# -*- coding: utf-8 -*-
"""
Batch views - READ ONLY
- IncomingBatch (Партии поступлений)
- StockBatch (Партии товара на складе)
"""
from django.views.generic import ListView, DetailView
from django.contrib.auth.mixins import LoginRequiredMixin
from ..models import IncomingBatch, Incoming, StockBatch, SaleBatchAllocation, WriteOff


class IncomingBatchListView(LoginRequiredMixin, ListView):
    """Список всех партий поступлений товара"""
    model = IncomingBatch
    template_name = 'inventory/incoming_batch/batch_list.html'
    context_object_name = 'batches'
    paginate_by = 30

    def get_queryset(self):
        return IncomingBatch.objects.all().select_related('warehouse').order_by('-created_at')

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        # Добавляем количество товаров в каждую партию
        for batch in context['batches']:
            batch.items_count = batch.items.count()
            batch.total_quantity = sum(item.quantity for item in batch.items.all())
        return context


class IncomingBatchDetailView(LoginRequiredMixin, DetailView):
    """Детальная информация по партии поступления"""
    model = IncomingBatch
    template_name = 'inventory/incoming_batch/batch_detail.html'
    context_object_name = 'batch'

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        batch = self.get_object()

        # Товары в этой партии
        context['items'] = batch.items.all().select_related('product', 'stock_batch')

        return context


class StockBatchListView(LoginRequiredMixin, ListView):
    """Список всех партий товара на складах"""
    model = StockBatch
    template_name = 'inventory/batch/batch_list.html'
    context_object_name = 'batches'
    paginate_by = 30

    def get_queryset(self):
        return StockBatch.objects.filter(
            is_active=True
        ).select_related('product', 'warehouse').order_by('-created_at')


class StockBatchDetailView(LoginRequiredMixin, DetailView):
    """
    Детальная информация по партии товара.
    Показывает историю операций с данной партией (продажи, списания, перемещения).
    """
    model = StockBatch
    template_name = 'inventory/batch/batch_detail.html'
    context_object_name = 'batch'

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        batch = self.get_object()

        # История продаж из этой партии
        context['sales'] = SaleBatchAllocation.objects.filter(
            batch=batch
        ).select_related('sale', 'sale__product')

        # История списаний из этой партии
        context['writeoffs'] = WriteOff.objects.filter(
            batch=batch
        ).order_by('-date')

        return context