import datetime

from django.http import HttpResponse, HttpResponseRedirect, Http404
from django.shortcuts import render_to_response, get_object_or_404, redirect
from django.template import RequestContext
from django.contrib import messages
from django.views.generic.list_detail import object_detail, object_list
from django.core.urlresolvers import reverse
from django.views.generic.create_update import create_object, delete_object, update_object
from django.conf import settings
from django.utils.translation import ugettext as _

from permissions.api import check_permissions
from documents.models import Document

from ocr import PERMISSION_OCR_DOCUMENT, PERMISSION_OCR_DOCUMENT_DELETE, \
    PERMISSION_OCR_QUEUE_ENABLE_DISABLE
from models import DocumentQueue, QueueDocument
from literals import QUEUEDOCUMENT_STATE_PENDING, \
    QUEUEDOCUMENT_STATE_PROCESSING, QUEUEDOCUMENT_STATE_ERROR, \
    DOCUMENTQUEUE_STATE_STOPPED, DOCUMENTQUEUE_STATE_ACTIVE
from exceptions import AlreadyQueued


def _display_thumbnail(ocr_document):
    try:
        preview_url = reverse('document_preview', args=[ocr_document.document.pk])
        thumbnail_url = reverse('document_thumbnail', args=[ocr_document.document.pk])
        return u'<a class="fancybox" href="%s"><img src="%s" alt="%s" /></a>' % (preview_url, thumbnail_url, _(u'thumbnail'))
    except:
        return u''


def queue_document_list(request, queue_name='default'):
    check_permissions(request.user, 'ocr', [PERMISSION_OCR_DOCUMENT])
        
    document_queue = get_object_or_404(DocumentQueue, name=queue_name)

    return object_list(
        request,
        queryset=document_queue.queuedocument_set.all(),
        template_name='generic_list.html',
        extra_context={
            'title':_(u'documents in queue: %s') % document_queue,
            'hide_object':True,
            'object':document_queue,
            'object_name':_(u'document queue'),
            'extra_columns':[
                {'name':'document', 'attribute': lambda x: '<a href="%s">%s</a>' % (x.document.get_absolute_url(), x.document) if hasattr(x, 'document') else _(u'Missing document.')},
                {'name':_(u'thumbnail'), 'attribute': lambda x: _display_thumbnail(x) },                
                {'name':'submitted', 'attribute': lambda x: unicode(x.datetime_submitted).split('.')[0], 'keep_together':True},
                {'name':'delay', 'attribute':'delay'},
                {'name':'state', 'attribute': lambda x: x.get_state_display()},
                {'name':'node', 'attribute':'node_name'},
                {'name':'result', 'attribute':'result'},
            ],
            'multi_select_as_buttons':True,            
            'sidebar_subtemplates_list':[
                {
                    'title':_(u'document queue properties'),
                    'name':'generic_subtemplate.html',
                    'content':_(u'Current state: %s') % document_queue.get_state_display(),
                }],
        },
    )    
            
        
def queue_document_delete(request, queue_document_id=None, queue_document_id_list=[]):
    check_permissions(request.user, 'ocr', [PERMISSION_OCR_DOCUMENT_DELETE])

    if queue_document_id:
        queue_documents = [get_object_or_404(QueueDocument, pk=queue_document_id)]
        post_redirect = None
    elif queue_document_id_list:
        queue_documents = [get_object_or_404(QueueDocument, pk=queue_document_id) for queue_document_id in queue_document_id_list.split(',')]
        post_redirect = None
    else:
        messages.error(request, _(u'Must provide at least one queue document.'))
        return HttpResponseRedirect(request.META.get('HTTP_REFERER', '/'))
            
    next = request.POST.get('next', request.GET.get('next', request.META.get('HTTP_REFERER', None)))
    previous = request.POST.get('previous', request.GET.get('previous', request.META.get('HTTP_REFERER', None)))

    if request.method == 'POST':
        for queue_document in queue_documents:
            try:
                queue_document.delete()
                messages.success(request, _(u'Document: %(document)s deleted successfully.') % {
                    'document':queue_document.document})

            except Exception, e:
                messages.error(request, _(u'Error deleting document: %(document)s; %(error)s') % {
                    'document':queue_document, 'error':e})
        return HttpResponseRedirect(next)

    context = {
        'next':next,
        'previous':previous,
        'delete_view':True
    }
    
    if len(queue_documents) == 1:
        context['object'] = queue_documents[0]  
        context['title'] = _(u'Are you sure you with to delete from queue document: %s?') % ', '.join([unicode(d) for d in queue_documents])
    elif len(queue_documents) > 1:
        context['title'] = _(u'Are you sure you with to delete from queue documents: %s?') % ', '.join([unicode(d) for d in queue_documents])
        
    return render_to_response('generic_confirm.html', context,
        context_instance=RequestContext(request))
        

def queue_document_multiple_delete(request):
    return queue_document_delete(request, queue_document_id_list=request.GET.get('id_list', []))
    

def submit_document(request, document_id):
    check_permissions(request.user, 'ocr', [PERMISSION_OCR_DOCUMENT])
        
    document = get_object_or_404(Document, pk=document_id)
    return submit_document_to_queue(request, document=document, 
        post_submit_redirect=request.META['HTTP_REFERER'])
  

def submit_document_to_queue(request, document, post_submit_redirect=None):
    """This view is meant to be reusable"""
    
    try:
        document_queue = DocumentQueue.objects.queue_document(document)
        messages.success(request, _(u'Document: %(document)s was added to the OCR queue: %(queue)s.') % {
            'document':document, 'queue':document_queue.label})
    except AlreadyQueued:
        messages.warning(request, _(u'Document: %(document)s is already queued.') % {
        'document':document})
    except Exception, e:
        messages.error(request, e)

    if post_submit_redirect:
        return HttpResponseRedirect(post_submit_redirect)
        

def re_queue_document(request, queue_document_id=None, queue_document_id_list=[]):
    check_permissions(request.user, 'ocr', [PERMISSION_OCR_DOCUMENT])

    if queue_document_id:
        queue_documents = [get_object_or_404(QueueDocument, pk=queue_document_id)]
        post_redirect = None
    elif queue_document_id_list:
        queue_documents = [get_object_or_404(QueueDocument, pk=queue_document_id) for queue_document_id in queue_document_id_list.split(',')]
        post_redirect = None
    else:
        messages.error(request, _(u'Must provide at least one queue document.'))
        return HttpResponseRedirect(request.META.get('HTTP_REFERER', '/'))
            
    next = request.POST.get('next', request.GET.get('next', request.META.get('HTTP_REFERER', None)))
    previous = request.POST.get('previous', request.GET.get('previous', request.META.get('HTTP_REFERER', None)))

    for queue_document in queue_documents:
        try:
            queue_document.document
        except Document.DoesNotExist:
            messages.error(request, _(u'Document id#: %d, no longer exists.') % queue_document.document_id)
            return HttpResponseRedirect(previous)

        if queue_document.state == QUEUEDOCUMENT_STATE_PENDING:
            messages.warning(request, _(u'Document: %s is already queued and pending processing.') % queue_document)
            return HttpResponseRedirect(previous)
        elif queue_document.state == QUEUEDOCUMENT_STATE_PROCESSING:
            messages.warning(request, _(u'Document: %s is already being processed and can\'t be re-queded.') % queue_document)
            return HttpResponseRedirect(previous)

    if request.method == 'POST':
        for queue_document in queue_documents:
            try:
                if queue_document.state == QUEUEDOCUMENT_STATE_ERROR:
                    queue_document.datetime_submitted = datetime.datetime.now()
                    queue_document.state = QUEUEDOCUMENT_STATE_PENDING
                    queue_document.delay = False
                    queue_document.save()
                    messages.success(request, _(u'Document: %(document)s was re-queued to the OCR queue: %(queue)s') % {
                        'document':queue_document.document, 'queue':queue_document.document_queue.label})

            except Exception, e:
                messages.error(request, e)
        return HttpResponseRedirect(next)

    context = {
        'next':next,
        'previous':previous,
    }
    
    if len(queue_documents) == 1:
        context['object'] = queue_documents[0]  
        context['title'] = _(u'Are you sure you with to re-queue document: %s?') % ', '.join([unicode(d) for d in queue_documents])
    elif len(queue_documents) > 1:
        context['title'] = _(u'Are you sure you with to re-queue documents: %s?') % ', '.join([unicode(d) for d in queue_documents])
        
    return render_to_response('generic_confirm.html', context,
        context_instance=RequestContext(request))


def re_queue_multiple_document(request):
    return re_queue_document(request, queue_document_id_list=request.GET.get('id_list', []))


def document_queue_disable(request, document_queue_id):
    check_permissions(request.user, 'ocr', [PERMISSION_OCR_QUEUE_ENABLE_DISABLE])

    next = request.POST.get('next', request.GET.get('next', request.META.get('HTTP_REFERER', None)))
    previous = request.POST.get('previous', request.GET.get('previous', request.META.get('HTTP_REFERER', None)))    
    document_queue = get_object_or_404(DocumentQueue, pk=document_queue_id)
    
    if document_queue.state == DOCUMENTQUEUE_STATE_STOPPED:
        messages.warning(request, _(u'Document queue: %s, already stopped.') % document_queue)
        return HttpResponseRedirect(previous)

    if request.method == 'POST':
        document_queue.state = DOCUMENTQUEUE_STATE_STOPPED
        document_queue.save()
        messages.success(request, _(u'Document queue: %s, stopped successfully.') % document_queue)
        return HttpResponseRedirect(next)
    
    return render_to_response('generic_confirm.html', {
        'object':document_queue,
        'title':_(u'Are you sure you wish to disable document queue: %s') % document_queue,
        'next':next,
        'previous':previous,
    }, context_instance=RequestContext(request))    
    

def document_queue_enable(request, document_queue_id):
    check_permissions(request.user, 'ocr', [PERMISSION_OCR_QUEUE_ENABLE_DISABLE])

    next = request.POST.get('next', request.GET.get('next', request.META.get('HTTP_REFERER', None)))
    previous = request.POST.get('previous', request.GET.get('previous', request.META.get('HTTP_REFERER', None)))    
    document_queue = get_object_or_404(DocumentQueue, pk=document_queue_id)
    
    if document_queue.state == DOCUMENTQUEUE_STATE_ACTIVE:
        messages.warning(request, _(u'Document queue: %s, already active.') % document_queue)
        return HttpResponseRedirect(previous)

    if request.method == 'POST':
        document_queue.state = DOCUMENTQUEUE_STATE_ACTIVE
        document_queue.save()
        messages.success(request, _(u'Document queue: %s, activated successfully.') % document_queue)
        return HttpResponseRedirect(next)
    
    return render_to_response('generic_confirm.html', {
        'object':document_queue,
        'title':_(u'Are you sure you wish to activate document queue: %s') % document_queue,
        'next':next,
        'previous':previous,
    }, context_instance=RequestContext(request))