from typing import List
import os
import shutil
import subprocess

class ImageProcessor:
	def __init__(self, public_dir: str, *lookup_dirs: List[str]):
		self.public_dir = public_dir
		self.lookup_dirs = lookup_dirs
		if not os.path.exists(self.public_dir):
			os.mkdir(self.public_dir)

	def process_image(self, input_filename: str, format: str, relative=True, width: int=None, height:int=None, quality: int=None, dpi: int=None) -> str:
		name = os.path.basename(input_filename)
		base, ext = os.path.splitext(name)
		ext = ext[1:]
		full_path = self.find_image(input_filename)
		if full_path is None:
			raise FileNotFoundError(f'Image {input_filename} not found.')
		
		suffix = ""
		geometry = None
		if width is not None or height is not None:
			geometry = f'{width if width is not None else ""}x{height if height is not None else ""}'
			suffix += "_"+geometry
		if quality is not None:
			suffix += f'_q{quality}'
		if quality is not None:
			suffix += f'_d{dpi}'
		target_name = base+suffix+"."+format
		target_path = self.public_dir + "/" + target_name
		
		if not os.path.isfile(target_path):
			if (((ext == format and width)
		     or (ext == "epdf" and format == "pdf")
			 or (ext == "jpg" and format == "jpeg"))
			 and width is None and height is None and quality is None and dpi is None):
				shutil.copyfile(full_path, target_path)

			elif self.find_image(target_name):
				shutil.copyfile(self.find_image(target_name), target_path)

			elif ext == "svg":
				width_arg = ['--export-width', str(width)] if width is not None else []
				height_arg = ['--export-height', str(height)] if height is not None else []
				dpi_arg = ['--export-dpi', str(dpi)] if dpi is not None else []
				if subprocess.run(['inkscape', full_path, '-o', target_path, *width_arg, *height_arg, *dpi_arg]).returncode != 0:
					raise Exception(f"Could not convert '{full_path}' to '{format}'")

			else:
				resize_arg = ['-resize', str(geometry)] if geometry is not None else []
				density_arg = ['-density', str(dpi)] if dpi is not None else []
				quality_arg = ['-quality', str(quality)] if quality is not None else []
				if subprocess.run(['convert', full_path, *resize_arg, *density_arg, *quality_arg, target_path]).returncode != 0:
					raise Exception(f"Could not convert '{full_path}' to '{format}'")

		return target_name if relative else target_path


			

	def find_image(self, input_filename) -> str:
		for dir in self.lookup_dirs:
			if os.path.isfile(dir + "/" + input_filename):
				return dir + "/" + input_filename