"use client";

import { CircleCheck, CircleX, Loader, TriangleAlert } from "lucide-react";
import {
  PARTICULAR_CODES,
  type LabelCheckResult,
  type LabelFinding,
  type LabelFindingCode,
} from "@/lib/label-templates/check";
import { Card, CardContent, CardHeader, CardTitle } from "@/components/ui/card";

export const PARTICULAR_LABELS: Record<(typeof PARTICULAR_CODES)[number], string> = {
  LEGAL_NAME: "Verkehrsbezeichnung",
  NET_QUANTITY: "Füllmenge",
  BEST_BEFORE: "Mindesthaltbarkeitsdatum",
  LOT: "Losnummer",
  ORIGIN: "Herkunftsland",
  FOOD_BUSINESS: "Name und Anschrift des Lebensmittelunternehmers",
};

function formatMm(value: number): string {
  return `${value.toLocaleString("de-DE", { maximumFractionDigits: 2 })} mm`;
}

function summaryOf(result: LabelCheckResult | null, pending: boolean): string | null {
  if (pending) return "Das Etikett wird geprüft …";
  if (!result) return null;
  const missing = result.gaps.length;
  if (missing === 0) return "Alle Pflichtangaben sind erfüllt.";
  return missing === 1 ? "Es fehlt 1 Pflichtangabe." : `Es fehlen ${missing} Pflichtangaben.`;
}

function ParticularRow({ code, gap }: { code: LabelFindingCode; gap: LabelFinding | undefined }) {
  const label = PARTICULAR_LABELS[code as keyof typeof PARTICULAR_LABELS];
  return (
    <li className="flex items-start gap-2 text-sm">
      {gap ? (
        <CircleX aria-hidden className="mt-0.5 size-4 shrink-0 text-destructive" />
      ) : (
        <CircleCheck aria-hidden className="mt-0.5 size-4 shrink-0 text-success" />
      )}
      <span className="flex flex-col">
        <span>
          <span className="font-medium">{label}:</span>{" "}
          <span className={gap ? "font-medium text-destructive" : "text-muted-foreground"}>
            {gap ? "Fehlt" : "Erfüllt"}
          </span>
        </span>
        {gap ? <span className="text-muted-foreground">{gap.detail || gap.title}</span> : null}
      </span>
    </li>
  );
}

interface LabelCompliancePanelProps {
  result: LabelCheckResult | null;
  pending: boolean;
  error: string | null;
  /** `result` answers an older draft; the current one cannot be checked. */
  stale?: boolean;
}

/**
 * Shows the answer of the label check: the six particulars with symbol and
 * word, the warnings apart (they never block printing) and the minimums the
 * server used. The panel decides nothing itself.
 */
export function LabelCompliancePanel({
  result,
  pending,
  error,
  stale = false,
}: LabelCompliancePanelProps) {
  const summary = stale
    ? "Veraltet: Dieser Stand passt nicht mehr zu deinen Eingaben."
    : summaryOf(result, pending);
  return (
    <Card>
      <CardHeader>
        <CardTitle className="text-base">Pflichtangaben</CardTitle>
      </CardHeader>
      <CardContent className="flex flex-col gap-3">
        {error ? (
          <p role="alert" className="text-sm font-medium text-destructive">
            {error}
          </p>
        ) : null}
        <div className="flex flex-col gap-3">
          {summary ? (
            <p aria-live="polite" className="flex items-center gap-2 text-sm font-medium">
              {pending ? <Loader aria-hidden className="size-4 motion-full:animate-spin" /> : null}
              {summary}
            </p>
          ) : null}
          {result ? (
            <>
              {result.sample ? (
                <p className="text-sm text-muted-foreground">
                  Geprüft mit Beispielwerten, nicht mit einer echten Abfüllung.
                </p>
              ) : null}
              <ul aria-label="Pflichtangaben" className="flex flex-col gap-2">
                {PARTICULAR_CODES.map((code) => (
                  <ParticularRow
                    key={code}
                    code={code}
                    gap={result.gaps.find((gap) => gap.code === code)}
                  />
                ))}
              </ul>
              <p className="text-xs text-muted-foreground">
                Mindest-x-Höhe: {formatMm(result.requirements.minXHeightMm)}
                {result.requirements.netQuantityMinCapHeightMm !== null
                  ? `. Ziffernhöhe der Füllmenge: mindestens ${formatMm(result.requirements.netQuantityMinCapHeightMm)}`
                  : ""}
                .
              </p>
              {result.warnings.length > 0 ? (
                <div className="flex flex-col gap-2">
                  <p className="text-sm font-medium">Hinweise (sie sperren den Druck nicht)</p>
                  <ul aria-label="Hinweise" className="flex flex-col gap-2">
                    {result.warnings.map((warning, index) => (
                      <li key={`${warning.code}-${index}`} className="flex items-start gap-2 text-sm">
                        <TriangleAlert aria-hidden className="mt-0.5 size-4 shrink-0 text-warning-ink" />
                        <span className="flex flex-col">
                          <span className="font-medium">Hinweis: {warning.title}</span>
                          {warning.detail ? (
                            <span className="text-muted-foreground">{warning.detail}</span>
                          ) : null}
                        </span>
                      </li>
                    ))}
                  </ul>
                </div>
              ) : null}
            </>
          ) : null}
        </div>
      </CardContent>
    </Card>
  );
}