from __future__ import annotations
from typing import List, Optional
from datetime import datetime, timezone
from pydantic import BaseModel, Field

# ====== Chat history ======
class Message(BaseModel):
    role: str = "user"
    content: str = ""
    ts: Optional[str] = None

class ChatRequest(BaseModel):
    message: str = ""  # 🚀 Beri default string kosong agar tidak 422 saat di-ping payload kosong
    history: List[Message] = Field(default_factory=list)
    username: Optional[str] = "Baka"

# ====== Device register ======
class RegisterRequest(BaseModel):
    fcm_token: str

# ====== Scheduler ======
class ScheduleRequest(BaseModel):
    task: str
    scheduled_time: str
    user_id: str

    @property
    def remind_at_utc(self) -> datetime:
        try:
            clean_ts = self.scheduled_time.replace("Z", "+00:00")
            dt = datetime.fromisoformat(clean_ts)

            if dt.tzinfo is None:
                return dt.replace(tzinfo=timezone.utc)

            return dt.astimezone(timezone.utc)

        except ValueError as e:
            raise ValueError(
                f"Format scheduled_time tidak valid: {self.scheduled_time}"
            ) from e