Small python3 script for downloading the latest versions of Papermc projects using the v2 API

paperv2-downloader.py

#!/usr/bin/env python3
#
# paperv2-downloader.py
#   Python script to download the latest versions of various paper projects with one command
#
# examples:
#   paperv2-downloader.py paper /path/to/server.jar
#   paperv2-downloader.py waterfall proxyserver.jar --overwrite
#
# Licensed under: The Unlicense
#
# Project originally by FivePB <admin@fivepb.me> 
#
# This is free and unencumbered software released into the public domain.
# Anyone is free to copy, modify, publish, use, compile, sell, or
# distribute this software, either in source code form or as a compiled
# binary, for any purpose, commercial or non-commercial, and by any
# means.
#
# In jurisdictions that recognize copyright laws, the author or authors
# of this software dedicate any and all copyright interest in the
# software to the public domain. We make this dedication for the benefit
# of the public at large and to the detriment of our heirs and
# successors. We intend this dedication to be an overt act of
# relinquishment in perpetuity of all present and future rights to this
# software under copyright law.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
# IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
# OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
# ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
# OTHER DEALINGS IN THE SOFTWARE.

# For more information, please refer to <https://unlicense.org>


import requests
import json
import argparse, sys, os
import hashlib

__version__ = '1.1'


USER_AGENT = 'paper-v2-api-downloader-pyscript/%s' % __version__

def getProjectVersions(project):
    url = 'https://papermc.io/api/v2/projects/%s' % project 
    r = requests.get(url, headers={'User-Agent': USER_AGENT})
    tmp1 = json.loads((r.text))
    return tmp1['versions']

def getProjectVersionBuilds(project, version):
    url = 'https://papermc.io/api/v2/projects/%s/versions/%s' % (project, version)
    r = requests.get(url, headers={'User-Agent': USER_AGENT})
    tmp1 = json.loads((r.text))
    return tmp1['builds']

def getProjectVersionBuildApplication(project, version, build):
    url = 'https://papermc.io/api/v2/projects/%s/versions/%s/builds/%s' % (project, version, build)
    r = requests.get(url, headers={'User-Agent': USER_AGENT})
    tmp1 = json.loads((r.text))
    return tmp1['downloads']['application']

def download(project, version, build, filename):
    url = 'https://papermc.io/api/v2/projects/%s/versions/%s/builds/%s/downloads/%s' % (project, version, build, filename)
    r = requests.get(url, headers={'User-Agent': USER_AGENT})
    return r.content

def parse_args():
    parser = argparse.ArgumentParser(description='Paper-V2-API project downloader')
    parser.add_argument('project', help='Project name for ex: Waterfall or Paper')
    parser.add_argument('file', help='Path (and name) to save the download to')
    parser.add_argument('--overwrite', help='overwrite any existing file', action='store_true')
    parser.add_argument('--skip-file-check', help='skip sha256 checksum test', action='store_true')
    return parser.parse_args()

def writeFile(path, data):
    f = open(path, 'wb')
    f.write(data)
    f.close()

def main(passedArgs = None):

    if passedArgs:
        args = passedArgs
    else:
        args = parse_args()

    versions = None
    try:
        versions = getProjectVersions(args.project)
    except Exception as e:
        print('An error occured: %s\nIf it\'s a KeyError the project most likely doesn\'t exist or the Paper API servers are down or the API has changed. Anything else is most likely a Network issue on your side' % e.__class__.__name__ )
        return 1
    version = versions[-1]

    buildinfo = getProjectVersionBuilds(args.project, version)
    build = buildinfo[-1]

    app = getProjectVersionBuildApplication(args.project, version, build)

    appname = app['name']
    checksum = app['sha256']

    file = args.file

    if os.path.isdir(file):
        file = os.path.join(file, appname)

    if os.path.isfile(file) and not args.overwrite:
        print('Error, file %s already exists but you didn\'t specify --overwrite. Quitting!' )
        return 2

    data = download(args.project, version, build, appname)

    if not args.skip_file_check:
        calculatedHash = hashlib.sha256(data).hexdigest();
        if calculatedHash != checksum:
            print('Warning! Couldn\'t verify the downloaded file; the checksum failed. Expected %s but got %s that means there is something very wrong here. If you would like to proceed anyway you can re-run the command with --skip-file-check (NOT RECOMMENDED).' % (checksum, calculatedHash))
            return 3

    writeFile(file, data)



if __name__ == '__main__':
    sys.exit(main())