/*
 * Copyright (C) 2012-2016 Canonical, Ltd.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 3.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#pragma once

// Qt
#include <QtCore/QCoreApplication>
#include <QtCore/QDir>
#include <QtGui/QIcon>
#include <QtQml/QQmlEngine>
#include <QStandardPaths>

inline QString installRoot() {
    static QString installRoot;
    static bool installRootSet = false;
    if (!installRootSet) {
        QString snapRoot = QFile::decodeName(qgetenv("SNAP"));
        if (!snapRoot.isEmpty() && QCoreApplication::applicationDirPath() ==
                   QDir(snapRoot + QStringLiteral("@CMAKE_INSTALL_PREFIX@/@CMAKE_INSTALL_BINDIR@")).canonicalPath()) {
            installRoot = snapRoot;
        } else if (QCoreApplication::applicationDirPath() ==
                   QDir(QStringLiteral("@CMAKE_INSTALL_PREFIX@/@CMAKE_INSTALL_BINDIR@")).canonicalPath()) {
            installRoot = QStringLiteral("");
        }
        installRootSet = true;
    }
    return installRoot;
}

inline bool isRunningInstalled() {
    return !installRoot().isNull();
}

inline QString buildDirectory() {
    if (!qEnvironmentVariableIsEmpty("UNITY_BINARY_DIR")) return qgetenv("UNITY_BINARY_DIR");
    return QStringLiteral("@CMAKE_BINARY_DIR@");
}

inline QString sourceDirectory() {
    if (!qEnvironmentVariableIsEmpty("UNITY_SOURCE_DIR")) return qgetenv("UNITY_SOURCE_DIR");
    return QStringLiteral("@CMAKE_SOURCE_DIR@");
}

inline QString translationDirectory() {
    if (isRunningInstalled()) {
        return installRoot() + QStringLiteral("@CMAKE_INSTALL_PREFIX@/share/locale");
    } else {
        return buildDirectory() + QStringLiteral("/po/locale");
    }
}

inline QString qmlDirectory() {
    if (isRunningInstalled()) {
        return installRoot() + QStringLiteral("@CMAKE_INSTALL_PREFIX@/@SHELL_APP_DIR@/");
    } else {
        return sourceDirectory() + QStringLiteral("/qml");
    }
}

inline QStringList overrideImportPaths() {
    QStringList paths;
    if (!isRunningInstalled()) {
        paths << buildDirectory() + QStringLiteral("/plugins");
    }
    return paths;
}

inline QStringList nonMirImportPaths() {
    QStringList paths;
    if (isRunningInstalled()) {
        paths << installRoot() + QStringLiteral("@CMAKE_INSTALL_PREFIX@/@SHELL_INSTALL_QML@/nonmirplugins");
    } else {
        paths << buildDirectory() + QStringLiteral("/nonmirplugins");
    }
    return paths;
}

inline QStringList fallbackImportPaths() {
    QStringList paths;
    if (isRunningInstalled()) {
        paths << installRoot() + QStringLiteral("@CMAKE_INSTALL_PREFIX@/@SHELL_INSTALL_QML@");
        paths << installRoot() + QStringLiteral("@USS_PRIVATE_PLUGINDIR@");
        paths << installRoot() + QStringLiteral("@SHELL_PLUGINDIR@");
        paths << installRoot() + QStringLiteral("@CMAKE_INSTALL_PREFIX@/@SHELL_INSTALL_QML@/mocks");
    } else {
        paths << QStringLiteral("@USS_PRIVATE_PLUGINDIR@");
        paths << QStringLiteral("@SHELL_PLUGINDIR@");
        paths << buildDirectory() + QStringLiteral("/tests/mocks");
    }
    return paths;
}

inline QString mockPluginsDir() {
    if (isRunningInstalled()) {
        return installRoot() + QStringLiteral("@CMAKE_INSTALL_PREFIX@/@SHELL_INSTALL_QML@/mocks");
    } else {
        return buildDirectory() + QStringLiteral("/tests/mocks");
    }
}

inline QStringList shellDataDirs() {
    QStringList dirs = QStandardPaths::standardLocations(QStandardPaths::GenericDataLocation);
    if (isRunningInstalled()) {
        // append so by default we use xdg files.
        dirs.append(qmlDirectory());
    }
    return dirs;
}

inline void prependImportPaths(QQmlEngine *engine, const QStringList &paths)
{
    QStringList importPathList = engine->importPathList();
    for (int i = paths.count() -1; i >= 0; i--) {
        // don't duplicate
        const QString& path = paths[i];
        QStringList::iterator iter = qFind(importPathList.begin(), importPathList.end(), path);
        if (iter == importPathList.end()) {
            engine->addImportPath(path);
        }
    }
}

/* When you append and import path to the list of import paths it will be the *last*
   place where Qt will search for QML modules.
   The usual QQmlEngine::addImportPath() actually prepends the given path.*/
inline void appendImportPaths(QQmlEngine *engine, const QStringList &paths)
{
    QStringList importPathList = engine->importPathList();
    Q_FOREACH(const QString& path, paths) {
        // don't duplicate
        QStringList::iterator iter = qFind(importPathList.begin(), importPathList.end(), path);
        if (iter == importPathList.end()) {
            importPathList.append(path);
        }
    }
    engine->setImportPathList(importPathList);
}