"use client";

import { useState } from "react";
import { useRouter } from "next/navigation";
import { Loader2, MapPin, Check, X, ExternalLink } from "lucide-react";

// Pin a site on the map.
//
// Deliberately plain number inputs plus a "open in maps" link, rather than a
// drag-to-pin map: the in-app Leaflet map is still being worked on, and a coordinate
// entered by hand is usually copied off a map anyway. A point can be pasted straight in.
//
// Bounds are enforced server-side as well as here — a stray 0,0 or a digit dropped in
// the wrong box would otherwise place the marker in the Gulf of Guinea.
export function SiteCoordinateEditor({
  siteId,
  name,
  latitude,
  longitude,
}: {
  siteId: string;
  name: string;
  latitude: number | null;
  longitude: number | null;
}) {
  const router = useRouter();
  const has = Boolean(latitude || longitude);
  const [open, setOpen] = useState(false);
  const [lat, setLat] = useState(latitude ? String(latitude) : "");
  const [lng, setLng] = useState(longitude ? String(longitude) : "");
  const [busy, setBusy] = useState(false);
  const [error, setError] = useState<string | null>(null);
  const [saved, setSaved] = useState(false);

  async function save(clear = false) {
    setBusy(true);
    setError(null);
    try {
      const res = await fetch(`/api/sites/${siteId}`, {
        method: "PATCH",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify(
          clear ? { latitude: null, longitude: null } : { latitude: Number(lat), longitude: Number(lng) },
        ),
      });
      const data = await res.json().catch(() => ({ ok: false, error: "Unexpected response" }));
      if (!data.ok) {
        setError(data.error || "Could not save");
      } else {
        setOpen(false);
        setSaved(true);
        setTimeout(() => setSaved(false), 2500);
        router.refresh();
      }
    } catch {
      setError("Could not reach the server");
    } finally {
      setBusy(false);
    }
  }

  if (!open) {
    return (
      <div className="flex flex-wrap items-center gap-3">
        <button
          type="button"
          onClick={() => setOpen(true)}
          className="inline-flex items-center gap-2 min-h-[44px] px-3 rounded-lg text-sm font-medium text-[#003D5B] dark:text-white hover:bg-gray-100 dark:hover:bg-white/5 transition"
        >
          {saved ? (
            <Check className="w-4 h-4 text-[#00798C]" />
          ) : (
            <MapPin className={`w-4 h-4 ${has ? "text-[#00798C]" : "text-gray-400"}`} />
          )}
          {has
            ? `${latitude!.toFixed(5)}, ${longitude!.toFixed(5)}`
            : "No location set — add coordinates"}
        </button>
        {has && (
          <a
            href={`https://www.openstreetmap.org/?mlat=${latitude}&mlon=${longitude}#map=16/${latitude}/${longitude}`}
            target="_blank"
            rel="noreferrer"
            className="inline-flex items-center gap-1.5 min-h-[44px] px-2 text-sm text-[#00798C] hover:underline"
          >
            Open in maps
            <ExternalLink className="w-3.5 h-3.5" />
          </a>
        )}
      </div>
    );
  }

  return (
    <div className="space-y-3">
      <div className="flex flex-col sm:flex-row gap-3">
        <div className="flex-1">
          <label htmlFor={`lat-${siteId}`} className="block text-xs text-gray-500 dark:text-gray-400 mb-1">
            Latitude
          </label>
          <input
            id={`lat-${siteId}`}
            type="number"
            step="0.000001"
            inputMode="decimal"
            value={lat}
            onChange={(e) => setLat(e.target.value)}
            placeholder="-26.101615"
            className="min-h-[44px] w-full px-3 rounded-lg border border-gray-200 dark:border-white/10 bg-white dark:bg-white/5 text-sm tabular-nums focus:outline-none focus:border-[#30638E]"
          />
        </div>
        <div className="flex-1">
          <label htmlFor={`lng-${siteId}`} className="block text-xs text-gray-500 dark:text-gray-400 mb-1">
            Longitude
          </label>
          <input
            id={`lng-${siteId}`}
            type="number"
            step="0.000001"
            inputMode="decimal"
            value={lng}
            onChange={(e) => setLng(e.target.value)}
            placeholder="28.348725"
            className="min-h-[44px] w-full px-3 rounded-lg border border-gray-200 dark:border-white/10 bg-white dark:bg-white/5 text-sm tabular-nums focus:outline-none focus:border-[#30638E]"
          />
        </div>
      </div>

      {error && <p className="text-sm text-[#D1495B]">{error}</p>}

      <div className="flex flex-wrap items-center gap-2">
        <button
          type="button"
          onClick={() => save(false)}
          disabled={busy || lat === "" || lng === ""}
          className="inline-flex items-center gap-2 min-h-[44px] px-4 rounded-lg text-sm font-semibold text-white bg-[#00798C] hover:opacity-90 transition disabled:opacity-40"
        >
          {busy && <Loader2 className="w-4 h-4 animate-spin" />}
          Save location
        </button>
        <button
          type="button"
          onClick={() => setOpen(false)}
          disabled={busy}
          className="inline-flex items-center gap-2 min-h-[44px] px-3 rounded-lg text-sm text-gray-600 dark:text-gray-300 hover:bg-gray-100 dark:hover:bg-white/5 transition"
        >
          <X className="w-4 h-4" />
          Cancel
        </button>
        {has && (
          <button
            type="button"
            onClick={() => save(true)}
            disabled={busy}
            className="inline-flex items-center min-h-[44px] px-3 text-sm text-[#D1495B] hover:underline disabled:opacity-40"
          >
            Clear location
          </button>
        )}
      </div>
      <p className="text-xs text-gray-500 dark:text-gray-400">
        Paste a point copied from any map. Only coordinates inside South Africa are accepted.
      </p>
    </div>
  );
}