from __future__ import annotations

from engine.character import Character
from engine.defs import DefRegistry


def apply_organ_interactions_tick(character: Character, registry: DefRegistry, ticks: int) -> None:
    """Damaged organs stress the organs they affect (OrganDef.affects_organs), e.g. a weakened
    heart gradually strains the kidneys. Damage per tick is proportional to both the source
    organ's own damage fraction and the elapsed ticks. Sources are snapshotted before any
    damage is applied, so effects don't cascade within the same tick (a heart hit doesn't also
    immediately hit whatever the newly-damaged kidneys affect, this call).
    """
    if ticks <= 0:
        return

    sources: list[tuple[str, float]] = []
    for part in character.resolved_body_parts().values():
        if part is None:
            continue
        for organ in part.organs:
            if organ.removed:
                continue
            organ_def = registry.get_organ_def(organ.organ_def_id)
            if not organ_def.affects_organs:
                continue
            damage_fraction = 1.0 - (organ.integrity / 100.0)
            if damage_fraction <= 0.0:
                continue
            sources.append((organ_def.id, damage_fraction))

    for source_id, damage_fraction in sources:
        source_def = registry.get_organ_def(source_id)
        for target_organ_id, rate in source_def.affects_organs.items():
            _damage_organ(character, target_organ_id, rate * damage_fraction * ticks)


def _damage_organ(character: Character, organ_def_id: str, amount: float) -> None:
    if amount <= 0:
        return
    for slot, part in character.resolved_body_parts().items():
        if part is None:
            continue
        if not any(o.organ_def_id == organ_def_id for o in part.organs):
            continue
        override = character.get_or_create_body_part_override(slot)
        assert override is not None
        organ = next(o for o in override.organs if o.organ_def_id == organ_def_id)
        organ.integrity = max(0.0, organ.integrity - amount)
        if organ.integrity <= 0.0:
            organ.removed = True
        return