from django import forms
from django.contrib import admin
from django.contrib.admin.utils import unquote
from django.core.urlresolvers import reverse
from django.db import models
from django.templatetags.static import static
from django.utils.safestring import mark_safe
from django.utils.translation import ugettext_lazy as _

from orchestra.admin import ExtendedModelAdmin
from orchestra.admin.utils import admin_date, insertattr
from orchestra.apps.accounts.admin import AccountAdminMixin, AccountAdmin
from orchestra.forms.widgets import paddingCheckboxSelectMultiple

from . import settings
from .actions import download_bills, view_bill, close_bills, send_bills, validate_contact
from .filters import BillTypeListFilter, HasBillContactListFilter
from .models import Bill, Invoice, AmendmentInvoice, Fee, AmendmentFee, ProForma, BillLine, BillContact


PAYMENT_STATE_COLORS = {
    Bill.PAID: 'green',
    Bill.PENDING: 'darkorange',
    Bill.BAD_DEBT: 'red',
}


class BillLineInline(admin.TabularInline):
    model = BillLine
    fields = ('description', 'rate', 'quantity', 'tax', 'subtotal', 'display_total')
    readonly_fields = ('display_total',)
    
    def display_total(self, line):
        total = line.get_total()
        sublines = line.sublines.all()
        if sublines:
            content = '\n'.join(['%s: %s' % (sub.description, sub.total) for sub in sublines])
            img = static('admin/img/icon_alert.gif')
            return '<span title="%s">%s<img src="%s"></img></span>' % (content, str(total), img)
        return total
    display_total.short_description = _("Total")
    display_total.allow_tags = True
    
    def formfield_for_dbfield(self, db_field, **kwargs):
        """ Make value input widget bigger """
        if db_field.name == 'description':
            kwargs['widget'] = forms.TextInput(attrs={'size':'110'})
        else:
            kwargs['widget'] = forms.TextInput(attrs={'size':'13'})
        return super(BillLineInline, self).formfield_for_dbfield(db_field, **kwargs)
    
    def get_queryset(self, request):
        qs = super(BillLineInline, self).get_queryset(request)
        return qs.prefetch_related('sublines')


class ClosedBillLineInline(BillLineInline):
    # TODO reimplement as nested inlines when upstream
    #      https://code.djangoproject.com/ticket/9025
    
    fields = ('display_description', 'rate', 'quantity', 'tax', 'display_subtotal', 'display_total')
    readonly_fields = fields
    
    def display_description(self, line):
        descriptions = [line.description]
        for subline in line.sublines.all():
            descriptions.append('&nbsp;'*4+subline.description)
        return '<br>'.join(descriptions)
    display_description.short_description = _("Description")
    display_description.allow_tags = True
    
    def display_subtotal(self, line):
        subtotals = ['&nbsp;&nbsp;' + str(line.subtotal)]
        for subline in line.sublines.all():
            subtotals.append(str(subline.total))
        return '<br>'.join(subtotals)
    display_subtotal.short_description = _("Subtotal")
    display_subtotal.allow_tags = True
    
    def has_add_permission(self, request):
        return False
    
    def has_delete_permission(self, request, obj=None):
        return False


class BillAdmin(AccountAdminMixin, ExtendedModelAdmin):
    list_display = (
        'number', 'type_link', 'account_link', 'created_on_display',
        'num_lines', 'display_total', 'display_payment_state', 'is_open', 'is_sent'
    )
    list_filter = (BillTypeListFilter, 'is_open', 'is_sent')
    add_fields = ('account', 'type', 'is_open', 'due_on', 'comments')
    fieldsets = (
        (None, {
            'fields': ('number', 'type', 'account_link', 'display_total',
                       'display_payment_state', 'is_sent', 'due_on', 'comments'),
        }),
        (_("Raw"), {
            'classes': ('collapse',),
            'fields': ('html',),
        }),
    )
    actions = [download_bills, close_bills, send_bills]
    change_view_actions = [view_bill, download_bills, send_bills, close_bills]
    change_readonly_fields = ('account_link', 'type', 'is_open')
    readonly_fields = ('number', 'display_total', 'is_sent', 'display_payment_state')
    inlines = [BillLineInline, ClosedBillLineInline]
    
    created_on_display = admin_date('created_on')
    
    def num_lines(self, bill):
        return bill.lines__count
    num_lines.admin_order_field = 'lines__count'
    num_lines.short_description = _("lines")
    
    def display_total(self, bill):
        return "%s &%s;" % (bill.total, settings.BILLS_CURRENCY.lower())
    display_total.allow_tags = True
    display_total.short_description = _("total")
    display_total.admin_order_field = 'total'
    
    def type_link(self, bill):
        bill_type = bill.type.lower()
        url = reverse('admin:bills_%s_changelist' % bill_type)
        return '<a href="%s">%s</a>' % (url, bill.get_type_display())
    type_link.allow_tags = True
    type_link.short_description = _("type")
    type_link.admin_order_field = 'type'
    
    def display_payment_state(self, bill):
        t_opts = bill.transactions.model._meta
        transactions = bill.transactions.all()
        if len(transactions) == 1:
            args = (transactions[0].pk,)
            url = reverse('admin:%s_%s_change' % (t_opts.app_label, t_opts.module_name), args=args)
        else:
            url = reverse('admin:%s_%s_changelist' % (t_opts.app_label, t_opts.module_name))
            url += '?bill=%i' % bill.pk
        state = bill.get_payment_state_display().upper()
        color = PAYMENT_STATE_COLORS.get(bill.payment_state, 'grey')
        return '<a href="{url}" style="color:{color}">{name}</a>'.format(
                url=url, color=color, name=state)
    display_payment_state.allow_tags = True
    display_payment_state.short_description = _("Payment")
    
    def get_readonly_fields(self, request, obj=None):
        fields = super(BillAdmin, self).get_readonly_fields(request, obj=obj)
        if obj and not obj.is_open:
            fields += self.add_fields
        return fields
    
    def get_fieldsets(self, request, obj=None):
        fieldsets = super(BillAdmin, self).get_fieldsets(request, obj=obj)
        if obj and obj.is_open:
            fieldsets = (fieldsets[0],)
        return fieldsets
    
    def get_change_view_actions(self, obj=None):
        actions = super(BillAdmin, self).get_change_view_actions(obj=obj)
        exclude = []
        if obj:
            if not obj.is_open:
                exclude.append('close_bills')
        return [action for action in actions if action.__name__ not in exclude]
    
    def get_inline_instances(self, request, obj=None):
        inlines = super(BillAdmin, self).get_inline_instances(request, obj=obj)
        if obj and not obj.is_open:
            return [inline for inline in inlines if not type(inline) == BillLineInline]
        return [inline for inline in inlines if not type(inline) == ClosedBillLineInline]
    
    def formfield_for_dbfield(self, db_field, **kwargs):
        """ Make value input widget bigger """
        if db_field.name == 'comments':
            kwargs['widget'] = forms.Textarea(attrs={'cols': 70, 'rows': 4})
        if db_field.name == 'html':
            kwargs['widget'] = forms.Textarea(attrs={'cols': 150, 'rows': 20})
        return super(BillAdmin, self).formfield_for_dbfield(db_field, **kwargs)
        
    def get_queryset(self, request):
        qs = super(BillAdmin, self).get_queryset(request)
        qs = qs.annotate(models.Count('lines'))
        qs = qs.prefetch_related('lines', 'lines__sublines', 'transactions')
        return qs
    
    def change_view(self, request, object_id, **kwargs):
        # TODO raise404, here and everywhere
        bill = self.get_object(request, unquote(object_id))
        validate_contact(request, bill, error=False)
        return super(BillAdmin, self).change_view(request, object_id, **kwargs)


admin.site.register(Bill, BillAdmin)
admin.site.register(Invoice, BillAdmin)
admin.site.register(AmendmentInvoice, BillAdmin)
admin.site.register(Fee, BillAdmin)
admin.site.register(AmendmentFee, BillAdmin)
admin.site.register(ProForma, BillAdmin)


class BillContactInline(admin.StackedInline):
    model = BillContact
    fields = ('name', 'address', ('city', 'zipcode'), 'country', 'vat')
    
    def formfield_for_dbfield(self, db_field, **kwargs):
        """ Make value input widget bigger """
        if db_field.name == 'address':
            kwargs['widget'] = forms.Textarea(attrs={'cols': 70, 'rows': 2})
        if db_field.name == 'email_usage':
            kwargs['widget'] = paddingCheckboxSelectMultiple(45)
        return super(BillContactInline, self).formfield_for_dbfield(db_field, **kwargs)


def has_bill_contact(account):
    return hasattr(account, 'billcontact')
has_bill_contact.boolean = True
has_bill_contact.admin_order_field = 'billcontact'


insertattr(AccountAdmin, 'inlines', BillContactInline)
insertattr(AccountAdmin, 'list_display', has_bill_contact)
insertattr(AccountAdmin, 'list_filter', HasBillContactListFilter)