fix(game): fight before departure and reorder the turn sequence

Per the documented turn order (game/rules.txt "Последовательность
действий"), no ship should dodge the pre-departure battle by slipping
into hyperspace. MakeTurn now runs merge -> battle -> load+launch routed
groups -> fly -> merge -> battle, so:

- ships ordered to depart (Launched) and ships being upgraded now take
  part in the pre-departure battle at their planet (CollectPlanetGroups /
  FilterBattleGroups); only survivors then enter hyperspace;
- routed transports are loaded and launched AFTER that battle, so they
  fight empty and cannot escape it.

A just-launched group has no stored hyperspace position, so moveShipGroup
starts its first leg from the origin planet; the previous code read the
nil launch coordinate and would panic.

Because upgrading groups can now lose ships in the battle, the pending
upgrade cost is recomputed from the group's current ship count instead of
the value stored when the order was validated.

Rules: reordered "Последовательность действий" and rewrote the combat
note that ordered/routed ships skip the battle.

Tests: launched-group move from origin, launched/upgrade groups taking
part in battle, upgrade cost tracking ship losses.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

game/internal/controller/battle.go

@@ -32,14 +32,23 @@ type BattleAction struct {
 func CollectPlanetGroups(c *Cache) map[uint]map[int]bool {
 	planetGroup := make(map[uint]map[int]bool)
 	for groupIndex := range c.ShipGroupsIndex() {
-		state := c.ShipGroup(groupIndex).State()
-		if state == game.StateInOrbit || state == game.StateUpgrade {
-			planetNumber := c.ShipGroup(groupIndex).Destination
-			if _, ok := planetGroup[planetNumber]; !ok {
-				planetGroup[planetNumber] = make(map[int]bool)
-			}
-			planetGroup[planetNumber][groupIndex] = false
+		sg := c.ShipGroup(groupIndex)
+		var planetNumber uint
+		switch sg.State() {
+		case game.StateInOrbit, game.StateUpgrade:
+			planetNumber = sg.Destination
+		case game.StateLaunched:
+			// Ordered to depart but still physically at the origin planet, so
+			// it joins the pre-departure battle there; only survivors then
+			// enter hyperspace.
+			planetNumber = sg.StateInSpace.Origin
+		default:
+			continue
 		}
+		if _, ok := planetGroup[planetNumber]; !ok {
+			planetGroup[planetNumber] = make(map[int]bool)
+		}
+		planetGroup[planetNumber][groupIndex] = false
 	}
 	for pl := range planetGroup {
 		if len(planetGroup[pl]) < 2 {
@@ -50,7 +59,18 @@ func CollectPlanetGroups(c *Cache) map[uint]map[int]bool {
 }
 
 func FilterBattleGroups(c *Cache, groups map[int]bool) []int {
-	return slices.DeleteFunc(slices.Collect(maps.Keys(groups)), func(groupIndex int) bool { return c.ShipGroup(groupIndex).State() != game.StateInOrbit })
+	return slices.DeleteFunc(slices.Collect(maps.Keys(groups)), func(groupIndex int) bool {
+		// Everything physically present at the planet fights: ships in orbit,
+		// ships being upgraded, and ships ordered to depart that have not yet
+		// entered hyperspace (Launched). Only ships already in hyperspace are
+		// out of reach.
+		switch c.ShipGroup(groupIndex).State() {
+		case game.StateInOrbit, game.StateUpgrade, game.StateLaunched:
+			return false
+		default:
+			return true
+		}
+	})
 }
 
 func FilterBattleOpponents(c *Cache, attIdx, defIdx int, cacheProbability map[int]map[int]float64) bool {

game/internal/controller/battle_test.go

@@ -326,3 +326,56 @@ func TestSingleBattleOneSidedWipe(t *testing.T) {
 	}
 	assert.Equal(t, 5, kills, "exactly the five transports are destroyed")
 }
+
+// TestCollectPlanetGroupsIncludesLaunchedAndUpgrade checks that every group
+// physically at a planet — in orbit, being upgraded, or ordered to depart but
+// not yet flown (Launched) — is collected for, and kept in, the battle.
+func TestCollectPlanetGroupsIncludesLaunchedAndUpgrade(t *testing.T) {
+	c, _ := newCache()
+	// group 0: in orbit at Planet_0
+	assert.NoError(t, c.CreateShips(Race_0_idx, Race_0_Gunship, R0_Planet_0_num, 1))
+	// group 1: ordered to depart Planet_0 (Launched), still physically there
+	assert.NoError(t, c.CreateShips(Race_0_idx, ShipType_Cruiser, R0_Planet_0_num, 1))
+	c.ShipGroup(1).StateInSpace = &game.InSpace{Origin: R0_Planet_0_num}
+	c.ShipGroup(1).Destination = R0_Planet_2_num
+	assert.Equal(t, game.StateLaunched, c.ShipGroup(1).State())
+	// group 2: being upgraded at Planet_0
+	assert.NoError(t, c.CreateShips(Race_0_idx, ShipType_Cruiser, R0_Planet_0_num, 1))
+	c.ShipGroup(2).StateUpgrade = &game.InUpgrade{UpgradeTech: []game.UpgradePreference{{Tech: game.TechDrive, Level: 2.0, Cost: 100}}}
+	assert.Equal(t, game.StateUpgrade, c.ShipGroup(2).State())
+
+	pg := controller.CollectPlanetGroups(c)
+	assert.Contains(t, pg, R0_Planet_0_num)
+	assert.Len(t, pg[R0_Planet_0_num], 3)
+	for _, idx := range []int{0, 1, 2} {
+		assert.Contains(t, pg[R0_Planet_0_num], idx)
+	}
+	battleGroups := controller.FilterBattleGroups(c, pg[R0_Planet_0_num])
+	assert.Len(t, battleGroups, 3)
+}
+
+// TestProduceBattlesLaunchedFightsAtOrigin checks that a group ordered to
+// depart (Launched) still fights the pre-departure battle at its origin
+// planet, rather than escaping into hyperspace before the fight.
+func TestProduceBattlesLaunchedFightsAtOrigin(t *testing.T) {
+	c, g := newCache()
+	assert.NoError(t, g.RaceRelation(Race_0.Name, Race_1.Name, game.RelationWar.String()))
+	assert.NoError(t, g.RaceRelation(Race_1.Name, Race_0.Name, game.RelationWar.String()))
+
+	// Race_0: armed group in orbit at Planet_0.
+	assert.NoError(t, c.CreateShips(Race_0_idx, Race_0_Gunship, R0_Planet_0_num, 10))
+	// Race_1: armed group ordered to depart Planet_0 (Launched), still there.
+	c.CreateShipsUnsafe_T(Race_1_idx, c.MustShipClass(Race_1_idx, Race_1_Gunship).ID, R0_Planet_0_num, 10)
+	c.ShipGroup(1).StateInSpace = &game.InSpace{Origin: R0_Planet_0_num}
+	c.ShipGroup(1).Destination = R0_Planet_2_num
+	assert.Equal(t, game.StateLaunched, c.ShipGroup(1).State())
+
+	battles := controller.ProduceBattles(c)
+	assert.Len(t, battles, 1)
+	assert.True(t, battles[0].ObserverGroups[1], "launched group must be marked in-battle")
+	if c.ShipGroup(0).Number == 0 {
+		assert.Greater(t, c.ShipGroup(1).Number, uint(0))
+	} else {
+		assert.Zero(t, c.ShipGroup(1).Number)
+	}
+}

game/internal/controller/generate_turn.go

@@ -20,25 +20,29 @@ func (c *Controller) MakeTurn() error {
 	c.Cache.g.Turn += 1
 	c.Cache.g.Stage = 0
 
-	// 01. Вышедшие расы удаляются из списка участвующих рас перед началом просчета очередного хода
+	// 01. Вышедшие расы удаляются из списка участвующих рас перед началом просчёта очередного хода.
 	c.Cache.TurnWipeExtinctRaces()
 
-	// 02. Товары загружаются на корабли, находящиеся в начале грузовых маршрутов, и корабли входят в гиперпространство (но ещё не полетели)
-	c.Cache.SendRoutedGroups()
-
-	// 03. Корабли, где это возможно, объединяются в группы.
+	// 02. Корабли, где это возможно, объединяются в группы (до боя и до отправки по маршрутам).
 	c.Cache.TurnMergeEqualShipGroups()
 
-	// 04. Враждующие корабли вступают в схватку.
+	// 03. Враждующие корабли вступают в схватку у планеты отправления. Корабли, которым отдан
+	//     приказ на отлёт (статус Launched), ещё стоят на планете и участвуют в бою; в
+	//     гиперпространство уходят только уцелевшие — так нельзя уклониться от боя.
 	battles := ProduceBattles(c.Cache)
 
+	// 04. Товары загружаются на корабли в начале грузовых маршрутов, и эти корабли входят в
+	//     гиперпространство. Загрузка после боя: маршрутные транспорты сражаются пустыми и не
+	//     могут уклониться от боя, скрывшись в гиперпространстве.
+	c.Cache.SendRoutedGroups()
+
 	// 05. Корабли пролетают сквозь гиперпространство.
 	c.Cache.MoveShipGroups()
 
 	// 06. Корабли, где это возможно, объединяются в группы.
 	c.Cache.TurnMergeEqualShipGroups()
 
-	// 07. Враждующие корабли снова вступают в схватку (это происходит после выхода из гиперпространства).
+	// 07. Враждующие корабли снова вступают в схватку (после выхода из гиперпространства).
 	battles = append(battles, ProduceBattles(c.Cache)...)
 
 	// 08. Корабли бомбят вражеские планеты.

game/internal/controller/planet.go

@@ -162,7 +162,7 @@ func (c *Cache) PlanetProductionCapacity(planetNumber uint) float64 {
 	p := c.MustPlanet(planetNumber)
 	var busyResources float64
 	for sg := range c.shipGroupsInUpgrade(p.Number) {
-		busyResources += sg.StateUpgrade.Cost()
+		busyResources += c.upgradeCostNow(sg)
 	}
 	return p.ProductionCapacity() - busyResources
 }
@@ -184,7 +184,7 @@ func (c *Cache) TurnPlanetProductions() {
 		// upgrade groups and return to in_orbit state
 		productionAvailable := c.PlanetProductionCapacity(pn)
 		for sg := range c.shipGroupsInUpgrade(p.Number) {
-			cost := sg.StateUpgrade.Cost()
+			cost := c.upgradeCostNow(sg)
 			if productionAvailable >= cost {
 				for i := range sg.StateUpgrade.UpgradeTech {
 					sg.Tech = sg.Tech.Set(sg.StateUpgrade.UpgradeTech[i].Tech, util.Fixed3(sg.StateUpgrade.UpgradeTech[i].Level.F()))

game/internal/controller/planet_test.go

@@ -208,7 +208,11 @@ func TestProduceShips(t *testing.T) {
 	assert.Equal(t, game.StateInOrbit, c.ShipGroup(0).State())
 	assert.Equal(t, 1.5, c.ShipGroup(0).TechLevel(game.TechDrive).F())
 
-	assert.Equal(t, 4346.676567656759, c.MustPlanet(R0_Planet_0_num).Material.F())
+	// Upgrade cost is now recomputed from the group's current ship count
+	// (calc raw float) rather than read from the Fixed12-rounded stored value,
+	// which shifts Material at the 12th decimal — far below the 3-decimal
+	// report precision, so an InDelta check is the robust expectation here.
+	assert.InDelta(t, 4346.6766, c.MustPlanet(R0_Planet_0_num).Material.F(), 0.001)
 }
 
 func TestProduceShip(t *testing.T) {

game/internal/controller/ship_group.go

@@ -491,7 +491,7 @@ func (c *Cache) shipGroupsInUpgrade(planetNumber uint) iter.Seq[*game.ShipGroup]
 			}
 		}
 		slices.SortFunc(result, func(a, b int) int {
-			return cmp.Compare(c.g.ShipGroups[b].StateUpgrade.Cost(), c.g.ShipGroups[a].StateUpgrade.Cost())
+			return cmp.Compare(c.upgradeCostNow(&c.g.ShipGroups[b]), c.upgradeCostNow(&c.g.ShipGroups[a]))
 		})
 		for i := range result {
 			if !yield(&c.g.ShipGroups[result[i]]) {

game/internal/controller/ship_group_move.go

@@ -34,15 +34,20 @@ func (c *Cache) MoveShipGroups() {
 
 func (c *Cache) moveShipGroup(i int, delta float64) {
 	sg := c.ShipGroup(i)
-	originX, originY, ok := sg.Coord()
-	if !ok {
-		panic(fmt.Sprintf("ship group state invalid: %v", sg.State()))
+	var originX, originY float64
+	switch sg.State() {
+	case game.StateLaunched:
+		// Just launched: the group is still at its origin planet and has not
+		// stored a hyperspace position yet, so the first leg starts there.
+		origin := c.MustPlanet(sg.StateInSpace.Origin)
+		originX, originY = origin.X.F(), origin.Y.F()
+	case game.StateInSpace:
+		originX, originY = sg.StateInSpace.X.F(), sg.StateInSpace.Y.F()
+	default:
+		panic(fmt.Sprintf("ship group state invalid for move: %v", sg.State()))
 	}
 	destPlanet := c.MustPlanet(sg.Destination)
-	arrived := false
-	var x, y float64
-	x, y, arrived =
-		util.NextTravelCoord(c.g.Map.Width, c.g.Map.Height, originX, originY, destPlanet.X.F(), destPlanet.Y.F(), delta)
+	x, y, arrived := util.NextTravelCoord(c.g.Map.Width, c.g.Map.Height, originX, originY, destPlanet.X.F(), destPlanet.Y.F(), delta)
 	fx, fy := game.F(x), game.F(y)
 	sg.StateInSpace.X = &fx
 	sg.StateInSpace.Y = &fy

game/internal/controller/ship_group_move_test.go

@@ -45,3 +45,20 @@ func TestListMoveableGroupIds(t *testing.T) {
 		assert.NotEqual(t, game.StateTransfer, sg.State())
 	}
 }
+
+// TestMoveLaunchedGroupFromOrigin guards the launched-coordinate fix: a group
+// just sent by an order is Launched with no stored hyperspace position, so its
+// first leg must start from the origin planet. The pre-fix code dereferenced
+// the nil launch coordinate and panicked.
+func TestMoveLaunchedGroupFromOrigin(t *testing.T) {
+	c, g := newCache()
+	assert.NoError(t, c.CreateShips(Race_0_idx, ShipType_Cruiser, R0_Planet_0_num, 1))
+	assert.NoError(t, g.ShipGroupSend(Race_0.Name, c.ShipGroup(0).ID, R0_Planet_2_num))
+	assert.Equal(t, game.StateLaunched, c.ShipGroup(0).State())
+
+	// Must not panic on the nil launch coordinate. Planet_0 (1,1) -> Planet_2
+	// (3,3) is ~2.83 ly; a Cruiser covers it in one turn and arrives.
+	c.MoveShipGroups()
+	assert.Equal(t, game.StateInOrbit, c.ShipGroup(0).State())
+	assert.Equal(t, R0_Planet_2_num, c.ShipGroup(0).Destination)
+}

game/internal/controller/ship_group_upgrade.go

@@ -196,6 +196,24 @@ func FutureUpgradeLevel(raceLevel, groupLevel, limit float64) float64 {
 	return target
 }
 
+// upgradeCostNow returns the production cost to apply group sg's pending
+// upgrade to its CURRENT ship count. The cost stored on StateUpgrade is fixed
+// when the order is validated; if the group has since lost ships (for example
+// in the pre-departure battle, now that upgrading groups take part in it), the
+// stored total is stale, so the cost is recomputed from the stored target
+// levels, the group's current tech, and its current ship count.
+func (c *Cache) upgradeCostNow(sg *game.ShipGroup) float64 {
+	if sg.StateUpgrade == nil {
+		return 0
+	}
+	st := c.MustShipType(c.RaceIndex(sg.OwnerID), sg.TypeID)
+	var perShip float64
+	for _, pref := range sg.StateUpgrade.UpgradeTech {
+		perShip += calc.BlockUpgradeCost(st.BlockMass(pref.Tech), sg.TechLevel(pref.Tech).F(), pref.Level.F())
+	}
+	return perShip * float64(sg.Number)
+}
+
 func UpgradeGroupPreference(sg game.ShipGroup, st game.ShipType, tech game.Tech, v float64) game.ShipGroup {
 	if v <= 0 || st.BlockMass(tech) == 0 || sg.TechLevel(tech).F() >= v {
 		return sg

game/internal/controller/ship_group_upgrade_test.go

@@ -170,3 +170,24 @@ func TestShipGroupUpgrade(t *testing.T) {
 		g.ShipGroupUpgrade(Race_0.Name, c.ShipGroup(3).ID, "DRIVE", 1.3),
 		e.GenericErrorText(e.ErrShipsBusy))
 }
+
+// TestUpgradeCostTracksShipLosses checks that the production reserved for a
+// pending upgrade follows the group's CURRENT ship count. Upgrading groups now
+// take part in the pre-departure battle and may lose ships, which would leave
+// the cost stored at order time stale; the cost is recomputed instead.
+func TestUpgradeCostTracksShipLosses(t *testing.T) {
+	c, _ := newCache()
+	assert.NoError(t, c.CreateShips(Race_0_idx, ShipType_Cruiser, R0_Planet_0_num, 4))
+	// Pending drive upgrade with a deliberately stale stored cost.
+	c.ShipGroup(0).StateUpgrade = &game.InUpgrade{
+		UpgradeTech: []game.UpgradePreference{{Tech: game.TechDrive, Level: 2.0, Cost: 9999}},
+	}
+	before := c.PlanetProductionCapacity(R0_Planet_0_num)
+	// Two ships lost, as in the pre-departure battle.
+	c.ShipGroupDestroyItem(0)
+	c.ShipGroupDestroyItem(0)
+	after := c.PlanetProductionCapacity(R0_Planet_0_num)
+	// Fewer ships reserve less production. With the stale stored cost this
+	// would be unchanged.
+	assert.Greater(t, after, before)
+}