module Pbw
  class Area
    include ::Mongoid::Document
    include ::Mongoid::Timestamps
    field :name, type: String
    validates_presence_of :name
    validates_uniqueness_of :name

    has_many :tokens
    has_many :item_containers
    has_and_belongs_to_many :constraints
    has_and_belongs_to_many :triggers

    attr_accessible :name

    def before_token_enters(token)
        # stub method
        true
    end

    def after_token_enters(token)
        # stub method
    end

    def before_token_leaves(token)
        # stub method
        true
    end

    def after_token_leaves(token)
        # stub method
    end

    def before_add_item(item, quantity)
        # stub method
        true
    end

    def after_add_item(item, quantity)
        # stub method
    end

    def before_remove_item(item, quantity)
        # stub method
        true
    end

    def after_remove_item(item, quantity)
        # stub method
    end

    def count_item(item)
        container = ItemContainer.find_for_area(self)
        container ? container.quantity : 0
    end

    def add_item!(item, quantity)
        return false unless quantity && quantity.responds_to?(:abs)
        return remove_item!(item, quantity.abs) if quantity < 0
        return false unless item && before_add_item(item,quantity)
        ItemContainer.find_or_create_for_area(self, item, quantity)
    end

    def remove_item!(item, quantity)
        return false unless quantity && quantity.responds_to?(:abs)
        return add_item!(item, quantity.abs) if quantity < 0
        return false unless item && before_remove_item(item,quantity)
        ItemContainer.find_or_create_for_area(self, item, (0 - quantity))
    end

    def has_constraint?(constraint)
        constraint = Constraint.find(constraint) if constraint.is_a?(String)
        self.constraints.include?(constraint)
    end

    def add_constraint!(constraint)
        return false unless constraint && constraint.before_add(self)
        self.constraints << constraint
        save
        constraint.after_add(self)
        self
    end

    def remove_constraint!(constraint)
        return false unless constraint && constraint.before_remove(self)
        self.constraints.delete_if{|c| c.name == constraint.name}
        save
        constraint.after_remove(self)
        self
    end

    def check_constraints_and_capabilities(&changeset)
        self.constraints.any?{|c| !c.before_process(self, changeset)}
    end

    def check_triggers!
        self.triggers.each{|t| t.check! }
    end
  end
end