Implement Concert for Two (LC)

internal/lightcone/preservation/concertfortwo/concertfortwo.go

@@ -0,0 +1,93 @@
+package concertfortwo
+
+import (
+	"github.com/simimpact/srsim/pkg/engine"
+	"github.com/simimpact/srsim/pkg/engine/equip/lightcone"
+	"github.com/simimpact/srsim/pkg/engine/event"
+	"github.com/simimpact/srsim/pkg/engine/info"
+	"github.com/simimpact/srsim/pkg/engine/modifier"
+	"github.com/simimpact/srsim/pkg/engine/prop"
+	"github.com/simimpact/srsim/pkg/key"
+	"github.com/simimpact/srsim/pkg/model"
+)
+
+const (
+	Check = "concert-for-two"
+	Buff  = "concert-for-two-buff"
+)
+
+type state struct {
+	shieldCount int
+	dmgPerStack float64
+}
+
+// Increases the wearer's DEF by 16/20/24/28/32%.
+// For every on-field character that has a Shield, the DMG dealt by the wearer increases by 4/5/6/7/8%.
+
+func init() {
+	lightcone.Register(key.ConcertforTwo, lightcone.Config{
+		CreatePassive: Create,
+		Rarity:        4,
+		Path:          model.Path_PRESERVATION,
+		Promotions:    promotions,
+	})
+
+	modifier.Register(Check, modifier.Config{
+		Listeners: modifier.Listeners{
+			OnAdd: listenShield,
+		},
+	})
+
+	modifier.Register(Buff, modifier.Config{
+		Stacking:   modifier.Replace,
+		StatusType: model.StatusType_STATUS_BUFF,
+		CanDispel:  true,
+	})
+}
+
+func Create(engine engine.Engine, owner key.TargetID, lc info.LightCone) {
+	state := state{
+		shieldCount: 0,
+		dmgPerStack: 0.03 + 0.01*float64(lc.Imposition),
+	}
+
+	engine.AddModifier(owner, info.Modifier{
+		Name:   Check,
+		Source: owner,
+		Stats:  info.PropMap{prop.DEFPercent: 0.12 + 0.04*float64(lc.Imposition)},
+		State:  &state,
+	})
+}
+
+func listenShield(mod *modifier.Instance) {
+	st := mod.State().(*state)
+
+	// Makes sure initial shield count is correct
+	for _, trg := range mod.Engine().Characters() {
+		if mod.Engine().IsShielded(trg) {
+			st.shieldCount++
+		}
+	}
+
+	mod.Engine().Events().ShieldAdded.Subscribe(func(event event.ShieldAdded) {
+		if !mod.Engine().IsCharacter(event.Info.Target) {
+			return
+		}
+		st.shieldCount++
+		mod.Engine().AddModifier(mod.Source(), info.Modifier{
+			Name:   Buff,
+			Source: mod.Owner(),
+			Stats:  info.PropMap{prop.AllDamagePercent: st.dmgPerStack * float64(st.shieldCount)},
+		})
+	})
+
+	mod.Engine().Events().ShieldRemoved.Subscribe(func(event event.ShieldRemoved) {
+		if !mod.Engine().IsCharacter(event.Target) {
+			return
+		}
+		st.shieldCount--
+		if st.shieldCount == 0 {
+			mod.Engine().RemoveModifier(mod.Source(), Buff)
+		}
+	})
+}

pkg/key/lightcone.go

@@ -89,6 +89,7 @@ const (
 	Pioneering                LightCone = "pioneering"
 	WeAreWildfire             LightCone = "we_are_wildfire"
 	LandausChoice             LightCone = "landaus_choice"
+	ConcertforTwo             LightCone = "concert_for_two"
 )
 
 // Abundance

pkg/simulation/imports.go

@@ -99,6 +99,7 @@ import (
 	_ "github.com/simimpact/srsim/internal/lightcone/nihility/void"
 	_ "github.com/simimpact/srsim/internal/lightcone/nihility/wewillmeetagain"
 	_ "github.com/simimpact/srsim/internal/lightcone/preservation/amber"
+	_ "github.com/simimpact/srsim/internal/lightcone/preservation/concertfortwo"
 	_ "github.com/simimpact/srsim/internal/lightcone/preservation/dayoneofmynewlife"
 	_ "github.com/simimpact/srsim/internal/lightcone/preservation/defense"
 	_ "github.com/simimpact/srsim/internal/lightcone/preservation/landauschoice"