"""Unit test della logica pura del move-toward (no I/O)."""
from __future__ import annotations

import numpy as np
import pytest

from presa_mano.right_arm.move import (
    DeltaOversize,
    apply_z_floor,
    compute_delta_wrist,
)


def test_zero_offset_returns_centroid_with_signs():
    delta = compute_delta_wrist(
        centroid_camera_m=np.array([0.0, 0.0, 1.0]),
        offset_camera_m=np.array([0.0, 0.0, 0.0]),
        axis_signs=(1, 1, 1),
    )
    assert np.allclose(delta, [0.0, 0.0, 1.0])


def test_offset_subtracted_before_signs():
    # centroid=(0,0,1) offset=(0,0,0.1) sign=(1,-1,-1) → (0, 0, -0.9)
    delta = compute_delta_wrist(
        centroid_camera_m=np.array([0.0, 0.0, 1.0]),
        offset_camera_m=np.array([0.0, 0.0, 0.1]),
        axis_signs=(1, -1, -1),
    )
    assert np.allclose(delta, [0.0, 0.0, -0.9])


def test_signs_applied_componentwise():
    delta = compute_delta_wrist(
        centroid_camera_m=np.array([0.05, 0.10, 0.20]),
        offset_camera_m=np.array([0.00, 0.00, 0.00]),
        axis_signs=(1, -1, -1),
    )
    assert np.allclose(delta, [0.05, -0.10, -0.20])


def test_permutation_maps_cam_axes_to_wrist_axes():
    # Mounting: cam guarda avanti = wrist_X. perm=(2,0,1): wrist_X<-cam_Z,
    # wrist_Y<-cam_X, wrist_Z<-cam_Y. signs=(+1,-1,-1).
    # centroid=(0.10, 0.05, 0.30) → wrist=(+0.30, -0.10, -0.05) prima offset/t_wc
    delta = compute_delta_wrist(
        centroid_camera_m=np.array([0.10, 0.05, 0.30]),
        offset_camera_m=np.array([0.0, 0.0, 0.0]),
        axis_signs=(1, -1, -1),
        cam_to_wrist_perm=(2, 0, 1),
    )
    assert np.allclose(delta, [0.30, -0.10, -0.05])


def test_permutation_default_is_identity_back_compat():
    # Senza perm esplicito, comportamento = sign-only (modello vecchio).
    delta_new = compute_delta_wrist(
        centroid_camera_m=np.array([0.10, 0.20, 0.30]),
        offset_camera_m=np.array([0.0, 0.0, 0.0]),
        axis_signs=(1, -1, -1),
    )
    assert np.allclose(delta_new, [0.10, -0.20, -0.30])


def test_invalid_permutation_raises():
    import pytest as _pt
    with _pt.raises(ValueError, match="permutation"):
        compute_delta_wrist(
            centroid_camera_m=np.zeros(3),
            offset_camera_m=np.zeros(3),
            axis_signs=(1, 1, 1),
            cam_to_wrist_perm=(0, 0, 1),
        )


def test_camera_offset_wrist_added_after_sign_flip():
    # centroid=(0,0,1) offset=(0,0,0) sign=(1,1,1) t_wc=(0.05,-0.02,0.08)
    #   → sign*(centroid-offset) = (0,0,1)
    #   → + t_wc = (0.05, -0.02, 1.08)
    delta = compute_delta_wrist(
        centroid_camera_m=np.array([0.0, 0.0, 1.0]),
        offset_camera_m=np.array([0.0, 0.0, 0.0]),
        axis_signs=(1, 1, 1),
        camera_offset_wrist_m=np.array([0.05, -0.02, 0.08]),
    )
    assert np.allclose(delta, [0.05, -0.02, 1.08])


def test_camera_offset_wrist_default_zero_back_compat():
    # Senza camera_offset_wrist_m la formula vecchia resta invariata.
    delta = compute_delta_wrist(
        centroid_camera_m=np.array([0.10, 0.20, 0.30]),
        offset_camera_m=np.array([0.00, 0.00, 0.10]),
        axis_signs=(1, -1, -1),
    )
    assert np.allclose(delta, [0.10, -0.20, -0.20])


def test_oversize_raises_when_not_forced():
    with pytest.raises(DeltaOversize):
        compute_delta_wrist(
            centroid_camera_m=np.array([0.0, 0.0, 0.5]),
            offset_camera_m=np.array([0.0, 0.0, 0.0]),
            axis_signs=(1, 1, 1),
            max_step_m=0.15,
            force=False,
        )


def test_oversize_message_includes_per_axis_breakdown():
    # delta = (1,-1,-1) * ((0.10, -0.02, 0.50) - 0) = (0.10, 0.02, -0.50)
    # ||delta|| = sqrt(0.01+0.0004+0.25) = ~0.510m, max=0.15
    with pytest.raises(DeltaOversize) as exc_info:
        compute_delta_wrist(
            centroid_camera_m=np.array([0.10, -0.02, 0.50]),
            offset_camera_m=np.array([0.0, 0.0, 0.0]),
            axis_signs=(1, -1, -1),
            max_step_m=0.15,
            force=False,
        )
    msg = str(exc_info.value)
    assert "X=100.0" in msg
    assert "Y=20.0" in msg
    assert "Z=-500.0" in msg
    # E l'oggetto espone il vettore strutturato
    assert np.allclose(exc_info.value.delta_m, [0.10, 0.02, -0.50])


def test_oversize_passes_when_forced():
    delta = compute_delta_wrist(
        centroid_camera_m=np.array([0.0, 0.0, 0.5]),
        offset_camera_m=np.array([0.0, 0.0, 0.0]),
        axis_signs=(1, 1, 1),
        max_step_m=0.15,
        force=True,
    )
    assert np.allclose(delta, [0.0, 0.0, 0.5])


def test_z_floor_clips_when_target_below():
    # wrist_before.z=0.10, delta.z=-0.30, target=-0.20, floor=0.05 → clip a 0.05
    # → delta.z = 0.05 - 0.10 = -0.05
    new_delta, clipped = apply_z_floor(
        wrist_z_m=0.10,
        delta=np.array([0.01, -0.02, -0.30]),
        z_floor_m=0.05,
    )
    assert clipped is True
    assert new_delta[2] == pytest.approx(-0.05)
    # X/Y invariati
    assert new_delta[0] == pytest.approx(0.01)
    assert new_delta[1] == pytest.approx(-0.02)


def test_z_floor_noop_when_target_above():
    new_delta, clipped = apply_z_floor(
        wrist_z_m=0.30,
        delta=np.array([0.0, 0.0, -0.10]),
        z_floor_m=0.05,
    )
    assert clipped is False
    assert np.allclose(new_delta, [0.0, 0.0, -0.10])


def test_z_floor_none_disables_clip():
    new_delta, clipped = apply_z_floor(
        wrist_z_m=0.10,
        delta=np.array([0.0, 0.0, -0.50]),
        z_floor_m=None,
    )
    assert clipped is False
    assert np.allclose(new_delta, [0.0, 0.0, -0.50])