import json

from app.core.db import get_connection
from app.schemas.analysis import (
    AnalysisSessionListResponse,
    AnalysisSessionResponse,
    AnalysisSessionSnapshot,
)


class AnalysisRepository:
    def save_snapshot(self, snapshot: AnalysisSessionSnapshot) -> None:
        payload_json = json.dumps(snapshot.model_dump())
        with get_connection() as connection:
            connection.execute(
                """
                INSERT OR REPLACE INTO analysis_sessions (
                    session_id,
                    observation_id,
                    status,
                    payload_json
                )
                VALUES (?, ?, ?, ?)
                """,
                (
                    snapshot.session_id,
                    snapshot.observation_id,
                    snapshot.status,
                    payload_json,
                ),
            )
            connection.commit()

    def get_snapshot(self, session_id: str) -> AnalysisSessionSnapshot | None:
        with get_connection() as connection:
            row = connection.execute(
                """
                SELECT payload_json
                FROM analysis_sessions
                WHERE session_id = ?
                """,
                (session_id,),
            ).fetchone()
        if row is None:
            return None
        return AnalysisSessionSnapshot.model_validate_json(row["payload_json"])

    def list_sessions(self) -> AnalysisSessionListResponse:
        with get_connection() as connection:
            rows = connection.execute(
                """
                SELECT session_id, observation_id, status
                FROM analysis_sessions
                ORDER BY created_at DESC
                """
            ).fetchall()
        items = [
            AnalysisSessionResponse(
                session_id=row["session_id"],
                observation_id=row["observation_id"],
                status=row["status"],
                message="Session snapshot available.",
            )
            for row in rows
        ]
        return AnalysisSessionListResponse(items=items)