"use client";

import Link from "next/link";
import { Card, CardContent, CardHeader, CardTitle } from "@/components/ui/card";
import { Badge } from "@/components/ui/badge";
import { Button } from "@/components/ui/button";
import { Skeleton } from "@/components/ui/skeleton";
import { cn } from "@/lib/utils";
import { acknowledgeAlarm, type Alarm } from "@/lib/api";
import { useState } from "react";
import { ChevronRight } from "lucide-react";

interface Props {
  alarms: Alarm[];
  loading?: boolean;
  onAcknowledge?: () => void;
  onAlarmClick?: (alarm: Alarm) => void;
}

const severityStyles: Record<string, { badge: string; dot: string }> = {
  critical: { badge: "bg-destructive/20 text-destructive border-destructive/30", dot: "bg-destructive" },
  warning:  { badge: "bg-amber-500/20 text-amber-400 border-amber-500/30",      dot: "bg-amber-400" },
  info:     { badge: "bg-primary/20 text-primary border-primary/30",            dot: "bg-primary" },
};

function timeAgo(iso: string) {
  const secs = Math.floor((Date.now() - new Date(iso).getTime()) / 1000);
  if (secs < 60)  return `${secs}s ago`;
  if (secs < 3600) return `${Math.floor(secs / 60)}m ago`;
  return `${Math.floor(secs / 3600)}h ago`;
}

export function AlarmFeed({ alarms, loading, onAcknowledge, onAlarmClick }: Props) {
  const [acking, setAcking] = useState<number | null>(null);

  async function handleAck(id: number) {
    setAcking(id);
    try {
      await acknowledgeAlarm(id);
      onAcknowledge?.();
    } catch { /* ignore */ }
    finally { setAcking(null); }
  }

  const activeCount = alarms.filter((a) => a.state === "active").length;

  return (
    <Card className="flex flex-col">
      <CardHeader className="pb-2">
        <div className="flex items-center justify-between">
          <CardTitle className="text-sm font-semibold">Active Alarms</CardTitle>
          <div className="flex items-center gap-2">
            {!loading && (
              <Badge variant={activeCount > 0 ? "destructive" : "outline"} className="text-[10px] h-4 px-1.5">
                {activeCount > 0 ? `${activeCount} active` : "All clear"}
              </Badge>
            )}
            <Link href="/alarms" className="text-[10px] text-muted-foreground hover:text-primary transition-colors">
              View all →
            </Link>
          </div>
        </div>
      </CardHeader>
      <CardContent className="flex-1 space-y-3 overflow-y-auto max-h-72">
        {loading ? (
          <Skeleton className="h-80 w-full" />
        ) : alarms.length === 0 ? (
          <div className="flex items-center justify-center h-24 text-sm text-muted-foreground">
            No active alarms
          </div>
        ) : (
          alarms.map((alarm) => {
            const style = severityStyles[alarm.severity] ?? severityStyles.info;
            const clickable = !!onAlarmClick;
            const locationLabel = [alarm.rack_id, alarm.room_id].find(Boolean);
            return (
              <div
                key={alarm.id}
                onClick={() => onAlarmClick?.(alarm)}
                className={cn(
                  "flex gap-2.5 group rounded-md px-1 py-1 -mx-1 transition-colors",
                  clickable && "cursor-pointer hover:bg-muted/40"
                )}
              >
                <div className="mt-1.5 shrink-0">
                  <span className={cn("block w-2 h-2 rounded-full", style.dot)} />
                </div>
                <div className="flex-1 min-w-0">
                  <p className="text-xs leading-snug text-foreground">{alarm.message}</p>
                  <div className="mt-0.5 flex items-center gap-1.5">
                    {locationLabel && (
                      <span className="text-[10px] text-muted-foreground font-medium">{locationLabel}</span>
                    )}
                    {locationLabel && <span className="text-[10px] text-muted-foreground/50">·</span>}
                    <span className="text-[10px] text-muted-foreground">{timeAgo(alarm.triggered_at)}</span>
                  </div>
                </div>
                <div className="flex flex-col items-end gap-1 shrink-0">
                  <Badge variant="outline" className={cn("text-[9px] h-4 px-1 uppercase tracking-wide", style.badge)}>
                    {alarm.severity}
                  </Badge>
                  {alarm.state === "active" && (
                    <Button
                      variant="ghost"
                      size="sm"
                      className="h-4 px-1 text-[9px] opacity-0 group-hover:opacity-100 transition-opacity"
                      disabled={acking === alarm.id}
                      onClick={(e) => { e.stopPropagation(); handleAck(alarm.id); }}
                    >
                      Ack
                    </Button>
                  )}
                  {clickable && (
                    <ChevronRight className="w-3 h-3 text-muted-foreground/40 group-hover:text-muted-foreground transition-colors mt-auto" />
                  )}
                </div>
              </div>
            );
          })
        )}
      </CardContent>
    </Card>
  );
}