/**
 * Locator — 定位 OpenClaw control-ui 目录和文件
 *
 * 唯一定位方法：require.resolve('openclaw')
 * 插件通过 symlink 依赖宿主 openclaw 包，如果 symlink 不存在，
 * 插件的 import 语句就会失败，根本执行不到这里。
 */

import { existsSync, readdirSync } from 'node:fs';
import { dirname, join, resolve } from 'node:path';
import { createRequire } from 'node:module';
import { logger } from '../../util/logger.js';

/**
 * 定位 control-ui 目录。
 *
 * require.resolve('openclaw')
 *   → /usr/lib/node_modules/openclaw/dist/index.js
 *   → dirname → dist/
 *   → join('control-ui') → dist/control-ui/
 */
export function resolveControlUiDir(): string | null {
  const candidates: string[] = [];

  try {
    const require = createRequire(import.meta.url);
    const entryPoint = require.resolve('openclaw');
    const distDir = dirname(entryPoint);

    candidates.push(
      // npm/global install: openclaw/dist/index.js → openclaw/dist/control-ui
      join(distDir, 'control-ui'),
      // package root entry fallback: openclaw/index.js → openclaw/dist/control-ui
      join(dirname(distDir), 'dist', 'control-ui'),
    );
  } catch {
    // Docker installs the plugin outside /app/node_modules, so resolving the
    // host package from the plugin path can fail even though OpenClaw is
    // running from /app. Fall through to cwd-based candidates below.
  }

  // Docker image layout: process cwd is /app, UI lives at /app/dist/control-ui.
  candidates.push(
    join(process.cwd(), 'dist', 'control-ui'),
    join(resolve(process.cwd(), '..'), 'dist', 'control-ui'),
  );

  for (const candidate of candidates) {
    if (existsSync(candidate)) {
      logger.debug(`[ui-ext] control-ui located: ${candidate}`);
      return candidate;
    }
  }

  logger.warn('[ui-ext] Could not locate control-ui directory');
  return null;
}

/**
 * 定位 OpenClaw dist 目录。
 *
 * control-ui 是 dist/control-ui 的子目录，后端 gateway-cli-*.js 也在同一个
 * dist 下。这里优先从已解析出的 control-ui 反推，避免 Docker 场景下
 * require.resolve('openclaw') 失效。
 */
export function resolveOpenClawDistDir(controlUiDir?: string | null): string | null {
  const candidates: string[] = [];

  if (controlUiDir) {
    candidates.push(dirname(controlUiDir));
  }

  try {
    const require = createRequire(import.meta.url);
    const entryPoint = require.resolve('openclaw');
    candidates.push(dirname(entryPoint));
    candidates.push(join(dirname(dirname(entryPoint)), 'dist'));
  } catch {
    // Docker 插件路径下可能无法 resolve 宿主 openclaw；继续走 cwd 兜底。
  }

  candidates.push(
    join(process.cwd(), 'dist'),
    join(resolve(process.cwd(), '..'), 'dist'),
  );

  for (const candidate of candidates) {
    if (existsSync(candidate)) {
      logger.debug(`[ui-ext] openclaw dist located: ${candidate}`);
      return candidate;
    }
  }

  logger.warn('[ui-ext] Could not locate OpenClaw dist directory');
  return null;
}

/**
 * 在目录中查找匹配前缀的第一个文件。
 * 用于定位 Vite code-split 后的文件（如 index-D7mg1IkY.js）。
 * @param suffix 文件后缀，默认 '.js'，传 '.js.map' 可找 source map
 */
export function findFileByPrefix(dir: string, prefix: string, suffix = '.js'): string | null {
  try {
    const entries = readdirSync(dir);
    const match = entries.find(e => e.startsWith(prefix) && e.endsWith(suffix));
    if (match) {
      logger.debug(`[ui-ext] Found file: ${match}`);
    }
    return match ? join(dir, match) : null;
  } catch {
    return null;
  }
}

/**
 * 获取 bundle 文件名中的 hash 部分，用作 bundleHash。
 * index-D7mg1IkY.js → D7mg1IkY
 */
export function extractBundleHash(bundlePath: string): string {
  const filename = bundlePath.split('/').pop() ?? '';
  const match = filename.match(/^index-(.+)\.js$/);
  return match?.[1] ?? filename;
}