import glob
import hashlib
import logging
import os.path
import re
import random
import string
import subprocess
import shutil
import sys
import tempfile
import requests
import solv
import yaml
from lxml import etree as ET

import osc.core
from osclib.cache_manager import CacheManager
from pkglistgen import file_utils

from urllib.parse import urljoin, urlparse

logger = logging.getLogger()


def dump_solv_build(baseurl):
    """Determine repo format and build string from remote repository."""

    buildre = re.compile(r'.*-Build(.*)')
    factoryre = re.compile(r'openSUSE-(\d*)-.*-Build.*')
    url = urljoin(baseurl, 'media.1/media')
    with requests.get(url) as media:
        media.encoding = 'utf-8'
        if media.status_code == requests.codes.ok:
            for i, line in enumerate(media.iter_lines(decode_unicode=True)):
                if i != 1:
                    continue
                build = factoryre.match(line)
                if build:
                    return build.group(1)
                build = buildre.match(line)
                if build:
                    return build.group(1)

    url = urljoin(baseurl, 'media.1/build')
    with requests.get(url) as build:
        if build.status_code == requests.codes.ok:
            name = build.content.strip()
            build = buildre.match(name)
            if build:
                return build.group(1)

    url = urljoin(baseurl, 'repodata/repomd.xml')
    with requests.get(url) as media:
        if media.status_code == requests.codes.ok:
            root = ET.parse(url)
            rev = root.find('.//{http://linux.duke.edu/metadata/repo}revision')
            if rev is not None:
                return rev.text

    raise Exception(baseurl + 'includes no build number')


def parse_repomd(repo, baseurl):
    url = urljoin(baseurl, 'repodata/repomd.xml')
    repomd = requests.get(url)
    if repomd.status_code != requests.codes.ok:
        return False

    ns = {'r': 'http://linux.duke.edu/metadata/repo'}
    root = ET.fromstring(repomd.content)
    primary_element = root.find('.//r:data[@type="primary"]', ns)
    location = primary_element.find('r:location', ns).get('href')
    sha256_or_512 = 0
    try:
        sha_expected = primary_element.find('r:checksum[@type="sha512"]', ns).text
        sha256_or_512 = 512
    except AttributeError:
        sha_expected = primary_element.find('r:checksum[@type="sha256"]', ns).text
        sha256_or_512 = 256

    f = tempfile.TemporaryFile()
    f.write(repomd.content)
    f.flush()
    os.lseek(f.fileno(), 0, os.SEEK_SET)
    repo.add_repomdxml(solv.xfopen_fd(None, f.fileno()), 0)
    url = urljoin(baseurl, location)
    with requests.get(url, stream=True) as primary:
        if primary.status_code != requests.codes.ok:
            raise Exception(url + ' does not exist')
        if sha256_or_512 == 512:
            sha = hashlib.sha512(primary.content).hexdigest()
        else:
            sha = hashlib.sha256(primary.content).hexdigest()

        if sha != sha_expected:
            raise Exception('checksums do not match {} != {}'.format(sha, sha_expected))

        os.lseek(f.fileno(), 0, os.SEEK_SET)
        f.write(primary.content)
        f.flush()
        os.lseek(f.fileno(), 0, os.SEEK_SET)
        repo.add_rpmmd(solv.xfopen_fd(url, f.fileno()), None, 0)
        return True

    return False


def parse_susetags(repo, baseurl):
    url = urljoin(baseurl, 'content')
    content = requests.get(url)
    if content.status_code != requests.codes.ok:
        return False

    f = tempfile.TemporaryFile()
    f.write(content.content)
    f.flush()
    os.lseek(f.fileno(), 0, os.SEEK_SET)
    repo.add_content(solv.xfopen_fd(None, f.fileno()), 0)

    defvendorid = repo.meta.lookup_id(solv.SUSETAGS_DEFAULTVENDOR)
    descrdir = repo.meta.lookup_str(solv.SUSETAGS_DESCRDIR)
    if not descrdir:
        descrdir = 'suse/setup/descr'

    url = urljoin(baseurl, descrdir + '/packages.gz')
    with requests.get(url, stream=True) as packages:
        if packages.status_code != requests.codes.ok:
            raise Exception(url + ' does not exist')

        os.lseek(f.fileno(), 0, os.SEEK_SET)
        f.write(packages.content)
        f.flush()
        os.lseek(f.fileno(), 0, os.SEEK_SET)
        try:
            repo.add_susetags(solv.xfopen_fd(url, f.fileno()), defvendorid, None,
                              solv.Repo.REPO_NO_INTERNALIZE | solv.Repo.SUSETAGS_RECORD_SHARES)
        except TypeError:
            logger.error(f"Failed to add susetags for {url}")
            return False
        return True
    return False


def dump_solv(name, baseurl):
    pool = solv.Pool()
    pool.setarch()

    repo = pool.add_repo(''.join(random.choice(string.ascii_letters) for _ in range(5)))
    if not parse_repomd(repo, baseurl) and not parse_susetags(repo, baseurl):
        raise Exception('neither repomd nor susetags exists in ' + baseurl)

    repo.create_stubs()

    ofh = solv.xfopen(name, 'w')
    repo.write(ofh)
    ofh.flush()

    return name


def print_repo_delta(pool, repo2, packages_file):
    print('=Ver: 2.0', file=packages_file)
    present = dict()
    for s in pool.solvables_iter():
        if s.repo != repo2:
            key = '{}/{}'.format(s.name, s.arch)
            present.setdefault(key, {})
            present[key][s.evr] = s.repo
    for s in repo2.solvables:
        if s.arch == 'src':
            continue
        key = '{}/{}'.format(s.name, s.arch)
        if present.get(key, {}).get(s.evr):
            continue
        elif key not in present:
            print('# NEW', s.name, s.arch, file=packages_file)
        evr = s.evr.split('-')
        release = evr.pop()
        print('=Pkg:', s.name, '-'.join(evr), release, s.arch, file=packages_file)
        print('+Prv:', file=packages_file)
        for dep in s.lookup_deparray(solv.SOLVABLE_PROVIDES):
            print(dep, file=packages_file)
        print('-Prv:', file=packages_file)


def merge_susetags(output, files):
    pool = solv.Pool()
    pool.setarch()

    for file in files:
        file_utils.add_susetags(pool, file)

    packages = dict()
    for s in pool.solvables_iter():
        evr = s.evr.split('-')
        release = evr.pop()
        version = '-'.join(evr)
        key = s.name + "-" + version + "." + s.arch
        if re.search('-release', s.name):  # just take one version of it
            key = s.name + "." + s.arch
        packages[key] = {'name': s.name, 'version': version, 'arch': s.arch, 'release': release, 'provides': set()}
        for dep in s.lookup_deparray(solv.SOLVABLE_PROVIDES):
            packages[key]['provides'].add(str(dep))
    output_file = open(output, 'w')
    print("=Ver: 2.0", file=output_file)
    for package in sorted(packages):
        infos = packages[package]
        print('=Pkg:', infos['name'], infos['version'], infos['release'], infos['arch'], file=output_file)
        print('+Prv:', file=output_file)
        for dep in sorted(infos['provides']):
            print(dep, file=output_file)
        print('-Prv:', file=output_file)


def fixate_target(root, package, fixate):
    for item in root:
        key = list(item)[0]
        opts = item[key]
        key = str(key)
        if key == fixate:
            if not opts.get('refresh', False):
                print(f"{fixate} is already fix. Please lookup config.yml", file=sys.stderr)
                return False
            del opts['refresh']
            oldfiles = target_files(package.dir, key)
            newfile = os.path.join(package.dir, f'{fixate}_packages')
            merge_susetags(newfile, oldfiles)
            for file in oldfiles:
                os.unlink(file)
                package.delete_file(os.path.basename(file))
            subprocess.check_call(['zstd', '-19', '--rm', newfile])
            package.addfile(os.path.basename(newfile) + ".zst")
    ystring = yaml.dump(root, default_flow_style=False)
    with open(os.path.join(package.dir, 'config.yml'), 'w') as f:
        f.write(ystring)
    package.commit(f'Remove refresh from {fixate}')
    return True


def target_files(repo_dir, key):
    files = list()
    for suffix in ['xz', 'zst']:
        files += glob.glob(os.path.join(repo_dir, f'{key}_*.packages.{suffix}'))
    return files


def update_project(apiurl, project, fixate=None):
    # Cache dir specific to hostname and project.
    host = urlparse(apiurl).hostname
    cache_dir = CacheManager.directory('update_repo_handler', host, project)
    repo_dir = os.path.join(cache_dir, '000update-repos')

    # development aid
    checkout = True
    if checkout:
        if os.path.exists(cache_dir):
            shutil.rmtree(cache_dir)
        os.makedirs(cache_dir)

        osc.core.checkout_package(apiurl, project, '000update-repos', expand_link=True, prj_dir=cache_dir)

    package = osc.core.Package(repo_dir)

    root = yaml.safe_load(open(os.path.join(repo_dir, 'config.yml')))
    if fixate:
        return fixate_target(root, package, fixate)

    for item in root:
        key = list(item)[0]
        opts = item[key]
        # cast 15.1 to string :)
        key = str(key)
        if not opts['url'].endswith('/'):
            opts['url'] += '/'

        if opts.get('refresh', False):
            opts['build'] = dump_solv_build(opts['url'])
            path = '{}_{}.packages'.format(key, opts['build'])
        else:
            path = key + '.packages'
        packages_file = os.path.join(repo_dir, path)

        if opts.get('refresh', False):
            oldfiles = target_files(repo_dir, key)
            if len(oldfiles) > 10:
                oldest = oldfiles[-1]
                if oldest.count('and_before') > 1:
                    raise Exception('The oldest is already a compated file')
                oldest = oldest.replace('.packages.xz', '_and_before.packages')
                oldest = oldest.replace('.packages.zst', '_and_before.packages')
                merge_susetags(oldest, oldfiles)
                for file in oldfiles:
                    os.unlink(file)
                    package.delete_file(os.path.basename(file))
                subprocess.check_call(['zstd', '-19', '--rm', oldest])
                package.addfile(os.path.basename(oldest) + ".zst")

        if os.path.exists(packages_file + '.zst') or os.path.exists(packages_file + '.xz'):
            print(path, 'already exists')
            continue

        solv_file = packages_file + '.solv'
        dump_solv(solv_file, opts['url'])

        pool = solv.Pool()
        pool.setarch()

        if opts.get('refresh', False):
            for file in target_files(repo_dir, key):
                file_utils.add_susetags(pool, file)

        repo1 = pool.add_repo(''.join(random.choice(string.ascii_letters) for _ in range(5)))
        repo1.add_solv(solv_file)

        print_repo_delta(pool, repo1, open(packages_file, 'w'))
        subprocess.call(['zstd', '-19', '--rm', packages_file])
        os.unlink(solv_file)

        package.addfile(os.path.basename(path + '.zst'))
        del pool

    package.commit('Automatic update')