#!/usr/bin/python3
__author__ = 'Dominik Krupke, dserv01.de'

#
# While you want to listen to lossless music on your computer you may not be able to also listen to it mobile because
# it takes too much space. A 32GB-SDCard does not suffice for your full music library so you only have the options to
# either only hearing to a subset mobile or converting the music to a lossy format. This script is for the second
# option.
# * Of course you don't want the lossy files on your computer because you already have your perfect lossless music there.
# * If you extend your music library you want a simple way to also have them mobile.
# * You don't want to convert already converted music twice
# This script synchronizes a lossless library folder (e.g. your music folder on your computer) to a lossy library
# folder (e.g. the music folder of your mobile device) by checking if for all music files in your lossless folder there
# is a converted version in your lossy folder. If this is not the case the file is converted. On the other side it
# checks if you still have the lossless file for each lossy file in your library, otherwise this file is removed (so
# removing a file from your lossless library also removes it from your lossy library)
#
# You can use your own commands for converting specific files. These commands have to convert a single file (check the
# commands-array).
#
# The configuration is done with the from_path and the to_path, as well as with the commands-array.


import os
import subprocess

##### CONFIGURATION ###########################################################################################

# This is the path of your lossless libray, e.g. '/home/YOURNAME/Music/'
FROM_PATH = '/home/glados/Music/HiFi/'
# This is the path of your lossy library, e.g. /mnt/SDCARD0/Music/'
TO_PATH = '/home/glados/Music/LoFi/'

# Use [INPUT] and [OUTPUT] to build your commands. Both will be replaced by the full path but without the file extension,
#   e.g. /home/doms/Music/Beethoven/FuerElise.flac -> /home/doms/Music/Beethoven/FuerElise
# You need to add the new and old fileextension for checking if the file is already converted and to remove old files
COMMANDS = [['flac', 'opus', 'opusenc --bitrate 72 [INPUT].flac [OUTPUT].opus'],
            ['mp3', 'opus', 'ffmpeg -i [INPUT].mp3 -c:v copy -f flac - | opusenc --bitrate 72 - [OUTPUT].opus'],
            ['m4a', 'opus', 'ffmpeg -i [INPUT].m4a -c:v copy -f flac - | opusenc --bitrate 72 - [OUTPUT].opus'],
            ['opus', 'opus', 'ffmpeg -i [INPUT].opus -c:v copy -f flac - | opusenc --bitrate 72 - [OUTPUT].opus'],
            ['jpg', 'jpg', 'cp [INPUT].jpg [OUTPUT].jpg'],
            ['png', 'jpg', 'convert [INPUT].png [OUTPUT].jpg']
            ]

# Remove files that are not in the original library
SYNC_DELETIONS = True
ASK_BEFORE_DELETE = False

###############################################################################################################

# Check path format
if (FROM_PATH[-1] != '/' or TO_PATH[-1] != '/'):
    exit(1)

# Create library paths if not existence
try:
    if (not os.path.exists(TO_PATH)):
        os.makedirs(TO_PATH)
    elif (os.path.isfile(TO_PATH)):
        raise Exception("Directory is file?!")
except Exception as e:
    exit(1)


# Create folders if not existing
def createFolder(subpath):
    if (os.path.exists(TO_PATH + subpath) and os.path.isdir(TO_PATH + subpath)):
        return True
    try:
        os.makedirs(TO_PATH + subpath)
        return True
    except Exception as e:
        return False


# Escape the paths for the os.system
def escapePath(s):
    return s.replace(" ", "\ ").replace(")", "\)").replace("(", "\(").replace("&", "\&").replace("'", "\\\'")


# Go through all files and convert
for root, dirs, files in os.walk(FROM_PATH, topdown=False):
    subpath = root[len(FROM_PATH):] + "/"

    if (createFolder(subpath)):
        for name in files:
            filename_without_extension = os.path.splitext(name)[0]
            file_extension = os.path.splitext(name)[1][1:]

            source_path_without_extension = FROM_PATH + subpath + filename_without_extension
            converted_path_without_extension = TO_PATH + subpath + filename_without_extension

            # Get command tripple - sure you can do this more efficient with a hashmap but there will only be a few entries
            command_tripple = None
            for tripple in COMMANDS:
                if (tripple[0] == file_extension):
                    command_tripple = tripple
                    break

            if (not command_tripple):
                continue

            source_path = source_path_without_extension + "." + command_tripple[0]
            goal_path = converted_path_without_extension + "." + command_tripple[1]
            if (os.path.isfile(source_path)):
                # If goal file does not exists or is older than source
                if (not os.path.exists(goal_path) or os.path.getctime(source_path) > os.path.getctime(goal_path)):
                    os.system(command_tripple[2].replace("[INPUT]", escapePath(source_path_without_extension)).replace(
                        "[OUTPUT]", escapePath(converted_path_without_extension)))

# Remove old files
if (SYNC_DELETIONS):
    for root, dirs, files in os.walk(TO_PATH, topdown=False):
        subpath = root[len(TO_PATH):] + "/"

        for name in files:
            filename_without_extension = os.path.splitext(name)[0]
            file_extension = os.path.splitext(name)[1][1:]

            source_path_without_extension = FROM_PATH + subpath + filename_without_extension
            converted_path_without_extension = TO_PATH + subpath + filename_without_extension

            original_exists = False
            for tripple in COMMANDS:
                if (tripple[1] == file_extension and os.path.exists(source_path_without_extension + "." + tripple[0])):
                    original_exists = True
                    break

            if (not original_exists):
                filepath_to_delete = escapePath(converted_path_without_extension) + "." + file_extension
                os.system("rm " + ("-i " if ASK_BEFORE_DELETE else "") + filepath_to_delete)

        # Remove old empty folders
        for folder in dirs:
            subpath = root[len(TO_PATH):] + "/"
            if not os.path.exists(FROM_PATH + subpath + folder):
                os.system("rmdir " + escapePath(TO_PATH + subpath + folder))