#!/usr/bin/env nix-shell
#!nix-shell --quiet -p nix-eval-jobs -p nix -p python3 -p python3Packages.pillow -i python

import json
import os
from PIL import Image
from PIL.ExifTags import TAGS

# https://stackoverflow.com/a/78462781
GPSINFO_TAG = next(
    tag for tag, name in TAGS.items() if name == "GPSInfo"
)
def decimal_coords(coords, ref):
    decimal_degrees = float(coords[0]) + float(coords[1]) / 60 + float(coords[2]) / 3600
    if ref == "S" or ref =='W' :
        decimal_degrees = -1 * decimal_degrees
    return decimal_degrees

with open('data/data.json') as f:
    data = json.loads(f.read())

for i, stand in enumerate(data['stands']):
    lats = []
    lons = []
    for view_image in stand['view']:
        im = Image.open(os.path.join('images', view_image))
        gpsinfo = im.getexif().get_ifd(GPSINFO_TAG)
        lats.append(decimal_coords(gpsinfo[2], gpsinfo[1]))
        lons.append(decimal_coords(gpsinfo[4], gpsinfo[3]))
    data['stands'][i]['location'] = [sum(lats)/len(lats), sum(lons)/len(lons)] # TODO: round
print(json.dumps(data, indent=4))