import type { App, TFile } from "obsidian";
import { normalizeVaultPath } from "../settings";

export class VocabularyLoader {
  /**
   * Loads a text file from the currently opened Obsidian vault.
   * @param app Obsidian App
   * @param vaultRelativePath e.g. "_system/dictionary/edge_vocabulary.md"
   */
  static async loadText(app: App, vaultRelativePath: string): Promise<string> {
    const p = normalizeVaultPath(vaultRelativePath);
    const abstract = app.vault.getAbstractFileByPath(p);

    if (!abstract) {
      throw new Error(`Vocabulary file not found in vault: "${p}"`);
    }

    // Guard: Only files can be read
    const file = abstract as TFile;
    // TFile has 'extension' and 'path' properties; if it isn't a file this will usually fail at runtime.
    if (!(file && typeof file.path === "string")) {
      throw new Error(`Path is not a file: "${p}"`);
    }

    return await app.vault.read(file);
  }
}