/**
 * The recents list as the UI sees it.
 *
 * Kept beside the graph store rather than inside it: what a repository's
 * history looks like and which repositories are worth offering are unrelated
 * concerns that happen to appear on the same screen.
 */

import { createSignal } from "solid-js";

import { forgetRecentRepository, listRecentRepositories } from "./api";
import { isGigitError, type RecentRepository, type RepositoryId } from "./bindings";

function describe(error: unknown): string {
  return isGigitError(error) ? error.message : String(error);
}

export function createRecents() {
  const [entries, setEntries] = createSignal<RecentRepository[]>([]);
  const [message, setMessage] = createSignal<string | undefined>();

  /** Fetch the list. Safe to call whenever the list may have changed. */
  async function refresh() {
    try {
      setEntries(await listRecentRepositories());
    } catch (error) {
      // A recents list that cannot be read is a nuisance, not a failure worth
      // blocking the app over — the picker still works.
      setMessage(describe(error));
    }
  }

  /** Drop one, removing it from the list straight away. */
  async function forget(id: RepositoryId) {
    // Removed locally first: the list is the user's own and waiting on a round
    // trip to see their own click take effect would feel broken.
    const before = entries();
    setEntries(before.filter((entry) => entry.id !== id));

    try {
      await forgetRecentRepository(id);
    } catch (error) {
      setEntries(before);
      setMessage(describe(error));
    }
  }

  return { entries, message, refresh, forget };
}

export type Recents = ReturnType<typeof createRecents>;