"""Представления документов: списки и формы создания/редактирования."""
import logging
from django.views.generic import ListView, CreateView, UpdateView, DeleteView, DetailView
from config.mixins import LoginRequiredMixin
from django.urls import reverse_lazy
from django.shortcuts import redirect, get_object_or_404
from django.contrib import messages
from django.http import HttpResponseRedirect

from users.utils import get_author_employee
from references.models import Employee, OrderStatus
from .models import (
    CustomerOrder,
    SupplierOrder,
    CashInflow,
    CashTransfer,
    CashExpense,
)
from .forms import (
    CustomerOrderForm,
    CustomerOrderItemFormSet,
    CustomerOrderItemFormSetUpdate,
    SupplierOrderForm,
    SupplierOrderItemFormSet,
    SupplierOrderItemFormSetUpdate,
    CashInflowForm,
    CashTransferForm,
    CashExpenseForm,
)
from .services import next_number

logger = logging.getLogger(__name__)


class SortableListMixin:
    """Миксин для сортировки списка по GET-параметрам sort и order."""
    sort_param = "sort"
    order_param = "order"
    sort_fields = {}  # ключ (из GET) -> поле order_by, например "date", "-date" не нужен, order добавляется в get_queryset
    default_sort = None   # например "date"
    default_order = "desc" # asc или desc

    def get_sort_fields(self):
        return self.sort_fields

    def get_queryset(self):
        qs = super().get_queryset()
        fields = self.get_sort_fields()
        if not fields:
            return qs
        sort_key = self.request.GET.get(self.sort_param)
        order = (self.request.GET.get(self.order_param) or "").lower()
        if order not in ("asc", "desc"):
            order = self.default_order or "asc"
        if sort_key and sort_key in fields:
            order_by_field = fields[sort_key]
            if order == "desc":
                order_by_field = "-" + order_by_field
            return qs.order_by(order_by_field)
        if self.default_sort and self.default_sort in fields:
            order_by_field = fields[self.default_sort]
            if (self.default_order or "asc") == "desc":
                order_by_field = "-" + order_by_field
            return qs.order_by(order_by_field)
        return qs

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        ctx["sort_key"] = self.request.GET.get(self.sort_param) or self.default_sort
        ctx["sort_order"] = (self.request.GET.get(self.order_param) or self.default_order or "asc").lower()
        if ctx["sort_order"] not in ("asc", "desc"):
            ctx["sort_order"] = "asc"
        ctx["sort_param"] = self.sort_param
        ctx["order_param"] = self.order_param
        return ctx


def set_author(form, request):
    """Подставить автора при создании документа: из профиля пользователя (UserProfile.employee) или сотрудник по имени пользователя."""
    if form.instance.pk:
        return  # при редактировании автора не меняем
    author = _get_author_for_request(request)
    if author:
        form.instance.author = author


def _get_author_for_request(request):
    """Сотрудник-автор: из профиля пользователя или по ФИО/логину."""
    if not request.user.is_authenticated:
        return None
    author = get_author_employee(request.user)
    if author:
        return author
    name = (request.user.get_full_name() or "").strip() or request.user.username
    author = Employee.objects.filter(name=name).first()
    if not author:
        author = Employee.objects.create(name=name)
    return author


# --- Заказы клиентов ---
class CustomerOrderList(LoginRequiredMixin, SortableListMixin, ListView):
    model = CustomerOrder
    template_name = "documents/customer_order_list.html"
    context_object_name = "object_list"
    default_sort = "date"
    default_order = "desc"
    sort_fields = {
        "date": "date",
        "number": "number",
        "status": "status__name",
        "order_kind": "order_kind__name",
        "organization": "organization__name",
        "client": "client__name",
        "total_amount": "total_amount",
    }

class CustomerOrderCreate(LoginRequiredMixin, CreateView):
    model = CustomerOrder
    form_class = CustomerOrderForm
    template_name = "documents/order_form.html"
    success_url = reverse_lazy("documents:customer_order_list")

    def get_initial(self):
        initial = super().get_initial()
        if not initial.get("status"):
            in_progress = OrderStatus.objects.filter(name="В работе").first()
            if in_progress:
                initial["status"] = in_progress
        return initial

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        ctx["formset"] = CustomerOrderItemFormSet(instance=self.object) if self.object and self.object.pk else CustomerOrderItemFormSet()
        ctx["title"] = "Заказ клиента"
        ctx["author_display"] = _get_author_for_request(self.request) if not self.object or not self.object.pk else self.object.author
        return ctx

    def form_valid(self, form):
        set_author(form, self.request)
        self.object = form.save()
        formset = CustomerOrderItemFormSet(self.request.POST, instance=self.object)
        if formset.is_valid():
            formset.save()
            self.object.recalc_total()
            self.object.save()
            logger.info("Создан заказ клиента %s", self.object)
            messages.success(self.request, "Заказ создан.")
            return redirect(self.success_url)
        return self.render_to_response(self.get_context_data(form=form, formset=formset))

    def get(self, request, *args, **kwargs):
        self.object = None
        return super().get(request, *args, **kwargs)


class CustomerOrderUpdate(LoginRequiredMixin, UpdateView):
    model = CustomerOrder
    form_class = CustomerOrderForm
    template_name = "documents/order_form.html"
    context_object_name = "object"
    success_url = reverse_lazy("documents:customer_order_list")

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        ctx["formset"] = CustomerOrderItemFormSetUpdate(instance=self.object)
        ctx["title"] = "Заказ клиента"
        ctx["author_display"] = self.object.author
        return ctx

    def form_valid(self, form):
        formset = CustomerOrderItemFormSetUpdate(self.request.POST, instance=self.object)
        if formset.is_valid():
            form.save()
            formset.save()
            self.object.recalc_total()
            self.object.save()
            logger.info("Обновлён заказ клиента %s", self.object)
            messages.success(self.request, "Заказ сохранён.")
            return redirect(self.success_url)
        return self.render_to_response(self.get_context_data(form=form, formset=formset))


class CustomerOrderDelete(LoginRequiredMixin, DeleteView):
    model = CustomerOrder
    template_name = "documents/confirm_delete.html"
    success_url = reverse_lazy("documents:customer_order_list")
    context_object_name = "object"


class CustomerOrderDetail(LoginRequiredMixin, DetailView):
    model = CustomerOrder
    template_name = "documents/customer_order_detail.html"
    context_object_name = "object"

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        ctx["economics"] = self.object.get_economics()
        return ctx


# --- Заказы поставщику ---
class SupplierOrderList(LoginRequiredMixin, SortableListMixin, ListView):
    model = SupplierOrder
    template_name = "documents/supplier_order_list.html"
    context_object_name = "object_list"
    default_sort = "date"
    default_order = "desc"
    sort_fields = {
        "date": "date",
        "number": "number",
        "organization": "organization__name",
        "supplier": "supplier__name",
        "total_in_currency": "total_in_currency",
        "total_amount": "total_amount",
    }

class SupplierOrderCreate(LoginRequiredMixin, CreateView):
    model = SupplierOrder
    form_class = SupplierOrderForm
    template_name = "documents/supplier_order_form.html"
    success_url = reverse_lazy("documents:supplier_order_list")

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        ctx["formset"] = SupplierOrderItemFormSet(instance=self.object) if self.object and self.object.pk else SupplierOrderItemFormSet()
        ctx["title"] = "Заказ поставщику"
        ctx["author_display"] = _get_author_for_request(self.request) if not self.object or not self.object.pk else self.object.author
        return ctx

    def form_valid(self, form):
        set_author(form, self.request)
        self.object = form.save()
        formset = SupplierOrderItemFormSet(self.request.POST, instance=self.object)
        if formset.is_valid():
            formset.save()
            self.object.recalc_totals()
            self.object.save()
            logger.info("Создан заказ поставщику %s", self.object)
            messages.success(self.request, "Заказ создан.")
            return redirect(self.success_url)
        return self.render_to_response(self.get_context_data(form=form, formset=formset))

    def get(self, request, *args, **kwargs):
        self.object = None
        return super().get(request, *args, **kwargs)


class SupplierOrderUpdate(LoginRequiredMixin, UpdateView):
    model = SupplierOrder
    form_class = SupplierOrderForm
    template_name = "documents/supplier_order_form.html"
    context_object_name = "object"
    success_url = reverse_lazy("documents:supplier_order_list")

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        ctx["formset"] = SupplierOrderItemFormSetUpdate(instance=self.object)
        ctx["title"] = "Заказ поставщику"
        ctx["author_display"] = self.object.author
        return ctx

    def form_valid(self, form):
        formset = SupplierOrderItemFormSetUpdate(self.request.POST, instance=self.object)
        if formset.is_valid():
            form.save()
            formset.save()
            self.object.recalc_totals()
            self.object.save()
            logger.info("Обновлён заказ поставщику %s", self.object)
            messages.success(self.request, "Заказ сохранён.")
            return redirect(self.success_url)
        return self.render_to_response(self.get_context_data(form=form, formset=formset))


class SupplierOrderDelete(LoginRequiredMixin, DeleteView):
    model = SupplierOrder
    template_name = "documents/confirm_delete.html"
    success_url = reverse_lazy("documents:supplier_order_list")
    context_object_name = "object"


# --- Поступление денежных средств ---
class CashInflowList(LoginRequiredMixin, SortableListMixin, ListView):
    model = CashInflow
    template_name = "documents/cash_inflow_list.html"
    context_object_name = "object_list"
    default_sort = "date"
    default_order = "desc"
    sort_fields = {
        "date": "date",
        "number": "number",
        "recipient": "recipient__name",
        "amount": "amount",
        "customer_order": "customer_order__number",
    }

class CashInflowCreate(LoginRequiredMixin, CreateView):
    model = CashInflow
    form_class = CashInflowForm
    template_name = "documents/cash_doc_form.html"
    success_url = reverse_lazy("documents:cash_inflow_list")

    def get_initial(self):
        initial = super().get_initial()
        initial["number"] = next_number(CashInflow)
        return initial

    def form_valid(self, form):
        set_author(form, self.request)
        form.save()
        logger.info("Создано поступление %s", form.instance)
        messages.success(self.request, "Поступление создано.")
        return redirect(self.success_url)

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        ctx["title"] = "Поступление денежных средств"
        ctx["cancel_url"] = reverse_lazy("documents:cash_inflow_list")
        return ctx


class CashInflowUpdate(LoginRequiredMixin, UpdateView):
    model = CashInflow
    form_class = CashInflowForm
    template_name = "documents/cash_doc_form.html"
    context_object_name = "object"
    success_url = reverse_lazy("documents:cash_inflow_list")

    def form_valid(self, form):
        form.save()
        logger.info("Обновлено поступление %s", self.object)
        messages.success(self.request, "Поступление сохранено.")
        return redirect(self.success_url)

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        ctx["title"] = "Поступление денежных средств"
        ctx["cancel_url"] = reverse_lazy("documents:cash_inflow_list")
        return ctx


class CashInflowDelete(LoginRequiredMixin, DeleteView):
    model = CashInflow
    template_name = "documents/confirm_delete.html"
    success_url = reverse_lazy("documents:cash_inflow_list")
    context_object_name = "object"


# --- Перемещение денежных средств ---
class CashTransferList(LoginRequiredMixin, SortableListMixin, ListView):
    model = CashTransfer
    template_name = "documents/cash_transfer_list.html"
    context_object_name = "object_list"
    default_sort = "date"
    default_order = "desc"
    sort_fields = {
        "date": "date",
        "number": "number",
        "sender": "sender__name",
        "recipient": "recipient__name",
        "amount": "amount",
    }

class CashTransferCreate(LoginRequiredMixin, CreateView):
    model = CashTransfer
    form_class = CashTransferForm
    template_name = "documents/cash_doc_form.html"
    success_url = reverse_lazy("documents:cash_transfer_list")

    def get_initial(self):
        initial = super().get_initial()
        initial["number"] = next_number(CashTransfer)
        return initial

    def form_valid(self, form):
        set_author(form, self.request)
        form.save()
        logger.info("Создано перемещение %s", form.instance)
        messages.success(self.request, "Перемещение создано.")
        return redirect(self.success_url)

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        ctx["title"] = "Перемещение денежных средств"
        ctx["cancel_url"] = reverse_lazy("documents:cash_transfer_list")
        return ctx


class CashTransferUpdate(LoginRequiredMixin, UpdateView):
    model = CashTransfer
    form_class = CashTransferForm
    template_name = "documents/cash_doc_form.html"
    context_object_name = "object"
    success_url = reverse_lazy("documents:cash_transfer_list")

    def form_valid(self, form):
        form.save()
        logger.info("Обновлено перемещение %s", self.object)
        messages.success(self.request, "Перемещение сохранено.")
        return redirect(self.success_url)

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        ctx["title"] = "Перемещение денежных средств"
        ctx["cancel_url"] = reverse_lazy("documents:cash_transfer_list")
        return ctx


class CashTransferDelete(LoginRequiredMixin, DeleteView):
    model = CashTransfer
    template_name = "documents/confirm_delete.html"
    success_url = reverse_lazy("documents:cash_transfer_list")
    context_object_name = "object"


# --- Расход денежных средств ---
class CashExpenseList(LoginRequiredMixin, SortableListMixin, ListView):
    model = CashExpense
    template_name = "documents/cash_expense_list.html"
    context_object_name = "object_list"
    default_sort = "date"
    default_order = "desc"
    sort_fields = {
        "date": "date",
        "number": "number",
        "sender": "sender__name",
        "amount": "amount",
        "supplier_order": "supplier_order__number",
    }

class CashExpenseCreate(LoginRequiredMixin, CreateView):
    model = CashExpense
    form_class = CashExpenseForm
    template_name = "documents/cash_doc_form.html"
    success_url = reverse_lazy("documents:cash_expense_list")

    def get_initial(self):
        initial = super().get_initial()
        initial["number"] = next_number(CashExpense)
        return initial

    def form_valid(self, form):
        set_author(form, self.request)
        form.save()
        logger.info("Создан расход %s", form.instance)
        messages.success(self.request, "Расход создан.")
        return redirect(self.success_url)

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        ctx["title"] = "Расход денежных средств"
        ctx["cancel_url"] = reverse_lazy("documents:cash_expense_list")
        return ctx


class CashExpenseUpdate(LoginRequiredMixin, UpdateView):
    model = CashExpense
    form_class = CashExpenseForm
    template_name = "documents/cash_doc_form.html"
    context_object_name = "object"
    success_url = reverse_lazy("documents:cash_expense_list")

    def form_valid(self, form):
        form.save()
        logger.info("Обновлён расход %s", self.object)
        messages.success(self.request, "Расход сохранён.")
        return redirect(self.success_url)

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        ctx["title"] = "Расход денежных средств"
        ctx["cancel_url"] = reverse_lazy("documents:cash_expense_list")
        return ctx


class CashExpenseDelete(LoginRequiredMixin, DeleteView):
    model = CashExpense
    template_name = "documents/confirm_delete.html"
    success_url = reverse_lazy("documents:cash_expense_list")
    context_object_name = "object"