CanUse for ultimates (#329)

* Function signature

* Function signature

* Implementation

* mock regen

* Added proper check for ult usability

* regen mocks

Author: aaron-hwang

pkg/engine/engine.go

@@ -211,6 +211,9 @@ type Info interface {
 	// Check if the character can use the skill (enough Skill Points and not blocked by Skill.CanUse,
 	// see implementation of each character)
 	CanUseSkill(target key.TargetID) (bool, error)
+
+	// Check if the character can use the Ult (Energy is equal to max energy of char OR fulfills Ult.canUse)
+	CanUseUlt(target key.TargetID) (bool, error)
 }
 
 type Target interface {

pkg/engine/target/character/config.go

@@ -50,6 +50,7 @@ type SkillInfo struct {
 }
 
 type SkillValidateFunc func(engine engine.Engine, char info.CharInstance) bool
+type UltValidateFunc func(engine engine.Engine, char info.CharInstance) bool
 
 type Attack struct {
 	SPAdd      int
@@ -64,6 +65,7 @@ type Skill struct {
 
 type Ult struct {
 	TargetType model.TargetType
+	CanUse     UltValidateFunc `exhaustruct:"optional"`
 }
 
 type Technique struct {

pkg/mock/mock_engine.go

@@ -65,7 +65,11 @@ func (sim *Simulation) ultCheck() error {
 		return err
 	}
 	for _, act := range ults {
-		if sim.Attr.FullEnergy(act.Target) {
+		canuse, err := sim.CanUseUlt(act.Target)
+		if err != nil {
+			return err
+		}
+		if canuse {
 			sim.InsertUlt(act)
 			sim.Attr.SetEnergy(info.ModifyAttribute{
 				Key:    "ult",

pkg/simulation/action.go

@@ -30,3 +30,20 @@ func (sim *Simulation) CanUseSkill(id key.TargetID) (bool, error) {
 	check := skillInfo.Skill.CanUse
 	return sim.SP() >= skillInfo.Skill.SPNeed && (check == nil || check(sim, char)), nil
 }
+
+func (sim *Simulation) CanUseUlt(id key.TargetID) (bool, error) {
+	skillInfo, err := sim.Char.SkillInfo(id)
+	if err != nil {
+		return false, err
+	}
+	char, err := sim.Char.Get(id)
+	if err != nil {
+		return false, err
+	}
+
+	check := skillInfo.Ult.CanUse
+	if check == nil {
+		return sim.EnergyRatio(id) == 1, nil
+	}
+	return check(sim, char), nil
+}