Python: move language client functionality out of utils

There will be more lsp specific functionality so moving it into its own
space is reasonable.

Change-Id: Ic87d437182d68673b53f662c804707138fef5b6c
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

1 files changed, 451 insertions, 0 deletions

diff --git a/src/plugins/python/pythonlanguageclient.cpp b/src/plugins/python/pythonlanguageclient.cpp
new file mode 100644
index 0000000000..a0292f6797
--- /dev/null
+++ b/src/plugins/python/pythonlanguageclient.cpp
@@ -0,0 +1,451 @@
+/****************************************************************************
+**
+** Copyright (C) 2021 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of Qt Creator.
+**
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 as published by the Free Software
+** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+****************************************************************************/
+
+#include "pythonlanguageclient.h"
+
+#include "pythonconstants.h"
+#include "pythonplugin.h"
+#include "pythonutils.h"
+
+#include <coreplugin/editormanager/editormanager.h>
+#include <coreplugin/progressmanager/progressmanager.h>
+
+#include <languageclient/languageclientmanager.h>
+
+#include <texteditor/textdocument.h>
+
+#include <utils/infobar.h>
+#include <utils/qtcprocess.h>
+#include <utils/runextensions.h>
+
+#include <QFutureWatcher>
+#include <QRegularExpression>
+#include <QTimer>
+
+using namespace LanguageClient;
+using namespace Utils;
+
+namespace Python {
+namespace Internal {
+
+static constexpr char startPylsInfoBarId[] = "Python::StartPyls";
+static constexpr char installPylsInfoBarId[] = "Python::InstallPyls";
+static constexpr char enablePylsInfoBarId[] = "Python::EnablePyls";
+static constexpr char installPylsTaskId[] = "Python::InstallPylsTask";
+
+struct PythonLanguageServerState
+{
+    enum {
+        CanNotBeInstalled,
+        CanBeInstalled,
+        AlreadyInstalled,
+        AlreadyConfigured,
+        ConfiguredButDisabled
+    } state;
+    FilePath pylsModulePath;
+};
+
+static QString pythonName(const FilePath &pythonPath)
+{
+    static QHash<FilePath, QString> nameForPython;
+    if (!pythonPath.exists())
+        return {};
+    QString name = nameForPython.value(pythonPath);
+    if (name.isEmpty()) {
+        QtcProcess pythonProcess;
+        pythonProcess.setTimeoutS(2);
+        pythonProcess.setCommand({pythonPath, {"--version"}});
+        pythonProcess.runBlocking();
+        if (pythonProcess.result() != QtcProcess::FinishedWithSuccess)
+            return {};
+        name = pythonProcess.allOutput().trimmed();
+        nameForPython[pythonPath] = name;
+    }
+    return name;
+}
+
+FilePath getPylsModulePath(CommandLine pylsCommand)
+{
+    static QMutex mutex; // protect the access to the cache
+    QMutexLocker locker(&mutex);
+    static QMap<FilePath, FilePath> cache;
+    const FilePath &modulePath = cache.value(pylsCommand.executable());
+    if (!modulePath.isEmpty())
+        return modulePath;
+
+    pylsCommand.addArg("-h");
+
+    QtcProcess pythonProcess;
+    Environment env = pythonProcess.environment();
+    env.set("PYTHONVERBOSE", "x");
+    pythonProcess.setEnvironment(env);
+    pythonProcess.setCommand(pylsCommand);
+    pythonProcess.runBlocking();
+
+    static const QString pylsInitPattern = "(.*)"
+                                           + QRegularExpression::escape(
+                                               QDir::toNativeSeparators("/pylsp/__init__.py"))
+                                           + '$';
+    static const QRegularExpression regexCached(" matches " + pylsInitPattern,
+                                                QRegularExpression::MultilineOption);
+    static const QRegularExpression regexNotCached(" code object from " + pylsInitPattern,
+                                                   QRegularExpression::MultilineOption);
+
+    const QString output = pythonProcess.allOutput();
+    for (const auto &regex : {regexCached, regexNotCached}) {
+        const QRegularExpressionMatch result = regex.match(output);
+        if (result.hasMatch()) {
+            const FilePath &modulePath = FilePath::fromUserInput(result.captured(1));
+            cache[pylsCommand.executable()] = modulePath;
+            return modulePath;
+        }
+    }
+    return {};
+}
+
+QList<const StdIOSettings *> configuredPythonLanguageServer()
+{
+    using namespace LanguageClient;
+    QList<const StdIOSettings *> result;
+    for (const BaseSettings *setting : LanguageClientManager::currentSettings()) {
+        if (setting->m_languageFilter.isSupported("foo.py", Constants::C_PY_MIMETYPE))
+            result << dynamic_cast<const StdIOSettings *>(setting);
+    }
+    return result;
+}
+
+static PythonLanguageServerState checkPythonLanguageServer(const FilePath &python)
+{
+    using namespace LanguageClient;
+    const CommandLine pythonLShelpCommand(python, {"-m", "pylsp", "-h"});
+    const FilePath &modulePath = getPylsModulePath(pythonLShelpCommand);
+    for (const StdIOSettings *serverSetting : configuredPythonLanguageServer()) {
+        if (modulePath == getPylsModulePath(serverSetting->command())) {
+            return {serverSetting->m_enabled ? PythonLanguageServerState::AlreadyConfigured
+                                             : PythonLanguageServerState::ConfiguredButDisabled,
+                    FilePath()};
+        }
+    }
+
+    QtcProcess pythonProcess;
+    pythonProcess.setCommand(pythonLShelpCommand);
+    pythonProcess.runBlocking();
+    if (pythonProcess.allOutput().contains("Python Language Server"))
+        return {PythonLanguageServerState::AlreadyInstalled, modulePath};
+
+    pythonProcess.setCommand({python, {"-m", "pip", "-V"}});
+    pythonProcess.runBlocking();
+    if (pythonProcess.allOutput().startsWith("pip "))
+        return {PythonLanguageServerState::CanBeInstalled, FilePath()};
+    else
+        return {PythonLanguageServerState::CanNotBeInstalled, FilePath()};
+}
+
+PyLSConfigureAssistant *PyLSConfigureAssistant::instance()
+{
+    static auto *instance = new PyLSConfigureAssistant(PythonPlugin::instance());
+    return instance;
+}
+
+const StdIOSettings *PyLSConfigureAssistant::languageServerForPython(const FilePath &python)
+{
+    return findOrDefault(configuredPythonLanguageServer(),
+                         [pythonModulePath = getPylsModulePath(
+                              CommandLine(python, {"-m", "pylsp"}))](const StdIOSettings *setting) {
+                             return getPylsModulePath(setting->command()) == pythonModulePath;
+                         });
+}
+
+static Client *registerLanguageServer(const FilePath &python)
+{
+    auto *settings = new StdIOSettings();
+    settings->m_executable = python;
+    settings->m_arguments = "-m pylsp";
+    settings->m_name = PyLSConfigureAssistant::tr("Python Language Server (%1)")
+                           .arg(pythonName(python));
+    settings->m_languageFilter.mimeTypes = QStringList(Constants::C_PY_MIMETYPE);
+    LanguageClientManager::registerClientSettings(settings);
+    Client *client = LanguageClientManager::clientForSetting(settings).value(0);
+    PyLSConfigureAssistant::updateEditorInfoBars(python, client);
+    return client;
+}
+
+class PythonLSInstallHelper : public QObject
+{
+    Q_OBJECT
+public:
+    PythonLSInstallHelper(const FilePath &python, QPointer<TextEditor::TextDocument> document)
+        : m_python(python)
+        , m_document(document)
+    {
+        m_watcher.setFuture(m_future.future());
+    }
+
+    void run()
+    {
+        Core::ProgressManager::addTask(m_future.future(), "Install PyLS", installPylsTaskId);
+        connect(&m_process, &QtcProcess::finished, this, &PythonLSInstallHelper::installFinished);
+        connect(&m_process,
+                &QtcProcess::readyReadStandardError,
+                this,
+                &PythonLSInstallHelper::errorAvailable);
+        connect(&m_process,
+                &QtcProcess::readyReadStandardOutput,
+                this,
+                &PythonLSInstallHelper::outputAvailable);
+
+        connect(&m_killTimer, &QTimer::timeout, this, &PythonLSInstallHelper::cancel);
+        connect(&m_watcher, &QFutureWatcher<void>::canceled, this, &PythonLSInstallHelper::cancel);
+
+        QStringList arguments = {"-m", "pip", "install", "python-lsp-server[all]"};
+
+        // add --user to global pythons, but skip it for venv pythons
+        if (!QDir(m_python.parentDir().toString()).exists("activate"))
+            arguments << "--user";
+
+        m_process.setCommand({m_python, arguments});
+        m_process.start();
+
+        Core::MessageManager::writeDisrupting(
+            tr("Running \"%1\" to install Python language server.")
+                .arg(m_process.commandLine().toUserOutput()));
+
+        m_killTimer.setSingleShot(true);
+        m_killTimer.start(5 /*minutes*/ * 60 * 1000);
+    }
+
+private:
+    void cancel()
+    {
+        m_process.stopProcess();
+        Core::MessageManager::writeFlashing(
+            tr("The Python language server installation was canceled by %1.")
+                .arg(m_killTimer.isActive() ? tr("user") : tr("time out")));
+    }
+
+    void installFinished()
+    {
+        m_future.reportFinished();
+        if (m_process.result() == QtcProcess::FinishedWithSuccess) {
+            if (Client *client = registerLanguageServer(m_python))
+                LanguageClientManager::openDocumentWithClient(m_document, client);
+        } else {
+            Core::MessageManager::writeFlashing(
+                tr("Installing the Python language server failed with exit code %1")
+                    .arg(m_process.exitCode()));
+        }
+        deleteLater();
+    }
+
+    void outputAvailable()
+    {
+        const QString &stdOut = QString::fromLocal8Bit(m_process.readAllStandardOutput().trimmed());
+        if (!stdOut.isEmpty())
+            Core::MessageManager::writeSilently(stdOut);
+    }
+
+    void errorAvailable()
+    {
+        const QString &stdErr = QString::fromLocal8Bit(m_process.readAllStandardError().trimmed());
+        if (!stdErr.isEmpty())
+            Core::MessageManager::writeSilently(stdErr);
+    }
+
+    QFutureInterface<void> m_future;
+    QFutureWatcher<void> m_watcher;
+    QtcProcess m_process;
+    QTimer m_killTimer;
+    const FilePath m_python;
+    QPointer<TextEditor::TextDocument> m_document;
+};
+
+void PyLSConfigureAssistant::installPythonLanguageServer(const FilePath &python,
+                                                         QPointer<TextEditor::TextDocument> document)
+{
+    document->infoBar()->removeInfo(installPylsInfoBarId);
+
+    // Hide all install info bar entries for this python, but keep them in the list
+    // so the language server will be setup properly after the installation is done.
+    for (TextEditor::TextDocument *additionalDocument : m_infoBarEntries[python])
+        additionalDocument->infoBar()->removeInfo(installPylsInfoBarId);
+
+    auto install = new PythonLSInstallHelper(python, document);
+    install->run();
+}
+
+static void setupPythonLanguageServer(const FilePath &python,
+                                      QPointer<TextEditor::TextDocument> document)
+{
+    document->infoBar()->removeInfo(startPylsInfoBarId);
+    if (Client *client = registerLanguageServer(python))
+        LanguageClientManager::openDocumentWithClient(document, client);
+}
+
+static void enablePythonLanguageServer(const FilePath &python,
+                                       QPointer<TextEditor::TextDocument> document)
+{
+    document->infoBar()->removeInfo(enablePylsInfoBarId);
+    if (const StdIOSettings *setting = PyLSConfigureAssistant::languageServerForPython(python)) {
+        LanguageClientManager::enableClientSettings(setting->m_id);
+        if (const StdIOSettings *setting = PyLSConfigureAssistant::languageServerForPython(python)) {
+            if (Client *client = LanguageClientManager::clientForSetting(setting).value(0)) {
+                LanguageClientManager::openDocumentWithClient(document, client);
+                PyLSConfigureAssistant::updateEditorInfoBars(python, client);
+            }
+        }
+    }
+}
+
+void PyLSConfigureAssistant::documentOpened(Core::IDocument *document)
+{
+    auto textDocument = qobject_cast<TextEditor::TextDocument *>(document);
+    if (!textDocument || textDocument->mimeType() != Constants::C_PY_MIMETYPE)
+        return;
+
+    const FilePath &python = detectPython(textDocument->filePath());
+    if (!python.exists())
+        return;
+
+    instance()->openDocumentWithPython(python, textDocument);
+}
+
+void PyLSConfigureAssistant::openDocumentWithPython(const FilePath &python,
+                                                    TextEditor::TextDocument *document)
+{
+    using CheckPylsWatcher = QFutureWatcher<PythonLanguageServerState>;
+
+    QPointer<CheckPylsWatcher> watcher = new CheckPylsWatcher();
+
+    // cancel and delete watcher after a 10 second timeout
+    QTimer::singleShot(10000, this, [watcher]() {
+        if (watcher) {
+            watcher->cancel();
+            watcher->deleteLater();
+        }
+    });
+
+    connect(watcher,
+            &CheckPylsWatcher::resultReadyAt,
+            this,
+            [=, document = QPointer<TextEditor::TextDocument>(document)]() {
+                if (!document || !watcher)
+                    return;
+                handlePyLSState(python, watcher->result(), document);
+                watcher->deleteLater();
+            });
+    watcher->setFuture(Utils::runAsync(&checkPythonLanguageServer, python));
+}
+
+void PyLSConfigureAssistant::handlePyLSState(const FilePath &python,
+                                             const PythonLanguageServerState &state,
+                                             TextEditor::TextDocument *document)
+{
+    if (state.state == PythonLanguageServerState::CanNotBeInstalled)
+        return;
+    if (state.state == PythonLanguageServerState::AlreadyConfigured) {
+        if (const StdIOSettings *setting = languageServerForPython(python)) {
+            if (Client *client = LanguageClientManager::clientForSetting(setting).value(0))
+                LanguageClientManager::openDocumentWithClient(document, client);
+        }
+        return;
+    }
+
+    resetEditorInfoBar(document);
+    Utils::InfoBar *infoBar = document->infoBar();
+    if (state.state == PythonLanguageServerState::CanBeInstalled
+        && infoBar->canInfoBeAdded(installPylsInfoBarId)) {
+        auto message = tr("Install and set up Python language server (PyLS) for %1 (%2). "
+                          "The language server provides Python specific completion and annotation.")
+                           .arg(pythonName(python), python.toUserOutput());
+        Utils::InfoBarEntry info(installPylsInfoBarId,
+                                 message,
+                                 Utils::InfoBarEntry::GlobalSuppression::Enabled);
+        info.setCustomButtonInfo(tr("Install"),
+                                 [=]() { installPythonLanguageServer(python, document); });
+        infoBar->addInfo(info);
+        m_infoBarEntries[python] << document;
+    } else if (state.state == PythonLanguageServerState::AlreadyInstalled
+               && infoBar->canInfoBeAdded(startPylsInfoBarId)) {
+        auto message = tr("Found a Python language server for %1 (%2). "
+                          "Set it up for this document?")
+                           .arg(pythonName(python), python.toUserOutput());
+        Utils::InfoBarEntry info(startPylsInfoBarId,
+                                 message,
+                                 Utils::InfoBarEntry::GlobalSuppression::Enabled);
+        info.setCustomButtonInfo(tr("Set Up"),
+                                 [=]() { setupPythonLanguageServer(python, document); });
+        infoBar->addInfo(info);
+        m_infoBarEntries[python] << document;
+    } else if (state.state == PythonLanguageServerState::ConfiguredButDisabled
+               && infoBar->canInfoBeAdded(enablePylsInfoBarId)) {
+        auto message = tr("Enable Python language server for %1 (%2)?")
+                           .arg(pythonName(python), python.toUserOutput());
+        Utils::InfoBarEntry info(enablePylsInfoBarId,
+                                 message,
+                                 Utils::InfoBarEntry::GlobalSuppression::Enabled);
+        info.setCustomButtonInfo(tr("Enable"),
+                                 [=]() { enablePythonLanguageServer(python, document); });
+        infoBar->addInfo(info);
+        m_infoBarEntries[python] << document;
+    }
+}
+
+void PyLSConfigureAssistant::updateEditorInfoBars(const FilePath &python, Client *client)
+{
+    for (TextEditor::TextDocument *document : instance()->m_infoBarEntries.take(python)) {
+        instance()->resetEditorInfoBar(document);
+        if (client)
+            LanguageClientManager::openDocumentWithClient(document, client);
+    }
+}
+
+void PyLSConfigureAssistant::resetEditorInfoBar(TextEditor::TextDocument *document)
+{
+    for (QList<TextEditor::TextDocument *> &documents : m_infoBarEntries)
+        documents.removeAll(document);
+    Utils::InfoBar *infoBar = document->infoBar();
+    infoBar->removeInfo(installPylsInfoBarId);
+    infoBar->removeInfo(startPylsInfoBarId);
+    infoBar->removeInfo(enablePylsInfoBarId);
+}
+
+PyLSConfigureAssistant::PyLSConfigureAssistant(QObject *parent)
+    : QObject(parent)
+{
+    Core::EditorManager::instance();
+
+    connect(Core::EditorManager::instance(),
+            &Core::EditorManager::documentClosed,
+            this,
+            [this](Core::IDocument *document) {
+                if (auto textDocument = qobject_cast<TextEditor::TextDocument *>(document))
+                    resetEditorInfoBar(textDocument);
+            });
+}
+
+} // namespace Internal
+} // namespace Python
+
+#include "pythonlanguageclient.moc"