import os
import mimetypes

from django.http import HttpResponseRedirect, HttpResponseForbidden
from django.http import Http404
from django.http import HttpResponse, HttpResponseBadRequest
from django.template import RequestContext
from django.contrib.auth.decorators import login_required
from django.core.urlresolvers import reverse
from django.shortcuts import render_to_response, get_object_or_404

from personasbackend.personas import models
from personasbackend.personas import forms

NO_THUMBNAIL_IMAGE = "https://addons.mozilla.org/img/addon-icn.png"

def _render_static_persona( img_src, action ):
    if action == "footer":
        position = "bottom left"
    else:
        position = "top right"

    return render_to_response(
        "personas/static_persona.xul",
        { "image" : img_src, "position" : position },
        mimetype = "application/vnd.mozilla.xul+xml"
        )

def hosted_static_persona( request, persona_id ):
    persona = get_object_or_404( models.Persona, id=persona_id )

    if not (persona.header_img and persona.footer_img):
        raise Http404( "Persona is not statically hosted." )

    action = request.GET.get( "action", "" )

    if action == "footer":
        img_src = persona.get_absolute_footer_img_url()
    elif action == "header":
        img_src = persona.get_absolute_header_img_url()
    else:
        return HttpResponseBadRequest( "Invalid or unsupported action: %s" %
                                       action )

    return _render_static_persona( img_src, action )

def legacy_cbeard_persona( request, name ):
    urldict = {"name" : name}

    action = request.GET.get( "action", "" )

    if action == "footer":
        img_src = models.LEGACY_FOOTER_URL % urldict
    elif action == "header":
        img_src = models.LEGACY_HEADER_URL % urldict
    else:
        return HttpResponseBadRequest( "Invalid or unsupported action: %s" %
                                       action )

    return _render_static_persona( img_src, action )

def thumbnail( request, persona_id ):
    persona = get_object_or_404( models.Persona, id=persona_id )

    if not persona.create_thumbnail():
        return HttpResponseRedirect( NO_THUMBNAIL_IMAGE )

    filename = persona.thumbnail_filename

    mimetype = mimetypes.types_map[ os.path.splitext( filename )[1] ]

    image_data = open( filename, "rb" ).read()

    return HttpResponse( image_data,
                         mimetype = mimetype )

def list_view( request ):
    personas = models.Persona.objects.filter( status="published" )
    return render_to_response(
        "personas/list.html",
        { "personas" : personas,
          "title" : "Browse Personas" },
        context_instance = RequestContext(request)
        )

def home_view( request ):
    return render_to_response(
        "personas/home.html",
        { "title" : "Home" },
        context_instance = RequestContext(request)
        )

def todo_view( request ):
    return render_to_response(
        "personas/todo.html",
        { "title" : "Under Construction" },
        context_instance = RequestContext(request)
        )

def new_view( request ):
    return edit_view( request )

@login_required
def edit_view( request, persona_id=None ):
    if persona_id is None:
        persona = None
        pageTitle = "Create a new Persona"
        formClass = forms.NewPersonaForm
    else:
        persona = get_object_or_404( models.Persona, id=persona_id )
        if not persona.can_user_edit( request.user ):
            return HttpResponseForbidden(
                "<h1>You do not have permission to edit "
                "this Persona.</h1>"
                )
        pageTitle = "Edit Persona \"%s\"" % persona.name
        formClass = forms.EditPersonaForm

    if request.method == "POST":
        form = formClass( request.POST, request.FILES,
                          instance=persona )
        if form.is_valid():
            newPersona = form.save( commit=False )

            if persona is None:
                msgText = "Persona created successfully."
                waitText = ("It will need "
                            "to be reviewed by a staff member "
                            "before it is published.")
            else:
                if (not newPersona.header_img) and persona.header_img:
                    newPersona.header_img = persona.header_img
                if (not newPersona.footer_img) and persona.footer_img:
                    newPersona.footer_img = persona.footer_img
                msgText = "Persona edited successfully."
                waitText = ("Your changes "
                            "will need to be approved by a staff member "
                            "before they can take effect.")

            if not request.user.has_perm("personas.can_publish"):
                msgText += " " + waitText

            newPersona.save( updater = request.user )
            request.user.message_set.create( message = msgText )
            url = reverse("edit-persona", args=[newPersona.id])
            return HttpResponseRedirect( url )
    else:
        form = formClass( instance=persona )

    return render_to_response(
        "personas/edit.html",
        { "form" : form,
          "title" : pageTitle,
          "persona" : persona },
        context_instance = RequestContext(request)
        )