abstract class AbstractPolicy extends AbstractHook {
  abstract name: string;
  abstract description?: string;
  abstract relevantTools: string[];

  protected shouldBlockPreToolExecution(params, method): boolean | Promise<boolean>;
  protected shouldBlockPostParamsNormalization(params, method): boolean | Promise<boolean>;
  protected shouldBlockPostCoreAction(params, method): boolean | Promise<boolean>;
  protected shouldBlockPostSecondaryAction(params, method): boolean | Promise<boolean>;
}

import {
  AbstractPolicy,
  PreToolExecutionParams,
  PostParamsNormalizationParams,
} from '@hashgraph/hedera-agent-kit';

export class MyPolicy extends AbstractPolicy {
  name = 'My Policy';
  description = 'What this policy blocks, in one sentence';
  relevantTools = ['transfer_hbar', 'transfer_fungible_token'];

  // Stage 1 — block by raw input or method
  protected shouldBlockPreToolExecution(
    params: PreToolExecutionParams,
    method: string,
  ): boolean {
    if (!this.relevantTools.includes(method)) return false;
    // throw new Error('<custom message>') for tailored errors
    return /* condition */ false;
  }

  // Stage 3 — block on resolved/normalised values
  protected shouldBlockPostParamsNormalization(
    params: PostParamsNormalizationParams,
    method: string,
  ): boolean {
    if (!this.relevantTools.includes(method)) return false;
    return /* condition */ false;
  }
}

import { AgentMode } from '@hashgraph/hedera-agent-kit';
import { allCorePlugins } from '@hashgraph/hedera-agent-kit/plugins';
import { RejectToolPolicy, MaxRecipientsPolicy } from '@hashgraph/hedera-agent-kit/policies';
import { HederaLangchainToolkit } from '@hashgraph/hedera-agent-kit-langchain';
import { MyPolicy } from './my-policy';

const toolkit = new HederaLangchainToolkit({
  client,
  configuration: {
    plugins: allCorePlugins,
    context: {
      mode: AgentMode.AUTONOMOUS,
      hooks: [
        new RejectToolPolicy(['delete_account', 'freeze_token']),
        new MaxRecipientsPolicy(5),
        new MyPolicy(),
      ],
    },
  },
});

protected shouldBlockPostParamsNormalization(
  params: PostParamsNormalizationParams,
  method: string,
): boolean {
  if (!this.relevantTools.includes(method)) return false;
  const p = params.normalisedParams as { amount?: number };
  return (p.amount ?? 0) > this.maxAmount;
}

protected shouldBlockPreToolExecution(
  params: PreToolExecutionParams,
  method: string,
): boolean {
  if (!this.relevantTools.includes(method)) return false;
  const accountId = (params.rawParams as { accountId?: string }).accountId;
  return accountId !== undefined && this.blockedAccounts.has(accountId);
}

protected shouldBlockPreToolExecution(
  _params: PreToolExecutionParams,
  method: string,
): boolean {
  if (!this.relevantTools.includes(method)) return false;
  const hour = new Date().getUTCHours();
  return hour < 9 || hour > 17;  // outside business hours
}

protected shouldBlockPreToolExecution(
  params: PreToolExecutionParams,
  method: string,
): boolean {
  if (!this.relevantTools.includes(method)) return false;
  const counters = ((params.context as any).__rateCounts ??= {} as Record<string, number>);
  counters[method] = (counters[method] ?? 0) + 1;
  return counters[method] > this.maxCallsPerSession;
}

constructor(
  private maxRecipients: number,
  additionalTools: string[] = [],
  private customStrategies: Record<string, (p: any) => number> = {},
) {
  super();
  this.relevantTools = [...DEFAULT_TOOLS, ...additionalTools];
  for (const tool of additionalTools) {
    if (!this.customStrategies[tool]) {
      throw new Error(`Custom tool "${tool}" requires a strategy function`);
    }
  }
}

protected shouldBlockPostParamsNormalization(
  params: PostParamsNormalizationParams,
  method: string,
): boolean {
  if (!this.relevantTools.includes(method)) return false;
  const p = params.normalisedParams as { amount?: number };
  if ((p.amount ?? 0) > this.maxAmount) {
    throw new Error(
      `[max-amount-policy] Refusing ${method}: amount ${p.amount} exceeds limit ${this.maxAmount}`,
    );
  }
  return false;
}

import {
  AbstractPolicy,
  Context,
  PreToolExecutionParams,
  PostParamsNormalizationParams,
  PostCoreActionParams,
  PostSecondaryActionParams,
} from '@hashgraph/hedera-agent-kit';

// Built-in implementations live in the /policies subpath
import { RejectToolPolicy, MaxRecipientsPolicy } from '@hashgraph/hedera-agent-kit/policies';