from functools import partial

from django.contrib import messages
from django.contrib.admin import actions
from django.core.urlresolvers import reverse
from django.db import transaction
from django.shortcuts import render, redirect
from django.utils.safestring import mark_safe
from django.utils.text import capfirst
from django.utils.translation import ungettext, ugettext_lazy as _

from orchestra.admin.decorators import action_with_confirmation
from orchestra.admin.utils import change_url

from . import helpers
from .methods import PaymentMethod
from .models import Transaction


@transaction.atomic
def process_transactions(modeladmin, request, queryset):
    processes = []
    if queryset.exclude(state=Transaction.WAITTING_PROCESSING).exists():
        messages.error(request,
            _("Selected transactions must be on '{state}' state").format(
                state=Transaction.WAITTING_PROCESSING)
        )
        return
    for method, transactions in queryset.group_by('source__method').items():
        if method is not None:
            method = PaymentMethod.get(method)
            procs = method.process(transactions)
            processes += procs
            for transaction in transactions:
                modeladmin.log_change(request, transaction, _("Processed"))
    if not processes:
        return
    opts = modeladmin.model._meta
    num = len(queryset)
    context = {
        'title': ungettext(
            _("One selected transaction has been processed."),
            _("%s Selected transactions have been processed.") % num,
            num),
        'content_message': ungettext(
            _("The following transaction process has been generated, "
              "you may want to save it on your computer now."),
            _("The following %s transaction processes have been generated, "
              "you may want to save it on your computer now.") % len(processes),
            len(processes)),
        'action_name': _("Process"),
        'processes': processes,
        'opts': opts,
        'app_label': opts.app_label,
    }
    return render(request, 'admin/payments/transaction/get_processes.html', context)


@transaction.atomic
@action_with_confirmation()
def mark_as_executed(modeladmin, request, queryset):
    for transaction in queryset:
        transaction.mark_as_executed()
        modeladmin.log_change(request, transaction, _("Executed"))
    num = len(queryset)
    msg = ungettext(
        _("One selected transaction has been marked as executed."),
        _("%s selected transactions have been marked as executed.") % num,
        num)
    modeladmin.message_user(request, msg)
mark_as_executed.url_name = 'execute'
mark_as_executed.short_description = _("Mark as executed")


@transaction.atomic
@action_with_confirmation()
def mark_as_secured(modeladmin, request, queryset):
    for transaction in queryset:
        transaction.mark_as_secured()
        modeladmin.log_change(request, transaction, _("Secured"))
    num = len(queryset)
    msg = ungettext(
        _("One selected transaction has been marked as secured."),
        _("%s selected transactions have been marked as secured.") % num,
        num)
    modeladmin.message_user(request, msg)
mark_as_secured.url_name = 'secure'
mark_as_secured.short_description = _("Mark as secured")


@transaction.atomic
@action_with_confirmation()
def mark_as_rejected(modeladmin, request, queryset):
    for transaction in queryset:
        transaction.mark_as_rejected()
        modeladmin.log_change(request, transaction, _("Rejected"))
    num = len(queryset)
    msg = ungettext(
        _("One selected transaction has been marked as rejected."),
        _("%s selected transactions have been marked as rejected.") % num,
        num)
    modeladmin.message_user(request, msg)
mark_as_rejected.url_name = 'reject'
mark_as_rejected.short_description = _("Mark as rejected")


def _format_display_objects(modeladmin, request, queryset, related):
    objects = []
    opts = modeladmin.model._meta
    for obj in queryset:
        objects.append(
            mark_safe('{0}: <a href="{1}">{2}</a>'.format(
                capfirst(opts.verbose_name), change_url(obj), obj))
        )
        subobjects = []
        attr, verb = related
        for trans in getattr(obj.transactions, attr)():
            subobjects.append(
                mark_safe('Transaction: <a href="{}">{}</a> will be marked as {}'.format(
                    change_url(trans), trans, verb))
            )
        objects.append(subobjects)
    return {'display_objects': objects}

_format_executed = partial(_format_display_objects, related=('all', 'executed'))
_format_abort = partial(_format_display_objects, related=('processing', 'aborted'))
_format_commit = partial(_format_display_objects, related=('all', 'secured'))


@transaction.atomic
@action_with_confirmation(extra_context=_format_executed)
def mark_process_as_executed(modeladmin, request, queryset):
    for process in queryset:
        process.mark_as_executed()
        modeladmin.log_change(request, process, _("Executed"))
    num = len(queryset)
    msg = ungettext(
        _("One selected process has been marked as executed."),
        _("%s selected processes have been marked as executed.") % num,
        num)
    modeladmin.message_user(request, msg)
mark_process_as_executed.url_name = 'executed'
mark_process_as_executed.short_description = _("Mark as executed")


@transaction.atomic
@action_with_confirmation(extra_context=_format_abort)
def abort(modeladmin, request, queryset):
    for process in queryset:
        process.abort()
        modeladmin.log_change(request, process, _("Aborted"))
    num = len(queryset)
    msg = ungettext(
        _("One selected process has been aborted."),
        _("%s selected processes have been aborted.") % num,
        num)
    modeladmin.message_user(request, msg)
abort.url_name = 'abort'
abort.short_description = _("Abort")


@transaction.atomic
@action_with_confirmation(extra_context=_format_commit)
def commit(modeladmin, request, queryset):
    for transaction in queryset:
        transaction.mark_as_rejected()
        modeladmin.log_change(request, transaction, _("Rejected"))
    num = len(queryset)
    msg = ungettext(
        _("One selected transaction has been marked as rejected."),
        _("%s selected transactions have been marked as rejected.") % num,
        num)
    modeladmin.message_user(request, msg)
commit.url_name = 'commit'
commit.short_description = _("Commit")


def delete_selected(modeladmin, request, queryset):
    """ Has to have same name as admin.actions.delete_selected """
    related_transactions = helpers.pre_delete_processes(modeladmin, request, queryset)
    response = actions.delete_selected(modeladmin, request, queryset)
    if response is None:
        helpers.post_delete_processes(modeladmin, request, related_transactions)
    return response
delete_selected.short_description = actions.delete_selected.short_description


def report(modeladmin, request, queryset):
    if queryset.model == Transaction:
        transactions = queryset
    else:
        transactions = queryset.values_list('transactions__id', flat=True).distinct()
        transactions = Transaction.objects.filter(id__in=transactions)
    states = {}
    total = 0
    for transaction in transactions:
        state = transaction.get_state_display()
        try:
            states[state] += transaction.amount
        except KeyError:
            states[state] = transaction.amount
        total += transaction.amount
    context = {
        'states': states,
        'total': total,
        'transactions': transactions,
    }
    return render(request, 'admin/payments/transaction/report.html', context)


def reissue(modeladmin, request, queryset):
    if len(queryset) != 1:
        messages.error(request, _("One transaction should be selected."))
        return
    trans = queryset[0]
    if trans.state != trans.REJECTED:
        messages.error(request,
            _("Only rejected transactions can be reissued, "
              "please reject current transaction if necessary."))
        return
    url = reverse('admin:payments_transaction_add')
    url += '?account=%i&bill=%i&source=%s&amount=%s&currency=%s' % (
        trans.bill.account_id,
        trans.bill_id,
        trans.source_id or '',
        trans.amount,
        trans.currency,
    )
    return redirect(url)