feat(combat): expose class features and spell data in observation snapshot

src/pf1e_simulator/combat.py

@@ -183,6 +183,29 @@ def _save_label(result: SaveResult | None) -> str:
     return "SAVED" if result.success else "FAILED"
 
 
+def _spell_effect_summary(effect: SpellEffect) -> str:
+    """Short serializable summary of one spell effect (never the description)."""
+    if isinstance(effect, DamageEffect):
+        parts = [dice_to_str(effect.formula), *effect.types]
+        if effect.half_on_save:
+            parts.append("half on save")
+        return " ".join(parts)
+    if isinstance(effect, ConditionEffect):
+        return f"{effect.condition_name} {effect.duration_rounds}r"
+    if isinstance(effect, HealEffect):
+        return f"heal {dice_to_str(effect.formula)}"
+    if isinstance(effect, BuffEffect):
+        return f"buff {effect.duration_rounds}r"
+    if isinstance(effect, AreaEffect):
+        return f"area {effect.radius_ft}ft"
+    return f"summon {effect.creature}"
+
+
+def _spell_summary(spell: SpellSpec) -> str:
+    """Short serializable summary of a spell's effects, joined with ', '."""
+    return ", ".join(_spell_effect_summary(e) for e in spell.effects)
+
+
 _STEP_DELTAS: tuple[Pos, ...] = (
     (-1, -1),
     (-1, 0),
@@ -637,6 +660,10 @@ class CombatEngine:
                 }
                 for attack in state.combatant.attacks
             ),
+            "features": tuple(sorted(f.name for f in state.combatant.features)),
+            "spells": tuple(
+                self._spell_snapshot(state, name) for name in state.combatant.spells
+            ),
         }
 
     def _pair_snapshot(
@@ -2561,6 +2588,36 @@ class CombatEngine:
             return
         self._charge(state, target, result.weapon)
 
+    def _spell_dc(self, caster: CombatantState, spell: SpellSpec) -> int:
+        """Spell save DC: 10 + spell level + casting ability modifier."""
+        ability_name = caster.combatant.casting_ability.lower()
+        ability_score = getattr(caster.combatant.abilities, f"{ability_name}_score")
+        ability_mod = (ability_score - 10) // 2
+        return 10 + spell.level + ability_mod
+
+    def _spell_snapshot(self, state: CombatantState, spell_name: str) -> dict[str, object]:
+        """One per-spell dict for the Observation, enriched from the registry."""
+        spell = self._spell_registry.get(spell_name)
+        if spell is None:
+            return {
+                "name": spell_name,
+                "level": None,
+                "school": "",
+                "range_ft": 0,
+                "save": "none",
+                "dc": None,
+                "summary": "",
+            }
+        return {
+            "name": spell.name,
+            "level": spell.level,
+            "school": spell.school,
+            "range_ft": spell_range_ft(spell, state.combatant.level),
+            "save": spell.save,
+            "dc": self._spell_dc(state, spell),
+            "summary": _spell_summary(spell),
+        }
+
     def _cast_spell(
         self, caster: CombatantState, target: CombatantState | None, spell_name: str
     ) -> None:
@@ -2593,11 +2650,7 @@ class CombatEngine:
         if self._check_casting_aoo(caster, spell.level):
             return
         caster.spend_spell_slot(spell.level)
-        # DC = 10 + spell level + caster's casting ability modifier
+        dc = self._spell_dc(caster, spell)
-        ability_name = caster.combatant.casting_ability.lower()
-        ability_score = getattr(caster.combatant.abilities, f"{ability_name}_score")
-        ability_mod = (ability_score - 10) // 2
-        dc = 10 + spell.level + ability_mod
         save_result = (
             self.resolve_save(
                 target, spell.save, dc, save_descriptors=spell_save_descriptors(spell)

tests/test_observation_enriched.py

@@ -1,8 +1,8 @@
-"""Tests for E1: enriched per-combatant combat stats in the Observation snapshot.
+"""Tests for E1-E3: enriched per-combatant data in the Observation snapshot.
 
-Adds the static combat-stat fields to each ``combatants`` dict of the
+Adds the static combat-stat fields (E1), the attacks reference (E2) and the
-snapshot (name, level, size, speeds, ac, saves, cmb, cmd) — a strict
+class features + spell data (E3) to each ``combatants`` dict of the snapshot
-superset of the L1 schema. No existing key is modified or renamed.
+— a strict superset of the L1 schema. No existing key is modified or renamed.
 
 Covers:
 - The enriched schema 1v1 (exact values derived from the constructed
@@ -11,12 +11,16 @@ Covers:
   same state.
 - The optional ``speed_fly_ft`` field (``int | None``).
 - JSON serializability and frozen copies (same conventions as L1 tests 9/10).
+- ``features`` (sorted AbilitySpec names) and ``spells`` (registry-enriched
+  dicts, graceful for unknown spells).
 """
 
 from __future__ import annotations
 
 import json
+from pathlib import Path
 
+from pf1e_simulator.abilities import AbilitySpec
 from pf1e_simulator.combat import CombatantState, CombatEngine
 from pf1e_simulator.dice import dice_to_str, parse_dice
 from pf1e_simulator.grid import Grid
@@ -30,6 +34,7 @@ from pf1e_simulator.models import (
     Saves,
 )
 from pf1e_simulator.rng import ScriptedRng
+from pf1e_simulator.spells import SpellSpec, load_spell
 
 
 def make_combatant(
@@ -41,6 +46,8 @@ def make_combatant(
     attack_bonus: int = 5,
     speed: int = 30,
     speed_fly: int | None = None,
+    features: list[AbilitySpec] | None = None,
+    spells: list[str] | None = None,
 ) -> Combatant:
     """Build a single-weapon melee combatant with known static stats."""
     attack = AttackSpec(
@@ -71,6 +78,8 @@ def make_combatant(
         speed_fly_ft=speed_fly,
         saves=Saves(fort=0, ref=0, will=0),
         attacks=[attack],
+        features=features or [],
+        spells=spells or [],
     )
 
 
@@ -88,8 +97,13 @@ def make_grid() -> Grid:
     return Grid.from_spec(spec)
 
 
-def make_engine(states: list[CombatantState]) -> CombatEngine:
+def make_engine(
-    return CombatEngine(ScriptedRng([]), make_grid(), states)
+    states: list[CombatantState],
+    spell_registry: dict[str, SpellSpec] | None = None,
+) -> CombatEngine:
+    return CombatEngine(
+        ScriptedRng([]), make_grid(), states, spell_registry=spell_registry
+    )
 
 
 def _snapshot(engine: CombatEngine, state: CombatantState) -> dict:
@@ -377,3 +391,151 @@ def test_observation_enriched_attacks_formula_uses_dice_to_str() -> None:
     attacks = obs["combatants"][0]["attacks"]
     assert attacks[0]["damage"][0]["formula"] == dice_to_str(parse_dice("2d6+3"))
     assert attacks[1]["damage"][0]["formula"] == dice_to_str(parse_dice("2d6-1"))
+
+
+# ---------------------------------------------------------------------------
+# 6. E3: features — sorted AbilitySpec names
+# ---------------------------------------------------------------------------
+
+
+def test_observation_enriched_features_sorted() -> None:
+    """Given: a combatant with several class features
+    When: an Observation is built
+    Then: features lists the AbilitySpec names, sorted for determinism."""
+    hero = make_combatant(
+        "hero",
+        features=[
+            AbilitySpec(name="Channel Energy", category="class"),
+            AbilitySpec(name="Power Attack", category="feat"),
+            AbilitySpec(name="Toughness", category="feat"),
+        ],
+    )
+    foe = make_combatant("foe")
+    hero_state = make_state(hero, "players", (0, 0))
+    foe_state = make_state(foe, "monsters", (0, 3))
+    engine = make_engine([hero_state, foe_state])
+
+    obs = _snapshot(engine, hero_state)
+    features = obs["combatants"][0]["features"]
+    assert features == ("Channel Energy", "Power Attack", "Toughness")
+    assert obs["combatants"][1]["features"] == ()
+
+
+# ---------------------------------------------------------------------------
+# 7. E3: spells — known spell enriched from the registry
+# ---------------------------------------------------------------------------
+
+
+def test_observation_enriched_spells_known() -> None:
+    """Given: a combatant with a known spell and a populated registry
+    When: an Observation is built
+    Then: the spell dict carries level/school/range_ft/save/dc/summary."""
+    fireball = load_spell(Path("data/spells/fireball.json"))
+    hero = make_combatant("hero", spells=["Fireball"])
+    foe = make_combatant("foe")
+    hero_state = make_state(hero, "players", (0, 0))
+    foe_state = make_state(foe, "monsters", (0, 3))
+    engine = make_engine([hero_state, foe_state], spell_registry={"Fireball": fireball})
+
+    obs = _snapshot(engine, hero_state)
+    spells = obs["combatants"][0]["spells"]
+    assert len(spells) == 1
+    s = spells[0]
+    assert s["name"] == "Fireball"
+    assert s["level"] == 3
+    assert s["school"] == "evocation"
+    # long range: 400 + 40 * caster_level (level 1) = 440
+    assert s["range_ft"] == 440
+    assert s["save"] == "ref"
+    # DC = 10 + spell.level + casting ability mod (wis 10 -> 0) = 13
+    assert s["dc"] == 13
+    # AreaEffect -> "area {radius}ft"
+    assert s["summary"] == "area 20ft"
+
+
+def test_observation_enriched_spells_dc_matches_engine() -> None:
+    """Given: a combatant with a known spell and a non-default casting ability
+    When: an Observation is built
+    Then: the snapshot dc equals the engine's _cast_spell dc on the same state."""
+    fireball = load_spell(Path("data/spells/fireball.json"))
+    hero = make_combatant("hero", spells=["Fireball"])
+    hero = hero.model_copy(
+        update={
+            "abilities": hero.abilities.model_copy(
+                update={"cha_score": 16}
+            ),
+            "casting_ability": "cha",
+        }
+    )
+    foe = make_combatant("foe")
+    hero_state = make_state(hero, "players", (0, 0))
+    foe_state = make_state(foe, "monsters", (0, 3))
+    engine = make_engine([hero_state, foe_state], spell_registry={"Fireball": fireball})
+
+    obs = _snapshot(engine, hero_state)
+    s = obs["combatants"][0]["spells"][0]
+    # DC = 10 + 3 + 3 = 16
+    assert s["dc"] == 16
+
+
+# ---------------------------------------------------------------------------
+# 8. E3: spells — unknown spell -> empty dict, no exception
+# ---------------------------------------------------------------------------
+
+
+def test_observation_enriched_spells_unknown_graceful() -> None:
+    """Given: a combatant with a spell absent from the (possibly empty) registry
+    When: an Observation is built
+    Then: the spell dict is the empty template and no exception is raised."""
+    hero = make_combatant("hero", spells=["Mystery Spell"])
+    foe = make_combatant("foe")
+    hero_state = make_state(hero, "players", (0, 0))
+    foe_state = make_state(foe, "monsters", (0, 3))
+    engine = make_engine([hero_state, foe_state])
+
+    obs = _snapshot(engine, hero_state)
+    spells = obs["combatants"][0]["spells"]
+    assert spells == (
+        {
+            "name": "Mystery Spell",
+            "level": None,
+            "school": "",
+            "range_ft": 0,
+            "save": "none",
+            "dc": None,
+            "summary": "",
+        },
+    )
+
+
+# ---------------------------------------------------------------------------
+# 9. E3: spells/features JSON-serializable and frozen
+# ---------------------------------------------------------------------------
+
+
+def test_observation_enriched_spells_features_json_serializable() -> None:
+    """Given: an Observation with features and spells
+    When: to_dict() is serialized
+    Then: json.dumps succeeds and the new fields are frozen."""
+    fireball = load_spell(Path("data/spells/fireball.json"))
+    hero = make_combatant(
+        "hero",
+        spells=["Fireball", "Mystery Spell"],
+        features=[AbilitySpec(name="Channel Energy", category="class")],
+    )
+    foe = make_combatant("foe")
+    hero_state = make_state(hero, "players", (0, 0))
+    foe_state = make_state(foe, "monsters", (0, 3))
+    engine = make_engine([hero_state, foe_state], spell_registry={"Fireball": fireball})
+
+    obs = engine._build_observation(hero_state)
+    data = obs.to_dict()
+    json.dumps(data)
+
+    hero_state.hp = 5
+    data_after = obs.to_dict()
+    assert data_after == data
+    c = data_after["combatants"][0]
+    assert c["features"] == ("Channel Energy",)
+    assert c["spells"][0]["name"] == "Fireball"
+    assert c["spells"][1]["name"] == "Mystery Spell"