'use strict';
const path = require('path');
const pathType = require('path-type');

const getExtensions = (extensions) =>
  extensions.length > 1 ? `{${extensions.join(',')}}` : extensions[0];

const getPath = (filepath, cwd) => {
  const pth = filepath[0] === '!' ? filepath.slice(1) : filepath;
  return path.isAbsolute(pth) ? pth : path.join(cwd, pth);
};

const addExtensions = (file, extensions) => {
  if (path.extname(file)) {
    return `**/${file}`;
  }

  return `**/${file}.${getExtensions(extensions)}`;
};

const getGlob = (directory, options) => {
  if (options.files && !Array.isArray(options.files)) {
    throw new TypeError(
      `Expected \`files\` to be of type \`Array\` but received type \`${typeof options.files}\``
    );
  }

  if (options.extensions && !Array.isArray(options.extensions)) {
    throw new TypeError(
      `Expected \`extensions\` to be of type \`Array\` but received type \`${typeof options.extensions}\``
    );
  }

  if (options.files && options.extensions) {
    return options.files.map((x) =>
      path.posix.join(directory, addExtensions(x, options.extensions))
    );
  }

  if (options.files) {
    return options.files.map((x) => path.posix.join(directory, `**/${x}`));
  }

  if (options.extensions) {
    return [
      path.posix.join(directory, `**/*.${getExtensions(options.extensions)}`),
    ];
  }

  return [path.posix.join(directory, '**')];
};

module.exports = async (input, options) => {
  options = {
    cwd: process.cwd(),
    ...options,
  };

  if (typeof options.cwd !== 'string') {
    throw new TypeError(
      `Expected \`cwd\` to be of type \`string\` but received type \`${typeof options.cwd}\``
    );
  }

  const globs = await Promise.all(
    [].concat(input).map(async (x) => {
      const isDirectory = await pathType.isDirectory(getPath(x, options.cwd));
      return isDirectory ? getGlob(x, options) : x;
    })
  );

  return [].concat.apply([], globs); // eslint-disable-line prefer-spread
};

module.exports.sync = (input, options) => {
  options = {
    cwd: process.cwd(),
    ...options,
  };

  if (typeof options.cwd !== 'string') {
    throw new TypeError(
      `Expected \`cwd\` to be of type \`string\` but received type \`${typeof options.cwd}\``
    );
  }

  const globs = []
    .concat(input)
    .map((x) =>
      pathType.isDirectorySync(getPath(x, options.cwd)) ?
        getGlob(x, options)
      : x
    );

  return [].concat.apply([], globs); // eslint-disable-line prefer-spread
};