// Copyright (C) 2026 Whiterun LLC,
// This software is licensed under the GNU Lesser General Public License (LGPL), version 3.0 or later.
// A copy of the license can be found in the LICENSE file or at https://www.gnu.org/licenses/lgpl-3.0.html

/**
 * Serialization helpers specific to the hdwalletv1 sign-transaction flow.
 *
 * These convert between native libauth transaction types and the relay-safe
 * JSON used in SignTransactionRequest / SignTransactionResponse messages.
 */

import { binToHex, encodeTransaction } from "@bitauth/libauth";

// ---------------------------------------------------------------------------
// Interfaces (mirror libauth transaction shapes)
// ---------------------------------------------------------------------------

export interface SourceOutput {
  outpointTransactionHash: Uint8Array;
  outpointIndex: number;
  unlockingBytecode: Uint8Array;
  sequenceNumber: number;
  valueSatoshis: bigint;
  lockingBytecode: Uint8Array;
  token?: {
    category: Uint8Array;
    amount: bigint;
    nft?: { capability?: string; commitment?: Uint8Array };
  };
}

interface TxInput {
  outpointTransactionHash: Uint8Array;
  outpointIndex: number;
  unlockingBytecode: Uint8Array;
  sequenceNumber: number;
}

interface TxOutput {
  valueSatoshis: bigint;
  lockingBytecode: Uint8Array;
}

// ---------------------------------------------------------------------------
// Serialization (native types → relay JSON)
// ---------------------------------------------------------------------------

/**
 * Convert a source output to relay-safe JSON format.
 * Uint8Array fields become hex strings, BigInt becomes `<bigint: Xn>`.
 */
export function sourceOutputToRelay(so: SourceOutput): any {
  const result: any = {
    outpointTransactionHash: binToHex(so.outpointTransactionHash),
    outpointIndex: so.outpointIndex,
    unlockingBytecode: binToHex(so.unlockingBytecode),
    sequenceNumber: so.sequenceNumber,
    valueSatoshis: `<bigint: ${so.valueSatoshis}n>`,
    lockingBytecode: binToHex(so.lockingBytecode),
  };
  if (so.token) {
    result.token = {
      category: binToHex(so.token.category),
      amount: `<bigint: ${so.token.amount}n>`,
      ...(so.token.nft && {
        nft: {
          ...(so.token.nft.capability !== undefined && {
            capability: so.token.nft.capability,
          }),
          ...(so.token.nft.commitment !== undefined && {
            commitment: binToHex(so.token.nft.commitment),
          }),
        },
      }),
    };
  }
  return result;
}

/**
 * Encode a transaction to hex for relay transport.
 */
export function transactionToHex(
  inputs: TxInput[],
  outputs: TxOutput[],
  version = 2,
  locktime = 0,
): string {
  return binToHex(encodeTransaction({ inputs, outputs, version, locktime }));
}