from django.shortcuts import render, redirect
from django.contrib import messages
from django.contrib.auth.mixins import LoginRequiredMixin
from django.urls import reverse_lazy
from django.views.generic import ListView, CreateView, DeleteView

from .models import FriendCode
from .forms import FriendCodeForm


class ListFriendCodesView(LoginRequiredMixin, ListView):
    """
    Display the current user's friend codes.
    """
    model = FriendCode
    template_name = "friend_codes/list_friend_codes.html"
    context_object_name = "friend_codes"

    def get_queryset(self):
        # Only display friend codes that belong to the current user.
        return self.request.user.friend_codes.all()


class AddFriendCodeView(LoginRequiredMixin, CreateView):
    """
    Add a new friend code for the current user.
    """
    model = FriendCode
    form_class = FriendCodeForm
    template_name = "friend_codes/add_friend_code.html"
    success_url = reverse_lazy('list_friend_codes')

    def form_valid(self, form):
        # Set the friend code's user to the current user before saving.
        form.instance.user = self.request.user
        messages.success(self.request, "Friend code added successfully.")
        return super().form_valid(form)


class DeleteFriendCodeView(LoginRequiredMixin, DeleteView):
    """
    Remove an existing friend code.
    The friend code will not be removed if it is referenced by trade offers via
    either the initiated_by or accepted_by relationships.
    """
    model = FriendCode
    template_name = "friend_codes/confirm_delete_friend_code.html"
    context_object_name = "friend_code"
    success_url = reverse_lazy('list_friend_codes')

    def get_queryset(self):
        # Ensure the friend code belongs to the current user.
        return FriendCode.objects.filter(user=self.request.user)

    def post(self, request, *args, **kwargs):
        self.object = self.get_object()
        # Check if there are any trade offers associated with this friend code.
        if self.object.initiated_by.exists() or self.object.accepted_by.exists():
            messages.error(
                request,
                "Cannot remove this friend code because there are existing trade offers associated with it."
            )
            return redirect(self.success_url)
        else:
            self.object.delete()
            messages.success(request, "Friend code removed successfully.")
            return redirect(self.success_url)