import subprocess
import portage
import sys
import os
import re

from StringIO import StringIO
from datetime import datetime
from portage import versions
from optparse import make_option

from django.db.transaction import commit_on_success
from django.core.management.base import BaseCommand, CommandError
from euscanwww.euscan.models import Package, Version, EuscanResult

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('--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):
        if len(args) == 0 and options['all'] == False and options['feed'] == False:
            raise CommandError('You must specify a package or use --all')

        if options['feed']:
            self.parse_output(options, sys.stdin)
            return

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

        packages = []

        if len(args) == 0:
            for pkg in Package.objects.all():
                packages.append('%s/%s' % (pkg.category, pkg.name))
        else:
            packages = list(args)

        self.scan(options, packages)

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

    @commit_on_success
    def scan(self, options, packages=None):
        for package in packages:
            cmd = ['euscan', package]

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

            self.parse_output(options, output)

    def parse_output(self, options, 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(options, package, log)

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

            log += line

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

        if package:
            self.store_result(options, package, log)

    def store_result(self, options, package, log):
        obj = EuscanResult()
        obj.package = package
        obj.result = log
        obj.datetime = datetime.now()
        obj.save()

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

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

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

        # Delete previous versions to handle incremental scan correctly
        Version.objects.filter(package=obj, packaged=False).delete()

        obj.n_versions = Version.objects.filter(package=obj).count()
        obj.save()

        return obj

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

        if created or not obj.packaged:
            if not options['quiet']:
                sys.stdout.write('[u] %s/%s-%s %s\n' % (package.category, package.name,
                                                        ver, url))

            obj.url = url
            obj.packaged = False
            obj.save()

        if created:
            package.n_versions += 1
            package.save()