import os
import shutil
import pytest
from unittest.mock import patch, MagicMock
import trimesh
import numpy as np
import sys

sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), '..')))
from processing import create_layered_curves_dxf

ASSETS_DIR = os.path.join(os.path.dirname(__file__), "assets")
TEST_OUTPUT_DIR = os.path.join(os.path.dirname(__file__), "test_outputs")
VALID_FILE = os.path.join(ASSETS_DIR, "cube.obj")
EMPTY_FILE = os.path.join(ASSETS_DIR, "empty.obj")

@pytest.fixture(autouse=True)
def setup_and_teardown():
    if os.path.exists(TEST_OUTPUT_DIR):
        shutil.rmtree(TEST_OUTPUT_DIR)
    os.makedirs(TEST_OUTPUT_DIR)
    yield

def run_generator_to_completion(generator):
    final_result = None
    for result in generator:
        final_result = result
    return final_result

def test_happy_path_successful_processing():
    output_file = os.path.join(TEST_OUTPUT_DIR, "cube.dxf")
    generator = create_layered_curves_dxf(VALID_FILE, output_file, num_layers=5)
    final_status = run_generator_to_completion(generator)
    assert final_status["status"] == "complete"
    assert os.path.exists(output_file)

@patch('trimesh.Trimesh.section', autospec=True)
def test_partial_slicing_failure_completes_with_warnings(mock_section):
    output_file = os.path.join(TEST_OUTPUT_DIR, "partial.dxf")
    call_counter = {"count": 0}

    # FIX: Use 5+ points so scipy's splprep (m > k) doesn't fail
    fake_path = MagicMock()
    fake_path.discrete = [np.array([[0,0], [1,0], [1,1], [0,1], [0,0]])]

    fake_planar = MagicMock()
    fake_planar.discrete = fake_path.discrete
    fake_section = MagicMock()
    fake_section.to_planar.return_value = (fake_planar, None)

    def side_effect(self, *args, **kwargs):
        call_counter["count"] += 1
        return fake_section if call_counter["count"] <= 3 else None

    mock_section.side_effect = side_effect

    generator = create_layered_curves_dxf(VALID_FILE, output_file, num_layers=10)
    final_status = run_generator_to_completion(generator)

    assert final_status["status"] == "complete"
    assert "skipped" in final_status["message"] or "successfully" in final_status["message"]
    assert os.path.exists(output_file)

@patch('trimesh.Trimesh.section', return_value=None)
def test_total_slicing_failure_fails_job(mock_section):
    output_file = os.path.join(TEST_OUTPUT_DIR, "total_fail.dxf")
    generator = create_layered_curves_dxf(VALID_FILE, output_file, num_layers=5)
    final_status = run_generator_to_completion(generator)
    assert final_status["status"] == "failed"
    assert not os.path.exists(output_file)