import gzip
from pathlib import Path
import re
from typing import Mapping

from .base import Repository, Version

__all__ = [
    'buster_main_all',
    'buster_main_amd64',
    'buster_contrib_all',
    'buster_contrib_amd64',
    'buster_non_free_all',
    'buster_non_free_amd64',
    'testing_main_all',
    'testing_main_amd64',
    'testing_contrib_all',
    'testing_contrib_amd64',
    'testing_non_free_all',
    'testing_non_free_amd64',
]

PACKAGE_REVISION_INFO = re.compile(r'(\+\w+)*-\d+$')

def parse_cached(cached: Path) -> Mapping[str, Version]:
    result = dict()
    with gzip.open(cached, mode='rt') as file:
        this_package = None
        this_version = None
        for line in file:
            line = line.strip()
            pieces = line.split(': ', 1)
            if len(pieces) != 2:
                continue
            line_type, line_data = pieces
            if line_type == 'Package':
                this_package = line_data
            elif line_type == 'Version':
                this_version = line_data

            if this_package is not None and this_version is not None:
                clean_version = PACKAGE_REVISION_INFO.sub('', this_version)
                result[this_package] = Version(this_version, clean_version)
                this_version = None
                this_package = None
    return result

def build_repo(name: str, dist: str, section: str, arch: str = 'all') -> Repository:
    url = f'https://deb.debian.org/debian/dists/{dist}/{section}/binary-{arch}/Packages.gz'
    if arch != 'all':
        section = f'{section}/{arch}'
    return Repository(
        family='Debian',
        repo=name,
        section=section,
        index_url=url,
        parse=parse_cached,
    )

buster_main_all = build_repo('10 - Buster', 'buster', 'main')
buster_main_amd64 = build_repo('10 - Buster', 'buster', 'main', 'amd64')
buster_contrib_all = build_repo('10 - Buster', 'buster', 'contrib')
buster_contrib_amd64 = build_repo('10 - Buster', 'buster', 'contrib', 'amd64')
buster_non_free_all = build_repo('10 - Buster', 'buster', 'non-free')
buster_non_free_amd64 = build_repo('10 - Buster', 'buster', 'non-free', 'amd64')

testing_main_all = build_repo('Testing', 'testing', 'main')
testing_main_amd64 = build_repo('Testing', 'testing', 'main', 'amd64')
testing_contrib_all = build_repo('Testing', 'testing', 'contrib')
testing_contrib_amd64 = build_repo('Testing', 'testing', 'contrib', 'amd64')
testing_non_free_all = build_repo('Testing', 'testing', 'non-free')
testing_non_free_amd64 = build_repo('Testing', 'testing', 'non-free', 'amd64')