import argparse
import os
import random

import xml.etree.ElementTree as ET

ALLOWED_EXTENSIONS = [".jpg", ".jpeg", ".png"]
DEFAULT_DURATION = 120
DEFAULT_TRANSITION_DURATION = 0.5
GNOME_BACKGROUNDS_PATH = "$HOME/.local/share/gnome-background-properties"

def getFiles(path : str, recursive : bool) -> list:
    files = []
    with os.scandir(path) as it:
        for entry in it:
            if entry.is_file():
                if (os.path.splitext(entry.name)[1] in ALLOWED_EXTENSIONS):
                    files.append(f"{path}/{entry.name}")
            elif entry.is_dir() and recursive:
                files.append(getFiles(f"{path}/{entry.name}"))

    return files

def main():
    parser = argparse.ArgumentParser(description="Generate the XML files required to add a slideshow of images to GNOME desktop.")
    parser.add_argument("path", metavar="PATH", type=str, help="Path to the images directory to create a slideshow for")
    parser.add_argument("--recursive", "-r", action="store_true", help="Recursively search subdirectories for images")
    parser.add_argument("--name", "-n", type=str, help="Name of the slideshow")
    parser.add_argument("--xmlpath", type=str, help="Path to save the XML file containing the list of image files. (default: stored in the images folder)")
    parser.add_argument("--duration", "-d", type=int, help=f"Duration between each image in seconds (default: {DEFAULT_DURATION})")
    parser.add_argument("--transduration", "-t", type=int, help=f"Duration of transition between images (default: {DEFAULT_TRANSITION_DURATION})")
    parser.add_argument("-s", "--shuffle", action="store_true", help="Turn on shuffling of images")

    args = parser.parse_args()

    imagepath = os.path.abspath(args.path)
    xmlpath = args.xmlpath
    slideshowname = args.name
    recursive = args.recursive
    duration = args.duration
    transduration = args.transduration
    shuffle = args.shuffle

    gnomepath = os.path.abspath(os.path.expandvars(GNOME_BACKGROUNDS_PATH))

    if slideshowname == None:
        slideshowname = os.path.dirname(imagepath).split("/")[-1]

    if xmlpath == None:
        xmlpath = imagepath + f"/{slideshowname}.xml"

    if duration == None:
        duration = DEFAULT_DURATION

    if transduration == None:
        transduration = DEFAULT_TRANSITION_DURATION

    print(f"imagepath    : {imagepath}")
    print(f"xmlpath      : {xmlpath}")
    print(f"slideshowname: {slideshowname}")
    print(f"recursive    : {recursive}")
    print(f"duration     : {duration}")
    print(f"transduration: {transduration}")

    files = getFiles(imagepath, recursive)

    if shuffle:
        random.shuffle(files)

    if not os.path.exists(gnomepath):
        os.makedirs(gnomepath)

    with open(f"{gnomepath}/{slideshowname}.xml", "wb") as xmlfile:
        # Generate XML file
        wallpapers = ET.Element("wallpapers")
        wallpaper = ET.SubElement(wallpapers, "wallpaper", {
            "deleted": "false"
        })

        name = ET.SubElement(wallpaper, "name")
        name.text = slideshowname

        filename = ET.SubElement(wallpaper, "filename")
        filename.text = xmlpath

        options = ET.SubElement(wallpaper, "options")
        options.text = "zoom"

        xmlfile.write('<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE wallpapers SYSTEM "gnome-wp-list.dtd">'.encode("UTF-8"))

        xmlfile.write(ET.tostring(wallpapers))

    with open(xmlpath, "wb") as xmlfile:
        background = ET.Element("background")

        for i in range(len(files)):
            file = files[i]

            tofile = files[(i + 1) % len(files)]
            fromfile = file

            static = ET.SubElement(background, "static")
            durationelement = ET.SubElement(static, "duration")
            durationelement.text = str(duration)
            fileelement = ET.SubElement(static, "file")
            fileelement.text = file

            transition = ET.SubElement(background, "transition")
            transdurationelement = ET.SubElement(transition, "duration")
            transdurationelement.text = str(transduration)
            fromelement = ET.SubElement(transition, "from")
            fromelement.text = fromfile
            toelement = ET.SubElement(transition, "to")
            toelement.text = tofile

        xmlfile.write('<?xml version="1.0" ?>'.encode("UTF-8"))

        xmlfile.write(ET.tostring(background))







if __name__ == "__main__":
    main()