#!/usr/bin/python

import re
import subprocess
import sys
from math import floor
from os import path
from os import remove
from pydoc import pipepager

from time import sleep

# Configurations

max_file_size_display_width = 9 # For displaying file size in KB
col_spacing = 3 # Column spacing for files list

# Functions

def find_files_in_dir(dir, ext):
     found = subprocess.check_output(["find", dir, "-type", "f", "-name", '*.' + ext])
     return found.rstrip("\n").split("\n")

def fit_string_in_terminal_width(string, reserved_space=0):
    """Adjusts string to fit in terminal, taking into account reserved space"""
    string_width_available = int(subprocess.check_output(["stty", "size"]).split()[1]) - reserved_space

    if(len(string) > string_width_available):
        truncate_filler = '...'
        half_string_width = int(floor(string_width_available/2))
        string = string[0 : half_string_width - len(truncate_filler)] + truncate_filler + string[-half_string_width:]

    return string.ljust(string_width_available)

if len(sys.argv) != 2:
    print "Usage: %s <audio_dir>" % sys.argv[0]
    exit(1)

audio_dir = sys.argv[1]

if not path.isdir(audio_dir):
    print "No such directory: %s" % audio_dir
    exit(1)

audio_dir = path.join(audio_dir, '')

# Find FLACs and mp3s in the given audio_dir
mp3s = find_files_in_dir(dir=audio_dir, ext='mp3')
flacs = find_files_in_dir(dir=audio_dir, ext='flac')

# Intersect the lists of FLACs/mp3s to find unnecessary flacs
mp3s_noext  = [re.sub(".mp3$", "", mp3) for mp3 in mp3s]
flacs_noext = [re.sub(".flac$", "", flac) for flac in flacs]

files_found_noext = list(set(mp3s_noext) & set(flacs_noext))

if len(files_found_noext) == 0:
    print "No unnecessary FLACs found"
    exit(0)

# Prepare a list of mp3s names/sizes for the user to check
mp3s_to_check = [
    file.replace(audio_dir, '') + '.mp3'
    for file in files_found_noext
]
mp3s_to_check.sort()
space_outside_file_name = max_file_size_display_width + col_spacing * 2
col_spacer = ' ' * col_spacing

verify_dialog  = "\033[95mPossibly unnecessary FLACs found for the following mp3s\033[0m\n\033[95mPlease double-check and hit 'q' when done\033[0m\n\n"
verify_dialog += fit_string_in_terminal_width("FILENAME", space_outside_file_name) + col_spacer + "SIZE (KB)\n"

for file_name in mp3s_to_check:
    file_name_ascii = ''.join([i if ord(i) < 128 else ' ' for i in file_name]) # Strip non-ASCII chars to make displaying consistent
    file_name_fit = fit_string_in_terminal_width(file_name_ascii, space_outside_file_name)
    file_size_fit = str(path.getsize(audio_dir + file_name) / 1000).rjust(max_file_size_display_width)
    verify_dialog += file_name_fit + col_spacer + file_size_fit + "\n"

# Output list for user to check
pipepager(verify_dialog, cmd='less -R')

# Prompt for deletion of files
files_found_count = len(files_found_noext)
print "\nDelete %d FLAC(s) [y/N]? :" % files_found_count,

if raw_input().lower() != 'y':
    print "Exiting: cold feet"
    exit(0)

# Delete unnecessary FLACs
for index, file_name_noext in enumerate(files_found_noext):
    print "\rDeleting FLAC %d/%d" % (index+1, files_found_count),
    remove(file_name_noext + '.flac')

print "\nAll done."