#!/usr/bin/python3
# Requires: python3-rpm

import configparser
import json
import logging
import os
import os.path
import sqlite3
import tempfile
import urllib.request
from urllib.request import Request, urlopen
from typing import Optional, Tuple
import xml.etree.ElementTree as ET

import rpm

# PyPI API documentation https://warehouse.readthedocs.io/api-reference/
PyPI_base = "https://pypi.org/pypi/{}/json"
OBS_base = "https://api.opensuse.org"
ConfigRC = os.path.expanduser('~/.config/osc/oscrc')

config = configparser.ConfigParser()
config.read(ConfigRC)

logging.basicConfig(format='%(levelname)s:%(funcName)s:%(message)s',
                    level=logging.DEBUG)
log = logging.getLogger()

password_mgr = urllib.request.HTTPPasswordMgrWithDefaultRealm()
user = config[OBS_base]['user']
passw = config[OBS_base]['pass']
password_mgr.add_password(None, OBS_base, user, passw)

handler = urllib.request.HTTPBasicAuthHandler(password_mgr)
opener = urllib.request.build_opener(handler)

def get_version_from_pypi(name:str, etag: Optional[str] = None) -> Tuple[str, str, str]:
    req = Request(url=PyPI_base.format(name))

    if etag is not None:
        req.add_header('ETag', etag)

    with urlopen(req) as resp:
        if resp.getcode() == 200:
            data = json.load(resp)
            info_dict = data['info']
            return info_dict['name'], info_dict['version'], resp.info()['ETag']
        else:
            IOError(resp.info())

def list_packages(project:str, etag: Optional[str] = None) -> Tuple[str, ...]:
    req = Request(url=OBS_base+'/source/{}'.format(project))

    if etag is not None:
        req.add_header('ETag', etag)

    with opener.open(req) as resp:
        if resp.getcode() == 200:
            raw_xml_data = ET.parse(resp)
            root = raw_xml_data.getroot()
            out = []
            for elem in root.iter('entry'):
                out.append(elem.get('name'))

    return tuple(out)

def package_version(project:str, pkg:str, etag: Optional[str] = None) -> Tuple[str, ...]:
    # GET https://api.opensuse.org/source/devel:languages:python:singlespec-staging/python-venusian?rev=latest
    req_spc_name = Request(url=OBS_base+'/source/{}/{}'.format(project, pkg))

    if etag is not None:
        req_spc_name.add_header('ETag', etag)

    with opener.open(req_spc_name) as resp:
        if resp.getcode() == 200:
            raw_xml_data = ET.parse(resp)
            root = raw_xml_data.getroot()
            spec_files = []
            for elem in root.iter('entry'):
                name = elem.get('name')
                if name.endswith('.spec'):
                    spec_files.append(name)

    log.debug('spec_files = %s', spec_files)
    if spec_files:
        spc_fname = sorted(spec_files, key=len)
        log.debug('spc_fname = %s', spc_fname)
        spc_fname = spc_fname[0]
    else:
        return None

    req_spec = Request(url=OBS_base+'/source/{}/{}/{}'.format(project, pkg, spc_fname))
    with opener.open(req_spec) as resp:
        spec_file_str = resp.read()
        spec_file_name = ''
        with tempfile.NamedTemporaryFile(mode='w+b', delete=False) as spf:
            spec_file_name = spf.name
            spf.write(spec_file_str)
            spf.flush()
            os.fsync(spf.fileno())
            try:
                spc = rpm.spec(spec_file_name)
            except Exception as ex:
                print('Exception: {}\n'.format(ex))
                print("Cannot parse {}".format(pkg))
            else:
                try:
                    return spc.packages[0].header['Version'].decode()
                except IndexError:
                    pass


cutchars = len('python-')
project = 'devel:languages:python:singlespec-staging'
for pkg in list_packages(project):
    pkg = pkg.strip()
    if pkg:
        assert pkg.startswith('python-')
        pypi_name = pkg[cutchars:]
        print("{} {}".format(pkg, package_version(project, pkg)))