from __future__ import annotations

from typing import Any, cast

from world_simulator.domain import Npc, WorldLogEvent, WorldState
from world_simulator.observability import append_record
from world_simulator.simulation.mechanics import is_alive

DEFAULT_DIRECTIVE_TTL_TICKS = 24


def set_active_directive(
    npc: Npc,
    directive: str,
    *,
    source: str,
    tick: int,
    ttl_ticks: int = DEFAULT_DIRECTIVE_TTL_TICKS,
) -> None:
    npc.god_directive = directive
    npc.directive_source = source
    npc.directive_issued_tick = tick
    npc.directive_ttl_ticks = ttl_ticks


def clear_active_directive(npc: Npc) -> None:
    npc.god_directive = None
    npc.directive_source = None
    npc.directive_issued_tick = None
    npc.directive_ttl_ticks = None


def directive_remaining_ttl(npc: Npc, *, tick: int) -> int | None:
    if npc.god_directive is None:
        return None
    if npc.directive_issued_tick is None or npc.directive_ttl_ticks is None:
        return DEFAULT_DIRECTIVE_TTL_TICKS
    return max(0, npc.directive_issued_tick + npc.directive_ttl_ticks - tick)


def active_directive_payload(npc: Npc, *, tick: int) -> dict[str, Any] | None:
    if npc.god_directive is None:
        return None
    return {
        "text": npc.god_directive,
        "source": npc.directive_source or "unknown",
        "issued_tick": npc.directive_issued_tick,
        "ttl_ticks": npc.directive_ttl_ticks or DEFAULT_DIRECTIVE_TTL_TICKS,
        "remaining_ttl": directive_remaining_ttl(npc, tick=tick),
    }


def expire_directives(world: WorldState, *, tick: int) -> list[dict[str, Any]]:
    expired: list[dict[str, Any]] = []
    for npc in world.living_npcs():
        remaining = directive_remaining_ttl(npc, tick=tick)
        if remaining is None or remaining > 0:
            continue
        record = {
            "npc_id": npc.id,
            "directive": npc.god_directive,
            "source": npc.directive_source,
            "issued_tick": npc.directive_issued_tick,
            "ttl_ticks": npc.directive_ttl_ticks,
        }
        clear_active_directive(npc)
        world.event_log.append(
            WorldLogEvent(
                tick=tick,
                type="directive_expired",
                actor_id="engine",
                target_id=npc.id,
                object_id=None,
                summary=f"Directive expired for {npc.name}",
                severity=cast(Any, "neutral"),
            )
        )
        append_record({"tick": tick, "phase": "directive_expired", **record})
        expired.append(record)

    for npc in world.npcs:
        if not is_alive(npc):
            clear_active_directive(npc)
    return expired