from typing import Dict, Any, Tuple
from .contract import SafetyContract


def evaluate_action(contract: SafetyContract, state: Dict[str, Any], action: Dict[str, Any]) -> Tuple[str, Dict[str, Any]]:
    """Evaluate a proposed action against a SafetyContract.

    Returns a tuple (verdict, payload) where verdict is one of:
    - 'accept' (payload is possibly rewritten action)
    - 'veto' (payload contains reason)

    This minimal engine performs precondition and budget checks and may
    rewrite actions to a safe alternative when possible.
    """
    ok, reason = contract.check_preconditions(state, action)
    if not ok:
        return "veto", {"reason": reason}

    ok, reason = contract.check_budgets(state, action)
    if not ok:
        # attempt a simple rewrite: scale down costs/speeds if present
        if "speed" in action:
            safe_action = dict(action)
            safe_action["speed"] = action["speed"] * 0.5
            # Re-check budgets assuming cost scales with speed linearly
            costs = dict(action.get("costs", {}))
            for k in costs:
                costs[k] = costs[k] * 0.5
            safe_action["costs"] = costs
            ok2, reason2 = contract.check_budgets(state, safe_action)
            if ok2:
                contract.charge_budgets(safe_action)
                return "accept", safe_action
        return "veto", {"reason": reason}

    # Accept and charge budgets
    contract.charge_budgets(action)
    return "accept", action