from django.conf import settings
from django.contrib.admin.views.main import ALL_VAR, EMPTY_CHANGELIST_VALUE
from django.contrib.admin.views.main import ORDER_VAR, ORDER_TYPE_VAR, PAGE_VAR, SEARCH_VAR
from django.core.exceptions import ObjectDoesNotExist
from django.db import models
from django.utils import dateformat
from django.utils.html import escape
from django.utils.text import capfirst
from django.utils.translation import get_date_formats, get_partial_date_formats
from django.template import Library
import datetime

register = Library()

DOT = '.'

def paginator_number(cl,i):
    if i == DOT:
        return '... '
    elif i == cl.page_num:
        return '<span class="this-page">%d</span> ' % (i+1)
    else:
        return '<a href="%s"%s>%d</a> ' % (cl.get_query_string({PAGE_VAR: i}), (i == cl.paginator.pages-1 and ' class="end"' or ''), i+1)
paginator_number = register.simple_tag(paginator_number)

def pagination(cl):
    paginator, page_num = cl.paginator, cl.page_num

    pagination_required = (not cl.show_all or not cl.can_show_all) and cl.multi_page
    if not pagination_required:
        page_range = []
    else:
        ON_EACH_SIDE = 3
        ON_ENDS = 2

        # If there are 10 or fewer pages, display links to every page.
        # Otherwise, do some fancy
        if paginator.pages <= 10:
            page_range = range(paginator.pages)
        else:
            # Insert "smart" pagination links, so that there are always ON_ENDS
            # links at either end of the list of pages, and there are always
            # ON_EACH_SIDE links at either end of the "current page" link.
            page_range = []
            if page_num > (ON_EACH_SIDE + ON_ENDS):
                page_range.extend(range(0, ON_EACH_SIDE - 1))
                page_range.append(DOT)
                page_range.extend(range(page_num - ON_EACH_SIDE, page_num + 1))
            else:
                page_range.extend(range(0, page_num + 1))
            if page_num < (paginator.pages - ON_EACH_SIDE - ON_ENDS - 1):
                page_range.extend(range(page_num + 1, page_num + ON_EACH_SIDE + 1))
                page_range.append(DOT)
                page_range.extend(range(paginator.pages - ON_ENDS, paginator.pages))
            else:
                page_range.extend(range(page_num + 1, paginator.pages))

    need_show_all_link = cl.can_show_all and not cl.show_all and cl.multi_page
    return {
        'cl': cl,
        'pagination_required': pagination_required,
        'show_all_url': need_show_all_link and cl.get_query_string({ALL_VAR: ''}),
        'page_range': page_range,
        'ALL_VAR': ALL_VAR,
        '1': 1,
    }
pagination = register.inclusion_tag('admin/pagination.html')(pagination)

def result_headers(cl):
    lookup_opts = cl.lookup_opts

    for i, field_name in enumerate(lookup_opts.admin.list_display):
        try:
            f = lookup_opts.get_field(field_name)
        except models.FieldDoesNotExist:
            # For non-field list_display values, check for the function
            # attribute "short_description". If that doesn't exist, fall
            # back to the method name. And __str__ is a special-case.
            if field_name == '__str__':
                header = lookup_opts.verbose_name
            else:
                attr = getattr(cl.model, field_name) # Let AttributeErrors propagate.
                try:
                    header = attr.short_description
                except AttributeError:
                    header = field_name.replace('_', ' ')

            # It is a non-field, but perhaps one that is sortable
            if not getattr(getattr(cl.model, field_name), "admin_order_field", None):
                yield {"text": header}
                continue

            # So this _is_ a sortable non-field.  Go to the yield
            # after the else clause.
        else:
            if isinstance(f.rel, models.ManyToOneRel) and f.null:
                yield {"text": f.verbose_name}
                continue
            else:
                header = f.verbose_name

        th_classes = []
        new_order_type = 'asc'
        if field_name == cl.order_field:
            th_classes.append('sorted %sending' % cl.order_type.lower())
            new_order_type = {'asc': 'desc', 'desc': 'asc'}[cl.order_type.lower()]

        yield {"text": header,
               "sortable": True,
               "url": cl.get_query_string({ORDER_VAR: i, ORDER_TYPE_VAR: new_order_type}),
               "class_attrib": (th_classes and ' class="%s"' % ' '.join(th_classes) or '')}

def _boolean_icon(field_val):
    BOOLEAN_MAPPING = {True: 'yes', False: 'no', None: 'unknown'}
    return '<img src="%simg/admin/icon-%s.gif" alt="%s" />' % (settings.ADMIN_MEDIA_PREFIX, BOOLEAN_MAPPING[field_val], field_val)

def items_for_result(cl, result):
    first = True
    pk = cl.lookup_opts.pk.attname
    for field_name in cl.lookup_opts.admin.list_display:
        row_class = ''
        try:
            f = cl.lookup_opts.get_field(field_name)
        except models.FieldDoesNotExist:
            # For non-field list_display values, the value is either a method
            # or a property.
            try:
                attr = getattr(result, field_name)
                allow_tags = getattr(attr, 'allow_tags', False)
                boolean = getattr(attr, 'boolean', False)
                if callable(attr):
                    attr = attr()
                if boolean:
                    allow_tags = True
                    result_repr = _boolean_icon(attr)
                else:
                    result_repr = str(attr)
            except (AttributeError, ObjectDoesNotExist):
                result_repr = EMPTY_CHANGELIST_VALUE
            else:
                # Strip HTML tags in the resulting text, except if the
                # function has an "allow_tags" attribute set to True.
                if not allow_tags:
                    result_repr = escape(result_repr)
        else:
            field_val = getattr(result, f.attname)

            if isinstance(f.rel, models.ManyToOneRel):
                if field_val is not None:
                    result_repr = escape(getattr(result, f.name))
                else:
                    result_repr = EMPTY_CHANGELIST_VALUE
            # Dates and times are special: They're formatted in a certain way.
            elif isinstance(f, models.DateField) or isinstance(f, models.TimeField):
                if field_val:
                    (date_format, datetime_format, time_format) = get_date_formats()
                    if isinstance(f, models.DateTimeField):
                        result_repr = capfirst(dateformat.format(field_val, datetime_format))
                    elif isinstance(f, models.TimeField):
                        result_repr = capfirst(dateformat.time_format(field_val, time_format))
                    else:
                        result_repr = capfirst(dateformat.format(field_val, date_format))
                else:
                    result_repr = EMPTY_CHANGELIST_VALUE
                row_class = ' class="nowrap"'
            # Booleans are special: We use images.
            elif isinstance(f, models.BooleanField) or isinstance(f, models.NullBooleanField):
                result_repr = _boolean_icon(field_val)
            # FloatFields are special: Zero-pad the decimals.
            elif isinstance(f, models.FloatField):
                if field_val is not None:
                    result_repr = ('%%.%sf' % f.decimal_places) % field_val
                else:
                    result_repr = EMPTY_CHANGELIST_VALUE
            # Fields with choices are special: Use the representation
            # of the choice.
            elif f.choices:
                result_repr = dict(f.choices).get(field_val, EMPTY_CHANGELIST_VALUE)
            else:
                result_repr = escape(str(field_val))
        if result_repr == '':
            result_repr = '&nbsp;'
        # If list_display_links not defined, add the link tag to the first field
        if (first and not cl.lookup_opts.admin.list_display_links) or field_name in cl.lookup_opts.admin.list_display_links: 
            table_tag = {True:'th', False:'td'}[first]
            first = False
            url = cl.url_for_result(result)
            result_id = str(getattr(result, pk)) # str() is needed in case of 23L (long ints)
            yield ('<%s%s><a href="%s"%s>%s</a></%s>' % \
                (table_tag, row_class, url, (cl.is_popup and ' onclick="opener.dismissRelatedLookupPopup(window, %r); return false;"' % result_id or ''), result_repr, table_tag))
        else:
            yield ('<td%s>%s</td>' % (row_class, result_repr))

def results(cl):
    for res in cl.result_list:
        yield list(items_for_result(cl,res))

def result_list(cl):
    return {'cl': cl,
            'result_headers': list(result_headers(cl)),
            'results': list(results(cl))}
result_list = register.inclusion_tag("admin/change_list_results.html")(result_list)

def date_hierarchy(cl):
    if cl.lookup_opts.admin.date_hierarchy:
        field_name = cl.lookup_opts.admin.date_hierarchy
        year_field = '%s__year' % field_name
        month_field = '%s__month' % field_name
        day_field = '%s__day' % field_name
        field_generic = '%s__' % field_name
        year_lookup = cl.params.get(year_field)
        month_lookup = cl.params.get(month_field)
        day_lookup = cl.params.get(day_field)
        year_month_format, month_day_format = get_partial_date_formats()

        link = lambda d: cl.get_query_string(d, [field_generic])

        if year_lookup and month_lookup and day_lookup:
            day = datetime.date(int(year_lookup), int(month_lookup), int(day_lookup))
            return {
                'show': True,
                'back': {
                    'link': link({year_field: year_lookup, month_field: month_lookup}),
                    'title': dateformat.format(day, year_month_format)
                },
                'choices': [{'title': dateformat.format(day, month_day_format)}]
            }
        elif year_lookup and month_lookup:
            days = cl.query_set.filter(**{year_field: year_lookup, month_field: month_lookup}).dates(field_name, 'day')
            return {
                'show': True,
                'back': {
                    'link': link({year_field: year_lookup}),
                    'title': year_lookup
                },
                'choices': [{
                    'link': link({year_field: year_lookup, month_field: month_lookup, day_field: day.day}),
                    'title': dateformat.format(day, month_day_format)
                } for day in days]
            }
        elif year_lookup:
            months = cl.query_set.filter(**{year_field: year_lookup}).dates(field_name, 'month')
            return {
                'show' : True,
                'back': {
                    'link' : link({}),
                    'title': _('All dates')
                },
                'choices': [{
                    'link': link({year_field: year_lookup, month_field: month.month}),
                    'title': dateformat.format(month, year_month_format)
                } for month in months]
            }
        else:
            years = cl.query_set.dates(field_name, 'year')
            return {
                'show': True,
                'choices': [{
                    'link': link({year_field: year.year}),
                    'title': year.year
                } for year in years]
            }
date_hierarchy = register.inclusion_tag('admin/date_hierarchy.html')(date_hierarchy)

def search_form(cl):
    return {
        'cl': cl,
        'show_result_count': cl.result_count != cl.full_result_count and not cl.opts.one_to_one_field,
        'search_var': SEARCH_VAR
    }
search_form = register.inclusion_tag('admin/search_form.html')(search_form)

def filter(cl, spec):
    return {'title': spec.title(), 'choices' : list(spec.choices(cl))}
filter = register.inclusion_tag('admin/filter.html')(filter)

def filters(cl):
    return {'cl': cl}
filters = register.inclusion_tag('admin/filters.html')(filters)
