"""
Utility functions for handling return statements in BPF functions.

Provides handlers for different types of returns including XDP actions,
None returns, and standard returns.
"""

import logging
import ast

from llvmlite import ir

logger: logging.Logger = logging.getLogger(__name__)

XDP_ACTIONS = {
    "XDP_ABORTED": 0,
    "XDP_DROP": 1,
    "XDP_PASS": 2,
    "XDP_TX": 3,
    "XDP_REDIRECT": 4,
}


def _handle_none_return(builder) -> bool:
    """Handle return or return None -> returns 0."""
    builder.ret(ir.Constant(ir.IntType(64), 0))
    logger.debug("Generated default return: 0")
    return True


def _is_xdp_name(name: str) -> bool:
    """Check if a name is an XDP action"""
    return name in XDP_ACTIONS


def _handle_xdp_return(stmt: ast.Return, builder, ret_type) -> bool:
    """Handle XDP returns"""
    if not isinstance(stmt.value, ast.Name):
        return False

    action_name = stmt.value.id

    if action_name not in XDP_ACTIONS:
        raise ValueError(
            f"Unknown XDP action: {action_name}. Available: {XDP_ACTIONS.keys()}"
        )
        return False

    value = XDP_ACTIONS[action_name]
    builder.ret(ir.Constant(ret_type, value))
    logger.debug(f"Generated XDP action return: {action_name} = {value}")
    return True