#!/usr/bin/env python3
# SPDX-License-Identifier: BSD-3-Clause

from os import path
import sys
import glob
import struct
import png


class Graphic(object):
    def __init__(self, filepath):
        self.filepath = filepath
        self.filename = path.split(filepath)[1]
        self.name = path.splitext(self.filename)[0].upper().replace("^", "\\")
        self.has_offset = False
        self.get_png_offset()

    def get_png_offset(self):
        reader = png.Reader(file=open(self.filepath, "rb"))
        for chunk in reader.chunks():
            if chunk[0] == "grAb":
                self.xoffset, self.yoffset = struct.unpack(">ii", chunk[1])
                self.has_offset = True


def main():
    dirname = path.split(path.abspath(__file__))[0]
    graphics = []
    files = []
    if len(sys.argv) < 2:
        print(
            'This script takes the offsets stored in the "grAb" chunk of '
            + "the specified PNGs and adjusts the graphics offsets in the build_cfg file.\n"
        )
        print("Usage:\n\t fix-sprite-offsets <names> [names] [...]\n")
        print(
            "example: \n\tfix-sprite-offsets sprites/vilea1.png sprites/vileb1.png"
        )
        print("You can also use wildcards:")
        print("\t fix-sprite-offsets sprites/vile*.png")
        exit()
    else:
        for param in sys.argv[1:]:
            files.append(dirname + "/../" + param)

    for filepath in files:
        if not path.isfile(filepath):
            print("Could not find" + filepath + ", skipping...")
        elif path.splitext(filepath)[1] == ".png":
            graphics.append(Graphic(filepath))
    for graphic in graphics:
        if graphic.has_offset == False:
            graphics.remove(graphic)
    f = open(dirname + "/../buildcfg.txt", "r")
    lines = f.readlines()
    f.close()
    newlines = []
    for line in lines:
        replaced_line = False
        for graphic in graphics:
            if graphic.has_offset is True:
                thing = line.split()
                if len(thing) > 0 and thing[0] == graphic.name:
                    new_string = "%s\t%i\t%i" % (
                        graphic.name,
                        graphic.xoffset,
                        graphic.yoffset,
                    )
                    comments = line.split(";")
                    if len(comments) > 1:
                        new_string += "\t;" + "".join(comments[1:])
                    else:
                        new_string += "\n"
                    newlines.append(new_string)
                    replaced_line = True
                    print("Updated " + graphic.name + " offsets")
                    break
        if replaced_line is False:
            newlines.append(line)
    f = open(dirname + "/../buildcfg.txt", "w")
    f.writelines(newlines)
    f.close()


if __name__ == "__main__":
    main()