from decimal import Decimal

from django.contrib.auth.models import User
from drf_writable_nested import (UniqueFieldsMixin,
                                 WritableNestedModelSerializer)
from rest_framework import serializers
from rest_framework.exceptions import ValidationError

from cookbook.models import (Comment, CookLog, Food, Ingredient, Keyword,
                             MealPlan, MealType, NutritionInformation, Recipe,
                             RecipeBook, RecipeBookEntry, RecipeImport,
                             ShareLink, ShoppingList, ShoppingListEntry,
                             ShoppingListRecipe, Step, Storage, Sync, SyncLog,
                             Unit, UserPreference, ViewLog, SupermarketCategory, Supermarket, SupermarketCategoryRelation)
from cookbook.templatetags.custom_tags import markdown


class CustomDecimalField(serializers.Field):
    """
    Custom decimal field to normalize useless decimal places
    and allow commas as decimal separators
    """

    def to_representation(self, value):
        if isinstance(value, Decimal):
            return value.normalize()
        else:
            return Decimal(value).normalize()

    def to_internal_value(self, data):
        if type(data) == int or type(data) == float:
            return data
        elif type(data) == str:
            if data == '':
                return 0
            try:
                return float(data.replace(',', ''))
            except ValueError:
                raise ValidationError('A valid number is required')


class UserNameSerializer(WritableNestedModelSerializer):
    username = serializers.SerializerMethodField('get_user_label')

    def get_user_label(self, obj):
        return obj.get_user_name()

    class Meta:
        model = User
        fields = ('id', 'username')


class UserPreferenceSerializer(serializers.ModelSerializer):
    class Meta:
        model = UserPreference
        fields = (
            'user', 'theme', 'nav_color', 'default_unit', 'default_page',
            'search_style', 'show_recent', 'plan_share', 'ingredient_decimals',
            'comments'
        )
        read_only_fields = ['user']


class StorageSerializer(serializers.ModelSerializer):
    class Meta:
        model = Storage
        fields = (
            'id', 'name', 'method', 'username', 'password',
            'token', 'created_by'
        )

        extra_kwargs = {
            'password': {'write_only': True},
            'token': {'write_only': True},
        }


class SyncSerializer(serializers.ModelSerializer):
    class Meta:
        model = Sync
        fields = (
            'id', 'storage', 'path', 'active', 'last_checked',
            'created_at', 'updated_at'
        )


class SyncLogSerializer(serializers.ModelSerializer):
    class Meta:
        model = SyncLog
        fields = ('id', 'sync', 'status', 'msg', 'created_at')


class KeywordLabelSerializer(serializers.ModelSerializer):
    label = serializers.SerializerMethodField('get_label')

    def get_label(self, obj):
        return str(obj)

    class Meta:
        model = Keyword
        fields = (
            'id', 'label',
        )
        read_only_fields = ('id', 'label')


class KeywordSerializer(UniqueFieldsMixin, serializers.ModelSerializer):
    label = serializers.SerializerMethodField('get_label')

    def get_label(self, obj):
        return str(obj)

    def create(self, validated_data):
        # since multi select tags dont have id's
        # duplicate names might be routed to create
        obj, created = Keyword.objects.get_or_create(**validated_data)
        return obj

    class Meta:
        model = Keyword
        fields = (
            'id', 'name', 'icon', 'label', 'description',
            'created_at', 'updated_at'
        )

        read_only_fields = ('id',)


class UnitSerializer(UniqueFieldsMixin, serializers.ModelSerializer):

    def create(self, validated_data):
        # since multi select tags dont have id's
        # duplicate names might be routed to create
        obj, created = Unit.objects.get_or_create(**validated_data)
        return obj

    class Meta:
        model = Unit
        fields = ('id', 'name', 'description')
        read_only_fields = ('id',)


class SupermarketCategorySerializer(UniqueFieldsMixin, WritableNestedModelSerializer):

    def create(self, validated_data):
        # since multi select tags dont have id's
        # duplicate names might be routed to create
        obj, created = SupermarketCategory.objects.get_or_create(**validated_data)
        return obj

    def update(self, instance, validated_data):
        return super(SupermarketCategorySerializer, self).update(instance, validated_data)

    class Meta:
        model = SupermarketCategory
        fields = ('id', 'name')


class SupermarketCategoryRelationSerializer(serializers.ModelSerializer):
    category = SupermarketCategorySerializer()

    class Meta:
        model = SupermarketCategoryRelation
        fields = ('id', 'category', 'supermarket')


class SupermarketSerializer(UniqueFieldsMixin, serializers.ModelSerializer):
    category_to_supermarket = SupermarketCategoryRelationSerializer(many=True, read_only=True)

    class Meta:
        model = Supermarket
        fields = ('id', 'name', 'category_to_supermarket')


class FoodSerializer(UniqueFieldsMixin, WritableNestedModelSerializer):
    supermarket_category = SupermarketCategorySerializer(read_only=True)

    def create(self, validated_data):
        # since multi select tags dont have id's
        # duplicate names might be routed to create
        obj, created = Food.objects.get_or_create(**validated_data)
        return obj

    def update(self, instance, validated_data):
        return super(FoodSerializer, self).update(instance, validated_data)

    class Meta:
        model = Food
        fields = ('id', 'name', 'recipe', 'ignore_shopping', 'supermarket_category')


class IngredientSerializer(WritableNestedModelSerializer):
    food = FoodSerializer(allow_null=True)
    unit = UnitSerializer(allow_null=True)
    amount = CustomDecimalField()

    class Meta:
        model = Ingredient
        fields = (
            'id', 'food', 'unit', 'amount', 'note', 'order',
            'is_header', 'no_amount'
        )


class StepSerializer(WritableNestedModelSerializer):
    ingredients = IngredientSerializer(many=True)
    ingredients_markdown = serializers.SerializerMethodField('get_ingredients_markdown')
    ingredients_vue = serializers.SerializerMethodField('get_ingredients_vue')

    def get_ingredients_vue(self, obj):
        return obj.get_instruction_render()

    def get_ingredients_markdown(self, obj):
        return obj.get_instruction_render()

    class Meta:
        model = Step
        fields = (
            'id', 'name', 'type', 'instruction', 'ingredients', 'ingredients_markdown',
            'ingredients_vue', 'time', 'order', 'show_as_header'
        )


# used for the import export. temporary workaround until that module is finally fixed
class StepExportSerializer(WritableNestedModelSerializer):
    ingredients = IngredientSerializer(many=True)

    class Meta:
        model = Step
        fields = (
            'id', 'name', 'type', 'instruction', 'ingredients', 'time', 'order', 'show_as_header'
        )


class NutritionInformationSerializer(serializers.ModelSerializer):
    class Meta:
        model = NutritionInformation
        fields = ('carbohydrates', 'fats', 'proteins', 'calories', 'source')


class RecipeOverviewSerializer(WritableNestedModelSerializer):
    keywords = KeywordLabelSerializer(many=True)

    class Meta:
        model = Recipe
        fields = (
            'id', 'name', 'description', 'image', 'keywords', 'working_time',
            'waiting_time', 'created_by', 'created_at', 'updated_at',
            'internal', 'servings', 'file_path'
        )
        read_only_fields = ['image', 'created_by', 'created_at']


class RecipeSerializer(WritableNestedModelSerializer):
    nutrition = NutritionInformationSerializer(allow_null=True, required=False)
    steps = StepSerializer(many=True)
    keywords = KeywordSerializer(many=True)

    class Meta:
        model = Recipe
        fields = (
            'id', 'name', 'description', 'image', 'keywords', 'steps', 'working_time',
            'waiting_time', 'created_by', 'created_at', 'updated_at',
            'internal', 'nutrition', 'servings', 'file_path', 'servings_text',
        )
        read_only_fields = ['image', 'created_by', 'created_at']

    def create(self, validated_data):
        validated_data['created_by'] = self.context['request'].user
        return super().create(validated_data)


# used for the import export. temporary workaround until that module is finally fixed
class RecipeExportSerializer(RecipeSerializer):
    steps = StepExportSerializer(many=True)


class RecipeImageSerializer(WritableNestedModelSerializer):
    class Meta:
        model = Recipe
        fields = ['image', ]


class RecipeImportSerializer(serializers.ModelSerializer):
    class Meta:
        model = RecipeImport
        fields = '__all__'


class CommentSerializer(serializers.ModelSerializer):
    class Meta:
        model = Comment
        fields = '__all__'


class RecipeBookSerializer(serializers.ModelSerializer):
    class Meta:
        model = RecipeBook
        fields = '__all__'
        read_only_fields = ['id', 'created_by']


class RecipeBookEntrySerializer(serializers.ModelSerializer):
    class Meta:
        model = RecipeBookEntry
        fields = '__all__'


class MealTypeSerializer(serializers.ModelSerializer):
    class Meta:
        model = MealType
        fields = '__all__'


class MealPlanSerializer(serializers.ModelSerializer):
    recipe_name = serializers.ReadOnlyField(source='recipe.name')
    meal_type_name = serializers.ReadOnlyField(source='meal_type.name')
    note_markdown = serializers.SerializerMethodField('get_note_markdown')
    servings = CustomDecimalField()

    def get_note_markdown(self, obj):
        return markdown(obj.note)

    class Meta:
        model = MealPlan
        fields = (
            'id', 'title', 'recipe', 'servings', 'note', 'note_markdown',
            'date', 'meal_type', 'created_by', 'shared', 'recipe_name',
            'meal_type_name'
        )


class ShoppingListRecipeSerializer(serializers.ModelSerializer):
    recipe_name = serializers.ReadOnlyField(source='recipe.name')
    servings = CustomDecimalField()

    class Meta:
        model = ShoppingListRecipe
        fields = ('id', 'recipe', 'recipe_name', 'servings')
        read_only_fields = ('id',)


class ShoppingListEntrySerializer(WritableNestedModelSerializer):
    food = FoodSerializer(allow_null=True)
    unit = UnitSerializer(allow_null=True)
    amount = CustomDecimalField()

    class Meta:
        model = ShoppingListEntry
        fields = (
            'id', 'list_recipe', 'food', 'unit', 'amount', 'order', 'checked'
        )


class ShoppingListEntryCheckedSerializer(serializers.ModelSerializer):
    class Meta:
        model = ShoppingListEntry
        fields = ('id', 'checked')


class ShoppingListSerializer(WritableNestedModelSerializer):
    recipes = ShoppingListRecipeSerializer(many=True, allow_null=True)
    entries = ShoppingListEntrySerializer(many=True, allow_null=True)
    shared = UserNameSerializer(many=True)

    class Meta:
        model = ShoppingList
        fields = (
            'id', 'uuid', 'note', 'recipes', 'entries',
            'shared', 'finished', 'created_by', 'created_at'
        )
        read_only_fields = ('id',)


class ShoppingListAutoSyncSerializer(WritableNestedModelSerializer):
    entries = ShoppingListEntryCheckedSerializer(many=True, allow_null=True)

    class Meta:
        model = ShoppingList
        fields = ('id', 'entries',)
        read_only_fields = ('id',)


class ShareLinkSerializer(serializers.ModelSerializer):
    class Meta:
        model = ShareLink
        fields = '__all__'


class CookLogSerializer(serializers.ModelSerializer):
    def create(self, validated_data):  # TODO make mixin
        validated_data['created_by'] = self.context['request'].user
        return super().create(validated_data)

    class Meta:
        model = CookLog
        fields = '__all__'
        read_only_fields = ('id', 'created_by')


class ViewLogSerializer(serializers.ModelSerializer):
    class Meta:
        model = ViewLog
        fields = '__all__'