import subprocess
import portage
import sys
import re
from StringIO import StringIO
from optparse import make_option
from collections import defaultdict

from django.utils import timezone
from django.db.transaction import commit_on_success
from django.core.management.base import BaseCommand

from djeuscan.models import Package, Version, EuscanResult, VersionLog


class ScanUpstream(object):
    def __init__(self, options=None):
        if options is None:
            self.options = defaultdict(None)
        else:
            self.options = options

    def run(self, packages=None):
        for package in packages:
            cmd = ['euscan', package]

            fp = subprocess.Popen(cmd, stdout=subprocess.PIPE,
                                  stderr=subprocess.PIPE)
            output = StringIO(fp.communicate()[0])

            self.parse_output(output)

    def store_result(self, package, log):
        # Remove previous logs
        EuscanResult.objects.filter(package=package).delete()

        obj = EuscanResult()
        obj.package = package
        obj.result = log
        obj.datetime = timezone.now()
        obj.save()

    def store_package(self, cpv):
        cat, pkg, ver, rev = portage.catpkgsplit(cpv)

        obj, created = Package.objects.get_or_create(category=cat, name=pkg)

        if created and not self.options['quiet']:
            sys.stdout.write('+ [p] %s/%s\n' % (cat, pkg))

        # Set all versions dead, then set found versions alive and
        # delete old versions
        Version.objects.filter(package=obj, packaged=False).update(alive=False)

        return obj

    def store_version(self, package, ver, url):
        obj, created = Version.objects.get_or_create(
            package=package, slot='', revision='r0', version=ver, overlay=''
        )

        obj.alive = True
        obj.urls = url
        obj.packaged = False
        obj.save()

        # If it's not a new version, just update the object and continue
        if not created:
            return

        if not self.options['quiet']:
            sys.stdout.write('+ [u] %s %s\n' % (obj, url))

        entry = VersionLog.objects.create(
            package=package,
            action=VersionLog.VERSION_ADDED
        )
        entry.slot = ''
        entry.revision = 'r0'
        entry.version = ver
        entry.overlay = ''
        entry.save()

        package.n_versions += 1
        package.save()

    @commit_on_success
    def parse_output(self, output):
        from portage.versions import _cp

        package_re = re.compile(
            r'^ \* (?P<cpv>' + _cp + ') \[(?P<overlay>.*?)\]$'
        )
        version_re = re.compile(
            r'^Upstream Version: (?P<ver>.*?) (?P<url>.*?)$'
        )

        package = None
        log = ""

        while True:
            line = output.readline()
            if line == '':
                break
            match = package_re.match(line)
            if match:
                if package:
                    self.store_result(package, log)

                cpv = match.group('cpv')
                package = self.store_package(cpv)
                log = line
                continue

            log += line

            match = version_re.match(line)
            if match:
                ver = match.group('ver')
                url = match.group('url')
                self.store_version(package, ver, url)

        if package:
            self.store_result(package, log)


@commit_on_success
def purge_versions(options):
    # For each dead versions
    for version in Version.objects.filter(packaged=False, alive=False):
        entry = VersionLog.objects.create(
            package=version.package,
            action=VersionLog.VERSION_REMOVED
        )
        entry.slot = version.slot
        entry.revision = version.revision
        entry.version = version.version
        entry.overlay = version.overlay
        entry.save()

        version.package.n_versions -= 1
        version.package.save()

        if not options['quiet']:
            sys.stdout.write('- [u] %s %s\n' % (version, version.urls))
    Version.objects.filter(packaged=False, alive=False).delete()


class Command(BaseCommand):
    _overlays = {}

    option_list = BaseCommand.option_list + (
        make_option('--all',
            action='store_true',
            dest='all',
            default=False,
            help='Scan all packages'),
        make_option('--feed',
            action='store_true',
            dest='feed',
            default=False,
            help='Read euscan output from stdin'),
        make_option('--purge-versions',
            action='store_true',
            dest='purge-versions',
            default=False,
            help='Purge old versions'),
        make_option('--quiet',
            action='store_true',
            dest='quiet',
            default=False,
            help='Be quiet'),
        )
    args = '<package package ...>'
    help = 'Scans metadata and fills database'

    def handle(self, *args, **options):
        scan_upstream = ScanUpstream(options)

        if options['feed']:
            scan_upstream.parse_output(options, sys.stdin)
            if options['purge-versions']:
                purge_versions(options)
            return

        if not options['quiet']:
            self.stdout.write('Scanning upstream...\n')

        packages = []

        if options['all']:
            for pkg in Package.objects.all():
                packages.append('%s/%s' % (pkg.category, pkg.name))
        elif args:
            packages = list(args)
        else:
            packages = [package[:-1] for package in sys.stdin.readlines()]

        scan_upstream.run(packages)

        if options['purge-versions']:
            purge_versions(options)

        if not options['quiet']:
            self.stdout.write('Done.\n')