from __future__ import annotations

import copy
import importlib.util
import json
from pathlib import Path


REPO = Path(__file__).resolve().parents[2]
MODEL_DIR = REPO / "models" / "lcd25-reducer" / "semantic-assembly"
SCHEMA_PATH = (
    REPO
    / "designir-pipeline"
    / "contracts"
    / "assembly-designir-1.0.schema.json"
)
VALIDATOR_PATH = MODEL_DIR / "validate_assembly_design.py"


def load_validator():
    spec = importlib.util.spec_from_file_location(
        "assembly_design_validator", VALIDATOR_PATH
    )
    assert spec and spec.loader
    module = importlib.util.module_from_spec(spec)
    spec.loader.exec_module(module)
    return module


def load_json(path: Path):
    return json.loads(path.read_text(encoding="utf-8"))


def test_lcd25_coordinate_free_base_model_is_valid():
    validator = load_validator()
    schema = load_json(SCHEMA_PATH)
    payload = load_json(
        MODEL_DIR / "lcd25-harmonic-reducer.assembly-designir.json"
    )
    report = validator.validate(payload, schema)
    assert report["status"] == "pass"
    assert report["coordinate_free"] is True
    assert report["component_count"] == 10
    assert report["relation_count"] == 15


def test_output_shaft_patch_preserves_coordinate_free_contract():
    validator = load_validator()
    schema = load_json(SCHEMA_PATH)
    payload = load_json(
        MODEL_DIR / "lcd25-harmonic-reducer.assembly-designir.json"
    )
    patch = load_json(MODEL_DIR / "variants" / "add-output-shaft.patch.json")
    resolved = validator.apply_patch(payload, patch)
    report = validator.validate(resolved, schema)
    assert report["status"] == "pass"
    assert report["coordinate_free"] is True
    assert report["component_count"] == 11
    assert "output_shaft" in {
        component["id"] for component in resolved["components"]
    }
    assert "output_shaft" in next(
        group["members"]
        for group in resolved["kinematics"]["rigid_groups"]
        if group["id"] == "output_group"
    )


def test_authored_transform_is_rejected():
    validator = load_validator()
    schema = load_json(SCHEMA_PATH)
    payload = load_json(
        MODEL_DIR / "lcd25-harmonic-reducer.assembly-designir.json"
    )
    invalid = copy.deepcopy(payload)
    invalid["components"][0]["transform"] = [
        [1, 0, 0, 0],
        [0, 1, 0, 0],
        [0, 0, 1, 0],
    ]
    report = validator.validate(invalid, schema)
    assert report["status"] == "fail"
    assert report["coordinate_free"] is False
    assert any(
        "coordinate placement key is forbidden" in failure
        for failure in report["failures"]
    )