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.utils import timezone
from django.db.transaction import commit_on_success
from django.core.management.base import BaseCommand, CommandError
from djeuscan.models import Package, Version, EuscanResult, VersionLog

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

        self.scan(options, packages)

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

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

    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)

    @commit_on_success
    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):
        # 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, options, cpv):
        cat, pkg, ver, rev = portage.catpkgsplit(cpv)

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

        if created and not 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, options, 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 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 purge_versions(self, 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()