import gzip
import lzma
import re
from xml.etree import ElementTree as ET
from urllib.parse import urlparse
from os import path

import aiohttp
import yaml

NVRA_RE = re.compile(
    r"^(\S+)-([\w~%.+]+)-(\w+(?:\.[\w~%+]+)+?)(?:\.(\w+))?(?:\.rpm)?$"
)
NEVRA_RE = re.compile(
    r"^(\S+)-(\d):([\w~%.+]+)-(\w+(?:\.[\w~%+]+)+?)(?:\.(\w+))?(?:\.rpm)?$"
)
EPOCH_RE = re.compile(r"(\d+):")
DIST_RE = re.compile(r"(\.el\d(?:_\d|))")
MODULE_DIST_RE = re.compile(r"\.module.+$")


def clean_nvra_pkg(matching_pkg: ET.Element) -> str:
    name = matching_pkg.find("{http://linux.duke.edu/metadata/common}name").text
    version = matching_pkg.find(
        "{http://linux.duke.edu/metadata/common}version"
    ).attrib["ver"]
    release = matching_pkg.find(
        "{http://linux.duke.edu/metadata/common}version"
    ).attrib["rel"]
    arch = matching_pkg.find("{http://linux.duke.edu/metadata/common}arch").text

    clean_release = MODULE_DIST_RE.sub("", DIST_RE.sub("", release))
    return f"{name}-{version}-{clean_release}.{arch}"


def clean_nvra(nvra_raw: str) -> str:
    nvra = NVRA_RE.search(nvra_raw)
    name = nvra.group(1)
    version = nvra.group(2)
    release = nvra.group(3)
    arch = nvra.group(4)

    clean_release = MODULE_DIST_RE.sub("", DIST_RE.sub("", release))
    return f"{name}-{version}-{clean_release}.{arch}"


async def download_xml(
    url: str, gz: bool = False, xz: bool = False
) -> ET.Element:
    async with aiohttp.ClientSession() as session:
        async with session.get(url) as resp:
            if resp.status != 200:
                raise Exception(f"Failed to get {url}: {resp.status}")
            # Do an in memory gzip decompression if gz is set
            if gz:
                return ET.fromstring(
                    gzip.decompress(await resp.read()).decode("utf-8")
                )
            elif xz:
                return ET.fromstring(
                    lzma.decompress(await resp.read()).decode("utf-8")
                )
            return ET.fromstring(await resp.text())


async def download_yaml(url: str, gz: bool = False, xz: bool = False) -> any:
    async with aiohttp.ClientSession() as session:
        async with session.get(url) as resp:
            if resp.status != 200:
                raise Exception(f"Failed to get {url}: {resp.status}")
            # Do an in memory gzip decompression if gz is set
            if gz:
                return yaml.full_load_all(
                    gzip.decompress(await resp.read()).decode("utf-8")
                )
            elif xz:
                return yaml.full_load_all(
                    lzma.decompress(await resp.read()).decode("utf-8")
                )

            return yaml.full_load_all(await resp.text())


async def get_data_from_repomd(
    url: str,
    data_type: str,
    el: ET.Element,
    is_yaml=False,
):
    # There is a top-most repomd element in repomd
    # Under there is revision and multiple data elements
    # We want the data element with type="data_type"
    # Under that is location with href
    # That href is the location of the data
    for data in el.findall("{http://linux.duke.edu/metadata/repo}data"):
        if data.attrib["type"] == data_type:
            location = data.find(
                "{http://linux.duke.edu/metadata/repo}location"
            )
            parsed_url = urlparse(url)
            new_path = path.abspath(
                path.join(parsed_url.path, "../..", location.attrib["href"])
            )
            data_url = parsed_url._replace(path=new_path).geturl()

            if is_yaml:
                return await download_yaml(
                    data_url,
                    gz=data_url.endswith(".gz"),
                    xz=data_url.endswith(".xz"),
                )
            return await download_xml(
                data_url,
                gz=data_url.endswith(".gz"),
                xz=data_url.endswith(".xz"),
            )

    return None