src/world_simulator/simulation/goals.py

from __future__ import annotations

from world_simulator.domain import CitizenGoal, CitizenMode, Npc, WorldState
from world_simulator.simulation.mechanics import distance_between, has_hostile_intent, is_alive
from world_simulator.simulation.perception import (
    CitizenPerception,
    build_perception,
    nearby_threat_npc,
    recent_attacker_id,
)


def refresh_citizen_motivation(
    world: WorldState,
    npc: Npc,
) -> tuple[CitizenPerception, CitizenGoal | None]:
    perception = build_perception(world, npc)
    _update_needs_and_emotions(npc, perception)
    goal = select_goal(world, npc, perception)
    npc.current_goal = goal
    npc.mode = _mode_for_goal(goal)
    return perception, goal


def select_goal(
    world: WorldState,
    npc: Npc,
    perception: CitizenPerception,
) -> CitizenGoal | None:
    if not is_alive(npc):
        return None

    immediate_threat = next(
        (threat for threat in perception.nearby_threats if threat.get("can_attack_you")),
        None,
    )
    if immediate_threat is not None:
        return CitizenGoal(
            goal_type="survive",
            target_npc_id=_str_or_none(immediate_threat.get("npc_id")),
            priority=100,
            reason=f"{immediate_threat['name']} is close enough to attack",
        )

    hostile_target = resolve_hostile_directive_target(world, npc)
    if hostile_target is not None:
        return CitizenGoal(
            goal_type="pursue_and_attack_target",
            target_npc_id=hostile_target.id,
            priority=98,
            reason=f"Hostile directive targets {hostile_target.name}",
        )

    attacker_id = recent_attacker_id(world, npc)
    if attacker_id is not None:
        attacker = _npc_by_id(world, attacker_id)
        if attacker is not None and npc.emotions.anger > npc.emotions.fear:
            return CitizenGoal(
                goal_type="retaliate",
                target_npc_id=attacker.id,
                priority=92,
                reason=f"{attacker.name} attacked recently",
            )
        if attacker is not None and _wants_to_call_for_help(npc):
            return CitizenGoal(
                goal_type="call_for_help",
                target_npc_id=attacker.id,
                priority=90,
                reason=f"{attacker.name} attacked recently",
            )
        return CitizenGoal(
            goal_type="survive",
            target_npc_id=attacker_id,
            priority=94,
            reason="This citizen was attacked recently",
        )

    visible_threat = nearby_threat_npc(world, perception)
    if visible_threat is not None:
        return CitizenGoal(
            goal_type="survive",
            target_npc_id=visible_threat.id,
            priority=88,
            reason=f"{visible_threat.name} is remembered or acting as dangerous nearby",
        )

    ally_threat = _attacker_from_observed_attack(world, npc, perception)
    if ally_threat is not None:
        return CitizenGoal(
            goal_type="help_or_defend",
            target_npc_id=ally_threat.id,
            priority=82,
            reason=f"{ally_threat.name} attacked someone nearby",
        )

    if npc.needs.food >= 80:
        return CitizenGoal(
            goal_type="find_food",
            priority=60,
            reason="Food need is high",
        )

    return CitizenGoal(
        goal_type="routine_life",
        priority=20,
        reason="No urgent threat or directive is present",
    )


def resolve_hostile_directive_target(world: WorldState, npc: Npc) -> Npc | None:
    if not has_hostile_intent(npc):
        return None

    directive = (npc.god_directive or "").lower()
    explicit_target = _explicit_directive_target(world, npc, directive)
    if explicit_target is not None:
        return explicit_target

    if _directive_allows_any_target(directive):
        return _nearest_living_target(world, npc)

    return _nearest_living_target(world, npc)


def _update_needs_and_emotions(npc: Npc, perception: CitizenPerception) -> None:
    if not is_alive(npc):
        return

    if perception.under_threat:
        npc.needs.safety = max(npc.needs.safety, 95)
        npc.emotions.fear = max(npc.emotions.fear, 82)
        npc.emotions.stress = max(npc.emotions.stress, 72)
        return

    if has_hostile_intent(npc):
        npc.needs.safety = max(npc.needs.safety, 35)
        npc.emotions.anger = max(npc.emotions.anger, 70)
        npc.emotions.stress = max(npc.emotions.stress, 45)
        return

    npc.needs.safety = _move_toward(npc.needs.safety, 20, step=5)
    npc.emotions.fear = _move_toward(npc.emotions.fear, 0, step=5)
    npc.emotions.anger = _move_toward(npc.emotions.anger, 0, step=3)
    npc.emotions.stress = _move_toward(npc.emotions.stress, 0, step=5)


def _mode_for_goal(goal: CitizenGoal | None) -> CitizenMode:
    if goal is None:
        return "routine"

    match goal.goal_type:
        case "survive" | "call_for_help":
            return "threatened"
        case "pursue_and_attack_target" | "retaliate":
            return "hostile_pursuit"
        case "help_or_defend":
            return "helping"
        case "respond_to_event" | "investigate":
            return "investigating"
        case _:
            return "routine"


def _explicit_directive_target(world: WorldState, npc: Npc, directive: str) -> Npc | None:
    for candidate in world.living_npcs():
        if candidate.id == npc.id or not is_alive(candidate):
            continue
        if candidate.id.lower() in directive or candidate.name.lower() in directive:
            return candidate
    return None


def _directive_allows_any_target(directive: str) -> bool:
    return any(
        keyword in directive
        for keyword in (
            "everyone",
            "everybody",
            "all",
            "anyone",
            "else",
            "visible",
            "citizen",
            "npc",
        )
    )


def _nearest_living_target(world: WorldState, npc: Npc) -> Npc | None:
    candidates = [
        (distance_between(npc, candidate), candidate.id, candidate)
        for candidate in world.living_npcs()
        if candidate.id != npc.id and is_alive(candidate)
    ]
    if not candidates:
        return None
    return min(candidates, key=lambda item: (item[0], item[1]))[2]


def _attacker_from_observed_attack(
    world: WorldState,
    npc: Npc,
    perception: CitizenPerception,
) -> Npc | None:
    for episode in reversed(npc.structured_memory.episodes):
        if (
            episode.kind == "attack"
            and episode.subject_kind == "npc"
            and episode.perspective == "witness"
            and episode.actor_id != npc.id
        ):
            attacker = _npc_by_id(world, episode.actor_id)
            if attacker is not None and is_alive(attacker):
                return attacker

    for text in reversed(perception.last_hostile_actions):
        lowered = text.lower()
        if "attacked you" in lowered:
            continue
        if "attacked" not in lowered:
            continue
        for candidate in world.living_npcs():
            if candidate.id == npc.id:
                continue
            if candidate.name.lower() in lowered or candidate.id.lower() in lowered:
                return candidate
    return None


def _npc_by_id(world: WorldState, npc_id: str) -> Npc | None:
    return next((npc for npc in world.living_npcs() if npc.id == npc_id), None)


def _wants_to_call_for_help(npc: Npc) -> bool:
    personality = npc.personality.lower()
    return "social" in personality or "cautious" in personality or npc.role != "guard"


def _str_or_none(raw: object) -> str | None:
    return raw if isinstance(raw, str) else None


def _move_toward(value: int, target: int, *, step: int) -> int:
    if value < target:
        return min(value + step, target)
    if value > target:
        return max(value - step, target)
    return value