class Character < ApplicationRecord
  belongs_to :user
  belongs_to :activity, optional: true
  has_many :character_items
  has_many :items, through: :character_items
  has_many :character_skills
  validates :name, presence: true
  validates_length_of :name, maximum: 15, message: "can't be longer than 15 characters"
  validates_uniqueness_of :name, message: "is already being used"
  validates_format_of :name, with: /\A[a-z]+\z/i, message: "must consist of letters only"

  after_create :create_skills

  def shift_item(gid, amount)
    CharacterItem.transaction do
      item = self.character_items.find_or_initialize_by(item: Item.find_by_gid(gid))
      item.increment(:quantity, amount)
      item.save
    end
  end

  def skill_level(gid)
    self.character_skills.find_by(skill: Skill.find_by_gid(gid.to_s)).level
  end

  def activity_time_remaining
    return nil unless self.activity
    duration_data = self.activity.whatnot["duration"]
    duration = duration_data["base"]
    duration_data["scaling"].each do |skill, scaling_amount|
      duration -= self.skill_level(skill) * scaling_amount
    end
    duration = [duration, duration_data["minimum"]].max
    duration - (Time.now - self.activity_started_at)
  end

  private
    def create_skills
      Skill.all.each { |skill| self.character_skills.create(skill: skill, xp: 0) }
    end
end