jalyna/oakdex-battle

require 'forwardable'

module Oakdex
  class Battle
    # Represents one Action. One turn has many actions.
    class MoveExecution
      RECALL_PRIORITY = 6

      extend Forwardable

      def_delegators :@action, :battle, :turn, :pokemon,
                     :move, :trainer

      attr_reader :action, :target

      def initialize(action, target)
        @action = action
        @target = target
      end

      def hitting_probability
        ((move.accuracy / 100.0) * (pokemon.accuracy / target.evasion)) * 1000
      end

      def hitting?
        @hitting = rand(1..1000) <= hitting_probability ? 1 : 0
        @hitting == 1
      end

      def execute
        return if prevented_by_status_condition?
        pokemon.change_pp_by(move.name, -1)
        if hitting?
          add_uses_move_log
          execute_damage
          execute_stat_modifiers
          execute_status_conditions
          execute_status_condition_callbacks
        else
          add_move_does_not_hit_log
        end

        battle.remove_fainted
      end

      private

      def prevented_by_status_condition?
        pokemon.status_conditions.reduce(false) do |res, condition|
          res || condition.prevents_move?(self)
        end
      end

      def execute_status_condition_callbacks
        return if move.power.zero?
        target.status_conditions.each do |c|
          c.after_received_damage(self)
        end
      end

      def execute_status_conditions
        status_conditions.each do |condition|
          execute_status_condition(condition)
        end
      end

      def status_conditions
        return [] if move.in_battle_properties.nil?
        move.in_battle_properties['status_conditions'] || []
      end

      def execute_status_condition(condition)
        return unless rand(1..100) <= condition['probability']
        add_target_condition_added(condition['condition'])
        target.add_status_condition(condition['condition'])
      end

      def execute_stat_modifiers
        return if move.stat_modifiers.empty?
        move.stat_modifiers.each do |stat_modifier|
          modifier_target = stat_modifier['affects_user'] ? pokemon : target
          stat = stat_modifier['stat']
          stat = random_stat if stat == 'random'
          if modifier_target.change_stat_by(stat.to_sym,
                                            stat_modifier['change_by'])
            add_changes_stat_log(modifier_target, stat,
                                 stat_modifier['change_by'])
          else
            add_changes_no_stat_log(modifier_target, stat,
                                    stat_modifier['change_by'])
          end
        end
      end

      def execute_damage
        return if move.power.zero?
        @damage = Damage.new(turn, self)
        if @damage.damage > 0
          add_received_damage_log
          target.change_hp_by(-@damage.damage)
        else
          add_received_no_damage_log
        end
      end

      def random_stat
        (Oakdex::Pokemon::BATTLE_STATS + InBattlePokemon::OTHER_STATS).sample
      end

      def add_log(*args)
        battle.add_to_log(*args)
      end

      def add_changes_stat_log(target, stat, change_by)
        add_log 'changes_stat', target.trainer.name, target.name,
                stat, change_by
      end

      def add_changes_no_stat_log(target, stat, change_by)
        add_log 'changes_no_stat', target.trainer.name, target.name,
                stat, change_by
      end

      def add_target_condition_added(condition_name)
        add_log 'target_condition_added', target.trainer.name, target.name,
                condition_name
      end

      def add_uses_move_log
        add_log 'uses_move', trainer.name, pokemon.name, move.name
      end

      def add_move_does_not_hit_log
        add_log 'move_does_not_hit', trainer.name, pokemon.name, move.name
      end

      def add_received_damage_log
        add_log 'received_damage', target.trainer.name, target.name,
                move.name, @damage.damage
      end

      def add_received_no_damage_log
        add_log 'received_no_damage', target.trainer.name, target.name,
                move.name
      end
    end
  end
end