import os
from pathlib import Path
import tqdm
import multiprocessing.pool
import subprocess
from itertools import chain

import pytest

from .image_support import ImageDifference, run_cargo_cmd, ImageSupport


@pytest.fixture
def kicad_container(request):
    return request.config.kicad_container


@pytest.fixture()
def kicad_footprints_libdir(request):
    return request.config.kicad_footprints_libdir


@pytest.fixture()
def kicad_symbols_libdir(request):
    return request.config.kicad_symbols_libdir


@pytest.fixture()
def img_support(request):
    return request.config.image_support


def pytest_assertrepr_compare(op, left, right):
    if isinstance(left, ImageDifference) or isinstance(right, ImageDifference):
        diff = left if isinstance(left, ImageDifference) else right
        return [
            f'Image difference assertion failed.',
            f'    Calculated difference: {diff}',
            f'    Histogram: {diff.histogram}', ]


# store report in node object so tmp_gbr can determine if the test failed.
@pytest.hookimpl(tryfirst=True, hookwrapper=True)
def pytest_runtest_makereport(item, call):
    outcome = yield
    rep = outcome.get_result()
    setattr(item, f'rep_{rep.when}', rep)


fail_dir = Path('gerbonara_test_failures')
def pytest_sessionstart(session):
    if 'PYTEST_XDIST_WORKER' in os.environ: # only run this on the controller
        return

    for f in chain(fail_dir.glob('*.gbr'), fail_dir.glob('*.png')):
        f.unlink()

    try:
        run_cargo_cmd('resvg', '--help', stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)
    except FileNotFoundError:
        pytest.exit('resvg binary not found, aborting test.', 2)


def _update_repo_cache(lib_dir, repo_url, tag):
    if not lib_dir.is_dir():
        print(f'Checking out KiCad footprint repo tag {tag}')
        subprocess.run(['git', '-c', 'advice.detachedHead=false', 'clone', '--branch', tag, '--depth', '1', repo_url, str(lib_dir)], check=True)
    else:
        print(f'Found cached KiCad footprint checkout, updating to {tag}')
        subprocess.run(['git', '-C', str(lib_dir), 'fetch', '--depth', '1', 'origin', tag], check=True)
        subprocess.run(['git', '-c', 'advice.detachedHead=false', '-C', str(lib_dir), 'reset', '--hard', tag], check=True)
        subprocess.run(['git', '-C', str(lib_dir), 'clean', '--force', '-d', '-x'], check=True)


def pytest_addoption(parser):
    parser.addini('kicad_footprints_tag', 'git tag or branch for KiCad footprint library repo used as testdata', default='main')
    parser.addini('kicad_symbols_tag', 'git tag or branch for KiCad symbol library repo used as testdata', default='main')
    parser.addini('kicad_container_tag', 'docker hub tag for the KiCad container to use for exporting footprint images', default='main')


def pytest_configure(config):
    os.nice(20)
    # Resvg can sometimes consume a lot of memory. Make sure we don't kill the user's session.
    if (oom_adj := Path('/proc/self/oom_adj')).is_file():
        oom_adj.write_text('15\n')

    if 'PYTEST_XDIST_WORKER' in os.environ: # only run this on the controller
        return

    if (lib_dir := os.environ.get('KICAD_FOOTPRINTS')):
        config.kicad_footprints_libdir = Path(lib_dir).expanduser()
    else:
        config.kicad_footprints_libdir = config.cache.mkdir('kicad-footprints') / 'repo'

    if (lib_dir := os.environ.get('KICAD_SYMBOLS')):
        config.kicad_symbols_libdir = Path(lib_dir).expanduser()
    else:
        config.kicad_symbols_libdir = config.cache.mkdir('kicad-symbols') / 'repo'

    # Update cached library repos unless they are overridden from outside.
    if not os.environ.get('KICAD_FOOTPRINTS'):
        tag = config.getini('kicad_footprints_tag')
        _update_repo_cache(config.kicad_footprints_libdir, 'https://gitlab.com/kicad/libraries/kicad-footprints', tag)

    if not os.environ.get('KICAD_SYMBOLS'):
        tag = config.getini('kicad_symbols_tag')
        _update_repo_cache(config.kicad_symbols_libdir, 'https://gitlab.com/kicad/libraries/kicad-symbols', tag)

    print('Updating podman image')
    tag = config.getini("kicad_container_tag")
    config.kicad_container = os.environ.get('KICAD_CONTAINER', f'registry.hub.docker.com/kicad/kicad:{tag}')
    subprocess.run(['podman', 'pull', config.kicad_container], check=True)

    config.image_support = ImageSupport(config.cache.mkdir('image_cache'), config.kicad_container)
    print('Checking KiCad footprint library render cache')
    with multiprocessing.pool.ThreadPool() as pool: # use thread pool here since we're only monitoring podman processes 
        lib_dirs = list(config.kicad_footprints_libdir.glob('*.pretty'))
        res = list(tqdm.tqdm(pool.imap(lambda path: config.image_support.bulk_populate_kicad_fp_export_cache(path), lib_dirs), total=len(lib_dirs)))


def pytest_generate_tests(metafunc):
    if 'kicad_library_file' in metafunc.fixturenames:
        library_files = list(kicad_symbols_libdir(metafunc.config).glob('*.kicad_sym'))
        metafunc.parametrize('kicad_library_file', library_files, ids=list(map(str, library_files)))

    if 'kicad_mod_file' in metafunc.fixturenames:
        mod_files = list(kicad_footprints_libdir(metafunc.config).glob('*.pretty/*.kicad_mod'))
        metafunc.parametrize('kicad_mod_file', mod_files, ids=list(map(str, mod_files)))