'use strict';

/**
 * Module dependencies.
 */

// Public node modules.
const _ = require('lodash');
const request = require('request');

// Purest strategies.
const Purest = require('purest');

const facebook = new Purest({
  provider: 'facebook'
});

const github = new Purest({
  provider: 'github',
  defaults: {
    headers: {
      'user-agent': 'strapi'
    }
  }
});

const google = new Purest({
  provider: 'google'
});

const twitter = new Purest({
  provider: 'twitter'
});

/**
 * Connect thanks to a third-party provider.
 *
 *
 * @param {String}    provider
 * @param {String}    access_token
 *
 * @return  {*}
 */

exports.connect = (provider, query) => {
  const access_token = query.access_token || query.code || query.oauth_token;

  return new Promise((resolve, reject) => {
    if (!access_token) {
      return reject(null, {
        message: 'No access_token.'
      });
    }

    // Get the profile.
    getProfile(provider, query, async (err, profile) => {
      if (err) {
        return reject(err);
      }

      // We need at least the mail.
      if (!profile.email) {
        reject([{
          message: 'Email was not available.'
        }, null]);
      } else {
        try {
          const user = await strapi.query('user', 'users-permissions').findOne({email: profile.email});

          if (!strapi.plugins['users-permissions'].config.advanced.allow_register) {
            return resolve([null, [{ messages: [{ id: 'Auth.advanced.allow_register' }] }], 'Register action is actualy not available.']);
          }

          if (user && user.provider === provider) {
            return resolve([null, [{ messages: [{ id: 'Auth.form.error.email.taken' }] }], 'Email is already taken.']);
          }

          if (user && user.provider !== provider && strapi.plugins['users-permissions'].config.advanced.unique_email) {
            return resolve([null, [{ messages: [{ id: 'Auth.form.error.email.taken' }] }], 'Email is already taken.']);
          }

          if (!user || _.get(user, 'provider') !== provider) {
            // Create the new user.
            const params = _.assign(profile, {
              provider: provider
            });

            const createdUser = await strapi.query('user', 'users-permissions').create(params);

            return resolve([createdUser, null]);
          }

          resolve([user, null]);
        } catch (err) {
          reject([null, err]);
        }
      }
    });
  });
};

/**
 * Helper to get profiles
 *
 * @param {String}   provider
 * @param {Function} callback
 */

const getProfile = (provider, query, callback) => {
  const access_token = query.access_token || query.code || query.oauth_token;

  switch (provider) {
    case 'facebook':
      facebook.query().get('me?fields=name,email').auth(access_token).request((err, res, body) => {
        if (err) {
          callback(err);
        } else {
          callback(null, {
            username: body.name,
            email: body.email
          });
        }
      });
      break;
    case 'google':
      google.query('plus').get('people/me').auth(access_token).request((err, res, body) => {
        if (err) {
          callback(err);
        } else {
          callback(null, {
            username: body.displayName,
            email: body.emails[0].value
          });
        }
      });
      break;
    case 'github':
      request.post({
        url: 'https://github.com/login/oauth/access_token',
        form: {
          client_id: strapi.plugins['users-permissions'].config.grant.github.key,
          client_secret: strapi.plugins['users-permissions'].config.grant.github.secret,
          code: access_token
        }
      }, (err, res, body) => {
        github.query().get('user').auth(body.split('&')[0].split('=')[1]).request((err, res, body) => {
          if (err) {
            callback(err);
          } else {
            callback(null, {
              username: body.login,
              email: body.email
            });
          }
        });
      });
      break;
    case 'twitter':
      twitter.query().get('account/verify_credentials').auth(access_token, query.access_secret).qs({screen_name: query['raw[screen_name]']}).qs({include_email: 'true'}).request((err, res, body) => {
        if (err) {
          callback(err);
        } else {
          callback(null, {
            username: body.screen_name,
            email: body.email
          });
        }
      });
      break;
    default:
      callback({
        message: 'Unknown provider.'
      });
      break;
  }
}