/**
 * Copyright 2024 Google LLC
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import { Dotprompt, type PromptFunction } from 'dotprompt';
import { readFileSync } from 'fs';

/** Helper function to get current directory, isolated in a separate file to work with ESM */
export function getDirName() {
  return __dirname;
}

const dp = new Dotprompt();

export function loadPromptFile(path: string): Promise<PromptFunction> {
  return dp.compile(dp.parse(readFileSync(path, 'utf8')));
}

export async function renderText(
  prompt: PromptFunction,
  input
): Promise<string> {
  const renderred = await prompt({
    input,
  });
  return renderred.messages
    .map((m) => m.content.map((c) => c.text).join())
    .join();
}
