#!/usr/bin/env python

import copy
import os
import re
import shutil
import signal
import sys
import urllib.request

from getopt import getopt, GetoptError
from html.parser import HTMLParser

from grs import CONST
from grs import Execute
from grs import Log
from grs import Synchronize
from grs import WorldConf

from _emerge.main import emerge_main, parse_opts
from portage.exception import IsADirectory, ParseError, PermissionDenied
from portage import settings


def install_kernel(version = 'latest', logfile = CONST.LOGFILE):
    """ doc here
        more doc
    """
    class MyHTMLParser(HTMLParser):
        def __init__(self, **kwargs):
            HTMLParser.__init__(self, **kwargs)
            self.kernels = []
        def handle_starttag(self, tag, attrs):
            if tag != 'a':
                return
            for attr in attrs:
                if attr[0] == 'href' and re.match('linux-image-', attr[1]):
                    self.kernels.append(attr[1])
        def get_kernels(self):
            return self.kernels

    baseurl = settings['PORTAGE_BINHOST']
    if baseurl == '':
        print('PORTAGE_BINHOST is not set.  Install kernel manually.')
        return

    try:
        request = urllib.request.urlopen('%s/%s' % (baseurl,'linux-images'))
        dload = request.read().decode('utf-8')
    except urllib.error.HTTPError:
        print('Cannot open %s'  % baseurl)
        return

    parser = MyHTMLParser()
    parser.feed(dload)
    kernels = parser.get_kernels()
    kernels.sort()

    if version == 'latest':
        try:
            kernel = kernels[-1]
        except IndexError:
            print('No linux-image available')
            return
    else:
        for k in kernels:
            m = re.search('linux-image-(.+).tar.xz', k)
            if m.group(1) == version:
                kernel = k
                break
        else:
            print('No linux-image %s available' % version)
            return

    # Download the linux-image tarball to packages/linux-image
    request = urllib.request.urlopen('%s/%s/%s' % (baseurl, 'linux-images', kernel))
    package = '/usr/portage/packages/linux-images'
    os.makedirs(package, mode=0o755, exist_ok=True)
    kpath = os.path.join(package, kernel)
    with open(kpath, 'wb') as f:
        shutil.copyfileobj(request, f)

    # Try to mount /boot.  Fail silently since it may not be mountable.
    if not os.path.ismount('/boot'):
        cmd = 'mount /boot'
        Execute(cmd, timeout=60, failok=True, logfile=logfile)

    # Untar it at '/'.  tar will not clobber files.
    cwd = os.getcwd()
    os.chdir('/')
    cmd = 'tar --overwrite -Jxf %s' % kpath
    Execute(cmd, timeout=600, logfile=logfile)
    os.chdir(cwd)


def usage(rc=1):
    usage = """
usage: grsup [pkg(s)]       : update @world or pkg(s) if given
       grsup [-r|-d] pkg(s) : re-install or delete pkg(s)
       grsup -D             : download all @world pkgs, don't install
       grsup -k kernel      : install 'kernel' version, or 'latest'
       grsup -h             : print this help
"""
    print(usage)
    sys.exit(rc)


def main():
    myaction, myopts, myfiles = parse_opts(sys.argv[1:])

    try:
        opts, x = getopt(sys.argv[1:], 'Ck:rdh')
    except GetoptError:
        usage()

    do_install_kernel = False
    if len(opts) == 0:
        args = ['-1', '-g', '-K', '-u', '-D', '-q']
        if len(myfiles) == 0:
            myfiles = ['@world']
        args.extend(myfiles)
    else:
        exclude = 0
        for o, a in opts:
            if o == '-h':
                usage(rc=0)
            elif o == '-r':
                if len(myfiles) == 0 or exclude > 1:
                    usage()
                args = ['-1', '-g', '-K', '-D', '-q']
                args.extend(myfiles)
                exclude += 1
            elif o == '-d':
                if len(myfiles) == 0 or exclude > 1:
                    usage()
                args = ['-C', '-q']
                args.extend(myfiles)
                exclude += 1
            elif o == '-D':
                if len(myfiles) > 0:
                    usage()
                args = ['-g', '-e', '-f', '-q', '@world']
            elif o == '-k':
                if len(sys.argv[1:]) != 2:
                    usage()
                version = a
                do_install_kernel = True

    if len(CONST.names) > 1:
        sys.stderr.write('More than one GRS specified in systems.conf.  Using the first one.\n')

    name        = CONST.names[0]
    repo_uri    = CONST.repo_uris[0]
    stage_uri   = CONST.stage_uris[0]
    libdir      = CONST.libdirs[0]
    logfile     = CONST.logfiles[0]

    # Change the log name for the client.
    basename    = os.path.basename(logfile)
    dirname     = os.path.dirname(logfile)
    logfile     = os.path.join(dirname, 'grsup-%s' % basename)

    Log(logfile).rotate_logs()
    Synchronize(repo_uri, name, libdir, logfile).sync()

    # Copy the new world.conf to CONST.WORLD_CONFIG
    newconf = '%s/core%s' % (libdir, CONST.WORLD_CONFIG)
    shutil.copy(newconf, CONST.WORLD_CONFIG)

    if os.path.isfile(CONST.PORTAGE_DIRTYFILE):
        WorldConf.clean()
    open(CONST.PORTAGE_DIRTYFILE, 'a').close()
    WorldConf.install()

    if do_install_kernel:
        install_kernel(version=version)
    else:
        try:
            emerge_main(args)
        except PermissionDenied as e:
            sys.stderr.write("Permission denied: '%s'\n" % str(e))
            sys.stderr.flush()
            sys.exit(e.errno)
        except IsADirectory as e:
            sys.stderr.write("'%s' is a directory, but should be a file!\n" % sys.exit(e.errno))
            sys.stderr.flush()
        except ParseError as e:
            sys.stderr.write("%s\n" % str(e))
            sys.stderr.flush()
            sys.exit(1)

    WorldConf.clean()
    if os.path.exists(CONST.PORTAGE_DIRTYFILE):
        os.remove(CONST.PORTAGE_DIRTYFILE)


if __name__ == "__main__":
    try:
        main()
    except KeyboardInterrupt:
        sys.stderr.write("Cleaning up /etc/portage.  This make take some time.\n")
        WorldConf.clean()
        if os.path.exists(CONST.PORTAGE_DIRTYFILE):
            os.remove(CONST.PORTAGE_DIRTYFILE)