import { log } from './util.js';

/**
 * 從環境變數讀取並驗證所有輸入參數。
 *
 * @returns {{
 *   serverUrl: string,
 *   repository: string,
 *   owner: string,
 *   repo: string,
 *   token: string,
 *   sourceBranch: string,
 *   targetBranch: string,
 *   opencode: { baseUrl: string, model: string, provider: string },
 *   language: string,
 *   maxDiffChars: number,
 *   workspace: string,
 * }}
 */
export function loadInputs() {
  const serverUrl = trimSlash(required('GITEA_SERVER_URL'));
  const repository = required('GITEA_REPOSITORY'); // owner/repo
  const token = required('GITEA_TOKEN');
  const sourceBranch = required('SOURCE_BRANCH');
  const targetBranch = required('TARGET_BRANCH');

  const [owner, repo] = repository.split('/');
  if (!owner || !repo) {
    throw new Error(`GITEA_REPOSITORY 格式應為 owner/repo，收到: ${repository}`);
  }

  if (sourceBranch === targetBranch) {
    throw new Error(`來源分支與目標分支不可相同: ${sourceBranch}`);
  }

  const opencode = {
    baseUrl: trimSlash(process.env.OPENCODE_BASE_URL || ''),
    model: process.env.OPENCODE_MODEL || '',
    provider: process.env.OPENCODE_PROVIDER || '',
  };

  // PR 標題/描述固定使用繁體中文，diff 截斷上限固定，皆不透過參數控制
  const language = 'Traditional Chinese (繁體中文)';
  const maxDiffChars = 60000;
  const workspace = process.env.GITHUB_WORKSPACE || process.cwd();

  return {
    serverUrl,
    repository,
    owner,
    repo,
    token,
    sourceBranch,
    targetBranch,
    opencode,
    language,
    maxDiffChars,
    workspace,
  };
}

function required(name) {
  const value = process.env[name];
  if (!value || !value.trim()) {
    throw new Error(`缺少必要的環境變數: ${name}`);
  }
  return value.trim();
}

function trimSlash(url) {
  return url.replace(/\/+$/, '');
}

/** 印出輸入摘要（遮蔽敏感資訊）。 */
export function logInputs(inputs) {
  log.info(`Gitea Server : ${inputs.serverUrl}`);
  log.info(`Repository   : ${inputs.repository}`);
  log.info(`來源分支     : ${inputs.sourceBranch}`);
  log.info(`目標分支     : ${inputs.targetBranch}`);
  log.info(`opencode     : provider=${inputs.opencode.provider || '(未設定)'} model=${inputs.opencode.model || '(未設定)'} baseUrl=${inputs.opencode.baseUrl || '(未設定)'}`);
}