Allow users to specify Python executable path

Closes qbittorrent#19195.

src/base/preferences.cpp

@@ -1487,6 +1487,19 @@ void Preferences::setTrackerPortForwardingEnabled(const bool enabled)
     setValue(u"Preferences/Advanced/trackerPortForwarding"_s, enabled);
 }
 
+Path Preferences::getPythonExecutablePath() const
+{
+    return value(u"Preferences/Search/pythonExecutablePath"_s, Path());
+}
+
+void Preferences::setPythonExecutablePath(const Path &path)
+{
+    if (path == getPythonExecutablePath())
+        return;
+
+    setValue(u"Preferences/Search/pythonExecutablePath"_s, path);
+}
+
 #if defined(Q_OS_WIN) || defined(Q_OS_MACOS)
 bool Preferences::isUpdateCheckEnabled() const
 {

src/base/preferences.h

@@ -305,6 +305,8 @@ class Preferences final : public QObject
     void setTrackerPort(int port);
     bool isTrackerPortForwardingEnabled() const;
     void setTrackerPortForwardingEnabled(bool enabled);
+    Path getPythonExecutablePath() const;
+    void setPythonExecutablePath(const Path &path);
 #if defined(Q_OS_WIN) || defined(Q_OS_MACOS)
     bool isUpdateCheckEnabled() const;
     void setUpdateCheckEnabled(bool enabled);

src/base/utils/foreignapps.cpp

@@ -44,6 +44,8 @@
 
 #include "base/global.h"
 #include "base/logger.h"
+#include "base/path.h"
+#include "base/preferences.h"
 #include "base/utils/bytearray.h"
 
 using namespace Utils::ForeignApps;
@@ -52,6 +54,8 @@ namespace
 {
     bool testPythonInstallation(const QString &exeName, PythonInfo &info)
     {
+        info = {};
+
         QProcess proc;
         proc.start(exeName, {u"--version"_s}, QIODevice::ReadOnly);
         if (proc.waitForFinished() && (proc.exitCode() == QProcess::NormalExit))
@@ -77,7 +81,7 @@ namespace
                 return false;
 
             info = {exeName, version};
-            LogMsg(QCoreApplication::translate("Utils::ForeignApps", "Python detected, executable name: '%1', version: %2")
+            LogMsg(QCoreApplication::translate("Utils::ForeignApps", "Found Python executable. Name: \"%1\". Version: \"%2\"")
                 .arg(info.executableName, info.version.toString()), Log::INFO);
             return true;
         }
@@ -254,20 +258,36 @@ bool Utils::ForeignApps::PythonInfo::isSupportedVersion() const
 PythonInfo Utils::ForeignApps::pythonInfo()
 {
     static PythonInfo pyInfo;
-    if (!pyInfo.isValid())
+
+    if (const QString preferredPythonPath = Preferences::instance()->getPythonExecutablePath().toString();
+        !preferredPythonPath.isEmpty() && (preferredPythonPath != pyInfo.executableName))
+    {
+        if (testPythonInstallation(preferredPythonPath, pyInfo))
+            return pyInfo;
+        LogMsg(QCoreApplication::translate("Utils::ForeignApps", "Failed to find Python executable. Path: \"%1\".")
+            .arg(preferredPythonPath), Log::WARNING);
+    }
+    else if (!pyInfo.isValid())
     {
+        // auto detect only when there are no preferred python path
+
         if (testPythonInstallation(u"python3"_s, pyInfo))
             return pyInfo;
+        LogMsg(QCoreApplication::translate("Utils::ForeignApps", "Failed to find `python3` executable in PATH environment variable. PATH: \"%1\"")
+            .arg(qEnvironmentVariable("PATH")), Log::INFO);
 
         if (testPythonInstallation(u"python"_s, pyInfo))
             return pyInfo;
+        LogMsg(QCoreApplication::translate("Utils::ForeignApps", "Failed to find `python` executable in PATH environment variable. PATH: \"%1\"")
+            .arg(qEnvironmentVariable("PATH")), Log::INFO);
 
 #if defined(Q_OS_WIN)
         if (testPythonInstallation(findPythonPath(), pyInfo))
             return pyInfo;
+        LogMsg(QCoreApplication::translate("Utils::ForeignApps", "Failed to find `python` executable in Windows Registry."), Log::INFO);
 #endif
 
-        LogMsg(QCoreApplication::translate("Utils::ForeignApps", "Python not detected"), Log::INFO);
+        LogMsg(QCoreApplication::translate("Utils::ForeignApps", "Failed to find Python executable"), Log::WARNING);
     }
 
     return pyInfo;

src/gui/advancedsettings.cpp

@@ -99,6 +99,7 @@ namespace
         TRACKER_STATUS,
         TRACKER_PORT,
         TRACKER_PORT_FORWARDING,
+        PYTHON_EXECUTABLE_PATH,
         // libtorrent section
         LIBTORRENT_HEADER,
         BDECODE_DEPTH_LIMIT,
@@ -316,7 +317,8 @@ void AdvancedSettings::saveAdvancedSettings() const
     pref->setTrackerPort(m_spinBoxTrackerPort.value());
     pref->setTrackerPortForwardingEnabled(m_checkBoxTrackerPortForwarding.isChecked());
     session->setTrackerEnabled(m_checkBoxTrackerStatus.isChecked());
-
+    // Python executable path
+    pref->setPythonExecutablePath(Path(m_pythonExecutablePath.text().trimmed()));
     // Choking algorithm
     session->setChokingAlgorithm(m_comboBoxChokingAlgorithm.currentData().value<BitTorrent::ChokingAlgorithm>());
     // Seed choking algorithm
@@ -810,6 +812,10 @@ void AdvancedSettings::loadAdvancedSettings()
     // Tracker port forwarding
     m_checkBoxTrackerPortForwarding.setChecked(pref->isTrackerPortForwardingEnabled());
     addRow(TRACKER_PORT_FORWARDING, tr("Enable port forwarding for embedded tracker"), &m_checkBoxTrackerPortForwarding);
+    // Python executable path
+    m_pythonExecutablePath.setPlaceholderText(tr("(Auto detect if empty)"));
+    m_pythonExecutablePath.setText(pref->getPythonExecutablePath().toString());
+    addRow(PYTHON_EXECUTABLE_PATH, tr("Python executable path (requires restart)"), &m_pythonExecutablePath);
     // Choking algorithm
     m_comboBoxChokingAlgorithm.addItem(tr("Fixed slots"), QVariant::fromValue(BitTorrent::ChokingAlgorithm::FixedSlots));
     m_comboBoxChokingAlgorithm.addItem(tr("Upload rate based"), QVariant::fromValue(BitTorrent::ChokingAlgorithm::RateBased));

src/gui/advancedsettings.h

@@ -81,7 +81,7 @@ private slots:
               m_checkBoxSuggestMode, m_checkBoxSpeedWidgetEnabled, m_checkBoxIDNSupport;
     QComboBox m_comboBoxInterface, m_comboBoxInterfaceAddress, m_comboBoxDiskIOReadMode, m_comboBoxDiskIOWriteMode, m_comboBoxUtpMixedMode, m_comboBoxChokingAlgorithm,
               m_comboBoxSeedChokingAlgorithm, m_comboBoxResumeDataStorage;
-    QLineEdit m_lineEditAnnounceIP, m_lineEditDHTBootstrapNodes;
+    QLineEdit m_pythonExecutablePath, m_lineEditAnnounceIP, m_lineEditDHTBootstrapNodes;
 
 #ifndef QBT_USES_LIBTORRENT2
     QSpinBox m_spinBoxCache, m_spinBoxCacheTTL;

src/gui/mainwindow.cpp

@@ -1635,11 +1635,11 @@ void MainWindow::on_actionRSSReader_triggered()
 
 void MainWindow::on_actionSearchWidget_triggered()
 {
-    if (!m_hasPython && m_ui->actionSearchWidget->isChecked())
+    if (m_ui->actionSearchWidget->isChecked())
     {
         const Utils::ForeignApps::PythonInfo pyInfo = Utils::ForeignApps::pythonInfo();
 
-        // Not installed
+        // Not found
         if (!pyInfo.isValid())
         {
             m_ui->actionSearchWidget->setChecked(false);
@@ -1679,7 +1679,6 @@ void MainWindow::on_actionSearchWidget_triggered()
             return;
         }
 
-        m_hasPython = true;
         m_ui->actionSearchWidget->setChecked(true);
         Preferences::instance()->setSearchEnabled(true);
     }

src/gui/mainwindow.h

@@ -233,7 +233,6 @@ private slots:
     // Power Management
     PowerManagement *m_pwr = nullptr;
     QTimer *m_preventTimer = nullptr;
-    bool m_hasPython = false;
     QMenu *m_toolbarMenu = nullptr;
 
     SettingValue<bool> m_storeExecutionLogEnabled;

src/webui/api/appcontroller.cpp

@@ -404,6 +404,8 @@ void AppController::preferencesAction()
     data[u"enable_embedded_tracker"_s] = session->isTrackerEnabled();
     data[u"embedded_tracker_port"_s] = pref->getTrackerPort();
     data[u"embedded_tracker_port_forwarding"_s] = pref->isTrackerPortForwardingEnabled();
+    // Python executable path
+    data[u"python_executable_path"_s] = pref->getPythonExecutablePath().toString();
     // Choking algorithm
     data[u"upload_slots_behavior"_s] = static_cast<int>(session->chokingAlgorithm());
     // Seed choking algorithm
@@ -990,6 +992,9 @@ void AppController::setPreferencesAction()
         pref->setTrackerPortForwardingEnabled(it.value().toBool());
     if (hasKey(u"enable_embedded_tracker"_s))
         session->setTrackerEnabled(it.value().toBool());
+    // Python executable path
+    if (hasKey(u"python_executable_path"_s))
+        pref->setPythonExecutablePath(Path(it.value().toString()));
     // Choking algorithm
     if (hasKey(u"upload_slots_behavior"_s))
         session->setChokingAlgorithm(static_cast<BitTorrent::ChokingAlgorithm>(it.value().toInt()));

src/webui/webapplication.h

@@ -52,7 +52,7 @@
 #include "base/utils/version.h"
 #include "api/isessionmanager.h"
 
-inline const Utils::Version<3, 2> API_VERSION {2, 9, 4};
+inline const Utils::Version<3, 2> API_VERSION {2, 9, 5};
 
 class APIController;
 class AuthController;

src/webui/www/private/views/preferences.html

@@ -1050,6 +1050,14 @@
                     <input type="checkbox" id="embeddedTrackerPortForwarding" />
                 </td>
             </tr>
+            <tr>
+                <td>
+                    <label for="pythonExecutablePath">QBT_TR(Python executable path (requires restart):)QBT_TR[CONTEXT=OptionsDialog]</label>
+                </td>
+                <td>
+                    <input type="text" id="pythonExecutablePath" placeholder="QBT_TR((Auto detect if empty))QBT_TR[CONTEXT=OptionsDialog]" style="width: 15em;" />
+                </td>
+            </tr>
         </table>
     </fieldset>
     <fieldset class="settings">
@@ -2238,6 +2246,7 @@
                         $('enableEmbeddedTracker').setProperty('checked', pref.enable_embedded_tracker);
                         $('embeddedTrackerPort').setProperty('value', pref.embedded_tracker_port);
                         $('embeddedTrackerPortForwarding').setProperty('checked', pref.embedded_tracker_port_forwarding);
+                        $('pythonExecutablePath').setProperty('value', pref.python_executable_path);
                         $('uploadSlotsBehavior').setProperty('value', pref.upload_slots_behavior);
                         $('uploadChokingAlgorithm').setProperty('value', pref.upload_choking_algorithm);
                         $('announceAllTrackers').setProperty('checked', pref.announce_to_all_trackers);
@@ -2671,6 +2680,7 @@
             settings.set('enable_embedded_tracker', $('enableEmbeddedTracker').getProperty('checked'));
             settings.set('embedded_tracker_port', $('embeddedTrackerPort').getProperty('value'));
             settings.set('embedded_tracker_port_forwarding', $('embeddedTrackerPortForwarding').getProperty('checked'));
+            settings.set('python_executable_path', $('pythonExecutablePath').getProperty('value'));
             settings.set('upload_slots_behavior', $('uploadSlotsBehavior').getProperty('value'));
             settings.set('upload_choking_algorithm', $('uploadChokingAlgorithm').getProperty('value'));
             settings.set('announce_to_all_trackers', $('announceAllTrackers').getProperty('checked'));