"""Tests for the directional ``direction`` field on directional maneuvers.

L2 of the ``llm-policy-contract`` plan: ``Action`` gains a ``direction``
field that lets a policy steer the three directional maneuvers (reposition,
drag, bull_rush) instead of relying on the deterministic default direction
(first free neighbor / beyond the target / away from the attacker).

When ``direction`` is ``None`` the previous deterministic behavior is kept
bit-identical.
"""

from __future__ import annotations

from pf1e_simulator.combat import Action, CombatantState, CombatEngine
from pf1e_simulator.grid import Grid
from pf1e_simulator.map import MapSpec, TerrainType
from pf1e_simulator.models import (
    AbilityScores,
    ACProfile,
    AttackSpec,
    Combatant,
    DamageComponent,
    Saves,
)
from pf1e_simulator.rng import ScriptedRng, SeededRng


def make_combatant(cid: str, *, attack_bonus: int = 2) -> Combatant:
    attack = AttackSpec(
        id=f"{cid}-w",
        name="sword",
        kind="melee",
        attack_bonus=attack_bonus,
        damage=[DamageComponent(formula="1d4", types=["slashing"])],
    )
    return Combatant(
        id=cid,
        name=cid,
        level=1,
        size="Medium",
        abilities=AbilityScores(
            str_score=10, dex_score=10, con_score=10,
            int_score=10, wis_score=10, cha_score=10,
        ),
        hp_max=6,
        ac=ACProfile(total=13, touch=13, flat_footed=13),
        bab=attack_bonus,
        initiative_mod=0,
        speed_land_ft=30,
        saves=Saves(fort=0, ref=0, will=0),
        attacks=[attack],
    )


def make_state(combatant: Combatant, side: str, pos: tuple[int, int]) -> CombatantState:
    return CombatantState(combatant=combatant, side=side, pos=pos, hp=combatant.hp_max)


def make_grid() -> Grid:
    legend = {".": TerrainType(type="floor", move_cost=1)}
    spec = MapSpec(name="test", terrain=tuple(["." * 8] * 8), legend=legend)
    return Grid.from_spec(spec)


def make_engine(queue: list[int], states: list[CombatantState]) -> CombatEngine:
    # A maneuver provokes an AoO from the (threatening) target BEFORE the CMB
    # check (B13 conformance): the scripted queues carry a leading natural 1
    # so the provoking attack always misses.
    return CombatEngine(ScriptedRng(queue), make_grid(), states)


# --- Test 1: reposition with direction -------------------------------------

def test_reposition_direction_right() -> None:
    a_spec = make_combatant("a")
    b_spec = make_combatant("b")
    a = make_state(a_spec, "players", (1, 1))
    b = make_state(b_spec, "monsters", (1, 2))
    engine = make_engine([1, 12], [a, b])
    engine._execute_maneuver(a, b, "reposition", direction=(0, 1))
    assert b.pos == (1, 3)


def test_reposition_direction_down() -> None:
    a_spec = make_combatant("a")
    b_spec = make_combatant("b")
    a = make_state(a_spec, "players", (1, 1))
    b = make_state(b_spec, "monsters", (1, 2))
    engine = make_engine([1, 12], [a, b])
    engine._execute_maneuver(a, b, "reposition", direction=(1, 0))
    assert b.pos == (2, 2)


# --- Test 2: drag with direction -------------------------------------------

def test_drag_direction_up() -> None:
    a_spec = make_combatant("a")
    b_spec = make_combatant("b")
    a = make_state(a_spec, "players", (1, 1))
    b = make_state(b_spec, "monsters", (1, 2))
    engine = make_engine([1, 12], [a, b])
    engine._execute_maneuver(a, b, "drag", direction=(-1, 0))
    assert b.pos == (0, 2)
    assert a.pos == (1, 2)


# --- Test 3: bull_rush with direction --------------------------------------

def test_bull_rush_direction_left() -> None:
    a_spec = make_combatant("a")
    b_spec = make_combatant("b")
    a = make_state(a_spec, "players", (2, 2))
    b = make_state(b_spec, "monsters", (1, 2))
    engine = make_engine([1, 12], [a, b])
    engine._execute_maneuver(a, b, "bull_rush", direction=(0, -1))
    assert b.pos == (1, 1)


# --- Test 4: invalid direction -> no movement -------------------------------

def test_reposition_direction_out_of_bounds_no_move() -> None:
    a_spec = make_combatant("a")
    b_spec = make_combatant("b")
    a = make_state(a_spec, "players", (1, 1))
    b = make_state(b_spec, "monsters", (0, 0))
    engine = make_engine([1, 12], [a, b])
    engine._execute_maneuver(a, b, "reposition", direction=(-1, 0))
    assert b.pos == (0, 0)


def test_reposition_direction_occupied_no_move() -> None:
    a_spec = make_combatant("a")
    b_spec = make_combatant("b")
    a = make_state(a_spec, "players", (1, 1))
    b = make_state(b_spec, "monsters", (1, 2))
    engine = make_engine([1, 12], [a, b])
    # direction points at the attacker's own cell -> occupied -> no move
    engine._execute_maneuver(a, b, "reposition", direction=(0, -1))
    assert b.pos == (1, 2)


def test_bull_rush_direction_out_of_bounds_no_move() -> None:
    a_spec = make_combatant("a")
    b_spec = make_combatant("b")
    a = make_state(a_spec, "players", (1, 1))
    b = make_state(b_spec, "monsters", (0, 0))
    engine = make_engine([1, 12], [a, b])
    engine._execute_maneuver(a, b, "bull_rush", direction=(-1, 0))
    assert b.pos == (0, 0)


# --- Test 5: direction=None keeps previous behavior -------------------------

def test_reposition_none_uses_first_free_neighbor() -> None:
    a_spec = make_combatant("a")
    b_spec = make_combatant("b")
    a = make_state(a_spec, "players", (1, 1))
    b = make_state(b_spec, "monsters", (1, 2))
    engine = make_engine([1, 12], [a, b])
    engine._execute_maneuver(a, b, "reposition")
    # First free neighbor in _NEIGHBOR_OFFSETS order, skipping attacker's cell.
    assert b.pos == (0, 1)


def test_drag_none_uses_beyond_cell() -> None:
    a_spec = make_combatant("a")
    b_spec = make_combatant("b")
    a = make_state(a_spec, "players", (1, 1))
    b = make_state(b_spec, "monsters", (1, 2))
    engine = make_engine([1, 12], [a, b])
    engine._execute_maneuver(a, b, "drag")
    # Beyond the target from the attacker: (1, 3).
    assert b.pos == (1, 3)
    assert a.pos == (1, 2)


def test_bull_rush_none_uses_away_from_attacker() -> None:
    a_spec = make_combatant("a")
    b_spec = make_combatant("b")
    a = make_state(a_spec, "players", (2, 2))
    b = make_state(b_spec, "monsters", (1, 2))
    engine = make_engine([1, 12], [a, b])
    engine._execute_maneuver(a, b, "bull_rush")
    # Away from attacker (up, since target is above): (0, 2).
    assert b.pos == (0, 2)


# --- Test 6: determinism ----------------------------------------------------

def _run_with_direction(direction: tuple[int, int] | None) -> tuple[str, ...]:
    a_spec = make_combatant("a", attack_bonus=5)
    b_spec = make_combatant("b")
    a = make_state(a_spec, "players", (1, 1))
    b = make_state(b_spec, "monsters", (1, 2))

    def policy(engine: CombatEngine, state: CombatantState) -> tuple[Action, ...]:
        if state.combatant.id == "a":
            return (
                Action(
                    kind="maneuver", target_id="b", maneuver="reposition",
                    direction=direction,
                ),
            )
        return (Action(kind="wait"),)

    engine = CombatEngine(SeededRng(42), make_grid(), [a, b], policy=policy)
    return engine.run().transcript


def test_determinism_same_seed_same_transcript() -> None:
    assert _run_with_direction((0, 1)) == _run_with_direction((0, 1))
    assert _run_with_direction(None) == _run_with_direction(None)


def test_direction_changes_transcript() -> None:
    assert _run_with_direction((0, 1)) != _run_with_direction(None)