"use client";

import { useParams } from "next/navigation";
import Link from "next/link";
import { ArrowLeft, Mail, MessageSquare, Terminal } from "lucide-react";
import { SeverityBadge } from "@/components/ui/badge";
import { useAlert, useMarkAlertRead, useResolveAlert } from "@/hooks/use-alerts";
import { useCompany } from "@/hooks/use-companies";
import { formatDateTime } from "@/lib/format";
import type { NotificationDeliveryStatus } from "@/lib/types";

const DELIVERY_STATUS_CLASSES: Record<NotificationDeliveryStatus, string> = {
  sent: "bg-green-100 text-green-800",
  failed: "bg-red-100 text-red-800",
  pending: "bg-slate-200 text-slate-700",
};

const PROVIDER_ICON = {
  smtp: Mail,
  twilio_sms: MessageSquare,
  console: Terminal,
} as const;

export default function AlertDetailPage() {
  const params = useParams<{ id: string }>();
  const { data: alert, isLoading } = useAlert(params.id);
  const { data: company } = useCompany(alert?.company_id);
  const markRead = useMarkAlertRead();
  const resolve = useResolveAlert();

  if (isLoading || !alert) {
    return <p className="text-sm text-slate-500">Loading…</p>;
  }

  return (
    <div>
      <Link
        href="/alerts"
        className="inline-flex items-center gap-1 text-sm font-medium text-slate-600 hover:text-slate-900"
      >
        <ArrowLeft className="h-4 w-4" aria-hidden /> Back to alerts
      </Link>

      <div className="mt-4 rounded-lg border border-slate-200 bg-white p-6">
        <div className="flex flex-wrap items-center gap-2">
          <SeverityBadge severity={alert.severity} />
          {!alert.read && (
            <span className="rounded-full bg-brand-100 px-2 py-0.5 text-xs font-medium text-brand-700">
              Unread
            </span>
          )}
          {alert.resolved && (
            <span className="rounded-full bg-slate-200 px-2 py-0.5 text-xs font-medium text-slate-700">
              Resolved
            </span>
          )}
          <span className="text-xs text-slate-500">
            {Math.round(alert.confidence * 100)}% confidence
          </span>
        </div>

        <h1 className="mt-3 text-xl font-semibold text-slate-900">{alert.title}</h1>
        <p className="mt-1 text-sm text-slate-500">
          {company ? (
            <Link href={`/companies/${company.id}`} className="hover:text-brand-600">
              {company.name}
            </Link>
          ) : (
            "—"
          )}{" "}
          · {formatDateTime(alert.created_at)}
        </p>

        <div className="mt-6 grid gap-6 sm:grid-cols-2">
          <div>
            <h2 className="text-sm font-semibold text-slate-700">What changed</h2>
            <p className="mt-1 text-sm text-slate-600">{alert.summary}</p>
          </div>
          <div>
            <h2 className="text-sm font-semibold text-slate-700">Why it matters</h2>
            <p className="mt-1 text-sm text-slate-600">{alert.why_it_matters}</p>
          </div>
        </div>

        <div className="mt-6 flex gap-2">
          {!alert.read && (
            <button
              onClick={() => markRead.mutate(alert.id)}
              className="focus-ring rounded-md border border-slate-300 px-3 py-1.5 text-sm font-medium text-slate-700 hover:bg-slate-50"
            >
              Mark read
            </button>
          )}
          {!alert.resolved && (
            <button
              onClick={() => resolve.mutate(alert.id)}
              className="focus-ring rounded-md bg-brand-600 px-3 py-1.5 text-sm font-semibold text-white hover:bg-brand-700"
            >
              Resolve
            </button>
          )}
        </div>
      </div>

      <div className="mt-6 rounded-lg border border-slate-200 bg-white p-6">
        <h2 className="text-sm font-semibold text-slate-700">Notification deliveries</h2>
        {alert.deliveries.length === 0 ? (
          <p className="mt-2 text-sm text-slate-500">
            No destinations were notified for this alert.
          </p>
        ) : (
          <ul className="mt-3 divide-y divide-slate-100">
            {alert.deliveries.map((delivery) => {
              const Icon =
                PROVIDER_ICON[delivery.provider as keyof typeof PROVIDER_ICON] ?? Terminal;
              return (
                <li key={delivery.id} className="flex items-center justify-between py-3 text-sm">
                  <div className="flex items-center gap-2 text-slate-700">
                    <Icon className="h-4 w-4 text-slate-400" aria-hidden />
                    <span className="capitalize">{delivery.provider.replace("_", " ")}</span>
                    {delivery.error_message && (
                      <span className="text-xs text-red-600">{delivery.error_message}</span>
                    )}
                  </div>
                  <span
                    className={`inline-flex items-center rounded-full px-2 py-0.5 text-xs font-medium capitalize ${DELIVERY_STATUS_CLASSES[delivery.status]}`}
                  >
                    {delivery.status}
                  </span>
                </li>
              );
            })}
          </ul>
        )}
      </div>
    </div>
  );
}