// SPDX-License-Identifier: GPL-3.0-only
/*
 *  PolyMC - Minecraft Launcher
 *  Copyright (C) 2022 Sefa Eyeoglu <contact@scrumplex.net>
 *
 *  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 <https://www.gnu.org/licenses/>.
 *
 * This file incorporates work covered by the following copyright and
 * permission notice:
 *
 *      Copyright 2013-2021 MultiMC Contributors
 *
 *      Licensed under the Apache License, Version 2.0 (the "License");
 *      you may not use this file except in compliance with the License.
 *      You may obtain a copy of the License at
 *
 *          http://www.apache.org/licenses/LICENSE-2.0
 *
 *      Unless required by applicable law or agreed to in writing, software
 *      distributed under the License is distributed on an "AS IS" BASIS,
 *      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *      See the License for the specific language governing permissions and
 *      limitations under the License.
 */

#include "FileSystem.h"

#include <QDebug>
#include <QDir>
#include <QDirIterator>
#include <QFile>
#include <QFileInfo>
#include <QSaveFile>
#include <QStandardPaths>
#include <QTextStream>
#include <QUrl>
#include "DesktopServices.h"

#if defined Q_OS_WIN32
#include <objbase.h>
#include <objidl.h>
#include <shlguid.h>
#include <shlobj.h>
#include <shobjidl.h>
#include <sys/utime.h>
#include <windows.h>
#include <winnls.h>
#include <string>
#else
#include <utime.h>
#endif

// Snippet from https://github.com/gulrak/filesystem#using-it-as-single-file-header

#ifdef __APPLE__
#include <Availability.h> // for deployment target to support pre-catalina targets without std::fs
#endif // __APPLE__

#if ((defined(_MSVC_LANG) && _MSVC_LANG >= 201703L) || (defined(__cplusplus) && __cplusplus >= 201703L)) && defined(__has_include)
#if __has_include(<filesystem>) && (!defined(__MAC_OS_X_VERSION_MIN_REQUIRED) || __MAC_OS_X_VERSION_MIN_REQUIRED >= 101500)
#define GHC_USE_STD_FS
#include <filesystem>
namespace fs = std::filesystem;
#endif // MacOS min version check
#endif // Other OSes version check

#ifndef GHC_USE_STD_FS
#include <ghc/filesystem.hpp>
namespace fs = ghc::filesystem;
#endif

#if defined Q_OS_WIN32

std::wstring toStdString(QString s)
{
    return s.toStdWString();
}

#else

std::string toStdString(QString s)
{
    return s.toStdString();
}

#endif

namespace FS {

void ensureExists(const QDir& dir)
{
    if (!QDir().mkpath(dir.absolutePath())) {
        throw FileSystemException("Unable to create folder " + dir.dirName() + " (" + dir.absolutePath() + ")");
    }
}

void write(const QString& filename, const QByteArray& data)
{
    ensureExists(QFileInfo(filename).dir());
    QSaveFile file(filename);
    if (!file.open(QSaveFile::WriteOnly)) {
        throw FileSystemException("Couldn't open " + filename + " for writing: " + file.errorString());
    }
    if (data.size() != file.write(data)) {
        throw FileSystemException("Error writing data to " + filename + ": " + file.errorString());
    }
    if (!file.commit()) {
        throw FileSystemException("Error while committing data to " + filename + ": " + file.errorString());
    }
}

QByteArray read(const QString& filename)
{
    QFile file(filename);
    if (!file.open(QFile::ReadOnly)) {
        throw FileSystemException("Unable to open " + filename + " for reading: " + file.errorString());
    }
    const qint64 size = file.size();
    QByteArray data(int(size), 0);
    const qint64 ret = file.read(data.data(), size);
    if (ret == -1 || ret != size) {
        throw FileSystemException("Error reading data from " + filename + ": " + file.errorString());
    }
    return data;
}

bool updateTimestamp(const QString& filename)
{
#ifdef Q_OS_WIN32
    std::wstring filename_utf_16 = filename.toStdWString();
    return (_wutime64(filename_utf_16.c_str(), nullptr) == 0);
#else
    QByteArray filenameBA = QFile::encodeName(filename);
    return (utime(filenameBA.data(), nullptr) == 0);
#endif
}

bool ensureFilePathExists(QString filenamepath)
{
    QFileInfo a(filenamepath);
    QDir dir;
    QString ensuredPath = a.path();
    bool success = dir.mkpath(ensuredPath);
    return success;
}

bool ensureFolderPathExists(QString foldernamepath)
{
    QFileInfo a(foldernamepath);
    QDir dir;
    QString ensuredPath = a.filePath();
    bool success = dir.mkpath(ensuredPath);
    return success;
}

/// @brief Copies a directory and it's contents from src to dest
/// @param offset subdirectory form src to copy to dest
/// @return if there was an error during the filecopy
bool copy::operator()(const QString& offset)
{
    using copy_opts = fs::copy_options;

// NOTE always deep copy on windows. the alternatives are too messy.
#if defined Q_OS_WIN32
    m_followSymlinks = true;
#endif

    auto src = PathCombine(m_src.absolutePath(), offset);
    auto dst = PathCombine(m_dst.absolutePath(), offset);

    std::error_code err;

    fs::copy_options opt = copy_opts::none;

    // The default behavior is to follow symlinks
    if (!m_followSymlinks)
        opt |= copy_opts::copy_symlinks;

    // Function that'll do the actual copying
    auto copy_file = [&](QString src_path, QString relative_dst_path) {
        if (m_blacklist && m_blacklist->matches(relative_dst_path))
            return;

        auto dst_path = PathCombine(dst, relative_dst_path);
        ensureFilePathExists(dst_path);

        fs::copy(toStdString(src_path), toStdString(dst_path), opt, err);
        if (err) {
            qWarning() << "Failed to copy files:" << QString::fromStdString(err.message());
            qDebug() << "Source file:" << src_path;
            qDebug() << "Destination file:" << dst_path;
        }
    };

    // We can't use copy_opts::recursive because we need to take into account the
    // blacklisted paths, so we iterate over the source directory, and if there's no blacklist
    // match, we copy the file.
    QDir src_dir(src);
    QDirIterator source_it(src, QDir::Filter::Files | QDir::Filter::Hidden, QDirIterator::Subdirectories);

    while (source_it.hasNext()) {
        auto src_path = source_it.next();
        auto relative_path = src_dir.relativeFilePath(src_path);

        copy_file(src_path, relative_path);
    }

    // If the root src is not a directory, the previous iterator won't run.
    if (!fs::is_directory(toStdString(src)))
        copy_file(src, "");

    return err.value() == 0;
}

bool deletePath(QString path)
{
    std::error_code err;

    fs::remove_all(toStdString(path), err);

    if (err) {
        qWarning() << "Failed to remove files:" << QString::fromStdString(err.message());
    }

    return err.value() == 0;
}

bool trash(QString path, QString *pathInTrash = nullptr)
{
#if QT_VERSION < QT_VERSION_CHECK(5, 15, 0)
    return false;
#else
    // FIXME: Figure out trash in Flatpak. Qt seemingly doesn't use the Trash portal
    if (DesktopServices::isFlatpak())
        return false;
    return QFile::moveToTrash(path, pathInTrash);
#endif
}

QString PathCombine(const QString& path1, const QString& path2)
{
    if (!path1.size())
        return path2;
    if (!path2.size())
        return path1;
    return QDir::cleanPath(path1 + QDir::separator() + path2);
}

QString PathCombine(const QString& path1, const QString& path2, const QString& path3)
{
    return PathCombine(PathCombine(path1, path2), path3);
}

QString PathCombine(const QString& path1, const QString& path2, const QString& path3, const QString& path4)
{
    return PathCombine(PathCombine(path1, path2, path3), path4);
}

QString AbsolutePath(QString path)
{
    return QFileInfo(path).absolutePath();
}

QString ResolveExecutable(QString path)
{
    if (path.isEmpty()) {
        return QString();
    }
    if (!path.contains('/')) {
        path = QStandardPaths::findExecutable(path);
    }
    QFileInfo pathInfo(path);
    if (!pathInfo.exists() || !pathInfo.isExecutable()) {
        return QString();
    }
    return pathInfo.absoluteFilePath();
}

/**
 * Normalize path
 *
 * Any paths inside the current folder will be normalized to relative paths (to current)
 * Other paths will be made absolute
 */
QString NormalizePath(QString path)
{
    QDir a = QDir::currentPath();
    QString currentAbsolute = a.absolutePath();

    QDir b(path);
    QString newAbsolute = b.absolutePath();

    if (newAbsolute.startsWith(currentAbsolute)) {
        return a.relativeFilePath(newAbsolute);
    } else {
        return newAbsolute;
    }
}

QString badFilenameChars = "\"\\/?<>:;*|!+\r\n";

QString RemoveInvalidFilenameChars(QString string, QChar replaceWith)
{
    for (int i = 0; i < string.length(); i++) {
        if (badFilenameChars.contains(string[i])) {
            string[i] = replaceWith;
        }
    }
    return string;
}

QString DirNameFromString(QString string, QString inDir)
{
    int num = 0;
    QString baseName = RemoveInvalidFilenameChars(string, '-');
    QString dirName;
    do {
        if (num == 0) {
            dirName = baseName;
        } else {
            dirName = baseName + "(" + QString::number(num) + ")";
        }

        // If it's over 9000
        if (num > 9000)
            return "";
        num++;
    } while (QFileInfo(PathCombine(inDir, dirName)).exists());
    return dirName;
}

// Does the folder path contain any '!'? If yes, return true, otherwise false.
// (This is a problem for Java)
bool checkProblemticPathJava(QDir folder)
{
    QString pathfoldername = folder.absolutePath();
    return pathfoldername.contains("!", Qt::CaseInsensitive);
}

QString getDesktopDir()
{
    return QStandardPaths::writableLocation(QStandardPaths::DesktopLocation);
}

// Cross-platform Shortcut creation
bool createShortCut(QString location, QString dest, QStringList args, QString name, QString icon)
{
#if defined(Q_OS_LINUX) || defined(Q_OS_FREEBSD)
    location = PathCombine(location, name + ".desktop");

    QFile f(location);
    f.open(QIODevice::WriteOnly | QIODevice::Text);
    QTextStream stream(&f);

    QString argstring;
    if (!args.empty())
        argstring = " '" + args.join("' '") + "'";

    stream << "[Desktop Entry]"
           << "\n";
    stream << "Type=Application"
           << "\n";
    stream << "TryExec=" << dest.toLocal8Bit() << "\n";
    stream << "Exec=" << dest.toLocal8Bit() << argstring.toLocal8Bit() << "\n";
    stream << "Name=" << name.toLocal8Bit() << "\n";
    stream << "Icon=" << icon.toLocal8Bit() << "\n";

    stream.flush();
    f.close();

    f.setPermissions(f.permissions() | QFileDevice::ExeOwner | QFileDevice::ExeGroup | QFileDevice::ExeOther);

    return true;
#elif defined Q_OS_WIN
    // TODO: Fix
    //    QFile file(PathCombine(location, name + ".lnk"));
    //    WCHAR *file_w;
    //    WCHAR *dest_w;
    //    WCHAR *args_w;
    //    file.fileName().toWCharArray(file_w);
    //    dest.toWCharArray(dest_w);

    //    QString argStr;
    //    for (int i = 0; i < args.count(); i++)
    //    {
    //        argStr.append(args[i]);
    //        argStr.append(" ");
    //    }
    //    argStr.toWCharArray(args_w);

    //    return SUCCEEDED(CreateLink(file_w, dest_w, args_w));
    return false;
#else
    qWarning("Desktop Shortcuts not supported on your platform!");
    return false;
#endif
}

bool overrideFolder(QString overwritten_path, QString override_path)
{
    using copy_opts = fs::copy_options;

    if (!FS::ensureFolderPathExists(overwritten_path))
        return false;

    std::error_code err;
    fs::copy_options opt = copy_opts::recursive | copy_opts::overwrite_existing;

    // FIXME: hello traveller! Apparently std::copy does NOT overwrite existing files on GNU libstdc++ on Windows?
    fs::copy(toStdString(override_path), toStdString(overwritten_path), opt, err);

    if (err) {
        qCritical() << QString("Failed to apply override from %1 to %2").arg(override_path, overwritten_path);
        qCritical() << "Reason:" << QString::fromStdString(err.message());
    }

    return err.value() == 0;
}

}