import { authWithHeaders, authWithSession } from '../../middlewares/auth';
import _ from 'lodash';
import cloneDeep from 'lodash/cloneDeep';
import { model as Challenge } from '../../models/challenge';
import {
  model as Group,
  basicFields as basicGroupFields,
  TAVERN_ID,
} from '../../models/group';
import {
  model as User,
  nameFields,
} from '../../models/user';
import {
  NotFound,
  NotAuthorized,
} from '../../libs/errors';
import * as Tasks from '../../models/task';
import csvStringify from '../../libs/csvStringify';
import {
  createTasks,
} from '../../libs/taskManager';

import {
  addUserJoinChallengeNotification,
  getChallengeGroupResponse,
  createChallenge,
  cleanUpTask,
} from '../../libs/challenges';
import apiError from '../../libs/apiError';

let api = {};

/**
 * @apiDefine ChallengeLeader Challenge Leader
 * The leader of the challenge can use this route.
 */

/**
 * @apiDefine ChallengeNotFound
 * @apiError (404) {NotFound} ChallengeNotFound The specified challenge could not be found.
 */

/**
 * @apiDefine SuccessfulChallengeRequest
 * @apiSuccess {UUID} challenge.group._id The group id.
 * @apiSuccess {String} challenge.group.type Group type: `guild` or `party`.
 * @apiSuccess {String} challenge.group.privacy Group privacy: `public` or `private`.
 * @apiSuccess {String} challenge.name Full name of challenge.
 * @apiSuccess {String} challenge.shortName A shortened name for the challenge, to be used as a tag.
 * @apiSuccess {Object} challenge.leader User details of challenge leader.
 * @apiSuccess {UUID} challenge.leader._id User id of challenge leader.
 * @apiSuccess {Object} challenge.leader.profile Profile information of leader.
 * @apiSuccess {Object} challenge.leader.profile.name Display Name of leader.
 * @apiSuccess {String} challenge.updatedAt Timestamp of last update.
 * @apiSuccess {String} challenge.createdAt Timestamp of challenge creation.
 * @apiSuccess {UUID} challenge.id Id number of newly created challenge.
 * @apiSuccess {UUID} challenge._id Same as `challenge.id`.
 * @apiSuccess {String} challenge.prize Number of gems offered as prize to winner (can be 0).
 * @apiSuccess {String} challenge.memberCount Number users participating in challenge.
 * @apiSuccess {Object} challenge.tasksOrder Object containing IDs of the challenge's tasks and rewards in their preferred sort order.
 * @apiSuccess {Array} challenge.tasksOrder.rewards Array of `reward` task IDs.
 * @apiSuccess {Array} challenge.tasksOrder.todos Array of `todo` task IDs.
 * @apiSuccess {Array} challenge.tasksOrder.dailys Array of `daily` task IDs.
 * @apiSuccess {Array} challenge.tasksOrder.habits Array of `habit` task IDs.
 * @apiSuccess {Boolean} challenge.official Boolean indicating if this is an official Habitica challenge.
 *
 */

/**
 * @apiDefine ChallengeSuccessExample
 * @apiSuccessExample {json} Successful response with single challenge
 {
   "data": {
     "group": {
      "_id": "group-id-associated-with-challenge",
      "name": "MyGroup",
      "type": "guild",
      "privacy": "public"
     },
     "name": "Long Detailed Name of Challenge",
     "shortName": "my challenge",
     "leader": {
       "_id": "user-id-of-challenge-creator",
       "profile": {
         "name": "MyUserName"
       }
     },
     "updatedAt": "timestamp,
     "createdAt": "timestamp",
     "_id": "challenge-id",
     "prize": 0,
     "memberCount": 1,
     "tasksOrder": {
       "rewards": [
         "uuid-of-challenge-reward"
       ],
       "todos": [
         "uuid-of-challenge-todo"
       ],
       "dailys": [
         "uuid-of-challenge-daily"
       ],
       "habits": [
         "uuid-of-challenge-habit"
       ]
     },
     "official": false,
     "id": "challenge-id"
   }
 }
*/

/**
 * @apiDefine ChallengeArrayExample
 * @apiSuccessExample {json} Successful response with array of challenges
 {
   "data": [{
     "group": {
       "_id": "group-id-associated-with-challenge",
       "name": "MyGroup",
       "type": "guild",
       "privacy": "public"
     },
     "name": "Long Detailed Name of Challenge",
     "shortName": "my challenge",
     "leader": {
       "_id": "user-id-of-challenge-creator",
       "profile": {
         "name": "MyUserName"
       }
     },
     "updatedAt": "timestamp,
     "createdAt": "timestamp",
     "_id": "challenge-id",
     "prize": 0,
     "memberCount": 1,
     "tasksOrder": {
       "rewards": [
         "uuid-of-challenge-reward"
       ],
       "todos": [
         "uuid-of-challenge-todo"
       ],
       "dailys": [
         "uuid-of-challenge-daily"
       ],
       "habits": [
         "uuid-of-challenge-habit"
       ]
     },
     "official": false,
     "id": "challenge-id"
   }]
 }
*/

/**
 * @api {post} /api/v3/challenges Create a new challenge
 * @apiName CreateChallenge
 * @apiGroup Challenge
 * @apiDescription Creates a challenge. Cannot create associated tasks with this route. See <a href="#api-Task-CreateChallengeTasks">CreateChallengeTasks</a>.
 *
 * @apiParam (Body) {Object} challenge An object representing the challenge to be created
 * @apiParam (Body) {UUID} challenge.group The id of the group to which the challenge belongs
 * @apiParam (Body) {String} challenge.name The full name of the challenge
 * @apiParam (Body) {String} challenge.shortName A shortened name for the challenge, to be used as a tag
 * @apiParam (Body) {String} [challenge.summary] A short summary advertising the main purpose of the challenge; maximum 250 characters; if not supplied, challenge.name will be used
 * @apiParam (Body) {String} [challenge.description] A detailed description of the challenge
 * @apiParam (Body) {Boolean} [official=false] Whether or not a challenge is an official Habitica challenge (requires admin)
 * @apiParam (Body) {Number} [challenge.prize=0] Number of gems offered as a prize to challenge winner
 *
 * @apiSuccess (201) {Object} challenge The newly created challenge.
 * @apiUse SuccessfulChallengeRequest
 *
 * @apiUse ChallengeSuccessExample
 *
 * @apiError (401) {NotAuthorized} CantAffordPrize User does not have enough gems to offer this prize.
 * @apiError (400) {BadRequest} ChallengeValidationFailed Invalid or missing parameter in challenge body.
 *
 * @apiUse GroupNotFound
 * @apiUse UserNotFound
 */
api.createChallenge = {
  method: 'POST',
  url: '/challenges',
  middlewares: [authWithHeaders()],
  async handler (req, res) {
    let user = res.locals.user;

    req.checkBody('group', apiError('groupIdRequired')).notEmpty();

    const validationErrors = req.validationErrors();
    if (validationErrors) throw validationErrors;

    const {savedChal, group} = await createChallenge(user, req, res);

    let response = savedChal.toJSON();
    response.leader = { // the leader is the authenticated user
      _id: user._id,
      profile: {name: user.profile.name},
    };
    response.group = getChallengeGroupResponse(group);

    res.analytics.track('challenge create', {
      uuid: user._id,
      hitType: 'event',
      category: 'behavior',
      challengeID: response._id,
      groupID: group._id,
      groupName: group.privacy === 'private' ? null : group.name,
      groupType: group._id === TAVERN_ID ? 'tavern' : group.type,
    });

    res.respond(201, response);
  },
};

/**
 * @api {post} /api/v3/challenges/:challengeId/join Join a challenge
 * @apiName JoinChallenge
 * @apiGroup Challenge
 * @apiParam (Path) {UUID} challengeId The challenge _id
 *
 * @apiSuccess {Object} challenge The challenge the user joined
 * @apiUse SuccessfulChallengeRequest
 *
 * @apiUse ChallengeNotFound
 * @apiUse UserNotFound
 *
 * @apiUse ChallengeSuccessExample
 */
api.joinChallenge = {
  method: 'POST',
  url: '/challenges/:challengeId/join',
  middlewares: [authWithHeaders()],
  async handler (req, res) {
    let user = res.locals.user;

    req.checkParams('challengeId', res.t('challengeIdRequired')).notEmpty().isUUID();

    let validationErrors = req.validationErrors();
    if (validationErrors) throw validationErrors;

    let challenge = await Challenge.findOne({ _id: req.params.challengeId }).exec();
    if (!challenge) throw new NotFound(res.t('challengeNotFound'));
    if (challenge.isMember(user)) throw new NotAuthorized(res.t('userAlreadyInChallenge'));

    let group = await Group.getGroup({user, groupId: challenge.group, fields: basicGroupFields, optionalMembership: true});
    if (!group || !challenge.canJoin(user, group)) throw new NotFound(res.t('challengeNotFound'));

    challenge.memberCount += 1;

    addUserJoinChallengeNotification(user);

    // Add all challenge's tasks to user's tasks and save the challenge
    let results = await Promise.all([challenge.syncToUser(user), challenge.save()]);

    let response = results[1].toJSON();
    response.group = getChallengeGroupResponse(group);
    let chalLeader = await User.findById(response.leader).select(nameFields).exec();
    response.leader = chalLeader ? chalLeader.toJSON({minimize: true}) : null;

    res.analytics.track('challenge join', {
      uuid: user._id,
      hitType: 'event',
      category: 'behavior',
      challengeID: challenge._id,
      groupID: group._id,
      groupName: group.privacy === 'private' ? null : group.name,
      groupType: group._id === TAVERN_ID ? 'tavern' : group.type,
    });

    res.respond(200, response);
  },
};

/**
 * @api {post} /api/v3/challenges/:challengeId/leave Leave a challenge
 * @apiName LeaveChallenge
 * @apiGroup Challenge
 * @apiParam (Path) {UUID} challengeId The challenge _id
 * @apiParam (Body) {String="remove-all","keep-all"} [keep="keep-all"] Whether or not to keep or remove the challenge's tasks
 *
 * @apiSuccess {Object} data An empty object
 *
 * @apiUse ChallengeNotFound
 * @apiUse UserNotFound
 */
api.leaveChallenge = {
  method: 'POST',
  url: '/challenges/:challengeId/leave',
  middlewares: [authWithHeaders()],
  async handler (req, res) {
    let user = res.locals.user;
    let keep = req.body.keep === 'remove-all' ? 'remove-all' : 'keep-all';

    req.checkParams('challengeId', res.t('challengeIdRequired')).notEmpty().isUUID();

    let validationErrors = req.validationErrors();
    if (validationErrors) throw validationErrors;

    let challenge = await Challenge.findOne({ _id: req.params.challengeId }).exec();
    if (!challenge) throw new NotFound(res.t('challengeNotFound'));

    if (!challenge.isMember(user)) throw new NotAuthorized(res.t('challengeMemberNotFound'));

    // Unlink challenge's tasks from user's tasks and save the challenge
    await challenge.unlinkTasks(user, keep);

    res.analytics.track('challenge leave', {
      uuid: user._id,
      hitType: 'event',
      category: 'behavior',
      challengeID: challenge._id,
      groupID: challenge.group._id,
      groupName: challenge.group.privacy === 'private' ? null : challenge.group.name,
      groupType: challenge.group._id === TAVERN_ID ? 'tavern' : challenge.group.type,
    });

    res.respond(200, {});
  },
};

/**
 * @api {get} /api/v3/challenges/user Get challenges for a user
 * @apiName GetUserChallenges
 * @apiGroup Challenge
 * @apiDescription Get challenges the user has access to. Includes public challenges, challenges belonging to the user's group, and challenges the user has already joined.
 *
 * @apiSuccess {Object[]} challenges An array of challenges sorted with official challenges first, followed by the challenges in order from newest to oldest
 *
 * @apiUse SuccessfulChallengeRequest
 *
 * @apiUse ChallengeArrayExample
 *
 * @apiUse UserNotFound
 */
api.getUserChallenges = {
  method: 'GET',
  url: '/challenges/user',
  middlewares: [authWithHeaders()],
  async handler (req, res) {
    const CHALLENGES_PER_PAGE = 10;
    const page = req.query.page;

    const user = res.locals.user;
    let orOptions = [
      {_id: {$in: user.challenges}}, // Challenges where the user is participating
    ];

    const owned = req.query.owned;
    if (!owned)  {
      orOptions.push({leader: user._id});
    }

    if (!req.query.member) {
      orOptions.push({
        group: {$in: user.getGroups()},
      }); // Challenges in groups where I'm a member
    }

    let query = {
      $and: [{$or: orOptions}],
    };

    if (owned && owned === 'not_owned') {
      query.$and.push({leader: {$ne: user._id}});
    }

    if (owned && owned === 'owned') {
      query.$and.push({leader: user._id});
    }

    if (req.query.search) {
      const searchOr = {$or: []};
      const searchWords = _.escapeRegExp(req.query.search).split(' ').join('|');
      const searchQuery = { $regex: new RegExp(`${searchWords}`, 'i') };
      searchOr.$or.push({name: searchQuery});
      searchOr.$or.push({description: searchQuery});
      query.$and.push(searchOr);
    }

    if (req.query.categories) {
      let categorySlugs = req.query.categories.split(',');
      query.categories = { $elemMatch: { slug: {$in: categorySlugs} } };
    }

    let mongoQuery = Challenge.find(query)
      .sort('-createdAt');

    if (page) {
      mongoQuery = mongoQuery
        .limit(CHALLENGES_PER_PAGE)
        .skip(CHALLENGES_PER_PAGE * page);
    }

    // see below why we're not using populate
    // .populate('group', basicGroupFields)
    // .populate('leader', nameFields)
    const challenges = await mongoQuery.exec();


    let resChals = challenges.map(challenge => challenge.toJSON());

    resChals = _.orderBy(resChals, [challenge => {
      return challenge.categories.map(category => category.slug).includes('habitica_official');
    }], ['desc']);

    // Instead of populate we make a find call manually because of https://github.com/Automattic/mongoose/issues/3833
    await Promise.all(resChals.map((chal, index) => {
      return Promise.all([
        User.findById(chal.leader).select(nameFields).exec(),
        Group.findById(chal.group).select(basicGroupFields).exec(),
      ]).then(populatedData => {
        resChals[index].leader = populatedData[0] ? populatedData[0].toJSON({minimize: true}) : null;
        resChals[index].group = populatedData[1] ? populatedData[1].toJSON({minimize: true}) : null;
      });
    }));

    res.respond(200, resChals);
  },
};

/**
 * @api {get} /api/v3/challenges/groups/:groupId Get challenges for a group
 * @apiDescription Get challenges that the user is a member, public challenges and the ones from the user's groups.
 * @apiName GetGroupChallenges
 * @apiGroup Challenge
 *
 * @apiParam (Path) {UUID} groupId The group _id
 *
 * @apiSuccess {Array} data An array of challenges sorted with official challenges first, followed by the challenges in order from newest to oldest
 *
 * @apiUse SuccessfulChallengeRequest
 * @apiUse ChallengeArrayExample
 * @apiUse UserNotFound
 * @apiUse GroupNotFound
 */
api.getGroupChallenges = {
  method: 'GET',
  url: '/challenges/groups/:groupId',
  middlewares: [authWithHeaders({
    userFieldsToInclude: ['_id', 'party', 'guilds'],
  })],
  async handler (req, res) {
    let user = res.locals.user;
    let groupId = req.params.groupId;

    req.checkParams('groupId', apiError('groupIdRequired')).notEmpty();

    let validationErrors = req.validationErrors();
    if (validationErrors) throw validationErrors;

    if (groupId === 'party') groupId = user.party._id;
    if (groupId === 'habitrpg') groupId = TAVERN_ID;

    const group = await Group.getGroup({ user, groupId });
    if (!group) throw new NotFound(res.t('groupNotFound'));

    const challenges = await Challenge.find({ group: groupId })
      .sort('-createdAt')
      // .populate('leader', nameFields) // Only populate the leader as the group is implicit
      .exec();

    let resChals = challenges.map(challenge => challenge.toJSON());

    resChals = _.orderBy(resChals, [challenge => {
      return challenge.categories.map(category => category.slug).includes('habitica_official');
    }], ['desc']);

    // Instead of populate we make a find call manually because of https://github.com/Automattic/mongoose/issues/3833
    await Promise.all(resChals.map((chal, index) => {
      return User
        .findById(chal.leader)
        .select(nameFields)
        .exec()
        .then(populatedLeader => {
          resChals[index].leader = populatedLeader ? populatedLeader.toJSON({minimize: true}) : null;
        });
    }));

    res.respond(200, resChals);
  },
};

/**
 * @api {get} /api/v3/challenges/:challengeId Get a challenge given its id
 * @apiName GetChallenge
 * @apiGroup Challenge
 *
 * @apiParam (Path) {UUID} challengeId The challenge _id
 *
 * @apiSuccess {Object} data The challenge object
 * @apiUse SuccessfulChallengeRequest
*  @apiUse ChallengeSuccessExample
 *
 * @apiUse ChallengeNotFound
 */
api.getChallenge = {
  method: 'GET',
  url: '/challenges/:challengeId',
  middlewares: [authWithHeaders()],
  async handler (req, res) {
    req.checkParams('challengeId', res.t('challengeIdRequired')).notEmpty().isUUID();

    let validationErrors = req.validationErrors();
    if (validationErrors) throw validationErrors;

    let user = res.locals.user;
    let challengeId = req.params.challengeId;

    // Don't populate the group as we'll fetch it manually later
    // .populate('leader', nameFields)
    let challenge = await Challenge.findById(challengeId).exec();

    if (!challenge) throw new NotFound(res.t('challengeNotFound'));

    // Fetching basic group data
    let group = await Group.getGroup({user, groupId: challenge.group, fields: basicGroupFields, optionalMembership: true});
    if (!group || !challenge.canView(user, group)) throw new NotFound(res.t('challengeNotFound'));

    let chalRes = challenge.toJSON();
    chalRes.group = group.toJSON({minimize: true});
    // Instead of populate we make a find call manually because of https://github.com/Automattic/mongoose/issues/3833
    let chalLeader = await User.findById(chalRes.leader).select(nameFields).exec();
    chalRes.leader = chalLeader ? chalLeader.toJSON({minimize: true}) : null;

    res.respond(200, chalRes);
  },
};

/**
 * @api {get} /api/v3/challenges/:challengeId/export/csv Export a challenge in CSV
 * @apiName ExportChallengeCsv
 * @apiGroup Challenge
 *
 * @apiParam (Path) {UUID} challengeId The challenge _id
 *
 * @apiSuccess {String} challenge A csv file
 *
 * @apiUse ChallengeNotFound
 */
api.exportChallengeCsv = {
  method: 'GET',
  url: '/challenges/:challengeId/export/csv',
  middlewares: [authWithSession],
  async handler (req, res) {
    req.checkParams('challengeId', res.t('challengeIdRequired')).notEmpty().isUUID();

    let validationErrors = req.validationErrors();
    if (validationErrors) throw validationErrors;

    let user = res.locals.user;
    let challengeId = req.params.challengeId;

    let challenge = await Challenge.findById(challengeId).select('_id group leader tasksOrder').exec();
    if (!challenge) throw new NotFound(res.t('challengeNotFound'));
    let group = await Group.getGroup({user, groupId: challenge.group, fields: '_id type privacy', optionalMembership: true});
    if (!group || !challenge.canView(user, group)) throw new NotFound(res.t('challengeNotFound'));

    // In v2 this used the aggregation framework to run some computation on MongoDB but then iterated through all
    // results on the server so the perf difference isn't that big (hopefully)

    let [members, tasks] = await Promise.all([
      User.find({challenges: challengeId})
        .select(nameFields)
        .sort({_id: 1})
        .lean() // so we don't involve mongoose
        .exec(),

      Tasks.Task.find({
        'challenge.id': challengeId,
        userId: {$exists: true},
      }).sort({userId: 1, text: 1})
        .select('userId type text value notes streak')
        .lean().exec(),
    ]);

    let resArray = members.map(member => [member._id, member.profile.name, member.auth.local.username]);

    let lastUserId;
    let index = -1;
    tasks.forEach(task => {
      /**
       * Occasional error does not unlink a user's challenge tasks from that challenge's data
       * after the user leaves that challenge, which previously caused a failure when exporting
       * to a CSV. The following if statement makes sure that the task's attached user still
       * belongs to the challenge.
       * See more at https://github.com/HabitRPG/habitica/issues/8350
       */
      if (!resArray.map(line => line[0]).includes(task.userId)) {
        return;
      }
      while (task.userId !== lastUserId) {
        index++;
        lastUserId = resArray[index][0]; // resArray[index][0] is an user id
      }

      const streak = task.streak || 0;

      resArray[index].push(`${task.type}:${task.text}`, task.value, task.notes, streak);
    });

    // The first row is going to be UUID name Task Value Notes repeated n times for the n challenge tasks
    let challengeTasks = _.reduce(challenge.tasksOrder.toObject(), (result, array) => {
      return result.concat(array);
    }, []).sort();
    resArray.unshift(['UUID', 'Display Name', 'Username']);

    _.times(challengeTasks.length, () => resArray[0].push('Task', 'Value', 'Notes', 'Streak'));

    // Remove lines for users without tasks info
    resArray = resArray.filter((line) => {
      if (line.length === 2) { // only user data ([id, profile name]), no task data
        return false;
      }

      return true;
    });

    res.set({
      'Content-Type': 'text/csv',
      'Content-disposition': `attachment; filename=${challengeId}.csv`,
    });

    let csvRes = await csvStringify(resArray);
    res.status(200).send(csvRes);
  },
};

/**
 * @api {put} /api/v3/challenges/:challengeId Update the name, description, or leader of a challenge
 *
 * @apiName UpdateChallenge
 * @apiGroup Challenge
 *
 * @apiParam (Path) {UUID} challengeId The challenge _id
 * @apiParam (Body) {String} [challenge.name] The new full name of the challenge.
 * @apiParam (Body) {String} [challenge.summary] The new challenge summary.
 * @apiParam (Body) {String} [challenge.description] The new challenge description.
 * @apiParam (Body) {String} [challenge.leader] The UUID of the new challenge leader.
 *
 * @apiSuccess {Object} data The updated challenge
 * @apiPermission ChallengeLeader
 *
 * @apiUse ChallengeSuccessExample
 *
 * @apiUse ChallengeNotFound
 *
 * @apiError (401) {NotAuthorized} MustBeChallengeLeader Only challenge leader
 * can update the challenge.
 */
api.updateChallenge = {
  method: 'PUT',
  url: '/challenges/:challengeId',
  middlewares: [authWithHeaders()],
  async handler (req, res) {
    req.checkParams('challengeId', res.t('challengeIdRequired')).notEmpty().isUUID();

    let validationErrors = req.validationErrors();
    if (validationErrors) throw validationErrors;

    let user = res.locals.user;
    let challengeId = req.params.challengeId;

    let challenge = await Challenge.findById(challengeId).exec();
    if (!challenge) throw new NotFound(res.t('challengeNotFound'));

    let group = await Group.getGroup({user, groupId: challenge.group, fields: basicGroupFields, optionalMembership: true});
    if (!group || !challenge.canView(user, group)) throw new NotFound(res.t('challengeNotFound'));
    if (!challenge.canModify(user)) throw new NotAuthorized(res.t('onlyLeaderUpdateChal'));

    _.merge(challenge, Challenge.sanitizeUpdate(req.body));

    let savedChal = await challenge.save();
    let response = savedChal.toJSON();
    response.group = getChallengeGroupResponse(group);
    let chalLeader = await User.findById(response.leader).select(nameFields).exec();
    response.leader = chalLeader ? chalLeader.toJSON({minimize: true}) : null;
    res.respond(200, response);
  },
};

/**
 * @api {delete} /api/v3/challenges/:challengeId Delete a challenge
 * @apiName DeleteChallenge
 * @apiGroup Challenge
 *
 * @apiParam (Path) {UUID} challengeId The _id for the challenge to delete
 *
 * @apiSuccess {Object} data An empty object
 *
 * @apiUse ChallengeNotFound
 */
api.deleteChallenge = {
  method: 'DELETE',
  url: '/challenges/:challengeId',
  middlewares: [authWithHeaders()],
  async handler (req, res) {
    let user = res.locals.user;

    req.checkParams('challengeId', res.t('challengeIdRequired')).notEmpty().isUUID();

    let validationErrors = req.validationErrors();
    if (validationErrors) throw validationErrors;

    let challenge = await Challenge.findOne({_id: req.params.challengeId}).exec();
    if (!challenge) throw new NotFound(res.t('challengeNotFound'));
    if (!challenge.canModify(user)) throw new NotAuthorized(res.t('onlyLeaderDeleteChal'));

    // Close channel in background, some ops are run in the background without `await`ing
    await challenge.closeChal({broken: 'CHALLENGE_DELETED'});

    res.analytics.track('challenge delete', {
      uuid: user._id,
      hitType: 'event',
      category: 'behavior',
      challengeID: challenge._id,
      groupID: challenge.group._id,
      groupName: challenge.group.privacy === 'private' ? null : challenge.group.name,
      groupType: challenge.group._id === TAVERN_ID ? 'tavern' : challenge.group.type,
    });

    res.respond(200, {});
  },
};

/**
 * @api {post} /api/v3/challenges/:challengeId/selectWinner/:winnerId Select winner for challenge
 * @apiName SelectChallengeWinner
 * @apiGroup Challenge
 *
 * @apiParam (Path) {UUID} challengeId The _id for the challenge to close with a winner
 * @apiParam (Path) {UUID} winnerId The _id of the winning user
 *
 * @apiSuccess {Object} data An empty object
 *
 * @apiUse ChallengeNotFound
 */
api.selectChallengeWinner = {
  method: 'POST',
  url: '/challenges/:challengeId/selectWinner/:winnerId',
  middlewares: [authWithHeaders()],
  async handler (req, res) {
    let user = res.locals.user;

    req.checkParams('challengeId', res.t('challengeIdRequired')).notEmpty().isUUID();
    req.checkParams('winnerId', res.t('winnerIdRequired')).notEmpty().isUUID();

    let validationErrors = req.validationErrors();
    if (validationErrors) throw validationErrors;

    let challenge = await Challenge.findOne({_id: req.params.challengeId}).exec();
    if (!challenge) throw new NotFound(res.t('challengeNotFound'));
    if (!challenge.canModify(user)) throw new NotAuthorized(res.t('onlyLeaderDeleteChal'));

    let winner = await User.findOne({_id: req.params.winnerId}).exec();
    if (!winner || winner.challenges.indexOf(challenge._id) === -1) throw new NotFound(res.t('winnerNotFound', {userId: req.params.winnerId}));

    // Close channel in background, some ops are run in the background without `await`ing
    await challenge.closeChal({broken: 'CHALLENGE_CLOSED', winner});

    res.analytics.track('challenge close', {
      uuid: user._id,
      hitType: 'event',
      category: 'behavior',
      challengeID: challenge._id,
      challengeWinnerID: winner._id,
      groupID: challenge.group._id,
      groupName: challenge.group.privacy === 'private' ? null : challenge.group.name,
      groupType: challenge.group._id === TAVERN_ID ? 'tavern' : challenge.group.type,
    });

    res.respond(200, {});
  },
};

/**
 * @api {post} /api/v3/challenges/:challengeId/clone Clone a challenge
 * @apiName CloneChallenge
 * @apiGroup Challenge
 *
 * @apiParam (Path) {UUID} challengeId The _id for the challenge to clone
 *
 * @apiSuccess {Object} challenge The cloned challenge
 *
 * @apiUse ChallengeNotFound
 */
api.cloneChallenge = {
  method: 'POST',
  url: '/challenges/:challengeId/clone',
  middlewares: [authWithHeaders()],
  async handler (req, res) {
    let user = res.locals.user;

    req.checkParams('challengeId', res.t('challengeIdRequired')).notEmpty().isUUID();

    let validationErrors = req.validationErrors();
    if (validationErrors) throw validationErrors;

    const challengeToClone = await Challenge.findOne({_id: req.params.challengeId}).exec();
    if (!challengeToClone) throw new NotFound(res.t('challengeNotFound'));

    const {savedChal} = await createChallenge(user, req, res);

    const challengeTasks = await Tasks.Task.find({
      'challenge.id': challengeToClone._id,
      userId: {$exists: false},
    }).exec();

    const tasksToClone = challengeTasks.map(task => {
      let clonedTask = cloneDeep(task.toObject());
      let omittedTask = cleanUpTask(clonedTask);
      return omittedTask;
    });

    const taskRequest = {
      body: tasksToClone,
    };

    const clonedTasks = await createTasks(taskRequest, res, {user, challenge: savedChal});

    res.respond(200, {clonedTasks, clonedChallenge: savedChal});
  },
};

module.exports = api;