refactor: destroy ship_group item

internal/controller/ship_group.go

@@ -102,10 +102,14 @@ func (c *Cache) ShipGroupOwnerRace(groupIndex int) *game.Race {
 	return &c.g.Race[c.ShipGroupOwnerRaceIndex(groupIndex)]
 }
 
-func (c *Cache) ShipGroupNumber(i int, n uint) {
+func (c *Cache) ShipGroupDestroyItem(i int) {
 	c.validateShipGroupIndex(i)
-	c.g.ShipGroups[i].Number = n
-	// FIXME: cargo load must be decreased proportionally
+	sg := &c.g.ShipGroups[i]
+	if sg.Number == 0 {
+		panic("group has no ships")
+	}
+	sg.Load = game.F(sg.Load.F() / float64(sg.Number) * float64(sg.Number-1))
+	sg.Number -= 1
 }
 
 func (c *Cache) DeleteShipGroup(i int) {

internal/controller/ship_group_test.go

@@ -526,3 +526,16 @@ func TestDisassembleGroup(t *testing.T) {
 	assert.Equal(t, uint(7), c.ShipGroup(2).Number)
 	assert.Equal(t, 56.0, c.ShipGroup(2).Load.F())
 }
+
+func TestShipGroupDestroyItem(t *testing.T) {
+	c, _ := newCache()
+
+	assert.NoError(t, c.CreateShips(Race_0_idx, Race_0_Freighter, R0_Planet_0_num, 10))
+	c.ShipGroup(0).CargoType = game.CargoColonist.Ref()
+	c.ShipGroup(0).Load = 100.0
+
+	for c.ShipGroup(0).Number > 0 {
+		c.ShipGroupDestroyItem(0)
+		assert.Equal(t, float64(c.ShipGroup(0).Number)*10, c.ShipGroup(0).Load.F())
+	}
+}