import glob
from PIL import Image, ImageStat
from iteration_utilities import duplicates
from pathlib import Path
import json
import os
import pytest


def validate_brightness_image(working_path, theme_config, high_light, image_list, brightness_way):
	image_pattern = theme_config.get("imageFilename")
	image_filenames = {}.fromkeys(glob.glob(str(Path(working_path, image_pattern))))
	# generate an image statistics for each images
	for an_imagefile in image_filenames:
		this_image = Image.open(an_imagefile).convert("L")
		this_image_stats = ImageStat.Stat(this_image)
		image_filenames[an_imagefile] = this_image_stats.mean[0]

	# get the brightest observed image from the list
	if high_light == "dayHighlight":
		actual_est_image = max(image_filenames, key=lambda key: image_filenames[key])
	else:
		actual_est_image = min(image_filenames, key=lambda key: image_filenames[key])

	# get the brightest referenced image OR in the daylist to compare to
	if theme_config.get(high_light):
		an_image = image_pattern.replace("*", str(theme_config.get(high_light)))
		ref_est_file = str(Path(working_path, an_image))
		assert actual_est_image == ref_est_file, f"✖ {brightness_way} image is {actual_est_image}, but the {high_light} image is {ref_est_file}."
	else:
		# if not highlight is given in theme.json, we suppose that brightest images are in the daylist
		ref_est_files = []
		for an_id in theme_config.get(image_list):
			an_image = image_pattern.replace('*', str(an_id))
			ref_est_files.append(str(Path(working_path, an_image)))
		assert actual_est_image in ref_est_files, f"✖ {brightness_way} image {actual_est_image} was not found in the '{image_list}' attribute."


@pytest.fixture
def working_path():
	# get the global variables containing gitlab-given project slug.
	project_slug = os.environ["PACKAGE_NAME"]
	root_folder = os.environ["ENTRY_FOLDER"]
	working_path = Path(root_folder, project_slug)
	if not working_path.is_dir():
		raise FileNotFoundError(f"No project found for the given {working_path}.")
	return working_path


@pytest.fixture
def manifest(working_path):
	with open(Path(working_path, "theme.json"), 'r') as fileobj:
		return json.load(fileobj)


def test_brightest_image(working_path, manifest):
	validate_brightness_image(working_path, manifest, "dayHighlight", "dayImageList", "Brightest")


def test_darkest_image(working_path, manifest):
	validate_brightness_image(working_path, manifest, "nightHighlight", "nightImageList", "Darkest")


def test_image_size(working_path, manifest):
	image_filename = manifest["imageFilename"].replace("*", str(manifest["dayImageList"][0]))
	w, h = Image.open(Path(working_path, image_filename)).size
	assert w >= 1920 and h >= 1080, f"✖ Image size is too small (must be at least 1920×1080, is {w}×{h})"
	assert w >= h, "✖ Image orientation is portrait (must be landscape or square)"

def test_overlapping_images(manifest):
	jointed_lists = manifest.get("dayImageList")
	jointed_lists.extend(manifest.get("nightImageList"))
	jointed_lists.extend(manifest.get("sunriseImageList", []))
	jointed_lists.extend(manifest.get("sunsetImageList", []))

	dup_refs = list(duplicates(jointed_lists))
	str_dup_refs = [manifest["imageFilename"].replace("*", str(int)) for int in dup_refs]
	separator = ", "

	assert not dup_refs, f"✖ Some images are referenced twice or more: {separator.join(str_dup_refs)}."