gogobee/internal/plugin/dnd_passives.go

package plugin

// Phase 3 — class passives applied via CombatModifiers.
//
// Phase 3 keeps abilities passive-only: they auto-trigger via the existing
// CombatModifiers machinery rather than being player-activated mid-fight
// (the combat engine is one-shot, no turn-based UI). Active/reactive
// abilities arrive once we have a model for them — likely tied to !arena
// pre-arming or to a turn-based PvP variant.

// ── Class passive definitions ────────────────────────────────────────────────

// DnDClassAbility is the lore/UI representation of a class's signature
// passive. Used by !abilities and !sheet for display; mechanics live in
// applyClassPassives below.
type DnDClassAbility struct {
	Name        string
	Description string
}

var dndClassAbilities = map[DnDClass]DnDClassAbility{
	ClassFighter: {
		Name:        "Battle Trained",
		Description: "Years of weapon drill add +5% to all damage you deal.",
	},
	ClassRogue: {
		Name:        "Sneak Attack",
		Description: "Your first strike each combat lands as a critical hit, doubling its damage.",
	},
	ClassMage: {
		Name:        "Arcane Focus",
		Description: "Practiced channeling adds +1 to your attack rolls.",
	},
	ClassCleric: {
		Name:        "Divine Favor",
		Description: "When you fall below half HP, divine intervention restores 5 HP. Once per combat.",
	},
	ClassRanger: {
		Name:        "Hunter's Mark",
		Description: "You read your prey's weak points: +5% damage and +1 to attack rolls.",
	},
}

// applyRacePassives sets the combat-impacting flags from the player's race.
// Races whose passives apply to skill checks or non-combat scenarios
// (Tiefling fire resist, Elf sleep immunity, Half-Elf bonus profs, Human
// floating +1) are handled in their respective phases and have no combat
// hook in Phase 3.
func applyRacePassives(stats *CombatStats, mods *CombatModifiers, c *DnDCharacter) {
	switch c.Race {
	case RaceHalfling:
		mods.LuckyReroll = true
	case RaceOrc:
		mods.RageReady = true
	case RaceDwarf:
		mods.PoisonResist = true
	}
}

// applyClassPassives mutates a player's CombatModifiers to apply their
// class passive. Called after applyDnDPlayerLayer + DerivePlayerStats but
// BEFORE consumable application (so consumables can stack on top).
//
// Some passives ride on existing CombatModifiers fields:
//   Rogue's Sneak Attack reuses AutoCritFirst (the consumable Crystal Berry
//   field) — the engine already implements first-hit-auto-crit semantics.
//   Cleric's Divine Favor reuses HealItem, the under-50%-HP heal trigger.
//
// This means:
//   - A Rogue carrying a Crystal Berry doesn't get *two* auto-crits;
//     AutoCritFirst is already a one-shot bool.
//   - A Cleric carrying a healing potion stacks: passive 5 + potion 8 = 13.
//     The passive heal triggers first since both use the same threshold.
func applyClassPassives(stats *CombatStats, mods *CombatModifiers, c *DnDCharacter) {
	switch c.Class {
	case ClassFighter:
		mods.DamageBonus += 0.05
	case ClassRogue:
		mods.AutoCritFirst = true
	case ClassMage:
		stats.AttackBonus++
	case ClassCleric:
		// Passive heal at <50% HP. Stacks additively with consumable HealItem.
		mods.HealItem += 5
	case ClassRanger:
		mods.DamageBonus += 0.05
		stats.AttackBonus++
	}
}