refactor: group launched/in_space state

internal/model/game/group.go

@@ -46,12 +46,10 @@ func (sgs ShipGroupState) String() string {
 }
 
 type InSpace struct {
-	Origin uint  `json:"origin"`
-	X      Float `json:"x"`
-	Y      Float `json:"y"`
-	// zero is for Launched status
-	// TODO: calculate range dynamically -BUT- if affects ShipGroup.State()
-	Range Float `json:"range"`
+	// X, Y are nil for Launched state
+	Origin uint   `json:"origin"`
+	X      *Float `json:"x,omitempty"`
+	Y      *Float `json:"y,omitempty"`
 }
 
 func (is InSpace) Equal(other InSpace) bool {
@@ -59,7 +57,10 @@ func (is InSpace) Equal(other InSpace) bool {
 }
 
 func (is InSpace) Launched() bool {
-	return is.Range == 0
+	if (is.X == nil && is.Y != nil) || (is.X != nil && is.Y == nil) {
+		panic("group in space state invalid: one of coordinate is not set")
+	}
+	return is.X == nil && is.Y == is.X
 }
 
 type InUpgrade struct {
@@ -132,7 +133,7 @@ func (sg ShipGroup) State() ShipGroupState {
 	case sg.StateInSpace == nil && sg.StateUpgrade == nil:
 		return StateInOrbit
 	case sg.StateInSpace != nil && sg.StateUpgrade == nil:
-		if sg.StateInSpace.Range > 0 {
+		if !sg.StateInSpace.Launched() {
 			return StateInSpace
 		}
 		if sg.StateTransfer {

internal/model/game/group_test.go

@@ -198,9 +198,11 @@ func TestShipGroupEqual(t *testing.T) {
 	assert.False(t, left.Equal(right))
 
 	right = *left
+	coord := game.Float(1)
 	left.StateInSpace = &game.InSpace{
 		Origin: 1,
-		Range:  1,
+		X:      &coord,
+		Y:      &coord,
 	}
 	assert.False(t, left.Equal(right))