Merge bitcoin/bitcoin#22918: rpc: Add level 3 verbosity to getblock RPC call (#21245 modified)

5c34507ecbbdc29c086276d1c62835b461823507 core_write: Rename calculate_fee to have_undo for clarity (fyquah)
8edf6204a87057a451160d1e61e79d8be112e81f release-notes: Add release note about getblock verbosity level 3. (fyquah)
459104b2aae6eeaadfa5a7e47944f1a34780dacd rest: Add test for prevout fields in getblock (fyquah)
4330af6f72172848f5971a052a8f325ed50eb576 rpc: Add test for level 3 verbosity getblock rpc call. (fyquah)
51dbc167e98daab317baa80cf80bfda337672dab rpc: Add level 3 verbosity to getblock RPC call. (fyquah)
3cc95345ca49b87e8caca9a0e6418c63ae1e463a rpc: Replace boolean argument for tx details with enum class. (fyquah)

Pull request description:

  Author of #21245 expressed [time issues](https://github.com/bitcoin/bitcoin/pull/21245#issuecomment-902332088) in the original PR. Given that #21245 has received a lot of review*, I have decided to open this new pull request with [modifications required to get ACK from luke-jr ](https://github.com/bitcoin/bitcoin/pull/21245#issuecomment-905150806) and a few nits of mine.

  ### Original PR description

  > Display the prevout in transaction inputs when calling getblock level 3 verbosity. This PR affects the existing `/rest/block` API by adding a `prevout` fields to tx inputs. This is mentioned in the change to the release notes.
  >
  > I added some functional tests that
  >
  >     * checks that the RPC call still works when TxUndo can't be found
  >
  >     * Doesn't display the "value" or "scriptPubKey" of the previous output when at a lower verbosity level
  >
  >
  > This "completes" the issue #18771

  ### Possible improvements

  * https://github.com/kiminuo/bitcoin/commit/b0bf4f255f86aeaddce68889087c22f9068f4d97 - I can include even this commit to this PR if deemed useful or I can leave it for a follow-up PR. See https://github.com/bitcoin/bitcoin/pull/21245#issuecomment-894853784 for more context.

  ### Examples

  Examples of the `getblock` output with various verbose levels. Note that `000000000000001f682b188971cc1a121546be4e9d5baf22934fdc7f538288d5` contains only 2 transactions.

  #### Verbose level 0

  ```bash
  ./bitcoin-cli -testnet getblock 000000000000001f682b188971cc1a121546be4e9d5baf22934fdc7f538288d5 0
  ```

  ##### Verbose level 1

  ```bash
  ./bitcoin-cli -testnet getblock 000000000000001f682b188971cc1a121546be4e9d5baf22934fdc7f538288d5 1
  ```

  ##### Verbose level 2

  ```bash
  ./bitcoin-cli -testnet getblock 000000000000001f682b188971cc1a121546be4e9d5baf22934fdc7f538288d5 2
  ```

  ##### Verbose level 3

  ```bash
  ./bitcoin-cli -testnet getblock 000000000000001f682b188971cc1a121546be4e9d5baf22934fdc7f538288d5 3
  ```

  #### REST

  ```bash
  curl -H "content-type:text/plain;" http://127.0.0.1:18332/rest/block/000000000000001f682b188971cc1a121546be4e9d5baf22934fdc7f538288d5.json
  ```

  <sub>* ... and my everyday obsessive checking of my email inbox whether the PR moves forward.</sub>

  Edit laanwj: Removed at symbol from message, and large example output to prevent it from all ending up in the commit message.

ACKs for top commit:
  0xB10C:
    ACK 5c34507ecbbdc29c086276d1c62835b461823507
  meshcollider:
    utACK 5c34507ecbbdc29c086276d1c62835b461823507
  theStack:
    ACK 5c34507ecbbdc29c086276d1c62835b461823507 👘
  promag:
    Concept ACK 5c34507ecbbdc29c086276d1c62835b461823507

Tree-SHA512: bbff120d8fd76e617b723b102b0c606e0d8eb27f21c631d5f4cdab0892137c4bc7c65b1df144993405f942c91be47a26e80480102af55bff22621c19f518aea3

1 files changed, 25 insertions, 6 deletions

diff --git a/src/core_write.cpp b/src/core_write.cpp
index 6b13e4c586..468694b011 100644
--- a/src/core_write.cpp
+++ b/src/core_write.cpp
@@ -163,7 +163,7 @@ void ScriptPubKeyToUniv(const CScript& scriptPubKey, UniValue& out, bool include
     out.pushKV("type", GetTxnOutputType(type));
 }
 
-void TxToUniv(const CTransaction& tx, const uint256& hashBlock, UniValue& entry, bool include_hex, int serialize_flags, const CTxUndo* txundo)
+void TxToUniv(const CTransaction& tx, const uint256& hashBlock, UniValue& entry, bool include_hex, int serialize_flags, const CTxUndo* txundo, TxVerbosity verbosity)
 {
     entry.pushKV("txid", tx.GetHash().GetHex());
     entry.pushKV("hash", tx.GetWitnessHash().GetHex());
@@ -179,7 +179,7 @@ void TxToUniv(const CTransaction& tx, const uint256& hashBlock, UniValue& entry,
 
     // If available, use Undo data to calculate the fee. Note that txundo == nullptr
     // for coinbase transactions and for transactions where undo data is unavailable.
-    const bool calculate_fee = txundo != nullptr;
+    const bool have_undo = txundo != nullptr;
     CAmount amt_total_in = 0;
     CAmount amt_total_out = 0;
 
@@ -203,9 +203,28 @@ void TxToUniv(const CTransaction& tx, const uint256& hashBlock, UniValue& entry,
             }
             in.pushKV("txinwitness", txinwitness);
         }
-        if (calculate_fee) {
-            const CTxOut& prev_txout = txundo->vprevout[i].out;
+        if (have_undo) {
+            const Coin& prev_coin = txundo->vprevout[i];
+            const CTxOut& prev_txout = prev_coin.out;
+
             amt_total_in += prev_txout.nValue;
+            switch (verbosity) {
+                case TxVerbosity::SHOW_TXID:
+                case TxVerbosity::SHOW_DETAILS:
+                    break;
+
+                case TxVerbosity::SHOW_DETAILS_AND_PREVOUT:
+                    UniValue o_script_pub_key(UniValue::VOBJ);
+                    ScriptPubKeyToUniv(prev_txout.scriptPubKey, o_script_pub_key, /* includeHex */ true);
+
+                    UniValue p(UniValue::VOBJ);
+                    p.pushKV("generated", bool(prev_coin.fCoinBase));
+                    p.pushKV("height", uint64_t(prev_coin.nHeight));
+                    p.pushKV("value", ValueFromAmount(prev_txout.nValue));
+                    p.pushKV("scriptPubKey", o_script_pub_key);
+                    in.pushKV("prevout", p);
+                    break;
+            }
         }
         in.pushKV("sequence", (int64_t)txin.nSequence);
         vin.push_back(in);
@@ -226,13 +245,13 @@ void TxToUniv(const CTransaction& tx, const uint256& hashBlock, UniValue& entry,
         out.pushKV("scriptPubKey", o);
         vout.push_back(out);
 
-        if (calculate_fee) {
+        if (have_undo) {
             amt_total_out += txout.nValue;
         }
     }
     entry.pushKV("vout", vout);
 
-    if (calculate_fee) {
+    if (have_undo) {
         const CAmount fee = amt_total_in - amt_total_out;
         CHECK_NONFATAL(MoneyRange(fee));
         entry.pushKV("fee", ValueFromAmount(fee));