import os
import uuid
import datetime as dt
import sys
from typing import Optional

from supabase import create_client, Client


def _utc_now_iso() -> str:
    return dt.datetime.now(dt.timezone.utc).isoformat()


class AnalyticsLogger:
    """
    Simple Supabase logger for:
      - Sessions (id: uuid, created_at: timestamptz)
      - Chats (id: uuid, session_id: uuid, timestamp: timestamptz, user: text, answer: text)
    """

    def __init__(self):
        url = os.getenv("SUPABASE_URL")
        key = os.getenv("SUPABASE_KEY")
        if not url or not key:
            raise RuntimeError("Missing SUPABASE_URL or SUPABASE_KEY env var.")
        self.client: Client = create_client(url, key)
        self.session_id: Optional[str] = None

    def start_session(self, model_id: str) -> str:
        """
        Creates a session row and returns the session UUID (string).
        """
        sid = str(uuid.uuid4())
        payload = {"id": sid, "created_at": _utc_now_iso(), "model_id": model_id}
        try:
            self.client.table("Sessions").insert(payload).execute()
            self.session_id = sid
            return sid
        except Exception as e:
            print(f"[AnalyticsLogger] Failed to start session: {e}", file=sys.stderr)
            raise e

    def log_interaction(self, user: str, answer: str, ts_iso: Optional[str] = None) -> None:
        """
        Inserts a single chat interaction.
        """
        if not self.session_id:
            raise ValueError("Session not started. Call start_session() first.")
        session_id = self.session_id

        chat_payload = {
            "id": str(uuid.uuid4()),
            "session_id": session_id,
            "timestamp": ts_iso or _utc_now_iso(),
            "user": user,
            "answer": answer,
        }
        try:
            self.client.table("Chats").insert(chat_payload).execute()
        except Exception as e:
            print(f"[AnalyticsLogger] Failed to log interaction: {e}", file=sys.stderr)