import requests
from requests.adapters import HTTPAdapter
from requests.adapters import Retry
import json
import os
import asyncio
import argparse
from datetime import datetime
import writer
from model import PictureType
import sys

session = requests.Session()
retries_strategies = Retry(
    total=5,
    backoff_factor=1,
    status_forcelist=[429,502, 503, 504],
    )
session.mount('https://', HTTPAdapter(max_retries=retries_strategies))

def parse_args(argv =None):
    parser = argparse.ArgumentParser()
    parser.add_argument('--sequence_ids', type=str, nargs='+', help='The mapillary sequence id(s) to download')
    parser.add_argument('--access_token', type=str, help='Your mapillary access token')
    parser.add_argument('--image_limit', type=int, default=None, help='How many images you want to download')

    global args
    args = parser.parse_args(argv)

def background(f):
    def wrapped(*args, **kwargs):
        return asyncio.get_event_loop().run_in_executor(None, f, *args, **kwargs)
    return wrapped

#TODO add try/except and retry (see https://www.zenrows.com/blog/python-requests-retry#avoid-getting-blocked)
@background
def download(url, fn, metadata=None):
    r = session.get(url, stream=True, timeout=6)
    image = write_exif(r.content, metadata)
    with open(str(fn), "wb") as f:
        f.write(image)

def get_single_image_data(image_id, mly_header):
    req_url = 'https://graph.mapillary.com/{}?fields=thumb_original_url,altitude,camera_type,captured_at,compass_angle,geometry,exif_orientation'.format(image_id)
    r = session.get(req_url, headers=mly_header)
    data = r.json()
    #print(data)
    return data

def get_image_data_from_sequences(sequences_id, mly_header):
    for i,sequence_id in enumerate(sequences_id):
        url = 'https://graph.mapillary.com/image_ids?sequence_id={}'.format(sequence_id)
        r = requests.get(url, headers=header)
        data = r.json()
        image_ids = data['data']
        total_image = len(image_ids)
        print("{} images in sequence {} of {}  - id : {}".format(total_image, i+1, len(sequences_id), sequence_id))
        print('getting images data')
        for x in range(0, total_image):
            image_id = image_ids[x]['id']
            image_data = get_single_image_data(image_id, mly_header)
            image_data['sequence_id'] = sequence_id
            yield image_data

def write_exif(picture, img_metadata):
    '''
    Write exif metadata
    '''
    #{'thumb_original_url': 'https://scontent-cdg4-2.xx.fbcdn.net/m1/v/t6/An9Zy2SrH9vXJIF01QkBODyUbg7XSKfwL48UwHyvihSwvECGjVbG0vSw9uhxe2-Dq-k2eUcigb83buO6zo-7eVbykfp5aQIe1kgd-MJr66nU_H-o_mwBLZXgVbj5I_5WX-C9c6FxJruHkV962F228O0?ccb=10-5&oh=00_AfDOKD869DxL-4ZNCbVo8Rn29vsc0JyjMAU2ctx4aAFVMQ&oe=65256C25&_nc_sid=201bca',
    #  'captured_at': 1603459736644, 'geometry': {'type': 'Point', 'coordinates': [2.5174596904057, 48.777089857534]}, 'id': '485924785946693'}
    
    picture = writer.writePictureMetadata(picture, img_metadata)
    picture = writer.add_altitude(picture, img_metadata)
    picture = writer.add_direction(picture, img_metadata)

    return picture

if __name__ == '__main__':
    parse_args()

    if args.sequence_ids == None:
        print('please provide the sequence_id')
        exit()

    if args.access_token == None:
        print('please provide the access_token')
        exit()

    sequence_ids= args.sequence_ids
    access_token = args.access_token
    images_data = []
    header = {'Authorization' : 'OAuth {}'.format(access_token)}
    
    # create the data folder
    if not os.path.exists('data'):
            os.makedirs('data')

    for i,image_data in enumerate(get_image_data_from_sequences(sequence_ids, header)):
        if args.image_limit is not None and i >= args.image_limit:
            break
        images_data.append(image_data)

    print('downloading.. this process will take a while. please wait')
    for i,image_data in enumerate(images_data):
        # create a folder for each unique sequence ID to group images by sequence
        if not os.path.exists('data/{}'.format(image_data['sequence_id'])):
            os.makedirs('data/{}'.format(image_data['sequence_id']))
        date_time_image_filename = datetime.utcfromtimestamp(int(image_data['captured_at'])/1000).strftime('%Y-%m-%d_%HH%Mmn%Ss%f')[:-3]
        path = 'data/{}/{}.jpg'.format(image_data['sequence_id'], date_time_image_filename)
        print(path)
        img_metadata = writer.PictureMetadata(
                capture_time = datetime.utcfromtimestamp(int(image_data['captured_at'])/1000),
                longitude = image_data['geometry']['coordinates'][0],
                latitude = image_data['geometry']['coordinates'][1],
                picture_type = PictureType("equirectangular") if image_data['camera_type'] == 'spherical' else None,
                direction = image_data['compass_angle'],
                altitude = image_data['altitude'],
        )
        download(image_data['thumb_original_url'],path, img_metadata)