"use client";

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

import { useCallback, useEffect, useState } from "react";
import { formatMessage } from "@/lib/i18n/shared";
import { localized } from "@/lib/types";
import type { CodeItem } from "@/lib/types";
import { useDict, useLanguages, useLocale } from "@/components/i18n/LocaleProvider";

export default function CodeListManager({
  table,
  translateEnabled,
}: {
  table: "allergens" | "additives";
  translateEnabled: boolean;
}) {
  const dict = useDict();
  const locale = useLocale();
  const languages = useLanguages().filter((l) => l.code !== "de");
  const title =
    table === "allergens" ? dict.codeList.allergensTitle : dict.codeList.additivesTitle;
  const codeLabel =
    table === "allergens"
      ? dict.codeList.allergenCodeLabel
      : dict.codeList.additiveCodeLabel;

  const [items, setItems] = useState<CodeItem[]>([]);
  const [editing, setEditing] = useState<{
    original: string | null; // code vor der Bearbeitung, null = neu
    code: string;
    name: string;
    translations: Record<string, string>;
  } | null>(null);
  const [error, setError] = useState<string | null>(null);
  const [notice, setNotice] = useState<string | null>(null);
  const [ioBusy, setIoBusy] = useState(false);
  const [translateState, setTranslateState] = useState<"idle" | "busy" | "done">(
    "idle"
  );

  const load = useCallback(async () => {
    const res = await fetch(`/api/${table}`);
    if (!res.ok) setError(formatMessage(dict.codeList.loadError, { message: String(res.status) }));
    else setItems(await res.json());
  }, [table, dict]);

  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;
    const payload = {
      code,
      name,
      translations: editing.translations,
    };

    const res = editing.original
      ? await fetch(`/api/${table}/${editing.original}`, {
          method: "PATCH",
          headers: { "Content-Type": "application/json" },
          body: JSON.stringify(payload),
        })
      : await fetch(`/api/${table}`, {
          method: "POST",
          headers: { "Content-Type": "application/json" },
          body: JSON.stringify(payload),
        });
    if (!res.ok) {
      const data = await res.json().catch(() => ({}));
      setError(
        data.error === "duplicate_code"
          ? formatMessage(dict.codeList.duplicateCode, { code })
          : formatMessage(dict.codeList.saveError, { message: data.error ?? String(res.status) })
      );
      return;
    }
    setEditing(null);
    await load();
  }

  async function remove(item: CodeItem) {
    if (
      !window.confirm(
        formatMessage(dict.codeList.confirmDelete, { code: item.code, name: item.name })
      )
    )
      return;
    const res = await fetch(`/api/${table}/${item.code}`, { method: "DELETE" });
    if (!res.ok)
      setError(formatMessage(dict.codeList.deleteError, { message: String(res.status) }));
    await load();
  }

  async function autoTranslate() {
    if (!editing || !editing.name.trim()) return;
    setTranslateState("busy");
    setError(null);
    try {
      const res = await fetch("/api/translate", {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({
          table,
          id: editing.original,
          text: editing.name.trim(),
        }),
      });
      const data = await res.json();
      if (!res.ok) throw new Error(data?.error ?? `Fehler (${res.status})`);
      setEditing((prev) =>
        prev
          ? { ...prev, translations: { ...prev.translations, ...(data.translations ?? {}) } }
          : prev
      );
      setTranslateState("done");
    } catch (err) {
      setError(err instanceof Error ? err.message : String(err));
      setTranslateState("idle");
    }
  }

  async function exportItems() {
    setError(null);
    setNotice(null);
    const res = await fetch(`/api/${table}/export`);
    if (!res.ok) {
      setError(formatMessage(dict.codeList.exportError, { message: String(res.status) }));
      return;
    }
    const blob = await res.blob();
    const url = URL.createObjectURL(blob);
    const a = document.createElement("a");
    a.href = url;
    a.download = table === "allergens" ? "allergene.csv" : "zusatzstoffe.csv";
    a.click();
    URL.revokeObjectURL(url);
  }

  async function importItems(e: React.ChangeEvent<HTMLInputElement>) {
    const file = e.target.files?.[0];
    e.target.value = "";
    if (!file) return;
    setError(null);
    setNotice(null);
    setIoBusy(true);
    const fd = new FormData();
    fd.append("file", file);
    const res = await fetch(`/api/${table}/import`, { method: "POST", body: fd });
    setIoBusy(false);
    if (!res.ok) {
      setError(formatMessage(dict.codeList.importError, { message: String(res.status) }));
      return;
    }
    const data = (await res.json()) as {
      created: number;
      updated: number;
      skipped: { row: number; reason: string }[];
    };
    let msg = formatMessage(dict.codeList.importSuccess, {
      created: data.created,
      updated: data.updated,
    });
    if (data.skipped.length > 0) {
      const reasons = data.skipped
        .map((s) => formatMessage(dict.codeList.importSkippedRow, s))
        .join("; ");
      msg +=
        " " + formatMessage(dict.codeList.importSkipped, { count: data.skipped.length, reasons });
    }
    setNotice(msg);
    await load();
  }

  return (
    <section className="card">
      <div className="flex flex-wrap 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-neutral" onClick={exportItems}>
          {dict.codeList.exportButton}
        </button>
        <label className="btn btn-neutral cursor-pointer">
          {dict.codeList.importButton}
          <input
            type="file"
            accept=".csv,text/csv"
            className="hidden"
            onChange={importItems}
            disabled={ioBusy}
          />
        </label>
        <button
          type="button"
          className="btn btn-add"
          onClick={() => {
            setEditing({ original: null, code: "", name: "", translations: {} });
            setTranslateState("idle");
          }}
        >
          {dict.common.add}
        </button>
      </div>

      {error && (
        <p className="mb-2 text-sm text-[var(--c-del)]" role="alert">
          {error}
        </p>
      )}
      {notice && <p className="mb-2 text-sm text-green-700">{notice}</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">{dict.codeList.nameLabel}</label>
            <input
              className="input"
              value={editing.name}
              onChange={(e) => setEditing({ ...editing, name: e.target.value })}
              required
            />
          </div>
          {languages.length > 0 && (
            <div className="grid gap-2 sm:grid-cols-2">
              {languages.map((lang) => (
                <div key={lang.code}>
                  <label className="label">{lang.label}</label>
                  <input
                    className="input"
                    value={editing.translations[lang.code] ?? ""}
                    onChange={(e) =>
                      setEditing({
                        ...editing,
                        translations: { ...editing.translations, [lang.code]: e.target.value },
                      })
                    }
                  />
                </div>
              ))}
            </div>
          )}
          {translateEnabled && languages.length > 0 && (
            <div>
              <button
                type="button"
                className="btn btn-neutral"
                onClick={autoTranslate}
                disabled={translateState === "busy" || !editing.name.trim()}
              >
                {translateState === "busy"
                  ? dict.dishManager.translating
                  : dict.dishManager.autoTranslate}
              </button>
              {translateState === "done" && (
                <span className="ml-2 text-sm text-green-700">
                  {dict.dishManager.translated}
                </span>
              )}
            </div>
          )}
          <div className="flex gap-2">
            <button type="submit" className="btn btn-add">
              {dict.common.save}
            </button>
            <button
              type="button"
              className="btn btn-neutral"
              onClick={() => setEditing(null)}
            >
              {dict.common.cancel}
            </button>
          </div>
        </form>
      )}

      <ul className="divide-y divide-gray-100">
        {items.map((item) => (
          <li key={item.code} className="flex flex-wrap items-center gap-2 py-1.5 text-sm">
            <span className="mr-auto">
              <span className="font-semibold">{item.code}</span> –{" "}
              {localized(item, locale)}
            </span>
            <button
              type="button"
              className="btn btn-primary"
              onClick={() => {
                setEditing({
                  original: item.code,
                  code: item.code,
                  name: item.name,
                  translations: { ...item.translations },
                });
                setTranslateState("idle");
              }}
            >
              {dict.common.edit}
            </button>
            <button
              type="button"
              className="btn btn-del"
              onClick={() => remove(item)}
            >
              {dict.common.delete}
            </button>
          </li>
        ))}
        {items.length === 0 && (
          <li className="py-2 text-gray-500 text-sm">{dict.codeList.empty}</li>
        )}
      </ul>
    </section>
  );
}