Files
gogobee/internal/plugin/combat_engine.go
prosolis 7c450aaefb Add forward-simulating combat engine with consumables, monster abilities, and narrative rendering
Replaces the single-roll probability system for dungeon and arena combat with
a multi-phase simulation engine where gear, buffs, pets, and NPCs are meaningful
mechanical inputs. Adds consumable items (auto-crafted from forage/mine/fish drops),
monster abilities for T2+ enemies, and Dragon Quest-style combat narrative with
phased message delivery.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
2026-04-18 01:05:22 -07:00

701 lines
21 KiB
Go

package plugin
import "math/rand/v2"
// ── Core Types ───────────────────────────────────────────────────────────────
type CombatStats struct {
MaxHP int
Attack int
Defense int
Speed int
CritRate float64
DodgeRate float64
BlockRate float64
}
type CombatModifiers struct {
DamageBonus float64 // additive: 0 = neutral, 0.25 = +25% damage. Applied as (1 + DamageBonus).
DamageReduct float64 // multiplicative damage-taken reduction, 1.0 = neutral
DeathSave bool // Sovereign reprieve — survive one lethal hit
PetAttackProc float64
PetAttackDmg int
PetDeflectProc float64
PetWhiffProc float64 // pet distracts enemy → guaranteed miss
SniperKillProc float64 // Arina instant-kill
MistyHealProc float64
MistyHealAmt int
CrowdRevengeProc float64 // Misty debuff: chance per round of crowd damage
CrowdRevengeDmg int // Misty debuff: damage per proc
HealItem int // consumable: HP restored at <50% HP (one-shot)
WardCharges int // consumable: hits fully absorbed
SporeCloud int // consumable: rounds of 15% enemy miss chance
ReflectNext float64 // consumable: fraction of next hit reflected
AutoCritFirst bool // consumable: first player hit is auto-crit
FlatDmgStart int // consumable: flat damage to enemy pre-combat
}
type Combatant struct {
Name string
Stats CombatStats
Mods CombatModifiers
IsPlayer bool
Ability *MonsterAbility // non-nil for monsters with a special ability
}
type CombatPhase struct {
Name string
Rounds int
AttackWeight float64
DefenseWeight float64
SpeedWeight float64
EnvironmentProc float64
}
type CombatEvent struct {
Round int
Phase string
Actor string // "player", "enemy", "pet", "environment", "npc", "consumable"
Action string
Damage int
PlayerHP int
EnemyHP int
Desc string // optional flavor (item name, ability name)
}
type CombatResult struct {
PlayerWon bool
Events []CombatEvent
PlayerStartHP int
EnemyStartHP int
PlayerEndHP int
EnemyEndHP int
TotalRounds int
Closeness float64
NearDeath bool
PetAttacked bool
PetDeflected bool
SniperKilled bool
MistyHealed bool
}
// ── Monster Abilities ────────────────────────────────────────────────────────
type MonsterAbility struct {
Name string
Phase string // "opening", "clash", "decisive", "any"
ProcChance float64
Effect string // "poison", "enrage", "armor_break", "stun", "lifesteal", "cleave"
}
// ── Default Phase Definitions ────────────────────────────────────────────────
var defaultCombatPhases = []CombatPhase{
{"Opening", 2, 0.6, 0.8, 1.5, 0.15},
{"Clash", 3, 1.2, 1.0, 0.8, 0.08},
{"Decisive", 1, 1.0, 0.7, 1.0, 0.05},
}
var dungeonCombatPhases = []CombatPhase{
{"Opening", 1, 0.8, 0.8, 1.2, 0.10},
{"Clash", 2, 1.0, 1.0, 0.8, 0.08},
{"Decisive", 1, 1.0, 0.7, 1.0, 0.05},
}
// ── Simulation ───────────────────────────────────────────────────────────────
// combatState tracks mutable state during the simulation.
type combatState struct {
playerHP int
enemyHP int
// Consumable one-shots
healUsed bool
wardCharges int
sporeRounds int
reflectFrac float64
autoCrit bool
// Monster ability effects
poisonTicks int
poisonDmg int
stunPlayer bool
enraged bool
armorBroken bool
armorBreakAmt float64
// Sovereign reprieve
deathSaveUsed bool
round int
events []CombatEvent
}
func SimulateCombat(player, enemy Combatant, phases []CombatPhase) CombatResult {
st := &combatState{
playerHP: player.Stats.MaxHP,
enemyHP: enemy.Stats.MaxHP,
wardCharges: player.Mods.WardCharges,
sporeRounds: player.Mods.SporeCloud,
reflectFrac: player.Mods.ReflectNext,
autoCrit: player.Mods.AutoCritFirst,
}
result := CombatResult{
PlayerStartHP: player.Stats.MaxHP,
EnemyStartHP: enemy.Stats.MaxHP,
}
// Pre-combat: Arina sniper check
if player.Mods.SniperKillProc > 0 && rand.Float64() < player.Mods.SniperKillProc {
st.enemyHP = 0
st.events = append(st.events, CombatEvent{
Round: 0, Phase: "pre_combat", Actor: "npc", Action: "sniper_kill",
Damage: enemy.Stats.MaxHP, PlayerHP: st.playerHP, EnemyHP: 0,
Desc: "Arina",
})
result.SniperKilled = true
return finalize(result, st, player, enemy)
}
// Pre-combat: Coal Bomb / flat start damage
if player.Mods.FlatDmgStart > 0 {
dmg := player.Mods.FlatDmgStart
st.enemyHP = max(0, st.enemyHP-dmg)
st.events = append(st.events, CombatEvent{
Round: 0, Phase: "pre_combat", Actor: "consumable", Action: "flat_damage",
Damage: dmg, PlayerHP: st.playerHP, EnemyHP: st.enemyHP,
})
if st.enemyHP <= 0 {
return finalize(result, st, player, enemy)
}
}
// Pre-combat: Misty gourmet is now a per-round heal, no pre-combat damage
// Main simulation loop
for _, phase := range phases {
roundsThisPhase := phase.Rounds
// Add slight variance: ±1 round for non-Decisive phases
if phase.Name != "Decisive" && roundsThisPhase > 1 {
roundsThisPhase += rand.IntN(2) // 0 or +1
}
for r := 0; r < roundsThisPhase; r++ {
st.round++
if simulateRound(st, &player, &enemy, &phase, &result) {
return finalize(result, st, player, enemy)
}
}
}
// If we exhaust all phases without a kill, the side with more HP% wins.
playerMax := max(1, player.Stats.MaxHP)
enemyMax := max(1, enemy.Stats.MaxHP)
playerPct := float64(st.playerHP) / float64(playerMax)
enemyPct := float64(st.enemyHP) / float64(enemyMax)
if playerPct < enemyPct {
st.playerHP = 0
} else {
st.enemyHP = 0
}
st.events = append(st.events, CombatEvent{
Round: st.round, Phase: "exhaust", Actor: "system", Action: "timeout",
PlayerHP: st.playerHP, EnemyHP: st.enemyHP,
})
return finalize(result, st, player, enemy)
}
// simulateRound runs one round. Returns true if combat is over.
func simulateRound(st *combatState, player, enemy *Combatant, phase *CombatPhase, result *CombatResult) bool {
phaseName := phase.Name
// Monster ability: check at round start
abilityDealtDamage := false
if enemy.Ability != nil {
if abilityFires(enemy.Ability, phaseName, st) {
if applyAbility(st, player, enemy, phase, result) {
return true
}
// Cleave and lifesteal deal damage — skip normal enemy attack this round
switch enemy.Ability.Effect {
case "cleave", "lifesteal":
abilityDealtDamage = true
}
}
}
// Poison tick from previous round
if st.poisonTicks > 0 {
st.playerHP = max(0, st.playerHP-st.poisonDmg)
st.poisonTicks--
st.events = append(st.events, CombatEvent{
Round: st.round, Phase: phaseName, Actor: "enemy", Action: "poison_tick",
Damage: st.poisonDmg, PlayerHP: st.playerHP, EnemyHP: st.enemyHP,
})
if st.playerHP <= 0 {
if trySave(st, player, phaseName) {
// survived
} else {
return true
}
}
}
// Pet whiff: if proc'd, enemy's attack this round is a guaranteed miss
petWhiff := player.Mods.PetWhiffProc > 0 && rand.Float64() < player.Mods.PetWhiffProc
// Pet deflect: halves incoming damage to player this round
petDeflect := player.Mods.PetDeflectProc > 0 && rand.Float64() < player.Mods.PetDeflectProc
if petDeflect {
result.PetDeflected = true
}
// Spore cloud: enemy has 15% miss chance (decremented when enemy actually attacks)
sporeMiss := st.sporeRounds > 0 && rand.Float64() < 0.15
// Determine initiative
playerSpeed := float64(player.Stats.Speed) * phase.SpeedWeight
enemySpeed := float64(enemy.Stats.Speed) * phase.SpeedWeight
playerInit := playerSpeed + rand.Float64()*10
enemyInit := enemySpeed + rand.Float64()*10
playerFirst := playerInit >= enemyInit
if playerFirst {
if resolvePlayerAttack(st, player, enemy, phase, result) {
return true
}
if !abilityDealtDamage {
if resolveEnemyAttack(st, player, enemy, phase, result, petWhiff, petDeflect, sporeMiss) {
return true
}
}
} else {
if !abilityDealtDamage {
if resolveEnemyAttack(st, player, enemy, phase, result, petWhiff, petDeflect, sporeMiss) {
return true
}
}
if resolvePlayerAttack(st, player, enemy, phase, result) {
return true
}
}
// Environmental hazard
if phase.EnvironmentProc > 0 && rand.Float64() < phase.EnvironmentProc {
envDmg := 2 + rand.IntN(5)
st.playerHP = max(0, st.playerHP-envDmg)
st.events = append(st.events, CombatEvent{
Round: st.round, Phase: phaseName, Actor: "environment", Action: "environmental",
Damage: envDmg, PlayerHP: st.playerHP, EnemyHP: st.enemyHP,
})
if st.playerHP <= 0 {
if !trySave(st, player, phaseName) {
return true
}
}
}
// Misty crowd revenge (debuff for declining Misty)
if player.Mods.CrowdRevengeProc > 0 && rand.Float64() < player.Mods.CrowdRevengeProc {
dmg := player.Mods.CrowdRevengeDmg
st.playerHP = max(0, st.playerHP-dmg)
st.events = append(st.events, CombatEvent{
Round: st.round, Phase: phaseName, Actor: "environment", Action: "crowd_revenge",
Damage: dmg, PlayerHP: st.playerHP, EnemyHP: st.enemyHP,
Desc: "Misty's crowd",
})
if st.playerHP <= 0 {
if !trySave(st, player, phaseName) {
return true
}
}
}
// Pet attack
if player.Mods.PetAttackProc > 0 && rand.Float64() < player.Mods.PetAttackProc {
petDmg := player.Mods.PetAttackDmg + rand.IntN(5)
st.enemyHP = max(0, st.enemyHP-petDmg)
result.PetAttacked = true
st.events = append(st.events, CombatEvent{
Round: st.round, Phase: phaseName, Actor: "pet", Action: "pet_attack",
Damage: petDmg, PlayerHP: st.playerHP, EnemyHP: st.enemyHP,
})
if st.enemyHP <= 0 {
return true
}
}
// Misty heal
if player.Mods.MistyHealProc > 0 && rand.Float64() < player.Mods.MistyHealProc {
healAmt := player.Mods.MistyHealAmt
st.playerHP = min(player.Stats.MaxHP, st.playerHP+healAmt)
result.MistyHealed = true
st.events = append(st.events, CombatEvent{
Round: st.round, Phase: phaseName, Actor: "npc", Action: "misty_heal",
Damage: healAmt, PlayerHP: st.playerHP, EnemyHP: st.enemyHP,
Desc: "Misty",
})
}
// Consumable heal: triggers once when player drops below 50%
if !st.healUsed && player.Mods.HealItem > 0 &&
st.playerHP > 0 && st.playerHP < player.Stats.MaxHP/2 {
st.healUsed = true
healAmt := player.Mods.HealItem
st.playerHP = min(player.Stats.MaxHP, st.playerHP+healAmt)
st.events = append(st.events, CombatEvent{
Round: st.round, Phase: phaseName, Actor: "consumable", Action: "heal_item",
Damage: healAmt, PlayerHP: st.playerHP, EnemyHP: st.enemyHP,
})
}
return false
}
// ── Attack Resolution ────────────────────────────────────────────────────────
func resolvePlayerAttack(st *combatState, player, enemy *Combatant, phase *CombatPhase, result *CombatResult) bool {
phaseName := phase.Name
// Stun: player skips attack
if st.stunPlayer {
st.stunPlayer = false
st.events = append(st.events, CombatEvent{
Round: st.round, Phase: phaseName, Actor: "player", Action: "stunned",
PlayerHP: st.playerHP, EnemyHP: st.enemyHP,
})
return false
}
// Enemy dodge
enemyDodge := enemy.Stats.DodgeRate * phase.SpeedWeight
if enemyDodge > 0 && rand.Float64() < enemyDodge {
st.events = append(st.events, CombatEvent{
Round: st.round, Phase: phaseName, Actor: "player", Action: "miss",
PlayerHP: st.playerHP, EnemyHP: st.enemyHP,
})
return false
}
// Calculate damage
dmg := calcDamage(player.Stats.Attack, phase.AttackWeight, player.Mods.DamageBonus,
enemy.Stats.Defense, phase.DefenseWeight, enemy.Mods.DamageReduct)
// Block: half damage
blocked := enemy.Stats.BlockRate > 0 && rand.Float64() < enemy.Stats.BlockRate
if blocked {
dmg = max(1, dmg/2)
}
// Crit check
critRate := player.Stats.CritRate
if phaseName == "Decisive" {
critRate *= 2
}
isCrit := false
if st.autoCrit {
isCrit = true
st.autoCrit = false
dmg *= 2
} else if critRate > 0 && rand.Float64() < critRate {
isCrit = true
dmg *= 2
}
dmg = max(1, dmg)
// Cleave handling for enemy is in resolveEnemyAttack
action := "hit"
if isCrit {
action = "crit"
} else if blocked {
action = "block"
}
st.enemyHP = max(0, st.enemyHP-dmg)
st.events = append(st.events, CombatEvent{
Round: st.round, Phase: phaseName, Actor: "player", Action: action,
Damage: dmg, PlayerHP: st.playerHP, EnemyHP: st.enemyHP,
})
return st.enemyHP <= 0
}
func resolveEnemyAttack(st *combatState, player, enemy *Combatant, phase *CombatPhase, result *CombatResult, petWhiff, petDeflect, sporeMiss bool) bool {
phaseName := phase.Name
// Spore cloud round consumed when enemy attacks (even if whiffed/missed)
if st.sporeRounds > 0 {
st.sporeRounds--
}
// Pet whiff → guaranteed miss
if petWhiff {
st.events = append(st.events, CombatEvent{
Round: st.round, Phase: phaseName, Actor: "pet", Action: "pet_whiff",
PlayerHP: st.playerHP, EnemyHP: st.enemyHP,
})
return false
}
// Spore cloud miss
if sporeMiss {
st.events = append(st.events, CombatEvent{
Round: st.round, Phase: phaseName, Actor: "consumable", Action: "spore_miss",
PlayerHP: st.playerHP, EnemyHP: st.enemyHP,
})
return false
}
// Player dodge
playerDodge := player.Stats.DodgeRate * phase.SpeedWeight
if playerDodge > 0 && rand.Float64() < playerDodge {
st.events = append(st.events, CombatEvent{
Round: st.round, Phase: phaseName, Actor: "enemy", Action: "miss",
PlayerHP: st.playerHP, EnemyHP: st.enemyHP,
})
return false
}
// Ward: absorb full hit
if st.wardCharges > 0 {
st.wardCharges--
st.events = append(st.events, CombatEvent{
Round: st.round, Phase: phaseName, Actor: "consumable", Action: "ward_absorb",
Damage: 0, PlayerHP: st.playerHP, EnemyHP: st.enemyHP,
})
return false
}
atkMult := 1.0
if st.enraged {
atkMult = 1.5
}
dmg := calcDamage(int(float64(enemy.Stats.Attack)*atkMult), phase.AttackWeight, enemy.Mods.DamageBonus,
playerDefense(player, st), phase.DefenseWeight, player.Mods.DamageReduct)
// Player block
blocked := player.Stats.BlockRate > 0 && rand.Float64() < player.Stats.BlockRate
if blocked {
dmg = max(1, dmg/2)
}
// Crit
critRate := enemy.Stats.CritRate
if phaseName == "Decisive" {
critRate *= 2
}
isCrit := critRate > 0 && rand.Float64() < critRate
if isCrit {
dmg *= 2
}
dmg = max(1, dmg)
// Pet deflect: halve damage
if petDeflect {
dmg = max(1, dmg/2)
st.events = append(st.events, CombatEvent{
Round: st.round, Phase: phaseName, Actor: "pet", Action: "pet_deflect",
PlayerHP: st.playerHP, EnemyHP: st.enemyHP,
})
}
action := "hit"
if isCrit {
action = "crit"
} else if blocked {
action = "block"
}
st.playerHP = max(0, st.playerHP-dmg)
st.events = append(st.events, CombatEvent{
Round: st.round, Phase: phaseName, Actor: "enemy", Action: action,
Damage: dmg, PlayerHP: st.playerHP, EnemyHP: st.enemyHP,
})
// Reflect: bounce portion back (after player takes the hit)
if st.reflectFrac > 0 {
reflected := max(1, int(float64(dmg)*st.reflectFrac))
st.reflectFrac = 0
st.enemyHP = max(0, st.enemyHP-reflected)
st.events = append(st.events, CombatEvent{
Round: st.round, Phase: phaseName, Actor: "consumable", Action: "reflect_damage",
Damage: reflected, PlayerHP: st.playerHP, EnemyHP: st.enemyHP,
})
if st.enemyHP <= 0 {
return true
}
}
if st.playerHP <= 0 {
return !trySave(st, player, phaseName)
}
return false
}
// ── Monster Ability Logic ────────────────────────────────────────────────────
func abilityFires(ability *MonsterAbility, phaseName string, st *combatState) bool {
phaseMatch := ability.Phase == "any" ||
(ability.Phase == "opening" && phaseName == "Opening") ||
(ability.Phase == "clash" && phaseName == "Clash") ||
(ability.Phase == "decisive" && phaseName == "Decisive")
if !phaseMatch {
return false
}
return rand.Float64() < ability.ProcChance
}
func applyAbility(st *combatState, player, enemy *Combatant, phase *CombatPhase, result *CombatResult) bool {
ab := enemy.Ability
phaseName := phase.Name
switch ab.Effect {
case "poison":
st.poisonTicks = 2
st.poisonDmg = 3 + rand.IntN(3)
st.events = append(st.events, CombatEvent{
Round: st.round, Phase: phaseName, Actor: "enemy", Action: "poison",
Desc: ab.Name, PlayerHP: st.playerHP, EnemyHP: st.enemyHP,
})
case "enrage":
if !st.enraged && st.enemyHP < int(float64(enemy.Stats.MaxHP)*0.4) {
st.enraged = true
st.events = append(st.events, CombatEvent{
Round: st.round, Phase: phaseName, Actor: "enemy", Action: "enrage",
Desc: ab.Name, PlayerHP: st.playerHP, EnemyHP: st.enemyHP,
})
}
case "armor_break":
if !st.armorBroken {
st.armorBroken = true
st.armorBreakAmt = 0.30
st.events = append(st.events, CombatEvent{
Round: st.round, Phase: phaseName, Actor: "enemy", Action: "armor_break",
Desc: ab.Name, PlayerHP: st.playerHP, EnemyHP: st.enemyHP,
})
}
case "stun":
st.stunPlayer = true
st.events = append(st.events, CombatEvent{
Round: st.round, Phase: phaseName, Actor: "enemy", Action: "stun",
Desc: ab.Name, PlayerHP: st.playerHP, EnemyHP: st.enemyHP,
})
case "lifesteal":
atkMult := 1.0
if st.enraged {
atkMult = 1.5
}
dmg := calcDamage(int(float64(enemy.Stats.Attack)*atkMult), phase.AttackWeight, enemy.Mods.DamageBonus,
playerDefense(player, st), phase.DefenseWeight, player.Mods.DamageReduct)
dmg = max(1, dmg)
st.playerHP = max(0, st.playerHP-dmg)
heal := dmg / 2
st.enemyHP = min(enemy.Stats.MaxHP, st.enemyHP+heal)
st.events = append(st.events, CombatEvent{
Round: st.round, Phase: phaseName, Actor: "enemy", Action: "lifesteal",
Damage: dmg, Desc: ab.Name, PlayerHP: st.playerHP, EnemyHP: st.enemyHP,
})
if st.playerHP <= 0 {
return !trySave(st, player, phaseName)
}
case "cleave":
atkMult := 1.0
if st.enraged {
atkMult = 1.5
}
dmg1 := calcDamage(int(float64(enemy.Stats.Attack)*atkMult), phase.AttackWeight, enemy.Mods.DamageBonus,
playerDefense(player, st), phase.DefenseWeight, player.Mods.DamageReduct)
dmg1 = max(1, dmg1)
st.playerHP = max(0, st.playerHP-dmg1)
st.events = append(st.events, CombatEvent{
Round: st.round, Phase: phaseName, Actor: "enemy", Action: "cleave",
Damage: dmg1, Desc: ab.Name, PlayerHP: st.playerHP, EnemyHP: st.enemyHP,
})
if st.playerHP <= 0 {
if !trySave(st, player, phaseName) {
return true
}
// Death save fired — skip follow-up hit (survived the first blow barely)
} else {
dmg2 := max(1, dmg1/2)
st.playerHP = max(0, st.playerHP-dmg2)
st.events = append(st.events, CombatEvent{
Round: st.round, Phase: phaseName, Actor: "enemy", Action: "cleave",
Damage: dmg2, Desc: ab.Name + " (follow-up)", PlayerHP: st.playerHP, EnemyHP: st.enemyHP,
})
if st.playerHP <= 0 {
return !trySave(st, player, phaseName)
}
}
}
return false
}
// ── Helpers ──────────────────────────────────────────────────────────────────
// calcDamage uses a penetration model: defense provides diminishing returns
// reduction rather than flat subtraction, so damage is never fully negated.
// Formula: rawAtk * reduction where reduction = K / (K + effectiveDef).
// K=40 means 40 defense halves incoming damage; 80 defense reduces by 67%.
func calcDamage(attack int, atkWeight, dmgBonus float64, defense int, defWeight, dmgReduct float64) int {
const K = 40.0
rawAtk := float64(attack) * atkWeight * (1 + dmgBonus)
effectiveDef := float64(defense) * defWeight * dmgReduct
reduction := K / (K + effectiveDef)
dmg := rawAtk * reduction
if dmg < 1 {
return 1
}
return int(dmg)
}
func playerDefense(player *Combatant, st *combatState) int {
def := player.Stats.Defense
if st.armorBroken {
def = int(float64(def) * (1 - st.armorBreakAmt))
}
return def
}
func trySave(st *combatState, player *Combatant, phaseName string) bool {
if player.Mods.DeathSave && !st.deathSaveUsed {
st.deathSaveUsed = true
st.playerHP = 1
st.events = append(st.events, CombatEvent{
Round: st.round, Phase: phaseName, Actor: "player", Action: "death_save",
PlayerHP: 1, EnemyHP: st.enemyHP, Desc: "Sovereign",
})
return true
}
return false
}
func finalize(result CombatResult, st *combatState, player, enemy Combatant) CombatResult {
result.Events = st.events
result.PlayerEndHP = st.playerHP
result.EnemyEndHP = st.enemyHP
result.TotalRounds = st.round
result.PlayerWon = st.enemyHP <= 0
playerMax := max(1, player.Stats.MaxHP)
enemyMax := max(1, enemy.Stats.MaxHP)
if result.PlayerWon && st.playerHP > 0 {
result.NearDeath = float64(st.playerHP) < float64(playerMax)*0.15
winnerRemaining := float64(st.playerHP) / float64(playerMax)
result.Closeness = 1.0 - winnerRemaining
} else if !result.PlayerWon {
enemyRemaining := float64(st.enemyHP) / float64(enemyMax)
result.NearDeath = enemyRemaining < 0.15
result.Closeness = 1.0 - enemyRemaining
}
return result
}