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** Copyright (C) 2016 The Qt Company Ltd.
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** 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
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#include "gerritparameters.h"
#include "gerritplugin.h"
#include "authenticationdialog.h"
#include "../gitplugin.h"
#include "../gitclient.h"
#include <coreplugin/shellcommand.h>

#include <utils/hostosinfo.h>
#include <utils/pathchooser.h>

#include <QDebug>
#include <QDir>
#include <QFileInfo>
#include <QJsonDocument>
#include <QRegularExpression>
#include <QSettings>
#include <QStandardPaths>

using namespace Utils;

namespace Gerrit {
namespace Internal {

static const char settingsGroupC[] = "Gerrit";
static const char hostKeyC[] = "Host";
static const char userKeyC[] = "User";
static const char portKeyC[] = "Port";
static const char portFlagKeyC[] = "PortFlag";
static const char sshKeyC[] = "Ssh";
static const char curlKeyC[] = "Curl";
static const char httpsKeyC[] = "Https";
static const char defaultHostC[] = "codereview.qt-project.org";
static const char savedQueriesKeyC[] = "SavedQueries";
static const char accountUrlC[] = "/accounts/self";

static const char defaultPortFlag[] = "-p";

enum { defaultPort = 29418 };

static inline QString detectApp(const char *defaultExe)
{
    const QString defaultApp = HostOsInfo::withExecutableSuffix(QLatin1String(defaultExe));
    QString app = QStandardPaths::findExecutable(defaultApp);
    if (!app.isEmpty() || !HostOsInfo::isWindowsHost())
        return app;
    // Windows: Use app.exe from git if it cannot be found.
    const FileName gitBinDir = GerritPlugin::gitBinDirectory();
    if (gitBinDir.isEmpty())
        return QString();
    FileName path = gitBinDir;
    path.appendPath(defaultApp);
    if (path.exists())
        return path.toString();

    // If app was not found, and git bin is Git/usr/bin (Git for Windows),
    // search also in Git/mingw{32,64}/bin
    if (!gitBinDir.endsWith("/usr/bin"))
        return QString();
    path = gitBinDir.parentDir().parentDir();
    QDir dir(path.toString());
    const QStringList entries = dir.entryList({"mingw*"});
    if (entries.isEmpty())
        return QString();
    path.appendPath(entries.first()).appendPath("bin").appendPath(defaultApp);
    if (path.exists())
        return path.toString();
    return QString();
}

static inline QString detectSsh()
{
    const QByteArray gitSsh = qgetenv("GIT_SSH");
    if (!gitSsh.isEmpty())
        return QString::fromLocal8Bit(gitSsh);
    return detectApp("ssh");
}

bool GerritUser::isSameAs(const GerritUser &other) const
{
    if (!userName.isEmpty() && !other.userName.isEmpty())
        return userName == other.userName;
    if (!fullName.isEmpty() && !other.fullName.isEmpty())
        return fullName == other.fullName;
    return false;
}

GerritServer::GerritServer()
    : host(defaultHostC)
    , port(defaultPort)
{
}

GerritServer::GerritServer(const QString &host, unsigned short port,
                           const QString &userName, HostType type)
    : host(host)
    , port(port)
    , type(type)
{
    user.userName = userName;
}

bool GerritServer::operator==(const GerritServer &other) const
{
    if (port && other.port && port != other.port)
        return false;
    return host == other.host && user.isSameAs(other.user) && type == other.type;
}

void GerritParameters::setPortFlagBySshType()
{
    bool isPlink = false;
    if (!ssh.isEmpty()) {
        const QString version = PathChooser::toolVersion(ssh, {"-V"});
        isPlink = version.contains("plink", Qt::CaseInsensitive);
    }
    portFlag = QLatin1String(isPlink ? "-P" : defaultPortFlag);
}

GerritParameters::GerritParameters()
    : https(true)
    , portFlag(defaultPortFlag)
{
}

QString GerritServer::hostArgument() const
{
    return user.userName.isEmpty() ? host : (user.userName + '@' + host);
}

QString GerritServer::url(bool withHttpUser) const
{
    QString protocol;
    switch (type) {
        case Ssh:   protocol = "ssh"; break;
        case Http:  protocol = "http"; break;
        case Https: protocol = "https"; break;
    }
    QString res = protocol + "://";
    if (type == Ssh || withHttpUser)
        res += hostArgument();
    else
        res += host;
    if (port)
        res += ':' + QString::number(port);
    if (type != Ssh)
        res += rootPath;
    return res;
}

QString GerritServer::restUrl() const
{
    QString res = url(true);
    if (type != Ssh && authenticated)
        res += "/a";
    return res;
}

bool GerritServer::fillFromRemote(const QString &remote, const GerritParameters &parameters)
{
    static const QRegularExpression remotePattern(
                "^(?:(?<protocol>[^:]+)://)?(?:(?<user>[^@]+)@)?(?<host>[^:/]+)"
                "(?::(?<port>\\d+))?:?(?<path>/.*)$");

    // Skip local remotes (refer to the root or relative path)
    if (remote.isEmpty() || remote.startsWith('/') || remote.startsWith('.'))
        return false;
    // On Windows, local paths typically starts with <drive>:
    if (HostOsInfo::isWindowsHost() && remote[1] == ':')
        return false;
    QRegularExpressionMatch match = remotePattern.match(remote);
    if (!match.hasMatch())
        return false;
    const QString protocol = match.captured("protocol");
    if (protocol == "https")
        type = GerritServer::Https;
    else if (protocol == "http")
        type = GerritServer::Http;
    else if (protocol.isEmpty() || protocol == "ssh")
        type = GerritServer::Ssh;
    else
        return false;
    const QString userName = match.captured("user");
    user.userName = userName.isEmpty() ? parameters.server.user.userName : userName;
    host = match.captured("host");
    port = match.captured("port").toUShort();
    if (host.contains("github.com")) // Clearly not gerrit
        return false;
    if (type != GerritServer::Ssh) {
        curlBinary = parameters.curl;
        if (curlBinary.isEmpty() || !QFile::exists(curlBinary))
            return false;
        rootPath = match.captured("path");
        // Strip the last part of the path, which is always the repo name
        // The rest of the path needs to be inspected to find the root path
        // (can be http://example.net/review)
        ascendPath();
        if (!resolveRoot())
            return false;
    }
    return true;
}

QStringList GerritServer::curlArguments()
{
    // -k - insecure - do not validate certificate
    // -f - fail silently on server error
    // -n - use credentials from ~/.netrc (or ~/_netrc on Windows)
    // -sS - silent, except server error (no progress)
    // --basic, --digest - try both authentication types
    return {"-kfnsS", "--basic", "--digest"};
}

int GerritServer::testConnection()
{
    static Git::Internal::GitClient *const client = Git::Internal::GitPlugin::client();
    const QStringList arguments = curlArguments() << (restUrl() + accountUrlC);
    const SynchronousProcessResponse resp = client->vcsFullySynchronousExec(
                QString(), FileName::fromString(curlBinary), arguments,
                Core::ShellCommand::NoOutput);
    if (resp.result == SynchronousProcessResponse::Finished) {
        QString output = resp.stdOut();
        output.remove(0, output.indexOf('\n')); // Strip first line
        QJsonDocument doc = QJsonDocument::fromJson(output.toUtf8());
        if (!doc.isNull())
            user.fullName = doc.object().value("name").toString();
        return 200;
    }
    const QRegularExpression errorRegexp("returned error: (\\d+)");
    QRegularExpressionMatch match = errorRegexp.match(resp.stdErr());
    if (match.hasMatch())
        return match.captured(1).toInt();
    return 400;
}

bool GerritServer::setupAuthentication()
{
    AuthenticationDialog dialog(this);
    if (!dialog.exec())
        return false;
    authenticated = dialog.isAuthenticated();
    return true;
}

bool GerritServer::ascendPath()
{
    const int lastSlash = rootPath.lastIndexOf('/');
    if (lastSlash == -1)
        return false;
    rootPath = rootPath.left(lastSlash);
    return true;
}

bool GerritServer::resolveRoot()
{
    for (;;) {
        switch (testConnection()) {
        case 200:
            return true;
        case 401:
            return setupAuthentication();
        case 404:
            if (!ascendPath())
                return false;
            break;
        default: // unknown error - fail
            return false;
        }
    }
    return false;
}

bool GerritParameters::equals(const GerritParameters &rhs) const
{
    return server == rhs.server && ssh == rhs.ssh && curl == rhs.curl && https == rhs.https;
}

void GerritParameters::toSettings(QSettings *s) const
{
    s->beginGroup(settingsGroupC);
    s->setValue(hostKeyC, server.host);
    s->setValue(userKeyC, server.user.userName);
    s->setValue(portKeyC, server.port);
    s->setValue(portFlagKeyC, portFlag);
    s->setValue(sshKeyC, ssh);
    s->setValue(curlKeyC, curl);
    s->setValue(httpsKeyC, https);
    s->endGroup();
}

void GerritParameters::saveQueries(QSettings *s) const
{
    s->beginGroup(settingsGroupC);
    s->setValue(savedQueriesKeyC, savedQueries.join(','));
    s->endGroup();
}

void GerritParameters::fromSettings(const QSettings *s)
{
    const QString rootKey = QLatin1String(settingsGroupC) + '/';
    server.host = s->value(rootKey + hostKeyC, defaultHostC).toString();
    server.user.userName = s->value(rootKey + userKeyC, QString()).toString();
    ssh = s->value(rootKey + sshKeyC, QString()).toString();
    curl = s->value(rootKey + curlKeyC).toString();
    server.port = s->value(rootKey + portKeyC, QVariant(int(defaultPort))).toInt();
    portFlag = s->value(rootKey + portFlagKeyC, defaultPortFlag).toString();
    savedQueries = s->value(rootKey + savedQueriesKeyC, QString()).toString()
            .split(',');
    https = s->value(rootKey + httpsKeyC, QVariant(true)).toBool();
    if (ssh.isEmpty() || !QFile::exists(ssh))
        ssh = detectSsh();
    if (curl.isEmpty() || !QFile::exists(curl))
        curl = detectApp("curl");
}

bool GerritParameters::isValid() const
{
    return !server.host.isEmpty() && !server.user.userName.isEmpty() && !ssh.isEmpty();
}

} // namespace Internal
} // namespace Gerrit