from datetime import datetime, timezone

from beanie import Document, PydanticObjectId
from pydantic import BaseModel, Field


class ChatMessage(BaseModel):
    role: str  # user / assistant
    content: str
    timestamp: datetime = Field(default_factory=lambda: datetime.now(timezone.utc))


class ChatSession(Document):
    user_id: PydanticObjectId
    report_id: PydanticObjectId
    messages: list[ChatMessage] = Field(default_factory=list)
    created_at: datetime = Field(default_factory=lambda: datetime.now(timezone.utc))
    updated_at: datetime = Field(default_factory=lambda: datetime.now(timezone.utc))

    class Settings:
        name = "chat_sessions"
        indexes = [
            [("user_id", 1), ("report_id", 1)],
        ]