from django.db import transaction
from django.utils import timezone
from django.utils.translation import ugettext as _

from .exceptions import ModerationError


__all__ = [
    'approve_post',
    'protect_post',
    'unprotect_post',
    'unhide_post',
    'hide_post',
    'delete_post',
]


def approve_post(user, post):
    if post.is_unapproved:
        post.is_unapproved = False
        post.save(update_fields=['is_unapproved'])
        return True
    else:
        return False


def protect_post(user, post):
    if not post.is_protected:
        post.is_protected = True
        post.save(update_fields=['is_protected'])
        if post.is_best_answer:
            post.thread.best_answer_is_protected = True
            post.thread.save(update_fields=['best_answer_is_protected'])
        return True
    else:
        return False


def unprotect_post(user, post):
    if post.is_protected:
        post.is_protected = False
        post.save(update_fields=['is_protected'])
        if post.is_best_answer:
            post.thread.best_answer_is_protected = False
            post.thread.save(update_fields=['best_answer_is_protected'])
        return True
    else:
        return False


def unhide_post(user, post):
    if post.is_first_post:
        raise ModerationError(_("You can't make original post visible without revealing thread."))

    if post.is_hidden:
        post.is_hidden = False
        post.save(update_fields=['is_hidden'])
        return True
    else:
        return False


def hide_post(user, post):
    if post.is_first_post:
        raise ModerationError(_("You can't hide original post without hiding thread."))

    if not post.is_hidden:
        post.is_hidden = True
        post.hidden_by = user
        post.hidden_by_name = user.username
        post.hidden_by_slug = user.slug
        post.hidden_on = timezone.now()
        post.save(
            update_fields=[
                'is_hidden',
                'hidden_by',
                'hidden_by_name',
                'hidden_by_slug',
                'hidden_on',
            ]
        )
        return True
    else:
        return False


@transaction.atomic
def delete_post(user, post):
    if post.is_first_post:
        raise ModerationError(_("You can't delete original post without deleting thread."))

    post.delete()
    return True