import glob from 'fast-glob';
import { getRepoRoot } from '../base-client/base-client.js';
import type { Message, Resource } from '@fluent/syntax';
import { FluentParser } from '@fluent/syntax';
import { readFileSync } from 'node:fs';
import { DEFAULT_LOCALE, SCREENSHOT_CHECK_EXCEPTIONS } from '../constants.js';

async function listFtlFiles() {
  const pattern = `**/${DEFAULT_LOCALE}.ftl`; // Matches all and only default locale .ftl files

  const gitRoot = getRepoRoot();
  const options = {
    cwd: gitRoot,
    absolute: true, // Return absolute paths
    ignore: [
      '**/node_modules/**',
      '**/dist/**',
      ...SCREENSHOT_CHECK_EXCEPTIONS.map(
        (exceptionPath) => `**/${exceptionPath}`,
      ),
    ], // Ignore node_modules and dist directories
  };

  const files = await glob(pattern, options);
  return files;
}

async function getFtlKeysFromFile(filePath: string) {
  const parser = new FluentParser();
  const data = readFileSync(filePath, 'utf8');
  const resource: Resource = parser.parse(data);

  const keys = resource.body
    .filter((entry): entry is Message => entry.type === 'Message')
    .map((message: Message) => message.id.name);

  return keys;
}

// eslint-disable-next-line max-statements
export async function checkScreenshots(): Promise<void> {
  const files = await listFtlFiles();
  const gitRootPath = getRepoRoot();

  const missingScreenshots = [];

  for (const filePath of files) {
    const keys = await getFtlKeysFromFile(filePath);

    for (const key of keys) {
      const screenshotPath = filePath.replace(
        `${DEFAULT_LOCALE}.ftl`,
        `context-screenshots/${key}.png`,
      );

      // Fail if screenshot doesn't exist
      try {
        readFileSync(screenshotPath);
      } catch {
        const relativePath = screenshotPath.replace(gitRootPath, '');
        missingScreenshots.push(relativePath);
      }
    }
  }

  if (missingScreenshots.length > 0) {
    console.error('The following screenshots are missing:');
    console.error(missingScreenshots);
    throw new Error('Screenshots are missing.');
  } else {
    console.log('All screenshots are present.');
  }
}