import "../types/structs.scrypt";
import "txHashPreimageUtils.scrypt";
import "txUtils.scrypt";
import "stdUtils.scrypt";




struct _opcat_labs_scrypt_ts_opcat_4_0_0__rs__ChainTxVerifyResponse {
  bytes prevPrevScript;
  bytes prevPrevOutpoint;
}

library _opcat_labs_scrypt_ts_opcat_4_0_0__rs__Backtrace {
  static const bytes GENESIS_SCRIPT_HASH = b'6712360d7ad09ba9a59cd236aab61db7183c8d881c74ea029debd1f6b26711f8';
  static function checkPrevTxHashPreimage(_opcat_labs_scrypt_ts_opcat_4_0_0__rs__TxHashPreimage txHashPreimage, bytes t_outpoint) : bool {
    bytes txHash = _opcat_labs_scrypt_ts_opcat_4_0_0__rs__TxHashPreimageUtils.getTxHashFromTxHashPreimage(txHashPreimage);
    require(txHash == t_outpoint[0 : 32]);
    return true;
  }
  static function verifyFromOutpoint(_opcat_labs_scrypt_ts_opcat_4_0_0__rs__BacktraceInfo backtraceInfo, int t_prevOutputIndex, bytes t_genesisOutpoint, bytes t_selfScript, bytes t_prevTxInputList) : bool {
    _opcat_labs_scrypt_ts_opcat_4_0_0__rs__ChainTxVerifyResponse res = _opcat_labs_scrypt_ts_opcat_4_0_0__rs__Backtrace.verifyChainTxs(backtraceInfo, t_prevTxInputList);
    if(res.prevPrevOutpoint == t_genesisOutpoint) {
        require(res.prevPrevScript == _opcat_labs_scrypt_ts_opcat_4_0_0__rs__Backtrace.GENESIS_SCRIPT_HASH);
        require(t_prevOutputIndex == 0);
      }
    require(res.prevPrevOutpoint == t_genesisOutpoint || res.prevPrevScript == t_selfScript);
    return true;
  }
  static function verifyFromScript(_opcat_labs_scrypt_ts_opcat_4_0_0__rs__BacktraceInfo backtraceInfo, bytes t_genesisScript, bytes t_selfScript, bytes t_prevTxInputList) : bool {
    _opcat_labs_scrypt_ts_opcat_4_0_0__rs__ChainTxVerifyResponse res = _opcat_labs_scrypt_ts_opcat_4_0_0__rs__Backtrace.verifyChainTxs(backtraceInfo, t_prevTxInputList);
    require(res.prevPrevScript == t_genesisScript || res.prevPrevScript == t_selfScript);
    return true;
  }
  static function verifyChainTxs(_opcat_labs_scrypt_ts_opcat_4_0_0__rs__BacktraceInfo backtraceInfo, bytes t_prevTxInputList) : _opcat_labs_scrypt_ts_opcat_4_0_0__rs__ChainTxVerifyResponse {
    require(t_prevTxInputList[backtraceInfo.prevTxInputIndex * 72 : (backtraceInfo.prevTxInputIndex + 1) * 72] == _opcat_labs_scrypt_ts_opcat_4_0_0__rs__TxUtils.mergeInput(backtraceInfo.prevTxInput));
    bytes prevPrevTxHash = backtraceInfo.prevTxInput.prevTxHash;
    require(prevPrevTxHash == _opcat_labs_scrypt_ts_opcat_4_0_0__rs__TxHashPreimageUtils.getTxHashFromTxHashPreimage(backtraceInfo.prevPrevTxPreimage));
    bytes prevPrevScript = backtraceInfo.prevPrevTxPreimage.outputList[backtraceInfo.prevTxInput.prevOutputIndex * 72 + 8 : (backtraceInfo.prevTxInput.prevOutputIndex) * 72 + 8 + 32];
    bytes prevPrevOutpoint = prevPrevTxHash + _opcat_labs_scrypt_ts_opcat_4_0_0__rs__StdUtils.uint32ToByteString(backtraceInfo.prevTxInput.prevOutputIndex);
    return {prevPrevScript, prevPrevOutpoint};
  }
}