const path = require('path');
const fs = require('fs-extra');
const execa = require('execa');
const chalk = require('chalk');
const { Extractor, ExtractorConfig } = require('@microsoft/api-extractor');

module.exports = function myPlugin(pkgName) {
  return {
    name: 'dts-plugin', // this name will show up in warnings and errors
    async closeBundle() {

      // build types
      const target = pkgName;
      const pkgDir = path.join(__dirname, '..', '..', 'packages', `${target}`);
      const pkg = require(`${pkgDir}/package.json`);
      
      const extractorConfigPath = path.resolve(pkgDir, `api-extractor.json`)
      const extractorConfig = ExtractorConfig.loadFileAndPrepare(
        extractorConfigPath
      );
      const extractorResult = Extractor.invoke(extractorConfig, {
        localBuild: true,
        showVerboseMessages: true
      });
      
      if (extractorResult.succeeded) {
        // concat additional d.ts to rolled-up dts
        const typesDir = path.resolve(pkgDir, 'types')
        if (await fs.exists(typesDir)) {
          const dtsPath = path.resolve(pkgDir, pkg.types)
          const existing = await fs.readFile(dtsPath, 'utf-8')
          const typeFiles = await fs.readdir(typesDir)
          const toAdd = await Promise.all(
            typeFiles.map(file => {
              return fs.readFile(path.resolve(typesDir, file), 'utf-8')
            })
          )
          await fs.writeFile(dtsPath, existing + '\n' + toAdd.join('\n'))
        }
        console.log(
          chalk.bold(chalk.green(`API Extractor completed successfully.`))
        )
      } else {
        console.error(
          `API Extractor completed with ${extractorResult.errorCount} errors` +
            ` and ${extractorResult.warningCount} warnings`
        )
        process.exitCode = 1
      }
      await fs.remove(`${pkgDir}/dist/packages`)
    }
  };
}