import fs from 'node:fs';
import path from 'node:path';
import { pathToFileURL } from 'node:url';
import { importMemind, resolveMemindLib } from './lib-path.mjs';

const ADMIN_METHODS = [
  'getVisionSettings',
  'setVisionKey',
  'clearVisionKey',
  'listExecutorBindings',
  'setExecutorBinding',
  'listExecutorRuntimeConfigs',
  'listExecutorLaunchPlans',
  'listExecutorLaunchStates',
  'launchExecutor',
  'stopExecutor',
  'restartExecutor',
];

function hasAdminMethods(createFactory) {
  if (typeof createFactory !== 'function') return false;
  const probe = createFactory(null, {});
  return ADMIN_METHODS.every((method) => typeof probe?.[method] === 'function');
}

async function importLlmProvidersModule(modulePath) {
  return import(pathToFileURL(modulePath).href);
}

export async function loadCreateLlmProviderService() {
  const primary = await importMemind('llm-providers.mjs');
  if (hasAdminMethods(primary.createLlmProviderService)) {
    return primary.createLlmProviderService;
  }

  const libRoot = resolveMemindLib();
  const fallbackCandidates = [
    path.join(libRoot, 'llm-providers.mjs.bak-20260625-221206'),
    path.join(libRoot, 'llm-providers.admin.mjs'),
  ];

  for (const candidate of fallbackCandidates) {
    if (!fs.existsSync(candidate)) continue;
    const fallback = await importLlmProvidersModule(candidate);
    if (hasAdminMethods(fallback.createLlmProviderService)) {
      console.warn(
        `[admin] Memind llm-providers.mjs 缺少管理端方法，已回退到 ${path.basename(candidate)}`,
      );
      return fallback.createLlmProviderService;
    }
  }

  throw new Error(
    'Memind llm-providers.mjs 缺少 getVisionSettings 等管理端方法。' +
      '请更新 MEMIND_LIB_ROOT 下的 llm-providers.mjs，或保留 llm-providers.mjs.bak-20260625-221206 备份文件。',
  );
}