const mongoose = require('../mongoose');
const uuid = require('uuid');
const Schema = mongoose.Schema;

const ActionSchema = new Schema({
  id: {
    type: String,
    default: uuid.v4,
    unique: true
  },
  action_type: String,
  item_type: String,
  item_id: String,
  user_id: String
}, {
  timestamps: {
    createdAt: 'created_at',
    updatedAt: 'updated_at'
  }
});

/**
 * Finds an action by the id.
 * @param {String} id  identifier of the action (uuid)
*/
ActionSchema.statics.findById = function(id) {
  return Action.findOne({id});
};

/**
 * Finds actions in an array of ids.
 * @param {String} ids array of user identifiers (uuid)
*/
ActionSchema.statics.findByItemIdArray = function(item_ids) {
  return Action.find({
    'item_id': {$in: item_ids}
  });
};

/**
 * Returns summaries of actions for an array of ids
 * @param {String} ids array of user identifiers (uuid)
*/
ActionSchema.statics.getActionSummaries = function(item_ids) {
  return ActionSchema.statics.findByItemIdArray(item_ids).then((rawActions) => {
    // Create an object with a count of each action type for each item
    const actionSummaries = rawActions.reduce((actionObj, action) => {
      if (!actionObj[action.item_id]) {
        actionObj[action.item_id] = {
          id: action.id,
          item_type: action.item_type,
          action_type: action.action_type,
          count: 1,
          current_user: false //Update this later when we have authentication
        };
      } else {
        actionObj[action.item_id].count ++;
      }
      return actionObj;
    }, {});

    // Return an array extracted from the actionSummaries object
    return Object.keys(actionSummaries).reduce((actions, key) => {
      let actionSummary = actionSummaries[key];
      actionSummary.item_id = key;
      actions.push(actionSummary);
      return actions;
    }, []);
  });
};

/*
 * Finds all comments for a specific action.
 * @param {String} action_type type of action
 * @param {String} item_type type of item the action is on
*/
ActionSchema.statics.findByType = function(action_type, item_type) {
  return Action.find({
    'action_type': action_type,
    'item_type': item_type
  });
};

/**
 * Finds all comments ids for a specific action.
 * @param {String} action_type type of action
 * @param {String} item_type type of item the action is on
*/
ActionSchema.statics.findCommentsIdByActionType = function(action_type, item_type) {
  return Action.find({
    'action_type': action_type,
    'item_type': item_type
  },
  'item_id'
  );
};

const Action = mongoose.model('Action', ActionSchema);

module.exports = Action;