import exifread
import os
import pandas as pd


def convert_metatag_to_decimal(metatag_coordinate, direction_reference=None):
    """
    Converts funky exif number format to float number
    :param metatag_coordinate: Metatag coordinate (ie "[28, 120289/10000, 0]")
    :param direction_reference: "N", "S", "E", or "W"
    :return: float number
    """
    coordinate_list = str(metatag_coordinate)[1:-1].split(', ')
    decimal_coordinates = float(coordinate_list[0] + str(float(coordinate_list[1].split('/')[0]) /
                                                         float(coordinate_list[1].split('/')[1]) / 60)[1:])
    if direction_reference and (str(direction_reference) == 'S' or str(direction_reference) == 'W'):
        decimal_coordinates *= -1
    return decimal_coordinates


file_path = os.path.dirname(__file__)

file_list = os.listdir(file_path)

# Get list of exif data tags
tag_list = []
for file_name in file_list:
    if file_name.split(".")[-1] == 'JPG' or file_name.split(".")[-1] == 'jpg':
        with open('{0}\\{1}'.format(file_path, file_name), 'rb') as picture:
            try:
                tags = exifread.process_file(picture)
            except TypeError:
                continue
            for tag in tags:
                if tag != 'JPEGThumbnail':
                    tag_list.append(str(tag))
        break

# List for pandas.DataFrame objects to concatenate later
dataframe_list = []

# Iterate through photos
for file_name in file_list:
    if file_name.split(".")[-1] == 'JPG' or file_name.split(".")[-1] == 'jpg':
        with open('{0}\\{1}'.format(file_path, file_name), 'rb') as picture:
            print "Working on", file_name
            try:
                tags = exifread.process_file(picture)
            except TypeError:
                continue

            value_list = [str(tags[tag]) for tag in tag_list if tag != 'file_name']
            new_row = pd.DataFrame([value_list], columns=tag_list, index=[file_name])

            # Convert values to decimal
            new_row.at[file_name, 'GPS GPSLatitude'] = \
                convert_metatag_to_decimal(new_row.loc[file_name, 'GPS GPSLatitude'],
                                           new_row.loc[file_name, 'GPS GPSLatitudeRef'])
            new_row.at[file_name, 'GPS GPSLongitude'] = \
                convert_metatag_to_decimal(new_row.loc[file_name, 'GPS GPSLongitude'],
                                           new_row.loc[file_name, 'GPS GPSLongitudeRef'])
            if len(new_row.loc[file_name, 'GPS GPSAltitude'].split('/')) > 1:
                fraction = new_row.loc[file_name, 'GPS GPSAltitude'].split('/')
                new_row.at[file_name, 'GPS GPSAltitude'] = float(fraction[0]) / float(fraction[1])
            else:
                new_row.at[file_name, 'GPS GPSAltitude'] = float(new_row.loc[file_name, 'GPS GPSAltitude'])

            dataframe_list.append(new_row)

final_frame = pd.concat(dataframe_list)
final_frame.index.name = 'FileName'
writer = pd.ExcelWriter('{0}\\AllTags.xlsx'.format(file_path), engine='xlsxwriter')
final_frame.sort_index(axis=1).to_excel(writer, sheet_name='Sheet1')
writer.save()