from __future__ import annotations

import abc
import datetime
import logging
from collections.abc import Sequence
from typing import ClassVar, Literal

from fansifter_common.utils import timezone
from pydantic import BaseModel, ConfigDict, Field, ValidationError

from preference_center.profile.constants import (
    ORIGIN_TYPE_AUTOMATED_EMAIL,
    ORIGIN_TYPE_EMAIL_CAMPAIGN,
)
from preference_center.profile.models import Profile, Subscription
from preference_center.profile.types import AnyValueStr

logger = logging.getLogger(__name__)

ProfileFieldName = Literal[
    "firstName",
    "lastName",
    "email",
    "phoneNumber",
    "dateOfBirth",
    "birthday",
    "gender",
    "countryCode",
    "city",
    "address",
    "zipCode",
]


class ProfileUpdateField(BaseModel):
    field_name: ProfileFieldName = Field(
        alias="fieldName",
        title="Field name",
        description="The target field or column name",
    )
    old_value: AnyValueStr | None = Field(alias="oldValue", title="Old value")
    new_value: AnyValueStr | None = Field(alias="newValue", title="New value")

    model_config = ConfigDict(frozen=True)


# Events


class ProfileEvent(BaseModel, abc.ABC):
    id: str = Field(title="ID", description="Unique profile identifier in UUID format")
    crm_id: str | None = Field(alias="crmId", title="CRM ID")


class ProfileUpdatedV1(ProfileEvent):
    updated_at: datetime.datetime = Field(alias="updatedAt", title="Updated at")
    updated_fields: set[ProfileUpdateField] = Field(
        alias="updatedFields", title="Updated fields"
    )
    updated_by: str | None = Field(default=None, alias="updatedBy", title="Updated by")

    fields_map: ClassVar[dict[str, ProfileFieldName]] = {
        "email": "email",
        "first_name": "firstName",
        "last_name": "lastName",
        "phone_number": "phoneNumber",
        "date_of_birth": "dateOfBirth",
        "birthday": "birthday",
        "gender": "gender",
        "country_code": "countryCode",
        "city": "city",
        "address": "address",
        "zip_code": "zipCode",
    }

    @classmethod
    def _get_updated_values(cls, profile: Profile) -> set[ProfileUpdateField]:
        update_fields = set()

        for origin_field_name, value_change in profile.changed_fields.items():
            try:
                field_name = cls.fields_map[origin_field_name]
            except KeyError:
                continue

            try:
                update_fields.add(
                    ProfileUpdateField(
                        fieldName=field_name,
                        oldValue=value_change.old_value,
                        newValue=value_change.new_value,
                    )
                )
            except ValidationError as exc:
                logger.error("Profile update field validation error", exc_info=exc)
                continue
        return update_fields

    @classmethod
    def from_profile(cls, profile: Profile) -> ProfileUpdatedV1:
        return cls.model_construct(
            id=profile.id,
            crm_id=profile.crm_id,
            updated_at=profile.updated_at,
            updated_fields=cls._get_updated_values(profile),
            updated_by=profile.updated_by,
        )


class ProfileDeletedV1(ProfileEvent):
    email_campaign_id: str | None = Field(
        default=None,
        alias="emailCampaignId",
        title="Email campaign ID",
        deprecated=True,
    )
    origin_id: str | None = Field(alias="originId", title="Origin ID")
    origin_type: str | None = Field(
        alias="originType", title="Origin type (EMAIL_CAMPAIGN|AUTOMATED_EMAIL)"
    )
    automated_email_trigger_id: str | None = Field(
        default=None,
        alias="automatedEmailTriggerId",
    )
    deleted_at: datetime.datetime = Field(alias="deletedAt", title="Deleted at")
    updated_by: str | None = Field(default=None, alias="updatedBy", title="Updated by")

    def model_post_init(self, __context: object) -> None:
        """Set email_campaign_id for backward compatibility when origin_type is EMAIL_CAMPAIGN."""
        if self.origin_type == ORIGIN_TYPE_EMAIL_CAMPAIGN:
            self.email_campaign_id = self.origin_id
        elif self.email_campaign_id is not None:
            self.origin_type = ORIGIN_TYPE_EMAIL_CAMPAIGN
            self.origin_id = self.email_campaign_id
        if self.origin_type != ORIGIN_TYPE_AUTOMATED_EMAIL:
            self.automated_email_trigger_id = None

    @classmethod
    def from_profile(
        cls,
        profile: Profile,
        *,
        origin_id: str | None,
        origin_type: str | None,
        automated_email_trigger_id: str | None = None,
    ) -> ProfileDeletedV1:
        return cls.model_construct(
            id=profile.id,
            crm_id=profile.crm_id,
            origin_id=origin_id,
            origin_type=origin_type,
            automated_email_trigger_id=automated_email_trigger_id,
            deleted_at=timezone.now(),
            updated_by=profile.updated_by,
        )


class SubscriptionStatusUpdate(BaseModel):
    id: str = Field(
        title="ID", description="Unique subscription identifier in UUID format"
    )
    crm_id: str | None = Field(alias="crmId", title="CRM ID")
    mailing_list_id: str | None = Field(alias="mailingListId", title="Mailing list ID")
    mailing_list_crm_id: str | None = Field(
        alias="mailingListCrmId", title="Mailing list CRM ID"
    )
    email_campaign_id: str | None = Field(
        default=None,
        alias="emailCampaignId",
        title="Email campaign ID",
        deprecated=True,
    )
    origin_id: str | None = Field(alias="originId", title="Origin ID")
    origin_type: str | None = Field(
        alias="originType", title="Origin type (EMAIL_CAMPAIGN|AUTOMATED_EMAIL)"
    )
    automated_email_trigger_id: str | None = Field(
        default=None,
        alias="automatedEmailTriggerId",
    )
    old_value: bool = Field(alias="oldValue", title="Old value")
    new_value: bool = Field(alias="newValue", title="New value")

    def model_post_init(self, __context: object) -> None:
        """Set email_campaign_id for backward compatibility when origin_type is EMAIL_CAMPAIGN."""
        if self.origin_type == ORIGIN_TYPE_EMAIL_CAMPAIGN:
            self.email_campaign_id = self.origin_id
        elif self.email_campaign_id is not None:
            self.origin_type = ORIGIN_TYPE_EMAIL_CAMPAIGN
            self.origin_id = self.email_campaign_id
        if self.origin_type != ORIGIN_TYPE_AUTOMATED_EMAIL:
            self.automated_email_trigger_id = None

    @classmethod
    def from_subscription(
        cls,
        subscription: Subscription,
        *,
        origin_id: str | None,
        origin_type: str | None,
        automated_email_trigger_id: str | None = None,
    ) -> SubscriptionStatusUpdate:
        crm_id = None
        mailing_list_crm_id = None
        return cls.model_construct(
            id=subscription.id,
            crm_id=crm_id,
            mailing_list_id=subscription.mailing_list_id,
            mailing_list_crm_id=mailing_list_crm_id,
            origin_id=origin_id,
            origin_type=origin_type,
            automated_email_trigger_id=automated_email_trigger_id,
            old_value=not subscription.is_active,
            new_value=subscription.is_active,
        )


class ProfileSubscriptionsUpdatedV1(ProfileEvent):
    updated_subscriptions: list[SubscriptionStatusUpdate] = Field(
        alias="updatedSubscriptions", title="Updated subscriptions"
    )
    updated_at: datetime.datetime = Field(alias="updatedAt", title="Updated at")
    updated_by: str | None = Field(default=None, alias="updatedBy", title="Updated by")

    @classmethod
    def from_profile_subscriptions(
        cls,
        profile: Profile,
        *,
        subscriptions: Sequence[Subscription],
        origin_id: str | None,
        origin_type: str | None,
        automated_email_trigger_id: str | None = None,
    ) -> ProfileSubscriptionsUpdatedV1:
        return cls.model_construct(
            id=profile.id,
            crm_id=profile.crm_id,
            updated_subscriptions=[
                SubscriptionStatusUpdate.from_subscription(
                    subscription,
                    origin_id=origin_id,
                    origin_type=origin_type,
                    automated_email_trigger_id=automated_email_trigger_id,
                )
                for subscription in subscriptions
            ],
            updated_at=timezone.now(),
            updated_by=profile.updated_by,
        )