"use client";

// Pflege der globalen Allergen-/Zusatzstofflisten, die unterhalb
// der öffentlichen Speisekarte angezeigt werden.

import { useCallback, useEffect, useMemo, useState } from "react";
import { createClient } from "@/lib/supabase/client";
import type { CodeItem } from "@/lib/types";

export default function CodeListManager({
  table,
  title,
  codeLabel,
}: {
  table: "allergens" | "additives";
  title: string;
  codeLabel: string;
}) {
  const supabase = useMemo(() => createClient(), []);
  const [items, setItems] = useState<CodeItem[]>([]);
  const [editing, setEditing] = useState<{
    original: string | null; // code vor der Bearbeitung, null = neu
    code: string;
    name: string;
  } | null>(null);
  const [error, setError] = useState<string | null>(null);

  const load = useCallback(async () => {
    const { data, error } = await supabase.from(table).select("*").order("sort");
    if (error) setError(`Laden fehlgeschlagen: ${error.message}`);
    else setItems(data as CodeItem[]);
  }, [supabase, table]);

  useEffect(() => {
    load();
  }, [load]);

  async function save(e: React.FormEvent) {
    e.preventDefault();
    if (!editing) return;
    setError(null);
    const code = editing.code.trim();
    const name = editing.name.trim();
    if (!code || !name) return;

    let dbError;
    if (editing.original) {
      ({ error: dbError } = await supabase
        .from(table)
        .update({ code, name })
        .eq("code", editing.original));
    } else {
      const maxSort = items.reduce((m, i) => Math.max(m, i.sort), 0);
      ({ error: dbError } = await supabase
        .from(table)
        .insert({ code, name, sort: maxSort + 1 }));
    }
    if (dbError) {
      setError(
        /duplicate key/i.test(dbError.message)
          ? `Das Kürzel „${code}“ existiert bereits.`
          : `Speichern fehlgeschlagen: ${dbError.message}`
      );
      return;
    }
    setEditing(null);
    await load();
  }

  async function remove(item: CodeItem) {
    if (!window.confirm(`„${item.code} – ${item.name}“ wirklich löschen?`))
      return;
    const { error } = await supabase.from(table).delete().eq("code", item.code);
    if (error) setError(`Löschen fehlgeschlagen: ${error.message}`);
    await load();
  }

  return (
    <section className="card">
      <div className="flex items-center gap-3 mb-3">
        <h2 className="text-lg font-bold text-[var(--c-primary)] mr-auto">
          {title}
        </h2>
        <button
          type="button"
          className="btn btn-add"
          onClick={() => setEditing({ original: null, code: "", name: "" })}
        >
          Hinzufügen
        </button>
      </div>

      {error && (
        <p className="mb-2 text-sm text-[var(--c-del)]" role="alert">
          {error}
        </p>
      )}

      {editing && (
        <form onSubmit={save} className="mb-3 space-y-2 border-b border-gray-200 pb-3">
          <div className="max-w-36">
            <label className="label">{codeLabel}</label>
            <input
              className="input"
              value={editing.code}
              onChange={(e) => setEditing({ ...editing, code: e.target.value })}
              required
            />
          </div>
          <div>
            <label className="label">Bezeichnung</label>
            <input
              className="input"
              value={editing.name}
              onChange={(e) => setEditing({ ...editing, name: e.target.value })}
              required
            />
          </div>
          <div className="flex gap-2">
            <button type="submit" className="btn btn-add">
              Speichern
            </button>
            <button
              type="button"
              className="btn btn-neutral"
              onClick={() => setEditing(null)}
            >
              Abbrechen
            </button>
          </div>
        </form>
      )}

      <ul className="divide-y divide-gray-100">
        {items.map((item) => (
          <li key={item.code} className="flex items-center gap-2 py-1.5 text-sm">
            <span className="mr-auto">
              <span className="font-semibold">{item.code}</span> – {item.name}
            </span>
            <button
              type="button"
              className="btn btn-primary"
              onClick={() =>
                setEditing({
                  original: item.code,
                  code: item.code,
                  name: item.name,
                })
              }
            >
              Bearbeiten
            </button>
            <button
              type="button"
              className="btn btn-del"
              onClick={() => remove(item)}
            >
              Löschen
            </button>
          </li>
        ))}
        {items.length === 0 && (
          <li className="py-2 text-gray-500 text-sm">Keine Einträge.</li>
        )}
      </ul>
    </section>
  );
}