#!/usr/bin/env python3
#
# Version:1.0
#
# To install this plugin, just drop it into
# /usr/lib/python3.6/site-packages/dnf-plugins, and
# make sure you have 'plugins=1' in your /etc/yum.conf.
# You also need to create the following configuration
# file, if not installed through an RPM:
#
#  /etc/yum/pluginconf.d/releasever_adaptation.conf:
#   [main]
#     enabled=1

#   [releasevermapping]
#     release_dict={'2.1903' : '7', '3' : '8'}

#   [reposlist]
#     include=docker-ce.repo, epel.repo
#

import re
import dnf
import ast
import logging
from dnf.yum import misc
from urllib.parse import urlparse, urlunparse

include = None
release_dict = None
done_repos = set()


class ReleaseverAdaptation(dnf.Plugin):
    """DNF Plugin to parse baseurl in repositories"""

    name = 'releasever-adapter'

    def __init__(self, base, cli):
        super().__init__(base, cli)
        self.base = base

    def config(self):
        conf = self.read_config(self.base.conf)
        include = conf.get('reposlist', 'include')
        release_dict = conf.get('releasevermapping', 'release_dict')
        release_dict = ast.literal_eval(release_dict)
        repos_list = include.replace(' ', '').split(',')
        releasever = self.get_releasever()
        mattching_repos = self.parse_repos(repos_list)
        repomirrors = {}
        for repo in mattching_repos:
            if repo.id in done_repos:
                continue
            if str(repo) in repomirrors:
                continue
            type = "baseurl" if repo.baseurl else "metalink" if \
                repo.metalink else "mirrorlist"
            repo_urls = parse_baseurl({"baseurl": repo.baseurl,
                                       "metalink": [repo.metalink],
                                       "mirrorlist": [repo.mirrorlist]}[type],
                                      releasever, release_dict)
            setattr(repo, type, repo_urls if repo.baseurl else repo_urls[0])
            repo.failovermethod = 'priority'
            done_repos.add(repo.id)

    def parse_repos(self, repos_list):
        mattching_repos = []
        for repo_name in repos_list:
            repo_key = repo_name.split('.')[0] + '*'
            matching = self.base.repos.get_matching(repo_key)
            for repo in matching:
                if repo.enabled:
                    mattching_repos.append(repo)
        return mattching_repos

    def get_releasever(self):
        return self.base.conf.substitutions['releasever']


def parse_baseurl(urllist, releasever, dict):
    """
    This function replaces the releasever variables in baseurl.
    @param urllist : list of baseurl or metalink or mirrorlist of a repository.
    @type urllist : list
    @releasever: the os releasever
    @type releasever: str
    @param dict : Mapping of releasever variables.
    @type dict : dict
    @rtype : list
    @return : The list of adaptaed baseurl or metalink or mirrorlist.
    """
    pattern = re.compile(r'[\/\-\=]' + releasever + r'[\/\&]')
    goodurls = []
    skipped = None
    for url in urllist:
        if url in ['', None]:
            continue
        try:
            (s, b, p, q, f, o) = urlparse(url)
        except (ValueError, IndexError, KeyError) as e:
            s = 'blah'
        if s not in ['http', 'ftp', 'file', 'https']:
            skipped = url
            continue
        url = urlunparse((s, b, p, q, f, o))
        release_var_group = re.search(pattern, url)
        try:
            release_var = release_var_group.group()
            release_version = dict[releasever]
        except (KeyError, AttributeError):
            goodurls.append(url)
        else:
            new_release_var = release_var.replace(releasever, dict[releasever])
            adapted_url = url.replace(release_var, new_release_var)
            goodurls.append(adapted_url)
    if skipped is not None:
        if goodurls:
            logger.warning('DnfRepo Warning: Some mirror URLs are not\
            using ftp, http[s] or file.\n Eg. %s' % misc.to_utf8(skipped))
        else:
            logger.error('DnfRepo Error: All mirror URLs are not using\
            ftp, http[s] or file.\n Eg. %s' % misc.to_utf8(skipped))
    return goodurls