from django.contrib import admin
from cashonly.core.models import *
from cashonly.core.formfields import DigitField
from cashonly.core.services import AccountManager
from django import forms
from django.template.defaultfilters import escape
from django.core.urlresolvers import reverse
from django.utils.translation import ugettext as _
from django.utils.translation import ugettext_lazy
from django.utils.translation import ugettext_noop


class AccountForm(forms.ModelForm):
    credit_change = forms.DecimalField(max_digits=5, decimal_places=2,
                                       required=False,
                                       label=ugettext_lazy('amount'))

    credit_change_comment = forms.CharField(max_length=64, required=False,
                                            label=ugettext_lazy('comment'))

    pin_change = DigitField(min_length=4, required=False,
                            label=ugettext_lazy('PIN'))

    pin_empty = forms.BooleanField(required=False,
                                   label=ugettext_lazy('clear PIN'))

    class Meta:
        model = Account

        # Include all fields (omitting this causes a RemovedInDjango18Warning)
        exclude = []


class AccountAdmin(admin.ModelAdmin):
    list_display = ('user', 'card_number', 'credit', 'debit_limit',
                    'transaction_link')
    form = AccountForm
    readonly_fields = ('user', 'credit',)
    fieldsets = (
        (None, {
            'fields': ('user', 'card_number', 'credit', 'debit_limit',
                       'avatar'),
        }),
        (ugettext_lazy('credit change'), {
            'fields': ('credit_change', 'credit_change_comment'),
        }),
        (ugettext_lazy('change PIN'), {
            'fields': ('pin_change', 'pin_empty'),
        }),
    )

    # Disable manual creation of accounts.
    # Accounts are create after user creation automatically.
    def has_add_permission(self, request):
        return False

    def transaction_link(self, account):
        return '<a href="%s?account__id__exact=%d">%s</a>' % \
            (reverse("admin:cashonly_core_transaction_changelist"), account.id,
             _('Transactions'))

    transaction_link.short_description = ugettext_lazy('Transaction link')

    transaction_link.allow_tags = True

    def save_model(self, request, obj, form, change):
        accmgr = AccountManager(obj)

        pin = form.cleaned_data['pin_change']
        pin_empty = form.cleaned_data['pin_empty']
        if pin_empty:
            accmgr.clear_pin()
        elif pin is not None and len(pin) != 0:
            accmgr.set_pin(pin)

        amount = form.cleaned_data['credit_change']
        comment = form.cleaned_data['credit_change_comment']
        if amount is not None and amount != 0:
            accmgr.change_credit(amount, request.user, comment)

        # TODO: check whether this can be dropped
        # Make sure the object is saved in any case
        obj.save()


class ProductBarcodeInline(admin.TabularInline):
    model = ProductBarcode
    extra = 1


class ProductAdmin(admin.ModelAdmin):
    list_display = ('name', 'category', 'price', 'active')
    list_filter = ['category', 'active']
    ordering = ('-active', 'name')
    inlines = [ProductBarcodeInline]
    fields = ('name', 'price', 'active', 'category', 'image')


class ProductCategoryAdmin(admin.ModelAdmin):
    list_display = ('name', 'comment')


class SalesLogEntryAdmin(admin.ModelAdmin):
    list_display = ('account', 'timestamp', 'product', 'count', 'unit_price')
    list_filter = ['account', 'timestamp', 'product']
    # Make sales log entries completely read-only
    readonly_fields = list(map(lambda f: f.name, SalesLogEntry._meta.fields))


class TransactionAdmin(admin.ModelAdmin):
    list_display = ('account', 'timestamp', 'subject', 'description', 'amount')
    list_filter = ['account', 'timestamp', 'subject']

    # Disable mass deletion in the overview page
    actions = None

    date_hierarchy = 'timestamp'

    # Disable tampering with the transactions completely.
    def has_add_permission(self, request):
        return False

    def has_change_permission(self, request, obj=None):
        if obj is None:
            return True
        return False

    def has_delete_permission(self, request, obj=None):
        return False

    # Needed to not trigger an ImproperlyConfigured exception.
    # FIXME: a bit too hacky
    def changelist_view(self, request, extra_context=None):
        self.list_display_links = (None, )
        return super(TransactionAdmin, self).changelist_view(
                request,
                extra_context=None,
            )

admin.site.register(Account, AccountAdmin)
admin.site.register(Product, ProductAdmin)
admin.site.register(ProductCategory, ProductCategoryAdmin)
admin.site.register(Transaction, TransactionAdmin)
admin.site.register(SalesLogEntry, SalesLogEntryAdmin)