<sig> <msg> <pubKey> OP_CHECKDATASIG

require 'tapyrus'
include Tapyrus::Opcodes

key = Tapyrus::Key.generate
message = 'hogehoge'
message_hex = message.bth
digest = Tapyrus.sha256(message_hex)
signature = key.sign(digest)

script = Tapyrus::Script.new << signature << message_hex << key.pubkey << OP_CHECKDATASIG
script.run
# => true

require 'tapyrus'
include Tapyrus::Opcodes
Tapyrus.chain_params = :dev

TAPYRUS_DEV_AGGREGATE_PRIV_KEY = "cUJN5RVzYWFoeY8rUztd47jzXCu1p57Ay8V7pqCzsBD3PEXN7Dd4"
TAPYRUS_RPC_CONFIG = { schema: 'http', host: 'localhost', port: 12381, user: 'rpcuser', password: 'rpcpassword' }
TAPYRUS_RPC_CLIENT = Tapyrus::RPC::TapyrusCoreClient.new(TAPYRUS_RPC_CONFIG)
FEE = 0.00003

key = Tapyrus::Key.generate
message = 'hogehoge'

# Prepare fund
TAPYRUS_RPC_CLIENT.generatetoaddress(1, TAPYRUS_RPC_CLIENT.getnewaddress, TAPYRUS_DEV_AGGREGATE_PRIV_KEY)
fund_utxo = TAPYRUS_RPC_CLIENT.listunspent.find {|utxo| utxo['amount'].to_i > 3 && utxo['token'] == 'TPC' }
fund_tx = Tapyrus::Tx.parse_from_payload(TAPYRUS_RPC_CLIENT.getrawtransaction(fund_utxo['txid']).htb)
fund_outpoint = Tapyrus::OutPoint.from_txid(fund_utxo['txid'], fund_utxo['vout'])

# P2SH as ScriptPubkey
redeem_script = Tapyrus::Script.new << message.bth << key.pubkey << OP_CHECKDATASIG
p2sh = redeem_script.to_p2sh
p2sh_amount = 1

# Create transaction
tx = Tapyrus::Tx.new
tx.in << Tapyrus::TxIn.new(out_point: fund_outpoint)
input_tapyrus = (fund_utxo['amount'].to_f * (10**8)).to_i
fee_tapyrus = (FEE * (10**8)).to_i
amount_tapyrus = (p2sh_amount * (10**8)).to_i
change_tapyrus = input_tapyrus - amount_tapyrus - fee_tapyrus
tx.out << Tapyrus::TxOut.new(value: amount_tapyrus, script_pubkey: p2sh)
tx.out << Tapyrus::TxOut.new(value: change_tapyrus, script_pubkey: Tapyrus::Script.parse_from_addr(TAPYRUS_RPC_CLIENT.getnewaddress))

# Sign
fund_utxo_script_pubkey = fund_tx.outputs[fund_utxo['vout'].to_i].script_pubkey
fund_utxo_key = Tapyrus::Key.from_wif(TAPYRUS_RPC_CLIENT.dumpprivkey(fund_utxo_script_pubkey.to_addr))
sig_hash = tx.sighash_for_input(0, fund_utxo_script_pubkey)
signature = fund_utxo_key.sign(sig_hash) + [Tapyrus::SIGHASH_TYPE[:all]].pack('C')
tx.in[0].script_sig << signature
tx.in[0].script_sig << fund_utxo_key.pubkey.htb
raise StandardError unless tx.verify_input_sig(0, fund_utxo_script_pubkey)
# => nil

# Broadcast P2SH transaction
p2sh_txid = TAPYRUS_RPC_CLIENT.sendrawtransaction(tx.to_payload.bth)
TAPYRUS_RPC_CLIENT.generatetoaddress(1, TAPYRUS_RPC_CLIENT.getnewaddress, TAPYRUS_DEV_AGGREGATE_PRIV_KEY)

p2sh_tx = Tapyrus::Tx.parse_from_payload(TAPYRUS_RPC_CLIENT.getrawtransaction(p2sh_txid).htb)
p2sh_utxo = p2sh_tx.outputs.first
p2sh_out_point = Tapyrus::OutPoint.from_txid(p2sh_txid, 0)


# =======================================================================================


# Create signature
signature = key.sign(Tapyrus.sha256(message.bth))

# Create transaction
tx = Tapyrus::Tx.new
tx.in << Tapyrus::TxIn.new(out_point: p2sh_out_point)
input_tapyrus = p2sh_utxo.value
fee_tapyrus = (FEE * (10**8)).to_i
amount_tapyrus = (0.5 * (10**8)).to_i
change_tapyrus = input_tapyrus - amount_tapyrus - fee_tapyrus
tx.out << Tapyrus::TxOut.new(value: amount_tapyrus, script_pubkey: Tapyrus::Script.parse_from_addr(TAPYRUS_RPC_CLIENT.getnewaddress))
tx.out << Tapyrus::TxOut.new(value: change_tapyrus, script_pubkey: Tapyrus::Script.parse_from_addr(TAPYRUS_RPC_CLIENT.getnewaddress))

# ScriptSig
script_sig = Tapyrus::Script.new << signature << redeem_script.to_payload.bth
tx.in[0].script_sig = script_sig
raise StandardError unless tx.verify_input_sig(0, p2sh)
# => nil

spent_p2sh_txid = TAPYRUS_RPC_CLIENT.sendrawtransaction(tx.to_payload.bth)
TAPYRUS_RPC_CLIENT.generatetoaddress(1, TAPYRUS_RPC_CLIENT.getnewaddress, TAPYRUS_DEV_AGGREGATE_PRIV_KEY)