from requests.auth import HTTPBasicAuth
from urllib.parse import urlparse
import argparse
import base64
import json
import os
import re
import requests
import subprocess
import sys

# in case you get rate limited
AUTH = HTTPBasicAuth('username', 'token')
AUTH = None

def get_default_branch(repo):
    r = requests.get('https://api.github.com/repos/{}'.format(repo), auth=AUTH)
    j = r.json()
    return j['default_branch']

def get_license(repo_url, MIT=False):
    u = urlparse(repo_url)
    if u.netloc == 'github.com':
        path = u.path.lstrip('/')
        path = '/'.join(path.split('/')[:2])
        if path.endswith('.git'):
            path = path.rsplit('.', 1)[0]

        branch = get_default_branch(path)
        license_mit = 'https://raw.githubusercontent.com/{}/{}/LICENSE-MIT'.format(path, branch)
        r = requests.get(license_mit)
        if r.status_code == requests.codes.ok:
            return r.text
        license_url = 'https://api.github.com/repos/{}/license'.format(path)
        r = requests.get(license_url, auth=AUTH)
        if r.status_code == requests.codes.ok:
            j = r.json()
            license_text = base64.b64decode(j['content'])
            return license_text.decode('utf8')
    return None

def get_licenses(path):
    os.chdir(path)
    p = subprocess.Popen(['cargo', 'metadata', '--format-version', '1'], stdout=subprocess.PIPE)
    out, _ = p.communicate()
    j = json.loads(out)
    for pkg in sorted(j['packages'], key=lambda x: x['name']):
        name = pkg['name']
        version = pkg['version']
        authors = pkg['authors']
        license = pkg['license'] or ''
        repo_url = pkg['repository']
        if re.search(r'\bMIT\b', license):
            license = 'MIT'
        if not license.strip():
            print('[!] WARNING: package {} has no license, skipping'.format(name), file=sys.stderr)
            continue
        license_text = get_license(repo_url)
        if license_text is None:
            print('[!] WARNING: package {} has no license, skipping'.format(name), file=sys.stderr)
            continue
        print('-' * 80)
        print('{} {}: {}'.format(name, version, repo_url))
        print('authors: {}'.format(', '.join(authors)))
        print()
        print(license_text.strip())
        print()
    return ''

if __name__ == '__main__':
    parser = argparse.ArgumentParser()
    parser.add_argument('path')
    args = parser.parse_args()

    print('=' * 80)
    print('======== RUST LICENSES ========')
    print('=' * 80)
    print()
    print(get_licenses(args.path))
    print('=' * 80)
    print('======== END RUST LICENSES ========')
    print('=' * 80)