#! /usr/bin/env python
# -*- coding: utf-8 -*-
# Author: Jan Götte <code@jaseg.de>
import os
import re
import math
import functools
import tempfile
import shutil
from argparse import Namespace
from itertools import chain
from pathlib import Path
from contextlib import contextmanager
from PIL import Image

import pytest

from ..rs274x import GerberFile
from ..cam import FileSettings

from .image_support import *


deg_to_rad = lambda a: a/180 * math.pi

fail_dir = Path('gerbonara_test_failures')
reference_path = lambda reference: Path(__file__).parent / 'resources' / reference

def path_test_name(request):
    """ Create a slug suitable for use in file names from the test's nodeid """
    module, _, test_name = request.node.nodeid.rpartition('::')
    _test, _, test_name = test_name.partition('_')
    test_name, _, _ext = test_name.partition('.')
    return re.sub(r'[^\w\d]', '_', test_name)

@pytest.fixture
def print_on_error(request):
    messages = []

    def register_print(*args, sep=' ', end='\n'):
        nonlocal messages
        messages.append(sep.join(str(arg) for arg in args) + end)

    yield register_print

    if request.node.rep_call.failed:
        for msg in messages:
            print(msg, end='')

@pytest.fixture
def tmpfile(request):
    registered = []

    def register_tempfile(name, suffix):
        nonlocal registered
        f = tempfile.NamedTemporaryFile(suffix=suffix)
        registered.append((name, suffix, f))
        return Path(f.name)

    yield register_tempfile

    if request.node.rep_call.failed:
        fail_dir.mkdir(exist_ok=True)
        test_name = path_test_name(request)
        for name, suffix, tmp in registered:
            slug = re.sub(r'[^\w\d]+', '_', name.lower())
            perm_path = fail_dir / f'failure_{test_name}_{slug}{suffix}'
            shutil.copy(tmp.name, perm_path)
            print(f'{name} saved to {perm_path}')

    for _name, _suffix, tmp in registered:
        tmp.close()

@pytest.fixture
def reference(request, print_on_error):
    ref = reference_path(request.param)
    yield ref
    print_on_error(f'Reference file: {ref}')

def filter_syntax_warnings(fun):
    a = pytest.mark.filterwarnings('ignore:Deprecated.*statement found.*:DeprecationWarning')
    b = pytest.mark.filterwarnings('ignore::SyntaxWarning')
    return a(b(fun))

to_gerbv_svg_units = lambda val, unit='mm': val*72 if unit == 'inch' else val/25.4*72

REFERENCE_FILES = [ l.strip() for l in '''
    board_outline.GKO
    example_outline_with_arcs.gbr
    example_two_square_boxes.gbr
    example_coincident_hole.gbr
    example_cutin.gbr
    example_cutin_multiple.gbr
    example_flash_circle.gbr
    example_flash_obround.gbr
    example_flash_polygon.gbr
    example_flash_rectangle.gbr
    example_fully_coincident.gbr
    example_guess_by_content.g0
    example_holes_dont_clear.gbr
    example_level_holes.gbr
    example_not_overlapping_contour.gbr
    example_not_overlapping_touching.gbr
    example_overlapping_contour.gbr
    example_overlapping_touching.gbr
    example_simple_contour.gbr
    example_single_contour_1.gbr
    example_single_contour_2.gbr
    example_single_contour_3.gbr
    example_am_exposure_modifier.gbr
    bottom_copper.GBL
    bottom_mask.GBS
    bottom_silk.GBO
    eagle_files/copper_bottom_l4.gbr
    eagle_files/copper_inner_l2.gbr
    eagle_files/copper_inner_l3.gbr
    eagle_files/copper_top_l1.gbr
    eagle_files/profile.gbr
    eagle_files/silkscreen_bottom.gbr
    eagle_files/silkscreen_top.gbr
    eagle_files/soldermask_bottom.gbr
    eagle_files/soldermask_top.gbr
    eagle_files/solderpaste_bottom.gbr
    eagle_files/solderpaste_top.gbr
    multiline_read.ger
    test_fine_lines_x.gbr
    test_fine_lines_y.gbr
    top_copper.GTL
    top_mask.GTS
    top_silk.GTO
'''.splitlines() if l ]

MIN_REFERENCE_FILES = [
    'example_two_square_boxes.gbr',
    'example_outline_with_arcs.gbr',
    'example_flash_circle.gbr',
    'example_flash_polygon.gbr',
    'example_flash_rectangle.gbr',
    'example_simple_contour.gbr',
    'example_am_exposure_modifier.gbr',
    'bottom_copper.GBL',
    'bottom_silk.GBO',
    'eagle_files/copper_bottom_l4.gbr'
    ]

HAS_ZERO_SIZE_APERTURES = [
    'bottom_copper.GBL',
    'bottom_silk.GBO',
    'top_copper.GTL',
    'top_silk.GTO',
    'board_outline.GKO',
    'eagle_files/silkscreen_top.gbr',
    ]


@filter_syntax_warnings
@pytest.mark.parametrize('reference', REFERENCE_FILES, indirect=True)
def test_round_trip(reference, tmpfile):
    tmp_gbr = tmpfile('Output gerber', '.gbr')

    GerberFile.open(reference).save(tmp_gbr)

    mean, _max, hist = gerber_difference(reference, tmp_gbr, diff_out=tmpfile('Difference', '.png'))
    assert mean < 5e-5
    assert hist[9] == 0
    assert hist[3:].sum() < 5e-5*hist.size

TEST_ANGLES = [90, 180, 270, 30, 1.5, 10, 360, 1024, -30, -90]
TEST_OFFSETS = [(0, 0), (100, 0), (0, 100), (2, 0), (10, 100)]

@filter_syntax_warnings
@pytest.mark.parametrize('reference', MIN_REFERENCE_FILES, indirect=True)
@pytest.mark.parametrize('angle', TEST_ANGLES)
def test_rotation(reference, angle, tmpfile):
    if 'flash_rectangle' in str(reference) and angle == 1024:
        # gerbv's rendering of this is broken, the hole is missing.
        pytest.skip()

    tmp_gbr = tmpfile('Output gerber', '.gbr')

    f = GerberFile.open(reference)
    f.rotate(deg_to_rad(angle))
    f.save(tmp_gbr)

    cx, cy = 0, to_gerbv_svg_units(10, unit='inch')
    mean, _max, hist = gerber_difference(reference, tmp_gbr, diff_out=tmpfile('Difference', '.png'),
            svg_transform=f'rotate({angle} {cx} {cy})')
    assert mean < 1e-3 # relax mean criterion compared to above.
    assert hist[9] == 0

@filter_syntax_warnings
@pytest.mark.parametrize('reference', MIN_REFERENCE_FILES, indirect=True)
@pytest.mark.parametrize('angle', TEST_ANGLES)
@pytest.mark.parametrize('center', [(0, 0), (-10, -10), (10, 10), (10, 0), (0, -10), (-10, 10), (10, 20)])
def test_rotation_center(reference, angle, center, tmpfile):
    if 'flash_rectangle' in str(reference) and angle in (30, 1024):
        # gerbv's rendering of this is broken, the hole is missing.
        pytest.skip()

    tmp_gbr = tmpfile('Output gerber', '.gbr')

    f = GerberFile.open(reference)
    f.rotate(deg_to_rad(angle), center=center)
    f.save(tmp_gbr)

    # calculate circle center in SVG coordinates 
    size = (10, 10) # inches
    cx, cy = to_gerbv_svg_units(center[0]), to_gerbv_svg_units(size[1], 'inch')-to_gerbv_svg_units(center[1], 'mm')
    mean, _max, hist = gerber_difference(reference, tmp_gbr, diff_out=tmpfile('Difference', '.png'),
            svg_transform=f'rotate({angle} {cx} {cy})',
            size=size)
    assert mean < 1e-3
    assert hist[9] < 50
    assert hist[3:].sum() < 1e-3*hist.size

@filter_syntax_warnings
@pytest.mark.parametrize('reference', MIN_REFERENCE_FILES, indirect=True)
@pytest.mark.parametrize('offset', TEST_OFFSETS)
def test_offset(reference, offset, tmpfile):
    tmp_gbr = tmpfile('Output gerber', '.gbr')

    f = GerberFile.open(reference)
    f.offset(*offset)
    f.save(tmp_gbr, settings=FileSettings(unit=f.unit, number_format=(4,7)))

    # flip y offset since svg's y axis is flipped compared to that of gerber
    dx, dy = to_gerbv_svg_units(offset[0]), -to_gerbv_svg_units(offset[1])
    mean, _max, hist = gerber_difference(reference, tmp_gbr, diff_out=tmpfile('Difference', '.png'),
            svg_transform=f'translate({dx} {dy})')
    assert mean < 1e-4
    assert hist[9] == 0

@filter_syntax_warnings
@pytest.mark.parametrize('reference', MIN_REFERENCE_FILES, indirect=True)
@pytest.mark.parametrize('angle', TEST_ANGLES)
@pytest.mark.parametrize('center', [(0, 0), (10, 0), (0, -10), (10, 20)])
@pytest.mark.parametrize('offset', [(0, 0), (100, 0), (0, 100), (100, 100), (100, 10)])
def test_combined(reference, angle, center, offset, tmpfile):
    if 'flash_rectangle' in str(reference) and angle in (30, 1024):
        # gerbv's rendering of this is broken, the hole is missing.
        pytest.skip()

    tmp_gbr = tmpfile('Output gerber', '.gbr')

    f = GerberFile.open(reference)
    f.rotate(deg_to_rad(angle), center=center)
    f.offset(*offset)
    f.save(tmp_gbr, settings=FileSettings(unit=f.unit, number_format=(4,7)))

    size = (10, 10) # inches
    cx, cy = to_gerbv_svg_units(center[0]), to_gerbv_svg_units(size[1], 'inch')-to_gerbv_svg_units(center[1], 'mm')
    dx, dy = to_gerbv_svg_units(offset[0]), -to_gerbv_svg_units(offset[1])
    mean, _max, hist = gerber_difference(reference, tmp_gbr, diff_out=tmpfile('Difference', '.png'),
            svg_transform=f'translate({dx} {dy}) rotate({angle} {cx} {cy})',
            size=size)
    assert mean < 1e-3
    assert hist[9] < 100
    assert hist[3:].sum() < 1e-3*hist.size

@filter_syntax_warnings
@pytest.mark.parametrize('file_a', MIN_REFERENCE_FILES)
@pytest.mark.parametrize('file_b', [
    'example_two_square_boxes.gbr',
    'example_outline_with_arcs.gbr',
    'example_am_exposure_modifier.gbr',
    'bottom_silk.GBO',
    'eagle_files/copper_bottom_l4.gbr', ])
@pytest.mark.parametrize('angle', [0, 10, 90])
@pytest.mark.parametrize('offset', [(0, 0, 0, 0), (100, 0, 0, 0), (0, 0, 0, 100), (100, 0, 0, 100)])
def test_compositing(file_a, file_b, angle, offset, tmpfile, print_on_error):

    # TODO bottom_silk.GBO renders incorrectly with gerbv: the outline does not exist in svg. In GUI, the logo only
    # renders at very high magnification. Skip, and once we have our own SVG export maybe use that instead. Or just use
    # KiCAD's gerbview.
    # TODO check if this and the issue with aperture holes not rendering in test_combined actually are bugs in gerbv
    # and fix/report upstream.
    if file_a == 'bottom_silk.GBO' or file_b == 'bottom_silk.GBO':
        pytest.skip()

    ref_a = reference_path(file_a)
    print_on_error('Reference file a:', ref_a)
    ref_b = reference_path(file_b)
    print_on_error('Reference file b:', ref_b)

    ax, ay, bx, by = offset
    grb_a = GerberFile.open(ref_a)
    grb_a.rotate(deg_to_rad(angle))
    grb_a.offset(ax, ay)

    grb_b = GerberFile.open(ref_b)
    grb_b.offset(bx, by)

    grb_a.merge(grb_b)
    tmp_gbr = tmpfile('Output gerber', '.gbr')
    grb_a.save(tmp_gbr, settings=FileSettings(unit=grb_a.unit, number_format=(4,7)))

    size = (10, 10) # inches
    ax, ay = to_gerbv_svg_units(ax), -to_gerbv_svg_units(ay)
    bx, by = to_gerbv_svg_units(bx), -to_gerbv_svg_units(by)
    # note that we have to specify cx, cy even if we rotate around the origin since gerber's origin lies at (x=0
    # y=+document size) in SVG's coordinate space because svg's y axis is flipped compared to gerber's.
    cx, cy = 0, to_gerbv_svg_units(size[1], 'inch')
    mean, _max, hist = gerber_difference_merge(ref_a, ref_b, tmp_gbr,
            composite_out=tmpfile('Composite', '.svg'), diff_out=tmpfile('Difference', '.png'),
            svg_transform1=f'translate({ax} {ay}) rotate({angle} {cx} {cy})',
            svg_transform2=f'translate({bx} {by})',
            size=size)
    assert mean < 1e-3
    assert hist[9] < 100
    assert hist[3:].sum() < 1e-3*hist.size

@filter_syntax_warnings
@pytest.mark.parametrize('reference', REFERENCE_FILES, indirect=True)
def test_svg_export(reference, tmpfile):

    grb = GerberFile.open(reference)

    bounds = (0.0, 0.0), (6.0, 6.0) # bottom left, top right

    out_svg = tmpfile('Output', '.svg')
    with open(out_svg, 'w') as f:
        f.write(str(grb.to_svg(force_bounds=bounds, arg_unit='inch', color='white')))

    # NOTE: Instead of having gerbv directly export a PNG, we ask gerbv to output SVG which we then rasterize using
    # resvg. We have to do this since gerbv's built-in cairo-based PNG export has severe aliasing issues. In contrast,
    # using resvg for both allows an apples-to-apples comparison of both results.
    ref_svg = tmpfile('Reference export', '.svg')
    ref_png = tmpfile('Reference render', '.png')
    gerbv_export(reference, ref_svg, origin=bounds[0], size=bounds[1])
    svg_to_png(ref_svg, ref_png, dpi=72) # make dpi match Cairo's default

    out_png = tmpfile('Output render', '.png')
    svg_to_png(out_svg, out_png, dpi=72) # make dpi match Cairo's default

    mean, _max, hist = image_difference(ref_png, out_png, diff_out=tmpfile('Difference', '.png'))
    assert mean < 1e-3
    assert hist[9] < 1
    assert hist[3:].sum() < 1e-3*hist.size

# FIXME test svg margin, bounding box computation

@filter_syntax_warnings
@pytest.mark.parametrize('reference', REFERENCE_FILES, indirect=True)
def test_bounding_box(reference, tmpfile):
    # skip this check on files that contain lines with a zero-size aperture at the board edge
    if any(reference.match(f'*/{f}') for f in HAS_ZERO_SIZE_APERTURES):
        pytest.skip()

    # skip this file because it does not contain any graphical objects
    if reference.match('*/multiline_read.ger'):
        pytest.skip()

    margin = 1.0 # inch
    dpi = 200
    margin_px = int(dpi*margin) # intentionally round down to avoid aliasing artifacts

    grb = GerberFile.open(reference)
    out_svg = tmpfile('Output', '.svg')
    with open(out_svg, 'w') as f:
        f.write(str(grb.to_svg(margin=margin, arg_unit='inch', color='white')))

    out_png = tmpfile('Render', '.png')
    svg_to_png(out_svg, out_png, dpi=dpi)

    img = np.array(Image.open(out_png))
    img = img[:, :, :3].mean(axis=2) # drop alpha and convert to grayscale
    img = np.round(img).astype(int) # convert to int
    assert (img > 0).any() # there must be some content, none of the test gerbers are completely empty.
    cols = img.sum(axis=1)
    rows = img.sum(axis=0)
    col_prefix, col_suffix = np.argmax(cols > 0), np.argmax(cols[::-1] > 0)
    row_prefix, row_suffix = np.argmax(rows > 0), np.argmax(rows[::-1] > 0)

    # Check that all margins are completely black and that the content touches the margins. Allow for some tolerance to
    # allow for antialiasing artifacts.
    assert margin_px-1 <= col_prefix <= margin_px+1
    assert margin_px-1 <= col_suffix <= margin_px+1
    assert margin_px-1 <= row_prefix <= margin_px+1
    assert margin_px-1 <= row_suffix <= margin_px+1