from django.db import models
from django.contrib.auth.models import User

from datetime import datetime

from .util import DiffableModel

from pgcommitfest.userprofile.models import UserProfile


# We have few enough of these, and it's really the only thing we
# need to extend from the user model, so just create a separate
# class.
class Committer(models.Model):
    user = models.OneToOneField(User, null=False, blank=False, primary_key=True, on_delete=models.CASCADE)
    active = models.BooleanField(null=False, blank=False, default=True)

    def __str__(self):
        return str(self.user)

    @property
    def fullname(self):
        return "%s %s (%s)" % (self.user.first_name, self.user.last_name, self.user.username)

    class Meta:
        ordering = ('user__last_name', 'user__first_name')


class CommitFest(models.Model):
    STATUS_FUTURE = 1
    STATUS_OPEN = 2
    STATUS_INPROGRESS = 3
    STATUS_CLOSED = 4
    _STATUS_CHOICES = (
        (STATUS_FUTURE, 'Future'),
        (STATUS_OPEN, 'Open'),
        (STATUS_INPROGRESS, 'In Progress'),
        (STATUS_CLOSED, 'Closed'),
    )
    name = models.CharField(max_length=100, blank=False, null=False, unique=True)
    status = models.IntegerField(null=False, blank=False, default=1, choices=_STATUS_CHOICES)
    startdate = models.DateField(blank=True, null=True)
    enddate = models.DateField(blank=True, null=True)

    @property
    def statusstring(self):
        return [v for k, v in self._STATUS_CHOICES if k == self.status][0]

    @property
    def periodstring(self):
        if self.startdate and self.enddate:
            return "{0} - {1}".format(self.startdate, self.enddate)
        return ""

    @property
    def title(self):
        return "Commitfest %s" % self.name

    @property
    def isopen(self):
        return self.status == self.STATUS_OPEN

    def __str__(self):
        return self.name

    class Meta:
        verbose_name_plural = 'Commitfests'
        ordering = ('-startdate',)


class Topic(models.Model):
    topic = models.CharField(max_length=100, blank=False, null=False)

    def __str__(self):
        return self.topic


class TargetVersion(models.Model):
    version = models.CharField(max_length=8, blank=False, null=False, unique=True)

    class Meta:
        ordering = ['-version', ]

    def __str__(self):
        return self.version


class Patch(models.Model, DiffableModel):
    name = models.CharField(max_length=500, blank=False, null=False, verbose_name='Description')
    topic = models.ForeignKey(Topic, blank=False, null=False, on_delete=models.CASCADE)

    # One patch can be in multiple commitfests, if it has history
    commitfests = models.ManyToManyField(CommitFest, through='PatchOnCommitFest')

    # If there is a wiki page discussing this patch
    wikilink = models.URLField(blank=True, null=False, default='')

    # If there is a git repo about this patch
    gitlink = models.URLField(blank=True, null=False, default='')

    # Version targeted by this patch
    targetversion = models.ForeignKey(TargetVersion, blank=True, null=True, verbose_name="Target version", on_delete=models.CASCADE)

    authors = models.ManyToManyField(User, related_name='patch_author', blank=True)
    reviewers = models.ManyToManyField(User, related_name='patch_reviewer', blank=True)

    committer = models.ForeignKey(Committer, blank=True, null=True, on_delete=models.CASCADE)

    # Users to be notified when something happens
    subscribers = models.ManyToManyField(User, related_name='patch_subscriber', blank=True)

    # Datestamps for tracking activity
    created = models.DateTimeField(blank=False, null=False, auto_now_add=True)
    modified = models.DateTimeField(blank=False, null=False)

    # Materialize the last time an email was sent on any of the threads
    # that's attached to this message.
    lastmail = models.DateTimeField(blank=True, null=True)

    map_manytomany_for_diff = {
        'authors': 'authors_string',
        'reviewers': 'reviewers_string',
    }

    # Some accessors
    @property
    def authors_string(self):
        return ", ".join(["%s %s (%s)" % (a.first_name, a.last_name, a.username) for a in self.authors.all()])

    @property
    def reviewers_string(self):
        return ", ".join(["%s %s (%s)" % (a.first_name, a.last_name, a.username) for a in self.reviewers.all()])

    @property
    def history(self):
        # Need to wrap this in a function to make sure it calls
        # select_related() and doesn't generate a bazillion queries
        return self.patchhistory_set.select_related('by').all()

    def set_modified(self, newmod=None):
        # Set the modified date to newmod, but only if that's newer than
        # what's currently set. If newmod is not specified, use the
        # current timestamp.
        if not newmod:
            newmod = datetime.now()
        if not self.modified or newmod > self.modified:
            self.modified = newmod

    def update_lastmail(self):
        # Update the lastmail field, based on the newest email in any of
        # the threads attached to it.
        threads = list(self.mailthread_set.all())
        if len(threads) == 0:
            self.lastmail = None
        else:
            self.lastmail = max(threads, key=lambda t: t.latestmessage).latestmessage

    def __str__(self):
        return self.name

    class Meta:
        verbose_name_plural = 'patches'


class PatchOnCommitFest(models.Model):
    # NOTE! This is also matched by the commitfest_patchstatus table,
    # but we hardcoded it in here simply for performance reasons since
    # the data should be entirely static. (Yes, that's something we
    # might re-evaluate in the future)
    STATUS_REVIEW = 1
    STATUS_AUTHOR = 2
    STATUS_COMMITTER = 3
    STATUS_COMMITTED = 4
    STATUS_NEXT = 5
    STATUS_REJECTED = 6
    STATUS_RETURNED = 7
    STATUS_WITHDRAWN = 8
    _STATUS_CHOICES = (
        (STATUS_REVIEW, 'Needs review'),
        (STATUS_AUTHOR, 'Waiting on Author'),
        (STATUS_COMMITTER, 'Ready for Committer'),
        (STATUS_COMMITTED, 'Committed'),
        (STATUS_NEXT, 'Moved to next CF'),
        (STATUS_REJECTED, 'Rejected'),
        (STATUS_RETURNED, 'Returned with feedback'),
        (STATUS_WITHDRAWN, 'Withdrawn'),
    )
    _STATUS_LABELS = (
        (STATUS_REVIEW, 'default'),
        (STATUS_AUTHOR, 'primary'),
        (STATUS_COMMITTER, 'info'),
        (STATUS_COMMITTED, 'success'),
        (STATUS_NEXT, 'warning'),
        (STATUS_REJECTED, 'danger'),
        (STATUS_RETURNED, 'danger'),
        (STATUS_WITHDRAWN, 'danger'),
    )
    OPEN_STATUSES = [STATUS_REVIEW, STATUS_AUTHOR, STATUS_COMMITTER]

    @classmethod
    def OPEN_STATUS_CHOICES(cls):
        return [x for x in cls._STATUS_CHOICES if x[0] in cls.OPEN_STATUSES]

    patch = models.ForeignKey(Patch, blank=False, null=False, on_delete=models.CASCADE)
    commitfest = models.ForeignKey(CommitFest, blank=False, null=False, on_delete=models.CASCADE)
    enterdate = models.DateTimeField(blank=False, null=False)
    leavedate = models.DateTimeField(blank=True, null=True)

    status = models.IntegerField(blank=False, null=False, default=STATUS_REVIEW, choices=_STATUS_CHOICES)

    @property
    def is_closed(self):
        return self.status not in self.OPEN_STATUSES

    @property
    def statusstring(self):
        return [v for k, v in self._STATUS_CHOICES if k == self.status][0]

    class Meta:
        unique_together = (('patch', 'commitfest',),)
        ordering = ('-commitfest__startdate', )


class PatchHistory(models.Model):
    patch = models.ForeignKey(Patch, blank=False, null=False, on_delete=models.CASCADE)
    date = models.DateTimeField(blank=False, null=False, auto_now_add=True, db_index=True)
    by = models.ForeignKey(User, blank=False, null=False, on_delete=models.CASCADE)
    what = models.CharField(max_length=500, null=False, blank=False)

    @property
    def by_string(self):
        return "%s %s (%s)" % (self.by.first_name, self.by.last_name, self.by.username)

    def __str__(self):
        return "%s - %s" % (self.patch.name, self.date)

    class Meta:
        ordering = ('-date', )

    def save_and_notify(self, prevcommitter=None,
                        prevreviewers=None, prevauthors=None):
        # Save this model, and then trigger notifications if there are any. There are
        # many different things that can trigger notifications, so try them all.
        self.save()

        recipients = []
        recipients.extend(self.patch.subscribers.all())

        # Current or previous committer wants all notifications
        try:
            if self.patch.committer and self.patch.committer.user.userprofile.notify_all_committer:
                recipients.append(self.patch.committer.user)
        except UserProfile.DoesNotExist:
            pass

        try:
            if prevcommitter and prevcommitter.user.userprofile.notify_all_committer:
                recipients.append(prevcommitter.user)
        except UserProfile.DoesNotExist:
            pass

        # Current or previous reviewers wants all notifications
        recipients.extend(self.patch.reviewers.filter(userprofile__notify_all_reviewer=True))
        if prevreviewers:
            # prevreviewers is a list
            recipients.extend(User.objects.filter(id__in=[p.id for p in prevreviewers], userprofile__notify_all_reviewer=True))

        # Current or previous authors wants all notifications
        recipients.extend(self.patch.authors.filter(userprofile__notify_all_author=True))

        for u in set(recipients):
            if u != self.by:  # Don't notify for changes we make ourselves
                PendingNotification(history=self, user=u).save()


class MailThread(models.Model):
    # This class tracks mail threads from the main postgresql.org
    # mailinglist archives. For each thread, we store *one* messageid.
    # Using this messageid we can always query the archives for more
    # detailed information, which is done dynamically as the page
    # is loaded.
    # For threads in an active or future commitfest, we also poll
    # the archives to fetch "updated entries" at (ir)regular intervals
    # so we can keep track of when there was last a change on the
    # thread in question.
    messageid = models.CharField(max_length=1000, null=False, blank=False, unique=True)
    patches = models.ManyToManyField(Patch, blank=False)
    subject = models.CharField(max_length=500, null=False, blank=False)
    firstmessage = models.DateTimeField(null=False, blank=False)
    firstauthor = models.CharField(max_length=500, null=False, blank=False)
    latestmessage = models.DateTimeField(null=False, blank=False)
    latestauthor = models.CharField(max_length=500, null=False, blank=False)
    latestsubject = models.CharField(max_length=500, null=False, blank=False)
    latestmsgid = models.CharField(max_length=1000, null=False, blank=False)

    def __str__(self):
        return self.subject

    class Meta:
        ordering = ('firstmessage', )


class MailThreadAttachment(models.Model):
    mailthread = models.ForeignKey(MailThread, null=False, blank=False, on_delete=models.CASCADE)
    messageid = models.CharField(max_length=1000, null=False, blank=False)
    attachmentid = models.IntegerField(null=False, blank=False)
    filename = models.CharField(max_length=1000, null=False, blank=True)
    date = models.DateTimeField(null=False, blank=False)
    author = models.CharField(max_length=500, null=False, blank=False)
    ispatch = models.BooleanField(null=True)

    class Meta:
        ordering = ('-date',)
        unique_together = (('mailthread', 'messageid',), )


class MailThreadAnnotation(models.Model):
    mailthread = models.ForeignKey(MailThread, null=False, blank=False, on_delete=models.CASCADE)
    date = models.DateTimeField(null=False, blank=False, auto_now_add=True)
    user = models.ForeignKey(User, null=False, blank=False, on_delete=models.CASCADE)
    msgid = models.CharField(max_length=1000, null=False, blank=False)
    annotationtext = models.TextField(null=False, blank=False, max_length=2000)
    mailsubject = models.CharField(max_length=500, null=False, blank=False)
    maildate = models.DateTimeField(null=False, blank=False)
    mailauthor = models.CharField(max_length=500, null=False, blank=False)

    @property
    def user_string(self):
        return "%s %s (%s)" % (self.user.first_name, self.user.last_name, self.user.username)

    class Meta:
        ordering = ('date', )


class PatchStatus(models.Model):
    status = models.IntegerField(null=False, blank=False, primary_key=True)
    statusstring = models.TextField(max_length=50, null=False, blank=False)
    sortkey = models.IntegerField(null=False, blank=False, default=10)


class PendingNotification(models.Model):
    history = models.ForeignKey(PatchHistory, blank=False, null=False, on_delete=models.CASCADE)
    user = models.ForeignKey(User, blank=False, null=False, on_delete=models.CASCADE)