from django.db.models import F, Sum

from core.apps.management.forms import DeviceForm, IncomeForm, WarehouseForm, UserCreateForm, ExpenseFormEmployee, \
    ExpenseFormManager, ExpenseFormBusinessman, ReportForm
from django.db import transaction
from django.shortcuts import render, redirect
from core.apps.management.forms import ToyMovementForm, ToyMovementFormEmployee
from django.contrib.auth.decorators import login_required
from core.apps.management.decorators import role_required
from core.apps.management.forms import UserCreateFormManagerToEmployee, UserCreateFormBusinessman
from core.apps.management.forms.RentForm import RentForm
from core.apps.management.models import ToyMovement, Warehouse, Report


@login_required
@role_required(["manager", "businessman"])
def create_device(request):
    user = request.user

    if request.method == "POST":
        form = DeviceForm(request.POST, user=user)
        if form.is_valid():
            form.save()
            return redirect("dashboard")
    else:
        form = DeviceForm(user=user)

    return render(
        request,
        "common/create/device_create.html",
        {
            "form": form,
            "title": "Aparat Yaratish"
        }
    )


@login_required
@role_required(["businessman"])
def create_income(request):
    if request.method == "POST":
        form = IncomeForm(request.POST, user=request.user)
        if form.is_valid():
            form.save()
            return redirect("income_list")
    else:
        form = IncomeForm(user=request.user)

    return render(
        request,
        "common/create/income_create.html",
        {"form": form, "title": "Kirim qo'shish"}
    )

@login_required
@role_required(['manager', 'businessman'])
def create_income_manager_and_businessman(request):
    if request.method == "POST":
        form = IncomeForm(request.POST, user=request.user)
        if form.is_valid():
            with transaction.atomic():
                income = form.save(commit=False)
                income.created_by = request.user
                income.save()

                warehouse = income.warehouse
                warehouse.toys_count += income.amount
                warehouse.save()
            return redirect("common/create/income_create.html")
    else:
        form = IncomeForm(user=request.user)
    return render(request=request, template_name="common/create/income_create.html", context={"form": form})

@login_required
def create_expense(request):
    user = request.user

    # select form based on role
    if user.role == "employee":
        form_class = ExpenseFormEmployee
    elif user.role == "manager":
        form_class = ExpenseFormManager
    else:  # businessman or superuser
        form_class = ExpenseFormBusinessman

    if request.method == "POST":
        form = form_class(request.POST)
        if form.is_valid():
            with transaction.atomic():
                expense = form.save(commit=False)
                expense.created_by = user

                # AUTO CONFIRM for manager & businessman
                if user.role in ["manager", "businessman"]:
                    expense.is_confirmed = True
                    expense.confirmed_by = user

                expense.save()

            return redirect("dashboard")
    else:
        form = form_class()

    return render(request, "common/create/expense_create.html", {
        "form": form,
        "title": "Xarajat qoʻshish",
        "user_role": user.role
    })


@login_required
@role_required(["businessman"])
def create_warehouse(request):
    form = WarehouseForm(request.POST or None)
    if form.is_valid():
        form.save()
        return redirect("businessman_dashboard")

    return render(request, "common/create/warehouse_create.html", {
        "form": form,
        "title": "Sklad Yaratish"
    })


@login_required
@role_required(["manager", "businessman"])
def create_user(request):
    if request.user.role == "businessman":
        form_class = UserCreateFormBusinessman
        form_kwargs = {}
        redirect_to = "businessman_dashboard"

    else:  # manager
        form_class = UserCreateFormManagerToEmployee
        form_kwargs = {"manager": request.user}
        redirect_to = "manager_dashboard"

    form = form_class(request.POST or None, **form_kwargs)

    if form.is_valid():
        form.save()
        return redirect(redirect_to)

    return render(request, "common/create/user_create.html", {
        "form": form,
        "title": "Foydalanuvchi yaratish",
    })

@login_required
def create_toy_movement(request):
    user = request.user

    if user.role == "employee":
        form_class = ToyMovementFormEmployee
    else:
        form_class = ToyMovementForm

    if request.method == "POST":
        form = form_class(request.POST, user=user)

        if form.is_valid():
            with transaction.atomic():

                quantity = form.cleaned_data["quantity"]

                if user.role == "employee":
                    # Auto determine warehouse by region
                    from_wh = Warehouse.objects.select_for_update().filter(
                        region=user.region
                    ).first()

                    if not from_wh:
                        form.add_error(None, "No warehouse assigned to your region.")
                        return render(request,
                                      "common/create/toy_movement_create.html",
                                      {"form": form})

                    if from_wh.toys_count < quantity:
                        form.add_error("quantity", "Not enough toys in warehouse.")
                        return render(request,
                                      "common/create/toy_movement_create.html",
                                      {"form": form})

                    # Deduct stock
                    Warehouse.objects.filter(pk=from_wh.pk).update(
                        toys_count=F("toys_count") - quantity
                    )

                    movement = form.save(commit=False)
                    movement.movement_type = "from_warehouse"
                    movement.from_warehouse = from_wh
                    movement.to_warehouse = None
                    movement.created_by = user
                    movement.save()

                else:
                    # Manager / Businessman normal logic
                    from_wh = form.cleaned_data["from_warehouse"]
                    movement_type = form.cleaned_data["movement_type"]
                    to_wh = form.cleaned_data.get("to_warehouse")

                    from_wh = Warehouse.objects.select_for_update().get(pk=from_wh.pk)

                    if from_wh.toys_count < quantity:
                        form.add_error("quantity", "Not enough toys in warehouse.")
                        return render(request,
                                      "common/create/toy_movement_create.html",
                                      {"form": form})

                    Warehouse.objects.filter(pk=from_wh.pk).update(
                        toys_count=F("toys_count") - quantity
                    )

                    if movement_type == "between_warehouses" and to_wh:
                        to_wh = Warehouse.objects.select_for_update().get(pk=to_wh.pk)
                        Warehouse.objects.filter(pk=to_wh.pk).update(
                            toys_count=F("toys_count") + quantity
                        )

                    movement = form.save(commit=False)
                    movement.created_by = user
                    movement.save()

            return redirect("dashboard")

    else:
        form = form_class(user=user)

    return render(
        request,
        "common/create/toy_movement_create.html",
        {"form": form}
    )

@login_required
@role_required(["manager", "businessman"])
def create_toy_movement_auto(request):
    user = request.user

    if request.method == "POST":
        form = ToyMovementForm(request.POST, user=user)

        if form.is_valid():
            with transaction.atomic():
                # Get cleaned data
                from_wh = form.cleaned_data.get("from_warehouse")
                to_wh = form.cleaned_data.get("to_warehouse")
                movement_type = form.cleaned_data.get("movement_type")
                quantity = form.cleaned_data.get("quantity")

                # Validate warehouse exists
                if not from_wh:
                    form.add_error("from_warehouse", "Source warehouse is required.")
                    return render(request, "common/create/toy_movement_create.html", {"form": form})

                # Lock and get fresh warehouse data
                from_wh = Warehouse.objects.select_for_update().get(pk=from_wh.pk)

                # Check stock
                if from_wh.toys_count < quantity:
                    form.add_error("quantity", "Not enough toys in warehouse.")
                    return render(request, "common/create/toy_movement_create.html", {"form": form})

                # Deduct from source warehouse
                Warehouse.objects.filter(pk=from_wh.pk).update(
                    toys_count=F("toys_count") - quantity
                )

                # Add to destination warehouse if between_warehouses
                if movement_type == "between_warehouses" and to_wh:
                    to_wh = Warehouse.objects.select_for_update().get(pk=to_wh.pk)
                    Warehouse.objects.filter(pk=to_wh.pk).update(
                        toys_count=F("toys_count") + quantity
                    )

                # Save movement
                movement = form.save(commit=False)
                movement.created_by = user
                movement.save()

            return redirect("toy_movement_list")
        else:
            # Form has errors, display them
            return render(request, "common/create/toy_movement_create.html", {"form": form})

    else:
        # GET request → render the create form
        form = ToyMovementForm(user=user)

    return render(
        request,
        "common/create/toy_movement_create.html",
        {"form": form}
    )

@login_required
@role_required(["manager", "businessman"])
def create_rent(request):

    if request.method == "POST":
        form = RentForm(request.POST)
        if form.is_valid():
            rent = form.save(commit=False)
            rent.created_by = request.user
            rent.save()
            return redirect("dashboard")
    else:
        form = RentForm()

    return render(request, "common/create/rent_create.html", {"form":form, "title":"Create Rent"})

@login_required
@role_required(["employee"])
def create_report(request):

    if request.method == "POST":
        form = ReportForm(request.POST, user=request.user)

        if form.is_valid():

            # 🔥 Employee MUST have warehouse
            if not request.user.warehouse:
                form.add_error(None, "Sizga ombor biriktirilmagan.")
                return render(
                    request,
                    "common/create/report_create.html",
                    {"form": form, "title": "Yakuniy Hisobot"}
                )

            device = form.cleaned_data["device"]
            entered_quantity = form.cleaned_data["quantity"]

            with transaction.atomic():

                # ✅ 1. Save last entered quantity as ToyMovement
                ToyMovement.objects.create(
                    movement_type="from_warehouse",
                    from_warehouse=request.user.warehouse,
                    device=device,
                    quantity=entered_quantity,
                    created_by=request.user,
                )

                # ✅ 2. Find last report for this device
                last_report = Report.objects.filter(
                    device=device
                ).order_by("-created_at").first()

                if last_report:
                    last_time = last_report.created_at

                    total_since_last = ToyMovement.objects.filter(
                        device=device,
                        created_at__gt=last_time
                    ).aggregate(
                        total=Sum("quantity")
                    )["total"] or 0
                else:
                    total_since_last = ToyMovement.objects.filter(
                        device=device
                    ).aggregate(
                        total=Sum("quantity")
                    )["total"] or 0

                # ✅ 3. Create Report
                Report.objects.create(
                    device=device,
                    quantity=total_since_last,
                    created_by=request.user
                )

            return redirect("employee_dashboard")

    else:
        form = ReportForm(user=request.user)

    return render(
        request,
        "common/create/report_create.html",
        {
            "form": form,
            "title": "Yakuniy Hisobot"
        }
    )