import sys
import os
import argparse
from PIL import Image
from PIL.ExifTags import TAGS, GPSTAGS
from PIL import UnidentifiedImageError
import csv
import simplekml


def summarized_output(image_list, outputfile):
    # File to be written to containing csv data of images
    heading = ['imagename', 'latitude', 'longitude', 'altitude']

    # catch open failing (move to main?)
    f = open(outputfile, 'w')

    writer = csv.writer(f)

    # Image processing begins here
    for each in os.listdir(image_list):
        filename = os.path.basename(each)
        filename = os.path.join(image_list, filename)
        try:
            new_image = Image.open(filename)
            exifdata = new_image._getexif()
            exifdata_cp = tuple(exifdata.keys())
            if exifdata is not None:
                for key in exifdata_cp:
                    Name = TAGS.get(key, key)
                    exifdata[Name] = exifdata.pop(key)

            if 'GPSInfo' in exifdata:
                GPSInfo_keys = tuple(exifdata['GPSInfo'].keys())
                for key in GPSInfo_keys:
                    Name = GPSTAGS.get(key, key)
                    exifdata['GPSInfo'][Name] = exifdata['GPSInfo'].pop(key)
            else:
                print("{} Image has no GPS exif data and will be skipped".format(filename))
                continue

            #Calculation to decimal for Latitude
            if 'GPSLatitude' in exifdata['GPSInfo'] and 'GPSLatitudeRef' in exifdata['GPSInfo']:
                e = exifdata['GPSInfo']['GPSLatitude']
                ref = exifdata['GPSInfo']['GPSLatitudeRef']
                degrees = e[0]
                minutes = e[1] / 60.0
                seconds = e[2] / 3600.0
                Latitude = round(degrees + minutes + seconds, 6)

            #Checking for neccessity of negative if South
            if exifdata['GPSInfo']['GPSLatitudeRef'] == 'S':
                Latitude = Latitude * -1


            #Calculation to decimal for Longitude
            if 'GPSLongitude' in exifdata['GPSInfo'] and 'GPSLongitudeRef' in exifdata['GPSInfo']:
                e = exifdata['GPSInfo']['GPSLongitude']
                ref = exifdata['GPSInfo']['GPSLongitudeRef']
                degrees = e[0]
                minutes = e[1] / 60.0
                seconds = e[2] / 3600.0
                Longitude = round(degrees + minutes + seconds, 6)

            #Checking for neccessity of negative if West
            if exifdata['GPSInfo']['GPSLongitudeRef'] == 'W':
                Longitude = Longitude * -1


            #Adding Altitude to the mix of data
            if 'GPSAltitude' in exifdata['GPSInfo']:
                Altitude = exifdata['GPSInfo']['GPSAltitude']
            else:
                Altitude = 'N/A'

            #Writing new line of data to file
            data = [filename, Latitude, Longitude, Altitude]
            writer.writerow(data)
        except:
            print("couldn't open this image: ", filename)
    f.close()

if __name__=="__main__":
    parser = argparse.ArgumentParser(description='Provides CSV output of longitude, latitude and altitude of image')
    parser.add_argument('-i', '--inputfiles', nargs='+', type=str, help='Path to images')
    parser.add_argument('-o', '--outputfilename', type=str, help='CSV/KML file name to store output')
    args = parser.parse_args()
    if args.inputfiles is None:
        print("Error, no input files were provided.")
        exit(-1)

    if args.outputfilename is None:
        print("Error, no output file was provided.")
        exit(-1)

    directory = args.inputfiles[0]
    for filename in os.listdir(directory):
        f = os.path.join(directory, filename)
        if not(os.path.isfile(f)):
            print("Error, summarize-images.py. File", everyfile, "does not exist, is not readable, etc.", file=sys.stderr)
            exit(-1)
    if args.outputfilename.endswith("kml"):
        summarized_output(directory, args.outputfilename.replace("klm", "csv"))
        inputfile = csv.reader(open(args.outputfilename.replace("klm", "csv"),'r'))
        kml=simplekml.Kml()
        for row in inputfile:
            kml.newpoint(name=row[0], coords=[(row[2],row[1])])
        if os.path.isfile(args.outputfilename):
            os.remove(args.outputfilename)
        kml.save(args.outputfilename)
    elif args.outputfilename.endswith("csv"):
        if os.path.isfile(args.outputfilename):
            os.remove(args.outputfilename)
        summarized_output(directory, args.outputfilename)
    else:
        print("Error, please provide a valid output format (.csv or .kml)", file=sys.stderr)
        exit(-1)

    exit(0)