From f86697163e5cdbc3bc4a65cfb7dbaa3d9eb602a9 Mon Sep 17 00:00:00 2001
From: Douglas Chimento <dchimento@gmail.com>
Date: Sun, 21 Nov 2021 11:17:59 +0200
Subject: rpc: Return fee and prevout(s) to getrawtransaction

* Add optional fee response in BTC to getrawtransaction
* Add optional prevout(s) response to getrawtransaction showing utxos being spent
* Add getrawtransaction_verbosity functional test to validate fields
---
 src/rpc/client.cpp                    |   1 +
 src/rpc/rawtransaction.cpp            | 112 ++++++++++++++++++++++++++--------
 test/functional/rpc_rawtransaction.py |  81 ++++++++++++++++++++++--
 3 files changed, 164 insertions(+), 30 deletions(-)

diff --git a/src/rpc/client.cpp b/src/rpc/client.cpp
index 8688263ef5..0398db964a 100644
--- a/src/rpc/client.cpp
+++ b/src/rpc/client.cpp
@@ -102,6 +102,7 @@ static const CRPCConvertParam vRPCConvertParams[] =
     { "getchaintxstats", 0, "nblocks" },
     { "gettransaction", 1, "include_watchonly" },
     { "gettransaction", 2, "verbose" },
+    { "getrawtransaction", 1, "verbosity" },
     { "getrawtransaction", 1, "verbose" },
     { "createrawtransaction", 0, "inputs" },
     { "createrawtransaction", 1, "outputs" },
diff --git a/src/rpc/rawtransaction.cpp b/src/rpc/rawtransaction.cpp
index d654de1862..a83bf9a03f 100644
--- a/src/rpc/rawtransaction.cpp
+++ b/src/rpc/rawtransaction.cpp
@@ -32,6 +32,7 @@
 #include <script/signingprovider.h>
 #include <script/standard.h>
 #include <uint256.h>
+#include <undo.h>
 #include <util/bip32.h>
 #include <util/check.h>
 #include <util/strencodings.h>
@@ -50,15 +51,17 @@ using node::FindCoins;
 using node::GetTransaction;
 using node::NodeContext;
 using node::PSBTAnalysis;
+using node::ReadBlockFromDisk;
+using node::UndoReadFromDisk;
 
-static void TxToJSON(const CTransaction& tx, const uint256 hashBlock, UniValue& entry, Chainstate& active_chainstate)
+static void TxToJSON(const CTransaction& tx, const uint256 hashBlock, UniValue& entry, Chainstate& active_chainstate, const CTxUndo* txundo = nullptr, TxVerbosity verbosity = TxVerbosity::SHOW_TXID)
 {
     // Call into TxToUniv() in bitcoin-common to decode the transaction hex.
     //
     // Blockchain contextual information (confirmations and blocktime) is not
     // available to code in bitcoin-common, so we query them here and push the
     // data into the returned UniValue.
-    TxToUniv(tx, /*block_hash=*/uint256(), entry, /*include_hex=*/true, RPCSerializationFlags());
+    TxToUniv(tx, /*block_hash=*/uint256(), entry, /*include_hex=*/true, RPCSerializationFlags(), txundo, verbosity);
 
     if (!hashBlock.IsNull()) {
         LOCK(cs_main);
@@ -166,26 +169,27 @@ static RPCHelpMan getrawtransaction()
 {
     return RPCHelpMan{
                 "getrawtransaction",
-                "Return the raw transaction data.\n"
 
-                "\nBy default, this call only returns a transaction if it is in the mempool. If -txindex is enabled\n"
+                "By default, this call only returns a transaction if it is in the mempool. If -txindex is enabled\n"
                 "and no blockhash argument is passed, it will return the transaction if it is in the mempool or any block.\n"
                 "If a blockhash argument is passed, it will return the transaction if\n"
-                "the specified block is available and the transaction is in that block.\n"
-                "\nHint: Use gettransaction for wallet transactions.\n"
+                "the specified block is available and the transaction is in that block.\n\n"
+                "Hint: Use gettransaction for wallet transactions.\n\n"
 
-                "\nIf verbose is 'true', returns an Object with information about 'txid'.\n"
-                "If verbose is 'false' or omitted, returns a string that is serialized, hex-encoded data for 'txid'.",
+                "If verbosity is 0 or omitted, returns the serialized transaction as a hex-encoded string.\n"
+                "If verbosity is 1, returns a JSON Object with information about transaction.\n"
+                "If verbosity is 2, returns a JSON Object with information about transaction, including fee and prevout information.",
                 {
                     {"txid", RPCArg::Type::STR_HEX, RPCArg::Optional::NO, "The transaction id"},
-                    {"verbose", RPCArg::Type::BOOL, RPCArg::Default{false}, "If false, return a string, otherwise return a json object"},
+                    {"verbosity|verbose", RPCArg::Type::NUM, RPCArg::Default{0}, "0 for hex-encoded data, 1 for a JSON object, and 2 for JSON object with fee and prevout"},
                     {"blockhash", RPCArg::Type::STR_HEX, RPCArg::Optional::OMITTED_NAMED_ARG, "The block in which to look for the transaction"},
                 },
                 {
-                    RPCResult{"if verbose is not set or set to false",
-                         RPCResult::Type::STR, "data", "The serialized, hex-encoded data for 'txid'"
+                    RPCResult{"if verbosity is not set or set to 0",
+                         RPCResult::Type::STR, "data", "The serialized transaction as a hex-encoded string for 'txid'"
                      },
-                     RPCResult{"if verbose is set to true",
+                     RPCResult{"if verbosity is set to 1",
+                         // When updating this documentation, update `decoderawtransaction` in the same way.
                          RPCResult::Type::OBJ, "", "",
                          Cat<std::vector<RPCResult>>(
                          {
@@ -198,20 +202,47 @@ static RPCHelpMan getrawtransaction()
                          },
                          DecodeTxDoc(/*txid_field_doc=*/"The transaction id (same as provided)")),
                     },
+                    RPCResult{"for verbosity = 2",
+                        RPCResult::Type::OBJ, "", "",
+                        {
+                            {RPCResult::Type::ELISION, "", "Same output as verbosity = 1"},
+                            {RPCResult::Type::NUM, "fee", /* optional */ true, "transaction fee in " + CURRENCY_UNIT + ", omitted if block undo data is not available"},
+                            {RPCResult::Type::ARR, "vin", "",
+                            {
+                                {RPCResult::Type::OBJ, "", /* optional */ true, "utxo being spent, omitted if block undo data is not available",
+                                {
+                                    {RPCResult::Type::ELISION, "", "Same output as verbosity = 1"},
+                                    {RPCResult::Type::OBJ, "prevout", "Only if undo information is available)",
+                                    {
+                                        {RPCResult::Type::BOOL, "generated", "Coinbase or not"},
+                                        {RPCResult::Type::NUM, "height", "The height of the prevout"},
+                                        {RPCResult::Type::STR_AMOUNT, "value", "The value in " + CURRENCY_UNIT},
+                                        {RPCResult::Type::OBJ, "scriptPubKey", "",
+                                        {
+                                             {RPCResult::Type::STR, "asm", "Disassembly of the public key script"},
+                                             {RPCResult::Type::STR, "desc", "Inferred descriptor for the output"},
+                                             {RPCResult::Type::STR_HEX, "hex", "The raw public key script bytes, hex-encoded"},
+                                             {RPCResult::Type::STR, "address", /*optional=*/true, "The Bitcoin address (only if a well-defined address exists)"},
+                                             {RPCResult::Type::STR, "type", "The type (one of: " + GetAllOutputTypes() + ")"},
+                                        }},
+                                    }},
+                                }},
+                            }},
+                        }},
                 },
                 RPCExamples{
                     HelpExampleCli("getrawtransaction", "\"mytxid\"")
-            + HelpExampleCli("getrawtransaction", "\"mytxid\" true")
-            + HelpExampleRpc("getrawtransaction", "\"mytxid\", true")
-            + HelpExampleCli("getrawtransaction", "\"mytxid\" false \"myblockhash\"")
-            + HelpExampleCli("getrawtransaction", "\"mytxid\" true \"myblockhash\"")
+            + HelpExampleCli("getrawtransaction", "\"mytxid\" 1")
+            + HelpExampleRpc("getrawtransaction", "\"mytxid\", 1")
+            + HelpExampleCli("getrawtransaction", "\"mytxid\" 0 \"myblockhash\"")
+            + HelpExampleCli("getrawtransaction", "\"mytxid\" 1 \"myblockhash\"")
+            + HelpExampleCli("getrawtransaction", "\"mytxid\" 2 \"myblockhash\"")
                 },
         [&](const RPCHelpMan& self, const JSONRPCRequest& request) -> UniValue
 {
     const NodeContext& node = EnsureAnyNodeContext(request.context);
     ChainstateManager& chainman = EnsureChainman(node);
 
-    bool in_active_chain = true;
     uint256 hash = ParseHashV(request.params[0], "parameter 1");
     const CBlockIndex* blockindex = nullptr;
 
@@ -220,10 +251,14 @@ static RPCHelpMan getrawtransaction()
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "The genesis block coinbase is not considered an ordinary transaction and cannot be retrieved");
     }
 
-    // Accept either a bool (true) or a num (>=1) to indicate verbose output.
-    bool fVerbose = false;
+    // Accept either a bool (true) or a num (>=0) to indicate verbosity.
+    int verbosity{0};
     if (!request.params[1].isNull()) {
-        fVerbose = request.params[1].isNum() ? (request.params[1].getInt<int>() != 0) : request.params[1].get_bool();
+        if (request.params[1].isBool()) {
+            verbosity = request.params[1].get_bool();
+        } else {
+            verbosity = request.params[1].getInt<int>();
+        }
     }
 
     if (!request.params[2].isNull()) {
@@ -234,7 +269,6 @@ static RPCHelpMan getrawtransaction()
         if (!blockindex) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Block hash not found");
         }
-        in_active_chain = chainman.ActiveChain().Contains(blockindex);
     }
 
     bool f_txindex_ready = false;
@@ -262,13 +296,43 @@ static RPCHelpMan getrawtransaction()
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, errmsg + ". Use gettransaction for wallet transactions.");
     }
 
-    if (!fVerbose) {
+    if (verbosity <= 0) {
         return EncodeHexTx(*tx, RPCSerializationFlags());
     }
 
     UniValue result(UniValue::VOBJ);
-    if (blockindex) result.pushKV("in_active_chain", in_active_chain);
-    TxToJSON(*tx, hash_block, result, chainman.ActiveChainstate());
+    if (blockindex) {
+        LOCK(cs_main);
+        result.pushKV("in_active_chain", chainman.ActiveChain().Contains(blockindex));
+    }
+    // If request is verbosity >= 1 but no blockhash was given, then look up the blockindex
+    if (request.params[2].isNull()) {
+        LOCK(cs_main);
+        blockindex = chainman.m_blockman.LookupBlockIndex(hash_block);
+    }
+    if (verbosity == 1) {
+        TxToJSON(*tx, hash_block, result, chainman.ActiveChainstate());
+        return result;
+    }
+
+    CBlockUndo blockUndo;
+    CBlock block;
+    const bool is_block_pruned{WITH_LOCK(cs_main, return chainman.m_blockman.IsBlockPruned(blockindex))};
+
+    if (tx->IsCoinBase() ||
+        !blockindex || is_block_pruned ||
+        !(UndoReadFromDisk(blockUndo, blockindex) && ReadBlockFromDisk(block, blockindex, Params().GetConsensus()))) {
+        TxToJSON(*tx, hash_block, result, chainman.ActiveChainstate());
+        return result;
+    }
+
+    CTxUndo* undoTX {nullptr};
+    auto it = std::find_if(block.vtx.begin(), block.vtx.end(), [tx](CTransactionRef t){ return *t == *tx; });
+    if (it != block.vtx.end()) {
+        // -1 as blockundo does not have coinbase tx
+        undoTX = &blockUndo.vtxundo.at(it - block.vtx.begin() - 1);
+    }
+    TxToJSON(*tx, hash_block, result, chainman.ActiveChainstate(), undoTX, TxVerbosity::SHOW_DETAILS_AND_PREVOUT);
     return result;
 },
     };
diff --git a/test/functional/rpc_rawtransaction.py b/test/functional/rpc_rawtransaction.py
index 930aaaa897..6c9f690f71 100755
--- a/test/functional/rpc_rawtransaction.py
+++ b/test/functional/rpc_rawtransaction.py
@@ -14,6 +14,7 @@ Test the following RPCs:
 
 from collections import OrderedDict
 from decimal import Decimal
+from itertools import product
 
 from test_framework.blocktools import COINBASE_MATURITY
 from test_framework.messages import (
@@ -80,6 +81,7 @@ class RawTransactionsTest(BitcoinTestFramework):
         self.generate(self.nodes[0], COINBASE_MATURITY + 1)
 
         self.getrawtransaction_tests()
+        self.getrawtransaction_verbosity_tests()
         self.createrawtransaction_tests()
         self.sendrawtransaction_tests()
         self.sendrawtransaction_testmempoolaccept_tests()
@@ -114,6 +116,7 @@ class RawTransactionsTest(BitcoinTestFramework):
                 # 4. valid parameters - supply txid and 1 for verbose.
                 # We only check the "hex" field of the output so we don't need to update this test every time the output format changes.
                 assert_equal(self.nodes[n].getrawtransaction(txId, 1)["hex"], tx['hex'])
+                assert_equal(self.nodes[n].getrawtransaction(txId, 2)["hex"], tx['hex'])
 
                 # 5. valid parameters - supply txid and True for non-verbose
                 assert_equal(self.nodes[n].getrawtransaction(txId, True)["hex"], tx['hex'])
@@ -124,13 +127,14 @@ class RawTransactionsTest(BitcoinTestFramework):
 
             # 6. invalid parameters - supply txid and invalid boolean values (strings) for verbose
             for value in ["True", "False"]:
-                assert_raises_rpc_error(-3, "not of expected type bool", self.nodes[n].getrawtransaction, txid=txId, verbose=value)
+                assert_raises_rpc_error(-3, "not of expected type number", self.nodes[n].getrawtransaction, txid=txId, verbose=value)
+                assert_raises_rpc_error(-3, "not of expected type number", self.nodes[n].getrawtransaction, txid=txId, verbosity=value)
 
             # 7. invalid parameters - supply txid and empty array
-            assert_raises_rpc_error(-3, "not of expected type bool", self.nodes[n].getrawtransaction, txId, [])
+            assert_raises_rpc_error(-3, "not of expected type number", self.nodes[n].getrawtransaction, txId, [])
 
             # 8. invalid parameters - supply txid and empty dict
-            assert_raises_rpc_error(-3, "not of expected type bool", self.nodes[n].getrawtransaction, txId, {})
+            assert_raises_rpc_error(-3, "not of expected type number", self.nodes[n].getrawtransaction, txId, {})
 
         # Make a tx by sending, then generate 2 blocks; block1 has the tx in it
         tx = self.wallet.send_self_transfer(from_node=self.nodes[2])['txid']
@@ -143,9 +147,10 @@ class RawTransactionsTest(BitcoinTestFramework):
             assert_equal(gottx['in_active_chain'], True)
             if n == 0:
                 self.log.info("Test getrawtransaction with -txindex, without blockhash: 'in_active_chain' should be absent")
-                gottx = self.nodes[n].getrawtransaction(txid=tx, verbose=True)
-                assert_equal(gottx['txid'], tx)
-                assert 'in_active_chain' not in gottx
+                for v in [1,2]:
+                    gottx = self.nodes[n].getrawtransaction(txid=tx, verbosity=v)
+                    assert_equal(gottx['txid'], tx)
+                    assert 'in_active_chain' not in gottx
             else:
                 self.log.info("Test getrawtransaction without -txindex, without blockhash: expect the call to raise")
                 assert_raises_rpc_error(-5, err_msg, self.nodes[n].getrawtransaction, txid=tx, verbose=True)
@@ -170,6 +175,70 @@ class RawTransactionsTest(BitcoinTestFramework):
         block = self.nodes[0].getblock(self.nodes[0].getblockhash(0))
         assert_raises_rpc_error(-5, "The genesis block coinbase is not considered an ordinary transaction", self.nodes[0].getrawtransaction, block['merkleroot'])
 
+    def getrawtransaction_verbosity_tests(self):
+        tx = self.wallet.send_self_transfer(from_node=self.nodes[1])['txid']
+        [block1] = self.generate(self.nodes[1], 1)
+        fields = [
+            'blockhash',
+            'blocktime',
+            'confirmations',
+            'hash',
+            'hex',
+            'in_active_chain',
+            'locktime',
+            'size',
+            'time',
+            'txid',
+            'vin',
+            'vout',
+            'vsize',
+            'weight',
+        ]
+        prevout_fields = [
+            'generated',
+            'height',
+            'value',
+            'scriptPubKey',
+        ]
+        script_pub_key_fields = [
+            'address',
+            'asm',
+            'hex',
+            'type',
+        ]
+        # node 0 & 2 with verbosity 1 & 2
+        for n, v in product([0, 2], [1, 2]):
+            self.log.info(f"Test getrawtransaction_verbosity {v} {'with' if n == 0 else 'without'} -txindex, with blockhash")
+            gottx = self.nodes[n].getrawtransaction(txid=tx, verbosity=v, blockhash=block1)
+            missing_fields = set(fields).difference(gottx.keys())
+            if missing_fields:
+                raise AssertionError(f"fields {', '.join(missing_fields)} are not in transaction")
+
+            assert(len(gottx['vin']) > 0)
+            if v == 1:
+                assert('fee' not in gottx)
+                assert('prevout' not in gottx['vin'][0])
+            if v == 2:
+                assert(isinstance(gottx['fee'], Decimal))
+                assert('prevout' in gottx['vin'][0])
+                prevout = gottx['vin'][0]['prevout']
+                script_pub_key = prevout['scriptPubKey']
+
+                missing_fields = set(prevout_fields).difference(prevout.keys())
+                if missing_fields:
+                    raise AssertionError(f"fields {', '.join(missing_fields)} are not in transaction")
+
+                missing_fields = set(script_pub_key_fields).difference(script_pub_key.keys())
+                if missing_fields:
+                    raise AssertionError(f"fields {', '.join(missing_fields)} are not in transaction")
+
+        # check verbosity 2 without blockhash but with txindex
+        assert('fee' in self.nodes[0].getrawtransaction(txid=tx, verbosity=2))
+        # check that coinbase has no fee or does not throw any errors for verbosity 2
+        coin_base = self.nodes[1].getblock(block1)['tx'][0]
+        gottx = self.nodes[1].getrawtransaction(txid=coin_base, verbosity=2, blockhash=block1)
+        assert('fee' not in gottx)
+
     def createrawtransaction_tests(self):
         self.log.info("Test createrawtransaction")
         # Test `createrawtransaction` required parameters
-- 
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