Move next_attack logic to CombatState

* Moves the decision of what attack is used next to CombatState and
  defers selecting the attack until the player is actually ready to hit
  their target for damage.

* Adds a distance check so combat is only initiated within the correct
  range. If the player isn't close enough to their target, they will run
  towards it and check every tick if they're close enough to make an
  attack.

data/plugins/combat/combat_action.rb

@@ -50,7 +50,19 @@ class CombatAction < Action
   end
 
   def update_idle
-    if @combat_state.queued_attacks.empty? and @combat_state.supports_weapon
+    next_attack      = @combat_state.next_attack true
+    current_distance = mob.position.get_distance @combat_state.target.position
+
+    if current_distance > next_attack.range
+      @combat_state.state = :chasing
+
+      mob.follow @combat_state.target, next_attack.range
+      set_delay 0
+
+      return
+    end
+
+    if @combat_state.supports_weapon
       weapon       = EquipmentUtil.equipped_weapon mob
       weapon_class = weapon.weapon_class
       combat_style = weapon_class.style_at mob.combat_style
@@ -62,16 +74,7 @@ class CombatAction < Action
         mob.attacking = true
       end
 
-      if mob.using_special and weapon.special_attack?
-        @combat_state.next_attack = weapon.special_attack
-      else
-        @combat_state.next_attack = weapon_class.attack(combat_style)
-      end
-
       @combat_state.state = :attacking
-    elsif @combat_state.queued_attacks.size > 0
-      @combat_state.next_attack = @combat_state.queued_attacks.pop
-      @combat_state.state       = :attacking
     else
       stop
       @combat_state.reset
@@ -79,20 +82,35 @@ class CombatAction < Action
   end
 
   def update_attacking
-    raise RuntimeError.new('no attack when in :attacking state') if @combat_state.next_attack.nil?
-
     begin
-      @combat_state.next_attack.do(mob, @combat_state.target)
+      next_attack = @combat_state.next_attack
+      next_attack.requirements.each do |requirement|
+        requirement.validate! mob
+      end
 
-      @combat_state.state = :idle
+      next_attack.requirements.each do |requirement|
-      set_delay 0
+        requirement.apply mob
+      end
+
+      next_attack.do(mob, @combat_state.target)
     rescue AttackRequirementException => e
       mob.send_message e.message
+    ensure
+      @combat_state.state = :idle
+      set_delay 0
     end
   end
 
   def update_chasing
+    next_attack      = @combat_state.next_attack true
+    current_distance = mob.position.get_distance @combat_state.target.position
 
+    if current_distance <= next_attack.range
+      @combat_state.state = :attacking
+
+      mob.following = -1
+      set_delay 0
+    end
   end
 
   def stop

data/plugins/combat/combat_state.rb

@@ -11,7 +11,7 @@ end
 private
 
 class CombatState
-  attr_accessor :state, :next_attack
+  attr_accessor :state
   attr_reader :queued_attacks, :supports_weapon
 
   def initialize(mob, supports_weapon = true)
@@ -41,6 +41,23 @@ class CombatState
   def queue_attack(attack)
     @queued_attacks.push(attack)
   end
+
+  def next_attack(peek = false)
+    if @queued_attacks.size > 0
+      peek ? @queued_attacks.first : @queued_attacks.pop
+    else
+      weapon = EquipmentUtil.equipped_weapon @mob
+
+      if @mob.using_special and weapon.special_attack?
+        weapon.special_attack
+      else
+        weapon_class = weapon.weapon_class
+        combat_style = weapon_class.style_at @mob.combat_style
+        
+        weapon_class.attack combat_style
+      end
+    end
+  end
 end
 
 MOB_COMBAT_STATE_CACHE = {