import { BrowserWindow, Extension, session } from 'electron';
import * as fs from 'fs';
import * as path from 'path';
import { createLogger } from '../../logger';

const logger = createLogger('main:yomitan-extension-loader');

export interface YomitanExtensionLoaderDeps {
  userDataPath: string;
  getYomitanParserWindow: () => BrowserWindow | null;
  setYomitanParserWindow: (window: BrowserWindow | null) => void;
  setYomitanParserReadyPromise: (promise: Promise<void> | null) => void;
  setYomitanParserInitPromise: (promise: Promise<boolean> | null) => void;
  setYomitanExtension: (extension: Extension | null) => void;
}

function ensureExtensionCopy(sourceDir: string, userDataPath: string): string {
  if (process.platform === 'win32') {
    return sourceDir;
  }

  const extensionsRoot = path.join(userDataPath, 'extensions');
  const targetDir = path.join(extensionsRoot, 'yomitan');

  const sourceManifest = path.join(sourceDir, 'manifest.json');
  const targetManifest = path.join(targetDir, 'manifest.json');

  let shouldCopy = !fs.existsSync(targetDir);
  if (!shouldCopy && fs.existsSync(sourceManifest) && fs.existsSync(targetManifest)) {
    try {
      const sourceVersion = (
        JSON.parse(fs.readFileSync(sourceManifest, 'utf-8')) as {
          version: string;
        }
      ).version;
      const targetVersion = (
        JSON.parse(fs.readFileSync(targetManifest, 'utf-8')) as {
          version: string;
        }
      ).version;
      shouldCopy = sourceVersion !== targetVersion;
    } catch {
      shouldCopy = true;
    }
  }

  if (shouldCopy) {
    fs.mkdirSync(extensionsRoot, { recursive: true });
    fs.rmSync(targetDir, { recursive: true, force: true });
    fs.cpSync(sourceDir, targetDir, { recursive: true });
    logger.info(`Copied yomitan extension to ${targetDir}`);
  }

  return targetDir;
}

export async function loadYomitanExtension(
  deps: YomitanExtensionLoaderDeps,
): Promise<Extension | null> {
  const searchPaths = [
    path.join(__dirname, '..', '..', 'vendor', 'yomitan'),
    path.join(__dirname, '..', '..', '..', 'vendor', 'yomitan'),
    path.join(process.resourcesPath, 'yomitan'),
    '/usr/share/SubMiner/yomitan',
    path.join(deps.userDataPath, 'yomitan'),
  ];

  let extPath: string | null = null;
  for (const p of searchPaths) {
    if (fs.existsSync(p)) {
      extPath = p;
      break;
    }
  }

  if (!extPath) {
    logger.error('Yomitan extension not found in any search path');
    logger.error('Install Yomitan to one of:', searchPaths);
    return null;
  }

  extPath = ensureExtensionCopy(extPath, deps.userDataPath);

  const parserWindow = deps.getYomitanParserWindow();
  if (parserWindow && !parserWindow.isDestroyed()) {
    parserWindow.destroy();
  }
  deps.setYomitanParserWindow(null);
  deps.setYomitanParserReadyPromise(null);
  deps.setYomitanParserInitPromise(null);

  try {
    const extensions = session.defaultSession.extensions;
    const extension = extensions
      ? await extensions.loadExtension(extPath, {
          allowFileAccess: true,
        })
      : await session.defaultSession.loadExtension(extPath, {
          allowFileAccess: true,
        });
    deps.setYomitanExtension(extension);
    return extension;
  } catch (err) {
    logger.error('Failed to load Yomitan extension:', (err as Error).message);
    logger.error('Full error:', err);
    deps.setYomitanExtension(null);
    return null;
  }
}