import argparse, pathlib, subprocess, sys
from wand.image import Image

supported_glob = "[jpJP][npNP][egEG]"

def sanity_check_system():
	r = subprocess.call("magick -version", shell=True) == 0
	if not r:
		sys.exit("ImageMagick not installed. Aborting...")

def parse_format(format_str):
	fmt = format_str.lower()
	if 'x' in fmt:
		w_h = fmt.split('x')
		w = int(w_h[0]) if w_h[0] != '' else 0
		h = int(w_h[1]) if w_h[1] != '' else 0
		return(w, h, fmt)
	return (None, None, None)

def convert(filepath : pathlib.Path, fmt : tuple, output_dir: pathlib.Path):
	(w, h, f) = fmt	

	# img exists?
	output = output_dir / filepath.name
	if output.exists() and output.is_file():
		with Image(filename=str(output)) as img:
			if w > 0 and img.width == w or h > 0 and img.height == h:				
				return output

	with Image(filename=str(filepath)) as img:
		print(f". converting {filepath}")
		print(f"	> {img.size}")
		img.resolution = (72, 72)
		if w > 0 and img.width > w or h > 0 and img.height > h:
			img.transform(resize=f)		
		print(f"	> {img.size}")
		img.save(filename=str(output))
		return output

def convert_all(input_dir: pathlib.Path, fmt : tuple, output_dir: pathlib.Path):
	img_files = input_dir.glob("*." + supported_glob + "*")
	for i in img_files:
		convert(i, fmt, output_dir)	

if __name__ == '__main__':

	p = argparse.ArgumentParser(description='Converts images files to other formats (using wand/ImageMagick)');
	p.add_argument('-i', '--input', help='input directory');
	p.add_argument('-o', '--output', help='output directory');
	p.add_argument('-f', '--format', help='output formats (ex. 1000x)');

	sanity_check_system()

	args = p.parse_args()

	if not args.format:
		sys.exit("No formats specified. Aborting.")

	input_dir = pathlib.Path(".")
	if args.input: 
		input_dir = pathlib.Path(args.input)

	if not input_dir.exists() or not input_dir.is_dir():
		sys.exit(f"Input {str(input_dir)} is not a directory. Aborting.")

	output_dir = input_dir / "img-resize"
	if args.output: 
		output_dir = pathlib.Path(args.output)
	
	output_dir.mkdir(parents=True, exist_ok=True)

	(w, h, fmt) = parse_format(args.format)
	if not fmt:
		sys.exit(f"Format {str(args.format)} is not valid. Aborting.")		

	img_files = input_dir.glob("*." + supported_glob + "*")
	for i in img_files:
		convert(i, (w, h, fmt), output_dir)