from datetime import datetime, timezone

from app.services.crypto_service import decrypt_value, encrypt_value
from app.services.db import db_transaction


def _row_to_session(row):
    access_token = decrypt_value(row[1]) if row[1] else None
    request_token = decrypt_value(row[2]) if row[2] else None
    return {
        "api_key": row[0],
        "access_token": access_token,
        "request_token": request_token,
        "user_name": row[3],
        "broker_user_id": row[4],
        "linked_at": row[5],
    }


def get_session(user_id: str):
    with db_transaction() as cur:
        cur.execute(
            """
            SELECT api_key, access_token, request_token, user_name, broker_user_id, linked_at
            FROM zerodha_session
            WHERE user_id = %s
            ORDER BY linked_at DESC NULLS LAST, id DESC
            LIMIT 1
            """,
            (user_id,),
        )
        row = cur.fetchone()
    if row:
        return _row_to_session(row)

    with db_transaction() as cur:
        cur.execute(
            """
            SELECT broker, connected, access_token, api_key, user_name, broker_user_id, connected_at
            FROM user_broker
            WHERE user_id = %s
            """,
            (user_id,),
        )
        row = cur.fetchone()
    if not row:
        return None
    broker, connected, access_token, api_key, user_name, broker_user_id, connected_at = row
    if not connected or not access_token or not api_key:
        return None
    if (broker or "").strip().upper() != "ZERODHA":
        return None
    return {
        "api_key": api_key,
        "access_token": decrypt_value(access_token),
        "request_token": None,
        "user_name": user_name,
        "broker_user_id": broker_user_id,
        "linked_at": connected_at,
    }


def set_session(user_id: str, data: dict):
    access_token = data.get("access_token")
    request_token = data.get("request_token")
    linked_at = datetime.now(timezone.utc)
    with db_transaction() as cur:
        cur.execute(
            """
            INSERT INTO zerodha_session (
                user_id, linked_at, api_key, access_token, request_token, user_name, broker_user_id
            )
            VALUES (%s, %s, %s, %s, %s, %s, %s)
            RETURNING linked_at
            """,
            (
                user_id,
                linked_at,
                data.get("api_key"),
                encrypt_value(access_token) if access_token else None,
                encrypt_value(request_token) if request_token else None,
                data.get("user_name"),
                data.get("broker_user_id"),
            ),
        )
        linked_at = cur.fetchone()[0]
    return {
        **data,
        "user_id": user_id,
        "linked_at": linked_at,
        "access_token": access_token,
        "request_token": request_token,
    }


def store_request_token(user_id: str, request_token: str):
    with db_transaction() as cur:
        cur.execute(
            """
            INSERT INTO zerodha_request_token (user_id, request_token)
            VALUES (%s, %s)
            ON CONFLICT (user_id)
            DO UPDATE SET request_token = EXCLUDED.request_token
            """,
            (user_id, encrypt_value(request_token)),
        )


def consume_request_token(user_id: str):
    with db_transaction() as cur:
        cur.execute(
            "SELECT request_token FROM zerodha_request_token WHERE user_id = %s",
            (user_id,),
        )
        row = cur.fetchone()
        if not row:
            return None
        cur.execute("DELETE FROM zerodha_request_token WHERE user_id = %s", (user_id,))
    return decrypt_value(row[0])


def clear_session(user_id: str):
    with db_transaction() as cur:
        cur.execute("DELETE FROM zerodha_session WHERE user_id = %s", (user_id,))
        cur.execute("DELETE FROM zerodha_request_token WHERE user_id = %s", (user_id,))