/*
 * Copyright (C) 2018 StApps
 * This program is free software: you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation, version 3.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program. If not, see <https://www.gnu.org/licenses/>.
 */
import {Api} from '@openstapps/gitlab-api';
import {Project} from '@openstapps/gitlab-api/lib/types';
import {Logger} from '@openstapps/logger';
import {asyncPool} from 'async-pool-native/dist/async-pool';
import {readFile, unlink, writeFile} from 'fs';
import * as glob from 'glob';
import {promisify} from 'util';
import {PACK_IDENTIFIER} from './configuration';

/**
 * Instantiated logger
 */
export const logger = new Logger();

/**
 * Get projects for a list of groups
 *
 * @param api GitLab API to make requests with
 * @param groups List of groups
 */
export async function getProjects(api: Api, groups: number[]): Promise<Project[]> {
  logger.info('Fetching all projects for specified groups (' + groups.length + ')...');

  const projectResults = await asyncPool(3, groups, (groupId) => {
    return api.getProjectsForGroup(groupId);
  });

  const projects = flatten2dArray(projectResults);

  logger.log('Fetched ' + projects.length + ' project(s).');

  return projects;
}

/**
 * Flatten 2d array
 *
 * @param arr Flattened array
 */
export function flatten2dArray<T>(arr: T[][]): T[] {
  // TODO: fix this
  return [].concat.apply([], arr as any);
}

/**
 * Promisified version of readFile
 */
export const readFilePromisified = promisify(readFile);
/**
 * Promisified version of glob
 */
export const globPromisified = promisify(glob);
/**
 * Promisified version of writeFile
 */
export const writeFilePromisified = promisify(writeFile);
/**
 * Promisified version of unlink
 */
export const unlinkPromisified = promisify(unlink);

/**
 * Delete file if it exists and is packed by this script
 *
 * @param path Path to file to check/delete
 */
export async function deleteFileIfExistingAndPacked(path: string): Promise<void> {
  try {
    const buffer = await readFilePromisified(path);
    const content = buffer.toString();

    // check if packed by this script
    if (content.indexOf(PACK_IDENTIFIER) === 0) {
      logger.log('Found `' + path + '` which is packed by this script. Deleting it...');
      return await unlinkPromisified(path);
    }
  } catch (err) {
    if (err.code === 'ENOENT') {
      return;
    }
  }
}

/**
 * Get all internal dependencies from the content of a module
 *
 * @param moduleContent Module content to analyze
 */
export function getAllInternalDependecies(moduleContent: string): string[] {
  // match all const <name> = require(<moduleName>);
  const requireLines =
    moduleContent.match(/^\s*(const|var) [a-z0-9_]* = require\("([^"]+)"\)|require\('([^']+)'\);$/gmi);

  if (Array.isArray(requireLines)) {
    return requireLines.map((requireLine) => {
      const matches = requireLine.match(/require\("([^"]+)"\)|require\('([^']+)'\);$/i);

      // previously matched require line does not contain a require?!
      if (matches === null) {
        throw new Error();
      }

      // return only the moduleName
      return matches[1];
    }).filter((moduleName) => {
      // filter out internal modules beginning with './' and not ending with '.json'
      return /^[.]{1,2}\/(?!.*\.json$).*$/i.test(moduleName);
    }).map((internalModuleName) => {
      // cut './' from the name
      return internalModuleName.substring(2);
    });
  }

  return [];
}