}
                className={cx(
                    'relative flex size-9 items-center justify-center rounded-lg border transition duration-100 ease-linear',
                    alerts.length > 0
                        ? 'border-error bg-error-primary text-fg-error-primary hover:bg-error-secondary'
                        : open
                            ? 'border-brand bg-active text-brand-secondary'
                            : 'border-secondary bg-primary text-fg-secondary hover:bg-primary_hover',
                )}
                title="Notifications"
            >
                <FontAwesomeIcon icon={faBell} className="size-5" />
                {alerts.length > 0 && (
                    <span className="absolute -top-1.5 -right-1.5 flex size-5 items-center justify-center rounded-full bg-error-solid text-[10px] font-bold text-white ring-2 ring-white">
                        {alerts.length > 9 ? '9+' : alerts.length}
                    </span>
                )}
            </button>

            {open && (
                <div className="absolute top-full right-0 mt-2 w-96 rounded-xl bg-primary shadow-xl ring-1 ring-secondary z-50 overflow-hidden">
                    {/* Header */}
                    <div className="flex items-center justify-between px-4 py-3 border-b border-secondary">
                        <div className="flex items-center gap-2">
                            <span className="text-sm font-semibold text-primary">Notifications</span>
                            {alerts.length > 0 && (
                                <Badge size="sm" color="error" type="pill-color">{alerts.length}</Badge>
                            )}
                        </div>
                        {alerts.length > 0 && (
                            <button
                                onClick={dismissAll}
                                className="text-xs font-medium text-brand-secondary hover:text-brand-secondary_hover transition duration-100 ease-linear"
                            >
                                Clear all
                            </button>
                        )}
                    </div>

                    {/* Alert list */}
                    <div className="max-h-96 overflow-y-auto">
                        {alerts.length === 0 ? (
                            <div className="flex flex-col items-center justify-center py-8 text-center">
                                <FontAwesomeIcon icon={faCheck} className="size-5 text-fg-success-primary mb-2" />
                                <p className="text-xs text-tertiary">No active alerts</p>
                            </div>
                        ) : (
                            alerts.map(alert => (
                                <div
                                    key={alert.id}
                                    className={cx(
                                        'flex items-center gap-3 px-4 py-3 border-b border-secondary last:border-b-0',
                                        alert.severity === 'error' ? 'bg-error-primary' : 'bg-warning-primary',
                                    )}
                                >
                                    <FontAwesomeIcon
                                        icon={faTriangleExclamation}
                                        className={cx(
                                            'size-4 shrink-0',
                                            alert.severity === 'error' ? 'text-fg-error-primary' : 'text-fg-warning-primary',
                                        )}
                                    />
                                    <div className="min-w-0 flex-1">
                                        <p className="text-sm font-medium text-primary">{alert.agent}</p>
                                        <p className="text-xs text-tertiary">{alert.type}</p>
                                    </div>
                                    <Badge size="sm" color={alert.severity === 'error' ? 'error' : alert.severity === 'warning' ? 'warning' : 'gray'} type="pill-color">{alert.value}</Badge>
                                    <button
                                        onClick={() => dismiss(alert.id)}
                                        className="text-fg-quaternary hover:text-fg-secondary shrink-0 transition duration-100 ease-linear"
                                        title="Dismiss"
                                    >
                                        <FontAwesomeIcon icon={faXmark} className="size-3.5" />
                                    </button>
                                </div>
                            ))
                        )}
                    </div>
                </div>
            )}
        </div>
    );
};