import type { PublicKey, ScriptElement} from "libnexa-ts";
import { Address, BNExtended, Hash, Opcode, Script, ScriptOpcode } from "libnexa-ts";

export function getVaultTemplate(): Script {
  return Script.empty()
    .add(Opcode.OP_FROMALTSTACK).add(Opcode.OP_DROP)
    .add(Opcode.OP_FROMALTSTACK).add(Opcode.OP_CHECKLOCKTIMEVERIFY).add(Opcode.OP_DROP)
    .add(Opcode.OP_FROMALTSTACK).add(Opcode.OP_CHECKSIGVERIFY);
}

export function getVaultTemplateHash(): Uint8Array {
  const template = getVaultTemplate();
  return Hash.sha256ripemd160(template.toBuffer());
}

export function generateVaultConstraint(pubKey: PublicKey): Script {
  return Script.empty().add(pubKey.toBuffer());
}

export function getVaultConstraintHash(pubKey: PublicKey): Uint8Array {
  const constraint = generateVaultConstraint(pubKey);
  return Hash.sha256ripemd160(constraint.toBuffer());
}

export function generateVaultVisibleArgs(args: number[]): ScriptElement[] {
  return args.map(arg => arg <= 16 ? ScriptOpcode.smallInt(arg) : BNExtended.fromNumber(arg).toScriptNumBuffer());
}

export function generateVaultAddress(pubKey: PublicKey, args: number[]): string | undefined {
  if (args.length !== 2) {
    return undefined;
  }

  const templateHash = getVaultTemplateHash();
  const constraintHash = getVaultConstraintHash(pubKey);
  const visibleArgs = generateVaultVisibleArgs(args);
  const address = Address.fromScriptTemplate(templateHash, constraintHash, visibleArgs);
  return address.toString();
}