import datetime

import time

from django.template import loader, RequestContext

from django.core.exceptions import ObjectDoesNotExist

from django.core.xheaders import populate_xheaders

from django.db.models.fields import DateTimeField

from django.http import Http404, HttpResponse

def archive_index(request, queryset, date_field, num_latest=15,

        template_name=None, template_loader=loader,

        extra_context=None, allow_empty=True, context_processors=None,

        mimetype=None, allow_future=False, template_object_name='latest'):

    """

    Generic top-level archive of date-based objects.

    Templates: ``<app_label>/<model_name>_archive.html``

    Context:

        date_list

            List of years

        latest

            Latest N (defaults to 15) objects by date

    """

    if extra_context is None: extra_context = {}

    model = queryset.model

    if not allow_future:

        queryset = queryset.filter(**{'%s__lte' % date_field: datetime.datetime.now()})

    date_list = queryset.dates(date_field, 'year')[::-1]

    if not date_list and not allow_empty:

        raise Http404, "No %s available" % model._meta.verbose_name

    if date_list and num_latest:

        latest = queryset.order_by('-'+date_field)[:num_latest]

    else:

        latest = None

    if not template_name:

        template_name = "%s/%s_archive.html" % (model._meta.app_label, model._meta.object_name.lower())

    t = template_loader.get_template(template_name)

    c = RequestContext(request, {

        'date_list' : date_list,

        template_object_name : latest,

    }, context_processors)

    for key, value in extra_context.items():

        if callable(value):

            c[key] = value()

        else:

            c[key] = value

    return HttpResponse(t.render(c), mimetype=mimetype)

def archive_year(request, year, queryset, date_field, template_name=None,

        template_loader=loader, extra_context=None, allow_empty=False,

        context_processors=None, template_object_name='object', mimetype=None,

        make_object_list=False, allow_future=False):

    """

    Generic yearly archive view.

    Templates: ``<app_label>/<model_name>_archive_year.html``

    Context:

        date_list

            List of months in this year with objects

        year

            This year

        object_list

            List of objects published in the given month

            (Only available if make_object_list argument is True)

    """

    if extra_context is None: extra_context = {}

    model = queryset.model

    now = datetime.datetime.now()

    lookup_kwargs = {'%s__year' % date_field: year}

    # Only bother to check current date if the year isn't in the past and future objects aren't requested.

    if int(year) >= now.year and not allow_future:

        lookup_kwargs['%s__lte' % date_field] = now

    date_list = queryset.filter(**lookup_kwargs).dates(date_field, 'month')

    if not date_list and not allow_empty:

        raise Http404

    if make_object_list:

        object_list = queryset.filter(**lookup_kwargs)

    else:

        object_list = []

    if not template_name:

        template_name = "%s/%s_archive_year.html" % (model._meta.app_label, model._meta.object_name.lower())

    t = template_loader.get_template(template_name)

    c = RequestContext(request, {

        'date_list': date_list,

        'year': year,

        '%s_list' % template_object_name: object_list,

    }, context_processors)

    for key, value in extra_context.items():

        if callable(value):

            c[key] = value()

        else:

            c[key] = value

    return HttpResponse(t.render(c), mimetype=mimetype)

def archive_month(request, year, month, queryset, date_field,

        month_format='%b', template_name=None, template_loader=loader,

        extra_context=None, allow_empty=False, context_processors=None,

        template_object_name='object', mimetype=None, allow_future=False):

    """

    Generic monthly archive view.

    Templates: ``<app_label>/<model_name>_archive_month.html``

    Context:

        month:

            (date) this month

        next_month:

            (date) the first day of the next month, or None if the next month is in the future

        previous_month:

            (date) the first day of the previous month

        object_list:

            list of objects published in the given month

    """

    if extra_context is None: extra_context = {}

    try:

        date = datetime.date(*time.strptime(year+month, '%Y'+month_format)[:3])

    except ValueError:

        raise Http404

    model = queryset.model

    now = datetime.datetime.now()

    # Calculate first and last day of month, for use in a date-range lookup.

    first_day = date.replace(day=1)

    if first_day.month == 12:

        last_day = first_day.replace(year=first_day.year + 1, month=1)

    else:

        last_day = first_day.replace(month=first_day.month + 1)

    lookup_kwargs = {

        '%s__gte' % date_field: first_day,

        '%s__lt' % date_field: last_day,

    }

    # Only bother to check current date if the month isn't in the past and future objects are requested.

    if last_day >= now.date() and not allow_future:

        lookup_kwargs['%s__lte' % date_field] = now

    object_list = queryset.filter(**lookup_kwargs)

    if not object_list and not allow_empty:

        raise Http404

    # Calculate the next month, if applicable.

    if allow_future:

        next_month = last_day + datetime.timedelta(days=1)

    elif last_day < datetime.date.today():

        next_month = last_day + datetime.timedelta(days=1)

    else:

        next_month = None

    if not template_name:

        template_name = "%s/%s_archive_month.html" % (model._meta.app_label, model._meta.object_name.lower())

    t = template_loader.get_template(template_name)

    c = RequestContext(request, {

        '%s_list' % template_object_name: object_list,

        'month': date,

        'next_month': next_month,

        'previous_month': first_day - datetime.timedelta(days=1),

    }, context_processors)

    for key, value in extra_context.items():

        if callable(value):

            c[key] = value()

        else:

            c[key] = value

    return HttpResponse(t.render(c), mimetype=mimetype)

def archive_week(request, year, week, queryset, date_field,

        template_name=None, template_loader=loader,

        extra_context=None, allow_empty=True, context_processors=None,

        template_object_name='object', mimetype=None, allow_future=False):

    """

    Generic weekly archive view.

    Templates: ``<app_label>/<model_name>_archive_week.html``

    Context:

        week:

            (date) this week

        object_list:

            list of objects published in the given week

    """

    if extra_context is None: extra_context = {}

    try:

        date = datetime.date(*time.strptime(year+'-0-'+week, '%Y-%w-%U')[:3])

    except ValueError:

        raise Http404

    model = queryset.model

    now = datetime.datetime.now()

    # Calculate first and last day of week, for use in a date-range lookup.

    first_day = date

    last_day = date + datetime.timedelta(days=7)

    lookup_kwargs = {

        '%s__gte' % date_field: first_day,

        '%s__lt' % date_field: last_day,

    }

    # Only bother to check current date if the week isn't in the past and future objects aren't requested.

    if last_day >= now.date() and not allow_future:

        lookup_kwargs['%s__lte' % date_field] = now

    object_list = queryset.filter(**lookup_kwargs)

    if not object_list and not allow_empty:

        raise Http404

    if not template_name:

        template_name = "%s/%s_archive_week.html" % (model._meta.app_label, model._meta.object_name.lower())

    t = template_loader.get_template(template_name)

    c = RequestContext(request, {

        '%s_list' % template_object_name: object_list,

        'week': date,

    })

    for key, value in extra_context.items():

        if callable(value):

            c[key] = value()

        else:

            c[key] = value

    return HttpResponse(t.render(c), mimetype=mimetype)

def archive_day(request, year, month, day, queryset, date_field,

        month_format='%b', day_format='%d', template_name=None,

        template_loader=loader, extra_context=None, allow_empty=False,

        context_processors=None, template_object_name='object',

        mimetype=None, allow_future=False):

    """

    Generic daily archive view.

    Templates: ``<app_label>/<model_name>_archive_day.html``

    Context:

        object_list:

            list of objects published that day

        day:

            (datetime) the day

        previous_day

            (datetime) the previous day

        next_day

            (datetime) the next day, or None if the current day is today

    """

    if extra_context is None: extra_context = {}

    try:

        date = datetime.date(*time.strptime(year+month+day, '%Y'+month_format+day_format)[:3])

    except ValueError:

        raise Http404

    model = queryset.model

    now = datetime.datetime.now()

    if isinstance(model._meta.get_field(date_field), DateTimeField):

        lookup_kwargs = {'%s__range' % date_field: (datetime.datetime.combine(date, datetime.time.min), datetime.datetime.combine(date, datetime.time.max))}

    else:

        lookup_kwargs = {date_field: date}

    # Only bother to check current date if the date isn't in the past and future objects aren't requested.

    if date >= now.date() and not allow_future:

        lookup_kwargs['%s__lte' % date_field] = now

    object_list = queryset.filter(**lookup_kwargs)

    if not allow_empty and not object_list:

        raise Http404

    # Calculate the next day, if applicable.

    if allow_future:

        next_day = date + datetime.timedelta(days=1)

    elif date < datetime.date.today():

        next_day = date + datetime.timedelta(days=1)

    else:

        next_day = None

    if not template_name:

        template_name = "%s/%s_archive_day.html" % (model._meta.app_label, model._meta.object_name.lower())

    t = template_loader.get_template(template_name)

    c = RequestContext(request, {

        '%s_list' % template_object_name: object_list,

        'day': date,

        'previous_day': date - datetime.timedelta(days=1),

        'next_day': next_day,

    }, context_processors)

    for key, value in extra_context.items():

        if callable(value):

            c[key] = value()

        else:

            c[key] = value

    return HttpResponse(t.render(c), mimetype=mimetype)

def archive_today(request, **kwargs):

    """

    Generic daily archive view for today. Same as archive_day view.

    """

    today = datetime.date.today()

    kwargs.update({

        'year': str(today.year),

        'month': today.strftime('%b').lower(),

        'day': str(today.day),

    })

    return archive_day(request, **kwargs)

def object_detail(request, year, month, day, queryset, date_field,

        month_format='%b', day_format='%d', object_id=None, slug=None,

        slug_field='slug', template_name=None, template_name_field=None,

        template_loader=loader, extra_context=None, context_processors=None,

        template_object_name='object', mimetype=None, allow_future=False):

    """

    Generic detail view from year/month/day/slug or year/month/day/id structure.

    Templates: ``<app_label>/<model_name>_detail.html``

    Context:

        object:

            the object to be detailed

    """

    if extra_context is None: extra_context = {}

    try:

        date = datetime.date(*time.strptime(year+month+day, '%Y'+month_format+day_format)[:3])

    except ValueError:

        raise Http404

    model = queryset.model

    now = datetime.datetime.now()

    if isinstance(model._meta.get_field(date_field), DateTimeField):

        lookup_kwargs = {'%s__range' % date_field: (datetime.datetime.combine(date, datetime.time.min), datetime.datetime.combine(date, datetime.time.max))}

    else:

        lookup_kwargs = {date_field: date}

    # Only bother to check current date if the date isn't in the past and future objects aren't requested.

    if date >= now.date() and not allow_future:

        lookup_kwargs['%s__lte' % date_field] = now

    if object_id:

        lookup_kwargs['%s__exact' % model._meta.pk.name] = object_id

    elif slug and slug_field:

        lookup_kwargs['%s__exact' % slug_field] = slug

    else:

        raise AttributeError, "Generic detail view must be called with either an object_id or a slug/slugfield"

    try:

        obj = queryset.get(**lookup_kwargs)

    except ObjectDoesNotExist:

        raise Http404, "No %s found for" % model._meta.verbose_name

    if not template_name:

        template_name = "%s/%s_detail.html" % (model._meta.app_label, model._meta.object_name.lower())

    if template_name_field:

        template_name_list = [getattr(obj, template_name_field), template_name]

        t = template_loader.select_template(template_name_list)

    else:

        t = template_loader.get_template(template_name)

    c = RequestContext(request, {

        template_object_name: obj,

    }, context_processors)

    for key, value in extra_context.items():

        if callable(value):

            c[key] = value()

        else:

            c[key] = value

    response = HttpResponse(t.render(c), mimetype=mimetype)

    populate_xheaders(request, response, model, getattr(obj, obj._meta.pk.name))

    return response