# Author: Guillaume Lambany
# Email: GLAMBANY@GMAIL.COM
# Date: 2016-06-09
# Final format needed:  2016\05\2016_05_29\20160529223016_0001.jpg
#                       YYYY\MM\YYYY_MM_DD\YYYYMMDDHHMMSS_COUNT.jpg
# This script needs exiftool.exe to work properly
# 'SRCPATH' and 'EXIFTOOL' constants needs to be set properly
# very important: rename exiftool(-k).exe to exiftool.exe

#import dependencies
import subprocess, sys, json
from os import listdir, rename, path, makedirs

#Total Character size of the incrementing number, at the end of the destination filename.
ZEROPAD = 4

#Source Path to process. Don't forget the "/" at the end
SRCPATH = 'C:/Photos/'

#EXIFTOOL location
EXIFTOOL = 'C:/apps_local/exiftool.exe'

#function that return a list of files in a given path
def list_files(pathname):
    # return empty array if folder doesn't exists
    if not path.exists(pathname):
        return []

    # returns a list of names (with extension, without full path) of all files in folder path
    files = []
    for name in listdir(pathname):
        if path.isfile(path.join(pathname, name)):
            files.append(name)
    return files

# Test if the source directory exists
if not path.exists(SRCPATH):
    print 'No such Path exists: ' + SRCPATH
    quit()

#Query exiftool for metadata
exifTl_Proc = subprocess.Popen(EXIFTOOL + ' -fast -json -DateTimeOriginal -CreateDate -ext jpg -ext jpeg -ext mp4 -ext mp4 ' + SRCPATH, stdin=subprocess.PIPE, stdout=subprocess.PIPE, shell=False)
exifTl_outRaw = exifTl_Proc.communicate()[0]
exifTl_RetCode = exifTl_Proc.returncode
exifTl_Proc.terminate()

#debug
#print exifTl_outRaw

#Verify if exiftool ran properly
if exifTl_RetCode == 0 and len(exifTl_outRaw) > 0:
    exifTl_outJson = json.loads(exifTl_outRaw)
else:
    print 'Error running EXIFTOOL. ReturnCode = ' + str(exifTl_RetCode)
    quit()

# Run through all the output data from exiftool
for exifTl_Dict in exifTl_outJson:
    sourceFile = exifTl_Dict['SourceFile']
    if 'DateTimeOriginal' in exifTl_Dict.keys():
        imgDateTimeRaw = exifTl_Dict['DateTimeOriginal']
    elif 'CreateDate' in exifTl_Dict.keys():
        imgDateTimeRaw = exifTl_Dict['CreateDate']
    else:
        #error, tags not found
        print 'Metadata tags not found (CreateDate or DateTimeOriginal) in file: ' + sourceFile
        continue

    #debug
    #print imgDateTimeRaw

    imgDate = imgDateTimeRaw.split(' ')[0].split(':')
    imgTime = imgDateTimeRaw.split(' ')[1].split(':')

    #debug
    #print sourceFile + ' DATE:' + '-'.join(imgDate) + ' TIME:' + ':'.join(imgTime)

    #Generate destination path
    dstPath = (SRCPATH +
                imgDate[0] + '/' + imgDate[1] + '/' +
                '_'.join(imgDate) + '/')

    # create the new folder if it doesn't already exists
    if not path.exists(dstPath):
        makedirs(dstPath)
        nbrFiles = 0
    else:
        # check number of files in the destination directory
        nbrFiles = len(list_files(SRCPATH + imgDate[0] + '/' + imgDate[1] + '/' + '_'.join(imgDate) + '/'))

    # the increment number that will be used in the final filename, starts at the number of files in the directory + 1
    countNumber = nbrFiles + 1

    # Increment the increment number until an unused filename is found
    while True:
        dstFile = (''.join(imgDate) +                           #YYYYMMDD
                    ''.join(imgTime) +                          #HHMMSS
                    "_{0:0>{1}}".format(countNumber, ZEROPAD) + #Increment number
                    path.splitext(sourceFile)[1])               #Extention

        #debug
        #print 'path+file::' + dstPath + '|' + dstFile

        #exit the loop if the new file name doesn't already exists
        if not path.isfile(dstPath + dstFile):
            break
        countNumber=+1

    # Move file to new folder
    rename(sourceFile, dstPath +  dstFile)