wip: Add initial support for loading signet UTXO snapshots

        Adds wiring to connect QML GUI to loading a signet UTXO snapshot via
        the connection settings. Modifies src/interfaces/node.h, src/node/interfaces.cpp
        and src/validation.h and src/validation.cpp
        to implement snapshot loading functionality through the options model.

        Current limitations:
        - Not integrated with onboarding process
        - Requires manual navigation to connection settings after initial startup

        Testing:
        1. Start the node
        2. Complete onboarding
        3. Navigate to connection settings
        4. Load snapshot from provided interface

Author: D33r-Gee

src/interfaces/node.h

@@ -35,6 +35,7 @@ struct CNodeStateStats;
 struct bilingual_str;
 struct PeersNumByType;
 namespace node {
+class SnapshotMetadata;
 struct NodeContext;
 } // namespace node
 namespace wallet {
@@ -45,6 +46,7 @@ namespace interfaces {
 class Handler;
 class WalletLoader;
 struct BlockTip;
+struct SnapshotLoadResult;
 
 //! Block and header tip information
 struct BlockAndHeaderTipInfo
@@ -199,6 +201,12 @@ class Node
     //! List rpc commands.
     virtual std::vector<std::string> listRpcCommands() = 0;
 
+    //! Get block time from hash.
+    virtual int64_t getBlockTime(const uint256& hash) const = 0;
+
+    //! Load UTXO Snapshot.
+    virtual SnapshotLoadResult snapshotLoad(const std::string& path_string, std::function<void(double)> progress_callback, node::SnapshotMetadata& metadata) = 0;
+
     //! Set RPC timer interface if unset.
     virtual void rpcSetTimerInterfaceIfUnset(RPCTimerInterface* iface) = 0;
 
@@ -280,6 +288,12 @@ struct BlockTip {
     uint256 block_hash;
 };
 
+//! Snapshot load result.
+struct SnapshotLoadResult {
+    bool success;
+    int block_height;
+};
+
 } // namespace interfaces
 
 #endif // BITCOIN_INTERFACES_NODE_H

src/kernel/chainparams.cpp

@@ -371,6 +371,13 @@ class SigNetParams : public CChainParams {
 
         vFixedSeeds.clear();
 
+        m_assumeutxo_data = MapAssumeutxo{
+            {
+                160000,
+                {AssumeutxoHash{uint256S("0x5225141cb62dee63ab3be95f9b03d60801f264010b1816d4bd00618b2736e7be")}, 1278002},
+            },
+        };
+
         base58Prefixes[PUBKEY_ADDRESS] = std::vector<unsigned char>(1,111);
         base58Prefixes[SCRIPT_ADDRESS] = std::vector<unsigned char>(1,196);
         base58Prefixes[SECRET_KEY] =     std::vector<unsigned char>(1,239);

src/node/interfaces.cpp

@@ -29,6 +29,7 @@
 #include <node/context.h>
 #include <node/interface_ui.h>
 #include <node/transaction.h>
+#include <node/utxo_snapshot.h>
 #include <policy/feerate.h>
 #include <policy/fees.h>
 #include <policy/policy.h>
@@ -68,6 +69,7 @@ using interfaces::Handler;
 using interfaces::MakeSignalHandler;
 using interfaces::Node;
 using interfaces::WalletLoader;
+using interfaces::SnapshotLoadResult;
 
 namespace node {
 // All members of the classes in this namespace are intentionally public, as the
@@ -395,9 +397,76 @@ class NodeImpl : public Node
     {
         m_context = context;
     }
+    SnapshotLoadResult snapshotLoad(const std::string& path_string, std::function<void(double)> progress_callback, SnapshotMetadata& metadata) override
+    {
+        const fs::path path = fs::u8path(path_string);
+        if (!fs::exists(path)) {
+            LogPrintf("[loadsnapshot] Snapshot file %s does not exist\n", path.u8string());
+            return {false, 0};
+        }
+
+        AutoFile afile{fsbridge::fopen(path, "rb")};
+        if (afile.IsNull()) {
+            LogPrintf("[loadsnapshot] Failed to open snapshot file %s\n", path.u8string());
+            return {false, 0};
+        }
+
+        try {
+            afile >> metadata;
+        } catch (const std::exception& e) {
+            LogPrintf("[loadsnapshot] Failed to read snapshot metadata: %s\n", e.what());
+            return {false, 0};
+        }
+
+        const uint256& base_blockhash = metadata.m_base_blockhash;
+        LogPrintf("[loadsnapshot] Waiting for blockheader %s in headers chain before snapshot activation\n",
+            base_blockhash.ToString());
+
+        if (!m_context->chainman) {
+            LogPrintf("[loadsnapshot] Chainman is null\n");
+            return {false, 0};
+        }
+
+        ChainstateManager& chainman = *m_context->chainman;
+        CBlockIndex* snapshot_start_block = nullptr;
+
+        // Wait for the block to appear in the block index
+        constexpr int max_wait_seconds = 600; // 10 minutes
+        for (int i = 0; i < max_wait_seconds; ++i) {
+            snapshot_start_block = WITH_LOCK(::cs_main, return chainman.m_blockman.LookupBlockIndex(base_blockhash));
+            if (snapshot_start_block) break;
+            std::this_thread::sleep_for(std::chrono::seconds(1));
+        }
+
+        if (!snapshot_start_block) {
+            LogPrintf("[loadsnapshot] Timed out waiting for snapshot start blockheader %s\n", base_blockhash.ToString());
+            return {false, 0};
+        }
+
+        // Activate the snapshot
+        if (!chainman.ActivateSnapshot(afile, metadata, false, progress_callback)) {
+            LogPrintf("[loadsnapshot] Unable to load UTXO snapshot %s\n", path.u8string());
+            return {false, 0};
+        }
+
+        CBlockIndex* new_tip = WITH_LOCK(::cs_main, return chainman.ActiveTip());
+        LogPrintf("[loadsnapshot] Loaded %d coins from snapshot %s at height %d\n",
+                  metadata.m_coins_count, new_tip->GetBlockHash().ToString(), new_tip->nHeight);
+
+        return {true, new_tip->nHeight};
+    }
     ArgsManager& args() { return *Assert(Assert(m_context)->args); }
     ChainstateManager& chainman() { return *Assert(m_context->chainman); }
     NodeContext* m_context{nullptr};
+    int64_t getBlockTime(const uint256& hash) const override
+    {
+        LOCK(cs_main);
+        const CBlockIndex* pblockindex = m_context->chainman->m_blockman.LookupBlockIndex(hash);
+        if (!pblockindex) {
+            return 0;
+        }
+        return pblockindex->GetBlockTime();
+    }
 };
 
 bool FillBlock(const CBlockIndex* index, const FoundBlock& block, UniqueLock<RecursiveMutex>& lock, const CChain& active, const BlockManager& blockman)
@@ -809,3 +878,4 @@ namespace interfaces {
 std::unique_ptr<Node> MakeNode(node::NodeContext& context) { return std::make_unique<node::NodeImpl>(context); }
 std::unique_ptr<Chain> MakeChain(node::NodeContext& context) { return std::make_unique<node::ChainImpl>(context); }
 } // namespace interfaces
+

src/qml/bitcoin.cpp

@@ -242,7 +242,7 @@ int QmlGuiMain(int argc, char* argv[])
 
     // Default printtoconsole to false for the GUI. GUI programs should not
     // print to the console unnecessarily.
-    gArgs.SoftSetBoolArg("-printtoconsole", false);
+    // gArgs.SoftSetBoolArg("-printtoconsole", false);
     InitLogging(gArgs);
     InitParameterInteraction(gArgs);
 
@@ -311,6 +311,8 @@ int QmlGuiMain(int argc, char* argv[])
     engine.rootContext()->setContextProperty("optionsModel", &options_model);
     engine.rootContext()->setContextProperty("needOnboarding", need_onboarding);
 
+    // QObject::connect(&node_model, &NodeModel::snapshotLoaded, &options_model, &OptionsQmlModel::setSnapshotLoadCompleted);
+
     AppMode app_mode = SetupAppMode();
 
     qmlRegisterSingletonInstance<AppMode>("org.bitcoincore.qt", 1, 0, "AppMode", &app_mode);
@@ -330,7 +332,7 @@ int QmlGuiMain(int argc, char* argv[])
     }
 
     // Install qDebug() message handler to route to debug.log
-    qInstallMessageHandler(DebugMessageHandler);
+    // qInstallMessageHandler(DebugMessageHandler);
 
     qInfo() << "Graphics API in use:" << QmlUtil::GraphicsApi(window);
 

src/qml/components/ConnectionSettings.qml

@@ -8,36 +8,59 @@ import QtQuick.Layouts 1.15
 import "../controls"
 
 ColumnLayout {
-    property bool snapshotImported: false
+    // TODO: Remove this once storing the snapshot path is implemented
+    property bool isOnboarding: false
+    property bool snapshotImported: optionsModel.snapshotLoadCompleted
+
+    Component.onCompleted: {
+        snapshotImported = optionsModel.snapshotLoadCompleted
+    }
+
     function setSnapshotImported(imported) {
         snapshotImported = imported
+        optionsModel.setSnapshotLoadCompleted(imported)
     }
     spacing: 4
-    Setting {
-        id: gotoSnapshot
+    Item {
+        // TODO: Remove this once storing the snapshot path is implemented
+        visible: !isOnboarding
+        height: visible ? implicitHeight : 0
         Layout.fillWidth: true
-        header: qsTr("Load snapshot")
-        description: qsTr("Instant use with background sync")
-        actionItem: Item {
-            width: 26
-            height: 26
-            CaretRightIcon {
-                anchors.centerIn: parent
-                visible: !snapshotImported
-                color: gotoSnapshot.stateColor
+        Layout.preferredHeight: gotoSnapshot.height
+
+        Setting {
+            id: gotoSnapshot
+            visible: parent.visible
+            Layout.fillWidth: true
+            header: qsTr("Load snapshot")
+            description: qsTr("Instant use with background sync")
+            actionItem: Item {
+                width: 26
+                height: 26
+                CaretRightIcon {
+                    // TODO: aligment will be fixed once Onboarding snapshot works
+                    anchors.right: parent.right
+                    anchors.verticalCenter: parent.verticalCenter
+                    visible: !snapshotImported
+                    color: gotoSnapshot.stateColor
+                }
+                GreenCheckIcon {
+                    anchors.centerIn: parent
+                    visible: snapshotImported
+                    color: Theme.color.transparent
+                }
             }
-            GreenCheckIcon {
-                anchors.centerIn: parent
-                visible: snapshotImported
-                color: Theme.color.transparent
+            onClicked: {
+                connectionSwipe.incrementCurrentIndex()
+                connectionSwipe.incrementCurrentIndex()
             }
         }
-        onClicked: {
-            connectionSwipe.incrementCurrentIndex()
-            connectionSwipe.incrementCurrentIndex()
-        }
     }
-    Separator { Layout.fillWidth: true }
+    Separator {
+        Layout.fillWidth: true
+        // TODO: Remove this once storing the snapshot path is implemented
+        visible: !isOnboarding
+    }
     Setting {
         Layout.fillWidth: true
         header: qsTr("Enable listening")

src/qml/components/SnapshotSettings.qml

@@ -5,20 +5,22 @@
 import QtQuick 2.15
 import QtQuick.Controls 2.15
 import QtQuick.Layouts 1.15
+import QtQuick.Dialogs 1.3
+
 
 import "../controls"
 
 ColumnLayout {
     signal snapshotImportCompleted()
     property int snapshotVerificationCycles: 0
     property real snapshotVerificationProgress: 0
-    property bool snapshotVerified: false
+    property bool snapshotVerified: optionsModel.snapshotLoadCompleted
 
     id: columnLayout
     width: Math.min(parent.width, 450)
     anchors.horizontalCenter: parent.horizontalCenter
 
-
+    // TODO: Remove simulation timer before release
     Timer {
         id: snapshotSimulationTimer
         interval: 50 // Update every 50ms
@@ -42,7 +44,7 @@ ColumnLayout {
 
     StackLayout {
         id: settingsStack
-        currentIndex: 0
+        currentIndex: optionsModel.snapshotLoadCompleted ? 2 : 0
 
         ColumnLayout {
             Layout.alignment: Qt.AlignHCenter
@@ -78,8 +80,26 @@ ColumnLayout {
                 Layout.alignment: Qt.AlignCenter
                 text: qsTr("Choose snapshot file")
                 onClicked: {
-                    settingsStack.currentIndex = 1
-                    snapshotSimulationTimer.start()
+                    // TODO: Connect this to snapshot loading
+                    // settingsStack.currentIndex = 1
+                    fileDialog.open()
+                }
+            }
+
+            FileDialog {
+                id: fileDialog
+                folder: shortcuts.home
+                selectMultiple: false
+                onAccepted: {
+                    console.log("File chosen:", fileDialog.fileUrls)
+                    var snapshotFileName = fileDialog.fileUrl.toString()
+                    console.log("Snapshot file name:", snapshotFileName)
+                    if (snapshotFileName.endsWith(".dat")) {
+                        // optionsModel.setSnapshotDirectory(snapshotFileName)
+                        // console.log("Snapshot directory set:", optionsModel.getSnapshotDirectory())
+                        optionsModel.initializeSnapshot(true, snapshotFileName)
+                        settingsStack.currentIndex = 1
+                    }
                 }
             }
         }
@@ -109,10 +129,27 @@ ColumnLayout {
                 Layout.topMargin: 20
                 width: 200
                 height: 20
-                progress: snapshotVerificationProgress
+                progress: optionsModel.snapshotProgress
                 Layout.alignment: Qt.AlignCenter
                 progressColor: Theme.color.blue
             }
+
+            Connections {
+                target: optionsModel
+                function onSnapshotProgressChanged() {
+                    progressIndicator.progress = optionsModel.snapshotProgress
+                }
+                function onSnapshotLoadCompletedChanged(success) {
+                    if (success) {
+                        progressIndicator.progress = 1
+                        settingsStack.currentIndex = 2  // Move to the "Snapshot Loaded" page
+                    } else {
+                        // Handle snapshot loading failure
+                        console.error("Snapshot loading failed")
+                        // You might want to show an error message or take other actions here
+                    }
+                }
+            }
         }
 
         ColumnLayout {
@@ -137,8 +174,8 @@ ColumnLayout {
                 descriptionColor: Theme.color.neutral6
                 descriptionSize: 17
                 descriptionLineHeight: 1.1
-                description: qsTr("It contains transactions up to January 12, 2024. Newer transactions still need to be downloaded." +
-                " The data will be verified in the background.")
+                description: qsTr("It contains transactions up to %1. Newer transactions still need to be downloaded." +
+                " The data will be verified in the background.").arg(optionsModel.snapshotDate)
             }
 
             ContinueButton {
@@ -188,14 +225,17 @@ ColumnLayout {
                         font.pixelSize: 14
                     }
                     CoreText {
-                        text: qsTr("200,000")
+                        // text: qsTr("160,000")
+                        text: optionsModel.snapshotBlockHeight.toLocaleString(Qt.locale(), 'f', 0)
                         Layout.alignment: Qt.AlignRight
                         font.pixelSize: 14
                     }
                 }
                 Separator { Layout.fillWidth: true }
                 CoreText {
-                    text: qsTr("Hash: 0x1234567890abcdef...")
+                    // text: qsTr("Hash: 0x1234567890abcdef...")
+                    // TODO: truncate the hash to 8 characters
+                    text: qsTr("Hash: %1").arg(optionsModel.snapshotBlockHash)
                     font.pixelSize: 14
                 }
             }