"""Pydantic models for Lambda event validation."""

from typing import Any

from pydantic import BaseModel, Field, field_serializer


class EventBridgeEventMetadata(BaseModel):
    """Metadata section for EventBridgeEvent."""

    correlation_id: str = Field(..., description='Correlation ID for tracing')
    outbox_event_id: int = Field(..., description='ID of the source outbox event')
    target_id: int = Field(..., description='ID of the target entity')
    target_type: str = Field(..., description='Type of the target entity')
    created_at: str = Field(
        ..., description='ISO 8601 timestamp when event was created in outbox'
    )
    processed_at: str = Field(
        ..., description='ISO 8601 timestamp when event was processed by Lambda'
    )


class EventBridgeEventDetail(BaseModel):
    """Event detail section for EventBridgeEvent."""

    metadata: EventBridgeEventMetadata = Field(..., description='Event metadata')
    data: Any | None = Field(..., description='Event business data')


class EventBridgeEvent(BaseModel):
    """Lambda event for adjustment file initialization."""

    source: str = Field(serialization_alias='Source')
    detail_type: str = Field(serialization_alias='DetailType')
    detail: EventBridgeEventDetail = Field(serialization_alias='Detail')
    event_bus_name: str = Field(default='default', serialization_alias='EventBusName')
    resources: list[str] | None = Field(default=None, serialization_alias='Resources')
    trace_header: str | None = Field(default=None, serialization_alias='TraceHeader')

    @field_serializer('detail')
    def serialize_detail(self, detail: EventBridgeEventDetail, _info: Any) -> str:
        """Serialize detail field to JSON string.

        EventBridge requires the Detail field to be a JSON string, not a dict.

        Args:
            detail: The EventBridgeEventDetail object to serialize.
            _info: Pydantic serialization context (unused).

        Returns:
            str: JSON string representation of the detail.
        """
        return detail.model_dump_json()