quetzal.py

import requests
import json


def prepare_file(quetzal_telemetry):
    telemetry_content = ''

    for single in quetzal_telemetry.telemetry:
        telemetry_content += single['frame'][40:]

    telemetry_content_bytearray = bytearray.fromhex(telemetry_content)

    file = open("telemetry.hex", "wb")
    file.write(telemetry_content_bytearray)
    file.close()

    print('\nAll frames count: ' + str(len(quetzal_telemetry.telemetry)), flush=True)


class QuetzalTelemetry:
    def __init__(self, token, start, end):
        self.token = 'Token {}'.format(token)
        self.start = start
        self.end = end

        self.filters = ''

        self.url = "https://db.satnogs.org/api/telemetry/?satellite=45598"

        self.startFrame = "404040404040604040404040406103F0"
        self.lengthFrame = 314

        self.telemetry = []

    def get_and_prepare_telemetry(self):
        self.filters += "&start=" + self.start if self.start else ''
        self.filters += "&end=" + self.end if self.end else ''

        page = 1

        while True:
            url = self.url + "&page=" + str(page) + self.filters
            response = requests.get(url, headers={'Authorization': self.token})

            if response.status_code == 401:
                print("The token is invalid. Try again.", flush=True)
                exit()

            elif response.status_code == 200:
                current_data = json.loads(response.text)

                if type(current_data) is list:
                    self.telemetry = self.telemetry + current_data
                    print('Page {} loaded. {} frames fetched.'.format(page, len(current_data)), flush=True)
                else:
                    print('There were no proper frames found. Received data: {}'.format(current_data), flush=True)

            elif response.status_code == 404: # no more pages
                print('All pages loaded.')
                break

            else:
                print('There is something wrong with the response. Status code: {}'.format(response.status_code), flush=True)
                exit()

            page += 1

        self.reverse_telemetry()
        self.filter_telemetry()

    def reverse_telemetry(self):
        self.telemetry = self.telemetry[::-1]

    def filter_telemetry(self):
        self.telemetry = list(
            filter(
                lambda single: single['frame'].startswith(self.startFrame) and len(single['frame']) == self.lengthFrame,
                self.telemetry))

        if (len(self.telemetry) > 0):
            print('Last valid frame timestamp: {}'.format(self.telemetry[len(self.telemetry) - 1]['timestamp']), flush=True)