serializers.py

#
# steering, Programme/schedule management for AURA
#
# Copyright (C) 2011-2017, 2020, Ernesto Rico Schmidt
# Copyright (C) 2017-2019, Ingo Leindecker
#
# 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.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#

import re
from collections.abc import Iterable
from datetime import datetime
from functools import cached_property
from zoneinfo import ZoneInfo

from drf_jsonschema_serializer import JSONSchemaField
from drf_spectacular.utils import extend_schema_field
from rest_framework import serializers
from rest_framework.permissions import exceptions

from django.conf import settings
from django.contrib.auth.models import User
from django.core.exceptions import ObjectDoesNotExist
from django.db import IntegrityError, transaction
from django.db.models import Q
from django.utils import text, timezone
from program.models import (
    CBA,
    Category,
    FundingCategory,
    Image,
    Language,
    License,
    LinkType,
    MusicFocus,
    Note,
    NoteLink,
    Playlist,
    PlaylistEntry,
    Profile,
    ProfileLink,
    ProgramEntry,
    RadioSettings,
    RRule,
    Schedule,
    Show,
    ShowLink,
    TimeSlot,
    Topic,
    Type,
    application_state_manager,
)
from program.typing import (
    Logo,
    MicroProgram,
    ProgramFallback,
    RadioCBASettings,
    RadioImageRequirementsSettings,
    RadioPlayoutSettings,
    RadioProgramSettings,
    RadioStationSettings,
)
from program.utils import update_links

SOLUTION_CHOICES = {
    "theirs": "Discard projected timeslot. Keep existing timeslot(s).",
    "ours": "Create projected timeslot. Delete existing timeslot(s).",
    "theirs-start": (
        "Keep existing timeslot. Create projected timeslot with start time of existing end."
    ),
    "ours-start": (
        "Create projected timeslot. Change end of existing timeslot to projected start time."
    ),
    "theirs-end": (
        "Keep existing timeslot. Create projected timeslot with end of existing start time."
    ),
    "ours-end": (
        "Create projected timeslot. Change start of existing timeslot to projected end time."
    ),
    "theirs-both": (
        "Keep existing timeslot. "
        "Create two projected timeslots with end of existing start and start of existing end."
    ),
    "ours-both": (
        "Create projected timeslot. Split existing timeslot into two: \n\n"
        "* set existing end time to projected start,\n"
        "* create another timeslot with start = projected end and end = existing end."
    ),
}


class UpdateFieldPermissionValidatorMixin:
    """
    Validates that fields can only be saved if the appropriate permissions have been given.

    The required field permissions are determined based the following strategy:
        1. If Serializer.Meta.custom_field_write_permission_map[{field_name}] has been set
           the permissions defined there will be used.
        2. If permission in the style of
             {app_label}.edit__{model_name}__{field_name}
           exists, that permission will be used.
        3. If none of the above are available, no permissions will be used for the field.

    The permissions for each field, for which specific write permissions have been defined,
    will be checked on update and create operations. If the user does not have any one of the
    required field permissions for the provided fields the request will be rejected with a
    403 error including a list of fields that the user is not allowed to set.
    """

    def get_validators(self):
        def validate_field_permissions(data, *args, **kwargs):
            user = self.context.get("request").user
            self._check_field_write_permissions(user, data, self.instance)

        return [*super().get_validators(), validate_field_permissions]

    def _generate_field_permission_name_candidates(self, model_name: str, field_name: str):
        prefix = f"edit__{model_name}__"
        yield prefix + field_name
        if field_name.endswith("_id"):
            yield prefix + field_name[:-3]
        if field_name.endswith("_ids"):
            yield prefix + field_name[:-4] + "s"

    def _get_field_write_permission_map(self, field_names: set[str]):
        custom_map: dict[str, str | Iterable[str]] = getattr(
            self.Meta, "custom_field_write_permission_map", {}
        )
        model = self.Meta.model
        custom_model_permissions = set(dict(model._meta.permissions).keys())
        app_label = model._meta.app_label
        model_name = model._meta.model_name
        result = {}
        for field_name in field_names:
            if perm := custom_map.get(field_name):
                if isinstance(perm, str):
                    result[field_name] = {perm}
                else:
                    result[field_name] = set(perm)
                continue
            for perm in self._generate_field_permission_name_candidates(model_name, field_name):
                if perm in custom_model_permissions:
                    result[field_name] = {f"{app_label}.{perm}"}
        return result

    def _check_field_write_permissions(self, user, validated_data, instance=None):
        field_error_map = {}
        field_write_permission_map = self._get_field_write_permission_map(validated_data.keys())
        client_name_map = {field.source: field.field_name for field in self._writable_fields}
        for field_name, required_permissions in field_write_permission_map.items():
            if not user.has_perms(required_permissions):
                # The name of the field in validated_data is not necessarily
                # the same as the field name the client sent.
                # The error mapping should reflect the name the client sent.
                client_field_name = client_name_map.get(field_name, field_name)
                field_error_map[client_field_name] = exceptions.ErrorDetail(
                    "You do not have permission to set this field.",
                    code="missing-field-permission",
                )
        if field_error_map:
            raise exceptions.PermissionDenied(field_error_map)


class SimpleAuditUpdaterMixin:
    def _update_audit_data(self, instance, *username_fields):
        username = self.context.get("request").user.username
        for field in username_fields:
            setattr(instance, field, username)
        instance.save(update_fields=username_fields)

    def update(self, instance, validated_data):
        instance = super().update(instance, validated_data)
        self._update_audit_data(instance, "updated_by")
        return instance

    def create(self, validated_data):
        instance = super().create(validated_data)
        self._update_audit_data(instance, "created_by", "updated_by")
        return instance


class ErrorSerializer(serializers.Serializer):
    message = serializers.CharField()
    code = serializers.CharField(allow_null=True)


class CBASerializer(serializers.ModelSerializer):
    class Meta:
        model = CBA
        read_only_fields = (
            "created_at",
            "created_by",
            "updated_at",
            "updated_by",
        )
        fields = (
            "username",
            "user_token",
        ) + read_only_fields

    def to_representation(self, instance):
        if not self.parent.context.get("request").user.is_authenticated:
            return None

        return super().to_representation(instance)


class UserSerializer(serializers.ModelSerializer):
    is_privileged = serializers.SerializerMethodField()
    permissions = serializers.SerializerMethodField()
    cba = CBASerializer(required=False)
    profile_ids = serializers.PrimaryKeyRelatedField(
        many=True, queryset=Profile.objects.all(), required=False, source="profiles"
    )

    class Meta:
        extra_kwargs = {
            "password": {"write_only": True},
        }
        model = User
        read_only_fields = (
            "id",
            "is_privileged",
            "permissions",
            "profile_ids",
        )
        fields = (
            "cba",
            "email",
            "first_name",
            "is_active",
            "is_staff",
            "is_superuser",
            "last_name",
            "password",
            "username",
        ) + read_only_fields

    @staticmethod
    def get_permissions(obj: User) -> list[str]:
        return sorted(
            [p for p in obj.get_all_permissions() if p.split(".", 1)[0] in ["auth", "program"]]
        )

    @staticmethod
    def get_is_privileged(obj: User) -> bool:
        return obj.is_superuser

    def create(self, validated_data):
        """
        Create and return a new User instance, given the validated data.
        """

        cba_data = validated_data.pop("cba") if "cba" in validated_data else None

        user = super(UserSerializer, self).create(validated_data)
        user.date_joined = timezone.now()
        user.set_password(validated_data["password"])
        user.save()

        if cba_data:
            CBA.objects.create(
                username=cba_data.get("username").strip(),
                user_token=cba_data.get("user_token").strip(),
                created_by=self.context.get("request").user.username,
                user=user,
            )

        return user

    def update(self, instance, validated_data):
        """
        Update and return an existing User instance, given the validated data.
        """

        if "first_name" in validated_data:
            instance.first_name = validated_data.get("first_name")

        if "last_name" in validated_data:
            instance.last_name = validated_data.get("last_name")

        if "email" in validated_data:
            instance.email = validated_data.get("email")

        if "is_active" in validated_data:
            instance.is_active = validated_data.get("is_active")

        if "is_staff" in validated_data:
            instance.is_staff = validated_data.get("is_staff")

        if "is_superuser" in validated_data:
            instance.is_superuser = validated_data.get("is_superuser")

        cba_data = validated_data.pop("cba") if "cba" in validated_data else None

        try:
            cba = instance.cba
        except ObjectDoesNotExist:
            cba = None

        if cba_data:
            user = self.context.get("request").user

            if cba:
                # having the update_cba permission overrides being the user
                if not (user.has_perm("program.update_cba") or user.id == instance.id):
                    raise exceptions.PermissionDenied(
                        detail="You do not have permission to update this user CBA profile."
                    )

                if "username" in cba_data:
                    cba.username = cba_data.get("username")

                if "user_token" in cba_data:
                    cba.user_token = cba_data.get("user_token")

                cba.updated_by = self.context.get("request").user.username
                cba.save()
            else:
                # having the create_cba permission overrides being the user
                if not (user.has_perm("program.create_cba") or user.id == instance.id):
                    raise exceptions.PermissionDenied(
                        detail="You do not have permission to create this user CBA profile."
                    )

                CBA.objects.create(
                    created_by=self.context.get("request").user.username,
                    user=instance,
                    **cba_data,
                )

        instance.save()

        return instance


class CategorySerializer(serializers.ModelSerializer):
    class Meta:
        model = Category
        fields = ("description", "id", "is_active", "name", "slug", "subtitle")


class LinkTypeSerializer(serializers.ModelSerializer):
    class Meta:
        model = LinkType
        fields = ("id", "is_active", "name")


class LicenseSerializer(serializers.ModelSerializer):
    class Meta:
        model = License
        fields = (
            "id",
            "identifier",
            "name",
            "needs_author",
            "requires_express_permission_for_publication",
            "url",
        )


class ProfileLinkSerializer(serializers.ModelSerializer):
    type_id = serializers.PrimaryKeyRelatedField(queryset=LinkType.objects.all(), source="type")

    class Meta:
        fields = ("type_id", "url")
        model = ProfileLink


class PPOIField(serializers.CharField):
    def validate_format(self, value: str):
        if not re.match(r"\d(?:\.\d+)?x\d(?:\.\d+)?", value):
            raise serializers.ValidationError("PPOI must match format: ${float}x${float}")

    def __init__(self, **kwargs):
        kwargs["max_length"] = 20
        kwargs.setdefault("validators", [])
        kwargs["validators"].append(self.validate_format)
        super().__init__(**kwargs)

    def to_representation(self, value: tuple[float, float]):
        [left, top] = value
        return f"{left}x{top}"


class ImageSerializer(serializers.ModelSerializer):
    license_id = serializers.PrimaryKeyRelatedField(
        allow_null=True,
        queryset=License.objects.all(),
        required=False,
        source="license",
        help_text="`License` ID of this image.",
    )
    ppoi = PPOIField(required=False, help_text="PPOI specifies the crop centerpoint of the image.")
    url = serializers.SerializerMethodField()

    @staticmethod
    def get_url(instance: Image) -> str:
        """Returns the image URL, using settings.SITE_URL to include the protocol and avoid mixed
        media warnings."""

        return f"{settings.SITE_URL}{instance.image.url}"

    class Meta:
        extra_kwargs = {"image": {"write_only": True}}
        model = Image
        read_only_fields = (
            "height",
            "id",
            "url",
            "width",
        )
        fields = (
            "alt_text",
            "credits",
            "image",
            "is_use_explicitly_granted_by_author",
            "license_id",
            "ppoi",
        ) + read_only_fields

    def create(self, validated_data):
        """Create and return a new Image instance, given the validated data."""

        image = Image.objects.create(
            owner=self.context.get("request").user.username, **validated_data
        )
        image.save()

        return image

    def update(self, instance, validated_data):
        """Update and return an existing Image instance, given the validated data."""

        if "alt_text" in validated_data:
            instance.alt_text = validated_data.get("alt_text")

        if "credits" in validated_data:
            instance.credits = validated_data.get("credits")

        if "license" in validated_data:
            instance.license = validated_data.get("license")

        if "ppoi" in validated_data:
            instance.image.ppoi = validated_data.get("ppoi")

        instance.save()

        return instance


class ImageRenderSerializer(serializers.Serializer):
    width = serializers.IntegerField(required=False, min_value=1)
    height = serializers.IntegerField(required=False, min_value=1)


class ProfileSerializer(serializers.ModelSerializer):
    image_id = serializers.PrimaryKeyRelatedField(
        allow_null=True,
        queryset=Image.objects.all(),
        required=False,
        source="image",
        help_text="`Image` id of the profile.",
    )
    links = ProfileLinkSerializer(
        many=True, required=False, help_text="Array of `Link` objects. Can be empty."
    )
    owner_ids = serializers.PrimaryKeyRelatedField(
        many=True,
        queryset=User.objects.all(),
        source="owners",
        help_text="User ID(s) that own this profile.",
    )

    class Meta:
        model = Profile
        read_only_fields = (
            "created_at",
            "created_by",
            "updated_at",
            "updated_by",
        )
        fields = (
            "biography",
            "email",
            "id",
            "image_id",
            "is_active",
            "links",
            "name",
            "owner_ids",
        ) + read_only_fields

    def to_representation(self, instance):
        representation = super().to_representation(instance)

        if not self.context.get("request").user.is_authenticated:
            del representation["email"]

        return representation

    def create(self, validated_data):
        """
        Create and return a new Profile instance, given the validated data.
        """

        # optional nested objects
        links_data = validated_data.pop("links", [])

        # optional many-to-many
        owners = validated_data.pop("owners", [])

        # optional foreign key
        validated_data["image"] = validated_data.pop("image", None)

        profile = Profile.objects.create(
            created_by=self.context.get("request").user.username, **validated_data
        )

        for link_data in links_data:
            ProfileLink.objects.create(profile=profile, **link_data)

        profile.owners.set(owners)

        profile.save()

        return profile

    def update(self, instance, validated_data):
        """Update and return an existing Profile instance, given the validated data."""

        user = self.context.get("request").user
        user_is_owner = user in instance.owners.all()
        user_permissions = set(
            permission.split("__")[-1]
            for permission in user.get_all_permissions()
            if permission.startswith("program.edit__profile")
        )
        update_fields = set(validated_data.keys())

        # having the update_profile permission overrides the ownership
        if not (user.has_perm("program.update_profile") or (user_is_owner and user_permissions)):
            raise exceptions.PermissionDenied(detail="You are not allowed to update this host.")

        # without the update_profile permission, fields without edit permission are not allowed
        if not user.has_perm("program.update_profile") and (
            not_allowed := update_fields.difference(user_permissions)
        ):
            detail = {field: "You are not allowed to edit this field" for field in not_allowed}
            raise exceptions.PermissionDenied(detail=detail)

        if "biography" in validated_data:
            instance.biography = validated_data.get("biography")

        if "name" in validated_data:
            instance.name = validated_data.get("name")

        if "email" in validated_data:
            instance.email = validated_data.get("email")

        if "image" in validated_data:
            instance.image = validated_data.get("image")

        if "is_active" in validated_data:
            instance.is_active = validated_data.get("is_active")

        # optional many-to-many
        if "owners" in validated_data:
            instance.owners.set(validated_data.get("owners"))

        # optional nested objects
        if "links" in validated_data:
            instance = update_links(instance, validated_data.get("links"))

        instance.updated_by = self.context.get("request").user.username

        instance.save()

        return instance


class LanguageSerializer(serializers.ModelSerializer):
    class Meta:
        model = Language
        fields = ("id", "is_active", "name")


class TopicSerializer(serializers.ModelSerializer):
    class Meta:
        model = Topic
        fields = ("id", "is_active", "name", "slug")


class MusicFocusSerializer(serializers.ModelSerializer):
    class Meta:
        model = MusicFocus
        fields = ("id", "is_active", "name", "slug")


class TypeSerializer(serializers.ModelSerializer):
    class Meta:
        model = Type
        fields = ("id", "is_active", "name", "slug")


class FundingCategorySerializer(serializers.ModelSerializer):
    class Meta:
        model = FundingCategory
        fields = ("id", "is_active", "name", "slug")


class ShowLinkSerializer(serializers.ModelSerializer):
    type_id = serializers.PrimaryKeyRelatedField(queryset=LinkType.objects.all(), source="type")

    class Meta:
        model = ShowLink
        fields = ("type_id", "url")


class ShowSerializer(serializers.HyperlinkedModelSerializer):
    category_ids = serializers.PrimaryKeyRelatedField(
        many=True,
        queryset=Category.objects.all(),
        source="category",
        help_text="Array of `Category` IDs.",
    )
    cba_series_id = serializers.IntegerField(
        allow_null=True, required=False, help_text="CBA series ID."
    )
    default_playlist_id = serializers.PrimaryKeyRelatedField(
        allow_null=True,
        help_text="Default `Playlist` ID for this show.",
        queryset=Playlist.objects.all(),
        required=False,
        source="default_playlist",
    )
    funding_category_id = serializers.PrimaryKeyRelatedField(
        queryset=FundingCategory.objects.all(),
        source="funding_category",
        help_text="`FundingCategory` ID.",
    )
    host_ids = serializers.PrimaryKeyRelatedField(
        many=True,
        queryset=Profile.objects.all(),
        source="hosts",
        help_text="`Profile` IDs that host this show.",
    )
    image_id = serializers.PrimaryKeyRelatedField(
        allow_null=True,
        queryset=Image.objects.all(),
        required=False,
        source="image",
        help_text="`Image` ID of this show.",
    )
    language_ids = serializers.PrimaryKeyRelatedField(
        many=True,
        queryset=Language.objects.all(),
        source="language",
        help_text="`Language` IDs of this show.",
    )
    links = ProfileLinkSerializer(many=True, required=False, help_text="Array of `Link` objects.")
    logo_id = serializers.PrimaryKeyRelatedField(
        allow_null=True,
        queryset=Image.objects.all(),
        required=False,
        source="logo",
        help_text="`Image` ID of the logo of this show.",
    )
    music_focus_ids = serializers.PrimaryKeyRelatedField(
        many=True,
        queryset=MusicFocus.objects.all(),
        source="music_focus",
        help_text="Array of `MusicFocus` IDs.",
    )
    owner_ids = serializers.PrimaryKeyRelatedField(
        many=True,
        queryset=User.objects.all(),
        source="owners",
        help_text="Array of `User` IDs owning this Show.",
    )
    predecessor_id = serializers.PrimaryKeyRelatedField(
        allow_null=True,
        queryset=Show.objects.all(),
        required=False,
        source="predecessor",
        help_text="`Show` ID that predeceeded this one.",
    )
    topic_ids = serializers.PrimaryKeyRelatedField(
        many=True, queryset=Topic.objects.all(), source="topic", help_text="Array of `Topic` IDs."
    )
    type_id = serializers.PrimaryKeyRelatedField(
        queryset=Type.objects.all(), source="type", help_text="Array of `Type` IDs."
    )

    class Meta:
        model = Show
        read_only_fields = (
            "created_at",
            "created_by",
            "updated_at",
            "updated_by",
        )
        fields = (
            "category_ids",
            "cba_series_id",
            "default_playlist_id",
            "description",
            "email",
            "funding_category_id",
            "host_ids",
            "id",
            "image_id",
            "internal_note",
            "is_active",
            "is_public",
            "language_ids",
            "links",
            "logo_id",
            "music_focus_ids",
            "name",
            "owner_ids",
            "predecessor_id",
            "short_description",
            "slug",
            "topic_ids",
            "type_id",
        ) + read_only_fields

    def to_internal_value(self, data):
        if data.get("cba_series_id") == "":
            data["cba_series_id"] = None

        if data.get("default_playlist_id") == "":
            data["default_playlist_id"] = None

        return super().to_internal_value(data)

    def to_representation(self, instance):
        representation = super().to_representation(instance)

        if not self.context.get("request").user.is_authenticated:
            del representation["email"]
        elif not self.context.get("request").user.has_perm("display__show__internal_note"):
            del representation["internal_note"]

        return representation

    def create(self, validated_data):
        """
        Create and return a new Show instance, given the validated data.
        """

        # required many-to-many
        category = validated_data.pop("category")
        hosts = validated_data.pop("hosts")
        language = validated_data.pop("language")
        music_focus = validated_data.pop("music_focus")
        owners = validated_data.pop("owners")
        topic = validated_data.pop("topic")

        # optional nested objects
        links_data = validated_data.pop("links", [])

        # required foreign key
        validated_data["funding_category"] = validated_data.pop("funding_category")
        validated_data["type"] = validated_data.pop("type")

        # optional foreign key
        validated_data["default_playlist"] = validated_data.pop("default_playlist", None)
        validated_data["image"] = validated_data.pop("image", None)
        validated_data["logo"] = validated_data.pop("logo", None)
        validated_data["predecessor"] = validated_data.pop("predecessor", None)

        validated_data["slug"] = validated_data.get(
            "slug", text.slugify(validated_data.get("name"))
        )

        show = Show.objects.create(
            created_by=self.context.get("request").user.username,
            **validated_data,
        )

        # Save many-to-many relationships
        show.category.set(category)
        show.hosts.set(hosts)
        show.language.set(language)
        show.music_focus.set(music_focus)
        show.owners.set(owners)
        show.topic.set(topic)

        for link_data in links_data:
            ShowLink.objects.create(show=show, **link_data)

        show.save()

        return show

    def update(self, instance, validated_data):
        """Update and return an existing Show instance, given the validated data."""

        user = self.context.get("request").user
        user_is_owner = user in instance.owners.all()
        user_permissions = set(
            permission.split("__")[-1]
            for permission in user.get_all_permissions()
            if permission.startswith("program.edit__show")
        )
        update_fields = set(validated_data.keys())

        # having update_show permission overrides the ownership
        if not (user.has_perm("program.update_show") or (user_is_owner and user_permissions)):
            raise exceptions.PermissionDenied(detail="You are not allowed to update this show.")

        # without the update_show permission, fields without edit permission are not allowed
        if not user.has_perm("program.update_show") and (
            not_allowed := update_fields.difference(user_permissions)
        ):
            detail = {field: "You are not allowed to edit this field" for field in not_allowed}
            raise exceptions.PermissionDenied(detail=detail)

        if "description" in validated_data:
            instance.description = validated_data.get("description")

        if "name" in validated_data:
            instance.name = validated_data.get("name")

        if "short_description" in validated_data:
            instance.short_description = validated_data.get("short_description")

        if "cba_series_id" in validated_data:
            instance.cba_series_id = validated_data.get("cba_series_id")

        if "default_playlist" in validated_data:
            instance.default_playlist = validated_data.get("default_playlist")

        if "email" in validated_data:
            instance.email = validated_data.get("email")

        if "funding_category" in validated_data:
            instance.funding_category = validated_data.get("funding_category")

        if "image" in validated_data:
            instance.image = validated_data.get("image")

        if "internal_note" in validated_data:
            instance.internal_note = validated_data.get("internal_note")

        if "is_active" in validated_data:
            instance.is_active = validated_data.get("is_active")

        if "is_public" in validated_data:
            instance.is_public = validated_data.get("is_public")

        if "logo" in validated_data:
            instance.logo = validated_data.get("logo")

        if "predecessor" in validated_data:
            instance.predecessor = validated_data.get("predecessor")

        if "slug" in validated_data:
            instance.slug = validated_data.get("slug")

        if "type" in validated_data:
            instance.type = validated_data.get("type")

        # optional many-to-many
        if "category" in validated_data:
            instance.category.set(validated_data.get("category", []))

        if "hosts" in validated_data:
            instance.hosts.set(validated_data.get("hosts", []))

        if "language" in validated_data:
            instance.language.set(validated_data.get("language", []))

        if "music_focus" in validated_data:
            instance.music_focus.set(validated_data.get("music_focus", []))

        if "owners" in validated_data:
            instance.owners.set(validated_data.get("owners", []))

        if "topic" in validated_data:
            instance.topic.set(validated_data.get("topic", []))

        # optional nested objects
        if "links" in validated_data:
            instance = update_links(instance, validated_data.get("links"))

        instance.updated_by = self.context.get("request").user.username

        instance.save()

        return instance


class RRuleSerializer(serializers.ModelSerializer):
    class Meta:
        model = RRule
        fields = (
            "by_set_pos",
            "by_weekdays",
            "count",
            "freq",
            "id",
            "interval",
            "name",
        )
        read_only_fields = fields


class ScheduleSerializer(serializers.ModelSerializer):
    class Meta:
        model = Schedule
        fields = (
            "add_business_days_only",
            "add_days_no",
            "by_weekday",
            "default_playlist_id",
            "end_time",
            "first_date",
            "id",
            "is_repetition",
            "last_date",
            "rrule_id",
            "show_id",
            "start_time",
        )


class UnsavedScheduleSerializer(ScheduleSerializer):
    id = serializers.IntegerField(allow_null=True)


class ScheduleInRequestSerializer(ScheduleSerializer):
    dryrun = serializers.BooleanField(
        write_only=True,
        required=False,
        help_text=(
            "Whether to simulate the database changes. If true, no database changes will occur. "
            "Instead a list of objects that would be created, updated and deleted if dryrun was "
            "false will be returned."
        ),
    )

    class Meta:
        model = Schedule
        fields = (
            "add_business_days_only",
            "add_days_no",
            "by_weekday",
            "default_playlist_id",
            "dryrun",
            "end_time",
            "first_date",
            "is_repetition",
            "last_date",
            "rrule_id",
            "show_id",
            "start_time",
        )

    def create(self, validated_data):
        """Create and return a new Schedule instance, given the validated data."""

        validated_data["default_playlist"] = validated_data.pop("default_playlist_id")
        validated_data["rrule"] = validated_data.pop("rrule_id")
        validated_data["show"] = validated_data.pop("show_id")

        schedule = Schedule.objects.create(**validated_data)

        schedule.save()
        return schedule

    def update(self, instance, validated_data):
        """Update and return an existing Schedule instance, given the validated data."""

        instance.by_weekday = validated_data.get("by_weekday", instance.by_weekday)
        instance.first_date = validated_data.get("first_date", instance.first_date)
        instance.start_time = validated_data.get("start_time", instance.start_time)
        instance.end_time = validated_data.get("end_time", instance.end_time)
        instance.last_date = validated_data.get("last_date", instance.last_date)
        instance.is_repetition = validated_data.get("is_repetition", instance.is_repetition)
        instance.default_playlist = validated_data.get(
            "default_playlist_id", instance.default_playlist
        )
        instance.rrule = validated_data.get("rrule_id", instance.rrule)
        instance.show = validated_data.get("show_id", instance.show)
        instance.add_days_no = validated_data.get("add_days_no", instance.add_days_no)
        instance.add_business_days_only = validated_data.get(