"""
Barn Web App - A collection of web-apps for my family's personal use,
including a recipe database.
Copyright © 2023 Benjamin Stadlbauer

This program is free software: you can redistribute it and/or modify it
under the terms of the GNU Affero General Public License as published by
the Free Software Foundation, either version 3 of the License, or (at
your option) any later version.

This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Affero
General Public License for more details.

This program comes with a copy of the GNU Affero General Public License
file at the root of this project.
"""

from django.shortcuts import render, get_object_or_404, redirect
from .models import Recipe, Version, Ingredient
from .forms import RecipeForm, VersionForm, IngredientFormSet
from django.contrib.auth.decorators import login_required
from django.urls import reverse
from django.http.response import HttpResponseRedirect
from django.conf import settings

RECIPE_FORM_PREFIX = 'recipe'
VERSION_FORM_PREFIX = 'version'
INGREDIENTS_FORMSET_PREFIX = 'ingredient'

def get_name_of_user(user):
	return user.first_name if user.first_name else user.username

@login_required
def recipes(request):
	recipes = Recipe.objects.all()
	return render(request, 'recipes.html', context={'recipes': recipes})

def version(request, slug_recipe, slug_version):
	recipe = get_object_or_404(Recipe, slug=slug_recipe)
	has_multiple_versions = recipe.versions.all().count() > 1 # type: ignore
	version = get_object_or_404(Version, recipe=recipe, slug=slug_version)
	ingredients = version.ingredients.all() # type: ignore

	return render(request, 'version.html', context={'recipe': recipe, 'has_multiple_versions': has_multiple_versions, 'version': version, 'ingredients': ingredients})

@login_required
def recipe(request, slug):
	recipe = get_object_or_404(Recipe, slug=slug)
	versions = recipe.versions.all() # type: ignore

	if (1 == versions.count()):
		return HttpResponseRedirect(reverse('version', kwargs={'slug_recipe': slug, 'slug_version': versions.get().slug}))
	else:
		return render(request, 'recipe.html', context={'recipe': recipe, 'versions': versions})

def create_version(request, recipe: Recipe, version_form: VersionForm) -> Version:
	version = version_form.save(commit=False)
	version.user = request.user
	version.recipe = recipe
	version.save()
	return version

def save_ingredients(version: Version, ingredients_formset: IngredientFormSet): # type: ignore
	for ingredient in ingredients_formset.save(commit=False):
		ingredient.version = version
		ingredient.save()

@login_required
def add_recipe(request):
	if request.method == 'POST':
		recipe_form = RecipeForm(request.POST, prefix=RECIPE_FORM_PREFIX)
		version_form = VersionForm(request.POST, prefix=VERSION_FORM_PREFIX, author_placeholder=get_name_of_user(request.user))
		ingredients_formset = IngredientFormSet(request.POST, queryset=Ingredient.objects.none(), prefix=INGREDIENTS_FORMSET_PREFIX)

		if recipe_form.is_valid() and version_form.is_valid() and ingredients_formset.is_valid():
			recipe = recipe_form.save(commit=True)
			version = create_version(request, recipe, version_form)
			save_ingredients(version, ingredients_formset)

			return HttpResponseRedirect(reverse('recipe', kwargs={'slug': recipe.slug}))
	else:
		recipe_form = RecipeForm(prefix=RECIPE_FORM_PREFIX)
		version_form = VersionForm(prefix=VERSION_FORM_PREFIX, author_placeholder=get_name_of_user(request.user))
		ingredients_formset = IngredientFormSet(queryset=Ingredient.objects.none(), prefix=INGREDIENTS_FORMSET_PREFIX)

	return render(request, 'recipe-form.html', {'recipe_form': recipe_form, 'version_form': version_form, 'ingredients_formset': ingredients_formset, 'title': 'Add recipe'})

@login_required
def edit_recipe(request, slug):
	recipe = get_object_or_404(Recipe, slug=slug)

	# It is assumed every recipe has at least one version
	if not request.user.is_superuser:
		users = set()

		for version in recipe.versions.all(): # type: ignore
			users.add(version.user)

		if len(users) > 1 or (len(users) == 1 and next(iter(users)) != request.user):
			return redirect(f"/accounts/login/?next={request.path}")

	if request.method == 'POST':
		form = RecipeForm(request.POST, instance=recipe, prefix=RECIPE_FORM_PREFIX)
		if form.is_valid():
			if form.has_changed():
				form.save()
			return HttpResponseRedirect(reverse('recipe', kwargs={'slug': recipe.slug}))
	else:
		form = RecipeForm(instance=recipe, prefix=RECIPE_FORM_PREFIX)

	return render(request, 'edit-recipe.html', {'form': form})

@login_required
def add_version(request, slug):
	recipe = get_object_or_404(Recipe, slug=slug)
	if (recipe.versions.all().count() > 0): # type: ignore
		version_initial = {'label': '', 'slug': ''}
	else:
		version_initial = {}

	if request.method == 'POST':
		version_form = VersionForm(request.POST, prefix=VERSION_FORM_PREFIX, initial=version_initial, author_placeholder=get_name_of_user(request.user))
		ingredients_formset = IngredientFormSet(request.POST, queryset=Ingredient.objects.none(), prefix=INGREDIENTS_FORMSET_PREFIX)
		version_form.recipe_id = recipe.id # type: ignore

		if version_form.is_valid() and ingredients_formset.is_valid():
			version = create_version(request, recipe, version_form)
			save_ingredients(version, ingredients_formset)

			return HttpResponseRedirect(reverse('version', kwargs={'slug_recipe': version.recipe.slug, 'slug_version': version.slug}))

	else:
		version_form = VersionForm(prefix=VERSION_FORM_PREFIX, initial=version_initial, author_placeholder=get_name_of_user(request.user))
		ingredients_formset = IngredientFormSet(queryset=Ingredient.objects.none(), prefix=INGREDIENTS_FORMSET_PREFIX)

	return render(request, 'recipe-form.html', {'version_form': version_form, 'ingredients_formset': ingredients_formset, 'title': f'Add version to {recipe.title}'})

@login_required
def edit_version(request, slug_recipe, slug_version):
	recipe = get_object_or_404(Recipe, slug=slug_recipe)
	version = get_object_or_404(Version, recipe=recipe, slug=slug_version)

	if version.user != request.user and not request.user.is_superuser:
		return redirect(f"/accounts/login/?next={request.path}")

	if request.method == 'POST':
		version_form = VersionForm(request.POST, prefix=VERSION_FORM_PREFIX, instance=version, author_placeholder=get_name_of_user(request.user))
		ingredients_formset = IngredientFormSet(request.POST, queryset=version.ingredients.all(), prefix=INGREDIENTS_FORMSET_PREFIX) # type: ignore
		version_form.recipe_id = recipe.id # type: ignore

		if version_form.is_valid() and ingredients_formset.is_valid():
			if version_form.has_changed():
				version = version_form.save()

			if ingredients_formset.has_changed():
				for ingredient in ingredients_formset.save(commit=False):
						ingredient.version = version
						ingredient.save()

			return HttpResponseRedirect(reverse('version', kwargs={'slug_recipe': version.recipe.slug, 'slug_version': version.slug}))
	else:
		version_form = VersionForm(instance=version, prefix=VERSION_FORM_PREFIX, author_placeholder=get_name_of_user(request.user))
		ingredients_formset = IngredientFormSet(queryset=version.ingredients.all(), prefix=INGREDIENTS_FORMSET_PREFIX) # type: ignore

	return render(request, 'recipe-form.html', {'version_form': version_form, 'ingredients_formset': ingredients_formset, 'title': f'Edit {recipe.title} ({version.label})'})