from django import http

from django.conf import settings

from utils import next_redirect, confirmation_view

from django.core.exceptions import ObjectDoesNotExist

from django.db import models

from django.shortcuts import render_to_response

from django.template import RequestContext

from django.template.loader import render_to_string

from django.utils.html import escape

from django.views.decorators.http import require_POST

from django.contrib import comments

from django.contrib.comments import signals

class CommentPostBadRequest(http.HttpResponseBadRequest):

    """

    Response returned when a comment post is invalid. If ``DEBUG`` is on a

    nice-ish error message will be displayed (for debugging purposes), but in

    production mode a simple opaque 400 page will be displayed.

    """

    def __init__(self, why):

        super(CommentPostBadRequest, self).__init__()

        if settings.DEBUG:

            self.content = render_to_string("comments/400-debug.html", {"why": why})

def post_comment(request, next=None):

    """

    Post a comment.

    HTTP POST is required. If ``POST['submit'] == "preview"`` or if there are

    errors a preview template, ``comments/preview.html``, will be rendered.

    """

    # Fill out some initial data fields from an authenticated user, if present

    data = request.POST.copy()

    if request.user.is_authenticated():

        if not data.get('name', ''):

            data["name"] = request.user.get_full_name() or request.user.username

        if not data.get('email', ''):

            data["email"] = request.user.email

    # Look up the object we're trying to comment about

    ctype = data.get("content_type")

    object_pk = data.get("object_pk")

    if ctype is None or object_pk is None:

        return CommentPostBadRequest("Missing content_type or object_pk field.")

    try:

        model = models.get_model(*ctype.split(".", 1))

        target = model._default_manager.get(pk=object_pk)

    except TypeError:

        return CommentPostBadRequest(

            "Invalid content_type value: %r" % escape(ctype))

    except AttributeError:

        return CommentPostBadRequest(

            "The given content-type %r does not resolve to a valid model." % \

                escape(ctype))

    except ObjectDoesNotExist:

        return CommentPostBadRequest(

            "No object matching content-type %r and object PK %r exists." % \

                (escape(ctype), escape(object_pk)))

    # Do we want to preview the comment?

    preview = "preview" in data

    # Construct the comment form

    form = comments.get_form()(target, data=data)

    # Check security information

    if form.security_errors():

        return CommentPostBadRequest(

            "The comment form failed security verification: %s" % \

                escape(str(form.security_errors())))

    # If there are errors or if we requested a preview show the comment

    if form.errors or preview:

        template_list = [

            "comments/%s_%s_preview.html" % tuple(str(model._meta).split(".")),

            "comments/%s_preview.html" % model._meta.app_label,

            "comments/preview.html",

        ]

        return render_to_response(

            template_list, {

                "comment" : form.data.get("comment", ""),

                "form" : form,

            },

            RequestContext(request, {})

        )

    # Otherwise create the comment

    comment = form.get_comment_object()

    comment.ip_address = request.META.get("REMOTE_ADDR", None)

    if request.user.is_authenticated():

        comment.user = request.user

    # Signal that the comment is about to be saved

    responses = signals.comment_will_be_posted.send(

        sender  = comment.__class__,

        comment = comment,

        request = request

    )

    for (receiver, response) in responses:

        if response == False:

            return CommentPostBadRequest(

                "comment_will_be_posted receiver %r killed the comment" % receiver.__name__)

    # Save the comment and signal that it was saved

    comment.save()

    signals.comment_was_posted.send(

        sender  = comment.__class__,

        comment = comment,

        request = request

    )

    return next_redirect(data, next, comment_done, c=comment._get_pk_val())

post_comment = require_POST(post_comment)

comment_done = confirmation_view(

    template = "comments/posted.html",

    doc = """Display a "comment was posted" success page."""

)