/**
 * @file ReflogView.tsx
 * @description The read-only reflog of HEAD or of one local branch, paged
 * (GET /git/reflog): each entry's selector, what moved it (commit, rebase,
 * reset, checkout…), git's message, when, and the commit it points at — a
 * click opens that commit in the Changes panel. "Reset here" hands the entry
 * to the reset dialog, which is how a lost commit is brought back.
 * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
 */

import { useEffect, useState } from "react";
import { useTranslation } from "react-i18next";
import { api, type GitTarget } from "../../../lib/api";
import { errText, gitRewrite, type ReflogEntry } from "../../../lib/gitRewrite";
import { BTN, ErrorLine, GitModal } from "./GitModal";

const PAGE = 50;

function when(time: number | null, lang: string): string {
  if (!time) return "";
  try {
    return new Date(time * 1000).toLocaleString(lang);
  } catch {
    return new Date(time * 1000).toISOString();
  }
}

export function ReflogView({
  target,
  onClose,
  onViewCommit,
  onReset,
}: {
  target: GitTarget;
  onClose: () => void;
  /** Open one commit (the panel's commit view). */
  onViewCommit?: (sha: string) => void;
  /** Open the reset dialog at this commit. */
  onReset?: (entry: ReflogEntry) => void;
}) {
  const { t, i18n } = useTranslation(["gitTools"]);
  const [ref, setRef] = useState("HEAD");
  const [branches, setBranches] = useState<string[]>([]);
  const [entries, setEntries] = useState<ReflogEntry[] | null>(null);
  const [more, setMore] = useState(false);
  const [busy, setBusy] = useState(false);
  const [error, setError] = useState<string | null>(null);
  const key = JSON.stringify(target);

  useEffect(() => {
    api.lanes
      .gitBranches(target)
      .then((b) => setBranches(b.branches ?? []))
      .catch(() => setBranches([]));
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, [key]);

  const page = async (skip: number) => {
    setBusy(true);
    setError(null);
    try {
      const r = await gitRewrite.reflog(target, { ref, skip, limit: PAGE });
      setEntries((prev) => (skip && prev ? [...prev, ...r.entries] : r.entries));
      setMore(r.more);
    } catch (e) {
      setError(errText(e));
      if (!skip) setEntries([]);
    } finally {
      setBusy(false);
    }
  };
  useEffect(() => {
    setEntries(null);
    void page(0);
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, [key, ref]);

  return (
    <GitModal title={t("reflog.title")} onClose={onClose} testId="reflog-view">
      <div className="mb-2 flex flex-wrap items-center gap-1.5">
        <label className="text-[11px]" htmlFor="reflog-ref">
          {t("reflog.of")}
        </label>
        <select
          id="reflog-ref"
          data-testid="reflog-ref"
          value={ref}
          onChange={(e) => setRef(e.target.value)}
          className="input min-w-0 max-w-full flex-1 py-0.5 text-[11px]"
        >
          <option value="HEAD">HEAD</option>
          {branches.map((b) => (
            <option key={b} value={b}>
              {b}
            </option>
          ))}
        </select>
      </div>
      <p className="mb-1.5 text-[11px] text-fg-muted">{t("reflog.hint")}</p>
      <ErrorLine error={error} />
      {entries == null ? (
        <p className="text-fg-muted">{t("loading")}</p>
      ) : !entries.length ? (
        <p className="text-fg-muted">{t("reflog.empty")}</p>
      ) : (
        <ul data-testid="reflog-list" className="divide-y divide-border">
          {entries.map((e) => (
            <li key={`${e.index}-${e.sha}`} className="flex flex-wrap items-start gap-1.5 py-1.5">
              <span className="shrink-0 font-mono text-[10px] text-fg-muted">{e.selector}</span>
              <span className="shrink-0 rounded bg-surface-3 px-1 text-[10px] text-fg-secondary">
                {e.action}
              </span>
              <span className="min-w-0 flex-1 break-words text-[11px] text-fg-primary">
                {e.message || e.subject}
                <span className="block text-[10px] text-fg-muted">
                  {when(e.time, i18n.language)}
                </span>
              </span>
              <span className="flex shrink-0 items-center gap-1">
                {onViewCommit ? (
                  <button
                    type="button"
                    className="font-mono text-[11px] text-accent hover:underline"
                    title={e.subject}
                    onClick={() => onViewCommit(e.sha)}
                  >
                    {e.short}
                  </button>
                ) : (
                  <span className="font-mono text-[11px]" title={e.subject}>
                    {e.short}
                  </span>
                )}
                {onReset && (
                  <button type="button" className={BTN} onClick={() => onReset(e)}>
                    {t("reflog.resetHere")}
                  </button>
                )}
              </span>
            </li>
          ))}
        </ul>
      )}
      {more && (
        <button
          type="button"
          data-testid="reflog-more"
          disabled={busy}
          className={`${BTN} mt-2 w-full`}
          onClick={() => void page(entries?.length ?? 0)}
        >
          {t("reflog.more")}
        </button>
      )}
    </GitModal>
  );
}