from django.db import models
from django.core.validators import RegexValidator
from django.contrib.auth.models import User
from django.contrib.sites.models import Site
from django.forms import ValidationError

from main.utils import cache_function, make_choice
from packages.models import PackageRelation
from packages.models import Signoff as PackageSignoff

from datetime import datetime
from itertools import groupby
import pytz

class PositiveBigIntegerField(models.BigIntegerField):
    _south_introspects = True

    def get_internal_type(self):
        return "BigIntegerField"

    def formfield(self, **kwargs):
        defaults = {'min_value': 0}
        defaults.update(kwargs)
        return super(PositiveBigIntegerField, self).formfield(**defaults)

class PGPKeyField(models.CharField):
    _south_introspects = True

    def to_python(self, value):
        if value == '':
            return None
        value = super(PGPKeyField, self).to_python(value)
        # remove all spaces
        value = value.replace(' ', '')
        # prune prefixes, either 0x or 2048R/ type
        if value.startswith('0x'):
            value = value[2:]
        value = value.split('/')[-1]
        return value

    def formfield(self, **kwargs):
        # override so we don't set max_length form field attribute
        return models.Field.formfield(self, **kwargs)

def validate_pgp_key_length(value):
    if len(value) not in (8, 16, 40):
        raise ValidationError(
                u'Ensure this value has 8, 16, or 40 characters (it has %d).' % len(value),
                'pgp_key_value')

class UserProfile(models.Model):
    notify = models.BooleanField(
        "Send notifications",
        default=True,
        help_text="When enabled, send user 'flag out-of-date' notifications")
    time_zone = models.CharField(
        max_length=100,
        choices=make_choice(pytz.common_timezones),
        default="UTC",
        help_text="Used for developer clock page")
    alias = models.CharField(
        max_length=50,
        help_text="Required field")
    public_email = models.CharField(
        max_length=50,
        help_text="Required field")
    other_contact = models.CharField(max_length=100, null=True, blank=True)
    pgp_key = PGPKeyField(max_length=40, null=True, blank=True,
        verbose_name="PGP key", validators=[RegexValidator(r'^[0-9A-F]+$',
            "Ensure this value consists of only hex characters.", 'hex_char'),
            validate_pgp_key_length],
        help_text="PGP Key ID or fingerprint (8, 16, or 40 hex digits)")
    website = models.CharField(max_length=200, null=True, blank=True)
    yob = models.IntegerField("Year of birth", null=True, blank=True)
    location = models.CharField(max_length=50, null=True, blank=True)
    languages = models.CharField(max_length=50, null=True, blank=True)
    interests = models.CharField(max_length=255, null=True, blank=True)
    occupation = models.CharField(max_length=50, null=True, blank=True)
    roles = models.CharField(max_length=255, null=True, blank=True)
    favorite_distros = models.CharField(max_length=255, null=True, blank=True)
    picture = models.FileField(upload_to='devs', default='devs/silhouette.png',
        help_text="Ideally 125px by 125px")
    user = models.OneToOneField(User, related_name='userprofile')
    allowed_repos = models.ManyToManyField('Repo', blank=True)
    class Meta:
        db_table = 'user_profiles'
        verbose_name = 'Additional Profile Data'
        verbose_name_plural = 'Additional Profile Data'


class TodolistManager(models.Manager):
    def incomplete(self):
        return self.filter(todolistpkg__complete=False).distinct()

class PackageManager(models.Manager):
    def flagged(self):
        """Used by dev dashboard."""
        return self.filter(flag_date__isnull=False)

    def normal(self):
        return self.select_related('arch', 'repo')

class Donor(models.Model):
    name = models.CharField(max_length=255, unique=True)
    visible = models.BooleanField(default=True,
            help_text="Should we show this donor on the public page?")

    def __unicode__(self):
        return self.name

    class Meta:
        db_table = 'donors'
        ordering = ['name']

class Arch(models.Model):
    name = models.CharField(max_length=255, unique=True)
    agnostic = models.BooleanField(default=False,
            help_text="Is this architecture non-platform specific?")

    def __unicode__(self):
        return self.name

    def __lt__(self, other):
        return self.name < other.name

    class Meta:
        db_table = 'arches'
        ordering = ['name']
        verbose_name_plural = 'arches'

class Repo(models.Model):
    name = models.CharField(max_length=255, unique=True)
    testing = models.BooleanField(default=False,
            help_text="Is this repo meant for package testing?")
    staging = models.BooleanField(default=False,
            help_text="Is this repo meant for package staging?")
    bugs_project = models.SmallIntegerField(default=1,
            help_text="Flyspray project ID for this repository.")
    bugs_category = models.SmallIntegerField(default=0,
            help_text="Flyspray category ID for this repository.")
    svn_root = models.CharField(max_length=64,
            help_text="SVN root (e.g. path) for this repository.")

    def __unicode__(self):
        return self.name

    def __lt__(self, other):
        return self.name < other.name

    class Meta:
        db_table = 'repos'
        ordering = ['name']
        verbose_name_plural = 'repos'

class Package(models.Model):
    repo = models.ForeignKey(Repo, related_name="packages",
            on_delete=models.PROTECT)
    arch = models.ForeignKey(Arch, related_name="packages",
            on_delete=models.PROTECT)
    pkgname = models.CharField(max_length=255, db_index=True)
    pkgbase = models.CharField(max_length=255, db_index=True)
    pkgver = models.CharField(max_length=255)
    pkgrel = models.CharField(max_length=255)
    epoch = models.PositiveIntegerField(default=0)
    pkgdesc = models.CharField(max_length=255, null=True)
    url = models.CharField(max_length=255, null=True)
    filename = models.CharField(max_length=255)
    compressed_size = PositiveBigIntegerField()
    installed_size = PositiveBigIntegerField()
    build_date = models.DateTimeField(null=True)
    last_update = models.DateTimeField()
    files_last_update = models.DateTimeField(null=True, blank=True)
    packager_str = models.CharField(max_length=255)
    packager = models.ForeignKey(User, null=True,
            on_delete=models.SET_NULL)
    flag_date = models.DateTimeField(null=True)

    objects = PackageManager()
    class Meta:
        db_table = 'packages'
        ordering = ('pkgname',)
        get_latest_by = 'last_update'

    def __unicode__(self):
        return self.pkgname

    @property
    def full_version(self):
        if self.epoch > 0:
            return u'%d:%s-%s' % (self.epoch, self.pkgver, self.pkgrel)
        return u'%s-%s' % (self.pkgver, self.pkgrel)

    def get_absolute_url(self):
        return '/packages/%s/%s/%s/' % (self.repo.name.lower(),
                self.arch.name, self.pkgname)

    def get_full_url(self, proto='http'):
        '''get a URL suitable for things like email including the domain'''
        domain = Site.objects.get_current().domain
        return '%s://%s%s' % (proto, domain, self.get_absolute_url())

    @property
    def maintainers(self):
        return User.objects.filter(
                package_relations__pkgbase=self.pkgbase,
                package_relations__type=PackageRelation.MAINTAINER)

    @property
    def signoffs(self):
        return PackageSignoff.objects.select_related('user').filter(
            pkgbase=self.pkgbase, pkgver=self.pkgver, pkgrel=self.pkgrel,
            epoch=self.epoch, arch=self.arch, repo=self.repo)

    def approved_for_signoff(self):
        count = self.signoffs.filter(revoked__isnull=True).count()
        return count >= PackageSignoff.REQUIRED

    @cache_function(300)
    def applicable_arches(self):
        '''The list of (this arch) + (available agnostic arches).'''
        arches = set(Arch.objects.filter(agnostic=True))
        arches.add(self.arch)
        return list(arches)

    @cache_function(300)
    def get_requiredby(self):
        """
        Returns a list of package objects. An attempt will be made to keep this
        list slim by including the corresponding package in the same testing
        category as this package if that check makes sense.
        """
        requiredby = PackageDepend.objects.select_related('pkg',
                'pkg__arch', 'pkg__repo').filter(
                depname=self.pkgname).order_by(
                'pkg__pkgname', 'pkg__arch__name', 'pkg__repo__name')
        if not self.arch.agnostic:
            # make sure we match architectures if possible
            requiredby = requiredby.filter(
                    pkg__arch__in=self.applicable_arches())
        # sort out duplicate packages; this happens if something has a double
        # versioned dep such as a kernel module
        requiredby = [list(vals)[0] for k, vals in
                groupby(requiredby, lambda x: x.pkg.id)]

        # find another package by this name in the opposite testing setup
        # TODO: figure out staging exclusions too
        if not Package.objects.filter(pkgname=self.pkgname,
                arch=self.arch).exclude(id=self.id).exclude(
                repo__testing=self.repo.testing).exists():
            # there isn't one? short circuit, all required by entries are fine
            return requiredby

        trimmed = []
        # for each unique package name, try to screen our package list down to
        # those packages in the same testing category (yes or no) iff there is
        # a package in the same testing category.
        for name, dep_pkgs in groupby(requiredby, lambda x: x.pkg.pkgname):
            dep_pkgs = list(dep_pkgs)
            dep = dep_pkgs[0]
            if len(dep_pkgs) > 1:
                dep_pkgs = [d for d in dep_pkgs
                        if d.pkg.repo.testing == self.repo.testing and
                        d.pkg.repo.staging == self.repo.staging]
                if len(dep_pkgs) > 0:
                    dep = dep_pkgs[0]
            trimmed.append(dep)
        return trimmed

    @cache_function(300)
    def get_depends(self):
        """
        Returns a list of dicts. Each dict contains ('pkg' and 'dep'). If it
        represents a found package both vars will be available; else pkg will
        be None if it is a 'virtual' dependency. Packages will match the
        testing status of this package if possible.
        """
        deps = []
        # TODO: we can use list comprehension and an 'in' query to make this more effective
        for dep in self.packagedepend_set.order_by('optional', 'depname'):
            pkgs = Package.objects.normal().filter(pkgname=dep.depname)
            if not self.arch.agnostic:
                # make sure we match architectures if possible
                pkgs = pkgs.filter(arch__in=self.applicable_arches())
            if len(pkgs) == 0:
                # couldn't find a package in the DB
                # it should be a virtual depend (or a removed package)
                pkg = None
            elif len(pkgs) == 1:
                pkg = pkgs[0]
            else:
                # more than one package, see if we can't shrink it down
                # grab the first though in case we fail
                pkg = pkgs[0]
                # prevents yet more DB queries, these lists should be short
                pkgs = [p for p in pkgs if p.repo.testing == self.repo.testing
                        and p.repo.staging == self.repo.staging]
                if len(pkgs) > 0:
                    pkg = pkgs[0]
            deps.append({'dep': dep, 'pkg': pkg})
        return deps

    def base_package(self):
        """
        Locate the base package for this package. It may be this very package,
        or if it was built in a way that the base package isn't real, will
        return None.
        """
        try:
            # start by looking for something in this repo
            return Package.objects.get(arch=self.arch,
                    repo=self.repo, pkgname=self.pkgbase)
        except Package.DoesNotExist:
            # this package might be split across repos? just find one
            # that matches the correct [testing] repo flag
            pkglist = Package.objects.filter(arch=self.arch,
                    repo__testing=self.repo.testing,
                    repo__staging=self.repo.staging, pkgname=self.pkgbase)
            if len(pkglist) > 0:
                return pkglist[0]
            return None

    def split_packages(self):
        """
        Return all packages that were built with this one (e.g. share a pkgbase
        value). The package this method is called on will never be in the list,
        and we will never return a package that does not have the same
        repo.testing and repo.staging flags. For any non-split packages, the
        return value will be an empty list.
        """
        return Package.objects.filter(arch__in=self.applicable_arches(),
                repo__testing=self.repo.testing, repo__staging=self.repo.staging,
                pkgbase=self.pkgbase).exclude(id=self.id)

    def is_same_version(self, other):
        'is this package similar, name and version-wise, to another'
        return self.pkgname == other.pkgname \
                and self.pkgver == other.pkgver \
                and self.pkgrel == other.pkgrel \
                and self.epoch == other.epoch

    def in_testing(self):
        '''attempt to locate this package in a testing repo; if we are in
        a testing repo we will always return None.'''
        if self.repo.testing:
            return None
        try:
            return Package.objects.normal().get(repo__testing=True,
                    pkgname=self.pkgname, arch=self.arch)
        except Package.DoesNotExist:
            return None

    def in_staging(self):
        '''attempt to locate this package in a staging repo; if we are in
        a staging repo we will always return None.'''
        if self.repo.staging:
            return None
        try:
            return Package.objects.normal().get(repo__staging=True,
                    pkgname=self.pkgname, arch=self.arch)
        except Package.DoesNotExist:
            return None

    def elsewhere(self):
        '''attempt to locate this package anywhere else, regardless of
        architecture or repository. Excludes this package from the list.'''
        return Package.objects.normal().filter(
                pkgname=self.pkgname).exclude(id=self.id).order_by(
                'arch__name', 'repo__name')

class Signoff(models.Model):
    pkg = models.ForeignKey(Package)
    pkgver = models.CharField(max_length=255)
    pkgrel = models.CharField(max_length=255)
    packager = models.ForeignKey(User)

class PackageFile(models.Model):
    pkg = models.ForeignKey(Package)
    is_directory = models.BooleanField(default=False)
    directory = models.CharField(max_length=255)
    filename = models.CharField(max_length=255, null=True, blank=True)

    def __unicode__(self):
        return "%s%s" % (self.directory, self.filename or '')

    class Meta:
        db_table = 'package_files'

class PackageDepend(models.Model):
    pkg = models.ForeignKey(Package)
    depname = models.CharField(max_length=255, db_index=True)
    depvcmp = models.CharField(max_length=255, default='')
    optional = models.BooleanField(default=False)
    description = models.TextField(null=True, blank=True)

    def __unicode__(self):
        return "%s%s" % (self.depname, self.depvcmp)

    class Meta:
        db_table = 'package_depends'

class Todolist(models.Model):
    creator = models.ForeignKey(User, on_delete=models.PROTECT)
    name = models.CharField(max_length=255)
    description = models.TextField()
    date_added = models.DateTimeField(db_index=True)
    objects = TodolistManager()

    def __unicode__(self):
        return self.name

    @property
    def packages(self):
        # select_related() does not use LEFT OUTER JOIN for nullable ForeignKey
        # fields. That is why we need to explicitly list the ones we want.
        return TodolistPkg.objects.select_related(
            'pkg__repo', 'pkg__arch').filter(list=self).order_by('pkg')

    @property
    def package_names(self):
        # depends on packages property returning a queryset
        return self.packages.values_list('pkg__pkgname', flat=True).distinct()

    class Meta:
        db_table = 'todolists'

    def get_absolute_url(self):
        return '/todo/%i/' % self.id

class TodolistPkg(models.Model):
    list = models.ForeignKey(Todolist)
    pkg = models.ForeignKey(Package)
    complete = models.BooleanField(default=False)
    class Meta:
        db_table = 'todolist_pkgs'
        unique_together = (('list','pkg'),)

def set_todolist_fields(sender, **kwargs):
    todolist = kwargs['instance']
    if not todolist.date_added:
        todolist.date_added = datetime.utcnow()

# connect signals needed to keep cache in line with reality
from main.utils import refresh_latest
from django.db.models.signals import pre_save, post_save

post_save.connect(refresh_latest, sender=Package,
        dispatch_uid="main.models")
pre_save.connect(set_todolist_fields, sender=Todolist,
        dispatch_uid="main.models")

# vim: set ts=4 sw=4 et: