'use strict';

var request = require('superagent');
var config = require('../lib/config');
var Promise = require('bluebird');

function getNextPage(headers) {
  if(!headers.link) {
    return null;
  }

  var match = headers.link.match(/page=(\d+)>; rel="next"/);

  if(!match) {
    return null;
  }

  return match[1];
}

var githubService = {
  /**
   * Fetch all members of the GitHub organization
   */
  getMembers: function(pageNum) {
    pageNum = pageNum || 0;

    return new Promise(function(resolve, reject) {
      request
      .get('https://api.github.com/orgs/koodiklinikka/members')
      .query({page: pageNum})
      .set('Authorization', 'token ' + config.github.token)
      .end(function(error, response){
        if (error) {
          reject(error);
        }

        resolve(response);
      });
    }).then(function(response) {

      var nextPage = getNextPage(response.headers);

      if(nextPage !== null) {
        return githubService.getMembers(nextPage).then(function(members) {
          return members.concat(response.body);
        });
      }

      return response.body;
    });
  },
  /**
   * Search member by email
   */
  findUserByEmail: function(email) {
    return new Promise(function(resolve, reject) {
      request
      .get('https://api.github.com/search/users')
      .query({q: email})
      .set('Authorization', 'token ' + config.github.token)
      .end(function(error, response){
        if(error) {
          return reject(error);
        }

        if(!response.body.items) {
          return reject(new Error(response.body.message));
        }

        if(response.body.items.length === 0) {
          return reject(new Error('Not Found'));
        }

        resolve(response.body.items[0]);
      });
    });
  },
  /**
   * Invite user to organization
   */
  inviteToOrg: function(user) {
    return new Promise(function(resolve, reject) {
      request
      .put('https://api.github.com/orgs/koodiklinikka/memberships/' + user.login)
      .set('Authorization', 'token ' + config.github.token)
      .send({role: 'member'})
      .end(function(error, response){

        if(error) {
          return reject(error);
        }

        if(response.statusCode !== 200) {
          return reject(response.error);
        }

        resolve(response.body.user);
      });
    });
  }
};

module.exports = githubService;