#include "main_window.hpp"

#include "config.hpp"
#include "luacxx.hpp"

#include <QString>
#include <cerrno>
#include <fcntl.h>
#include <filesystem>
#include <fud_result.hpp>
#include <fud_status.hpp>
#include <string>
#include <sys/stat.h>
#include <vector>

namespace getsuyomi {

using fud::FudStatus;
using GetEnvResult = fud::Result<GetsuyomiConfig, FudStatus>;
using GetConfigResult = fud::Result<GetsuyomiConfig, FudStatus>;

constexpr const char* HOME{"HOME"};

std::optional<std::string> getEnvVar(const char* envVar);
void getEnvVar(const std::string& homeVar, const std::string& envVar, std::string& envValue, const char* backup);
GetEnvResult getEnvironment();

FudStatus createXdgDirectory(const std::string& directoryName)
{
    constexpr mode_t xdgMode = 0700;
    auto dirStatus = mkdir(directoryName.c_str(), xdgMode);
    if (dirStatus == 0) {
        return FudStatus::Success;
    }

    if (errno != EEXIST) {
        return FudStatus::Failure;
    }
    struct stat statBuffer {};
    dirStatus = stat(directoryName.c_str(), &statBuffer);

    if (dirStatus != 0) {
        return FudStatus::Failure;
    }

    if ((statBuffer.st_mode & S_IFMT) != S_IFDIR) {
        return FudStatus::Failure;
    }

    return FudStatus::Success;
}

GetConfigResult getUserConfig()
{
    auto configResult = getEnvironment();
    if (configResult.isError()) {
        return GetConfigResult::error(configResult.getError());
    }
    auto config = configResult.getOkay();

    auto dirStatus = createXdgDirectory(config.dataHome);
    if (dirStatus != FudStatus::Success) {
        return GetConfigResult::error(dirStatus);
    }
    dirStatus = createXdgDirectory(config.configHome);
    if (dirStatus != FudStatus::Success) {
        return GetConfigResult::error(dirStatus);
    }
    dirStatus = createXdgDirectory(config.stateHome);
    if (dirStatus != FudStatus::Success) {
        return GetConfigResult::error(dirStatus);
    }

    auto configFileName = std::filesystem::path(config.configHome).append("config.lua");
    auto shortcutMap = Shortcuts::fromUserConfig(configFileName);

    auto binder = [&](ShortcutList& shortcuts, ActionType action) {
        shortcuts = shortcutListFromSet(shortcutMap.at(action));
    };

    binder(config.openFileShortcuts, ActionType::OpenFile);
    binder(config.openDirectoryShortcuts, ActionType::OpenDirectory);
    binder(config.quitShortcuts, ActionType::Quit);

    binder(config.settingsShortcuts, ActionType::Configure);

    binder(config.nextShortcuts, ActionType::Next);
    binder(config.backShortcuts, ActionType::Back);

    binder(config.singlePageShortcuts, ActionType::SinglePage);
    binder(config.dualPageShortcuts, ActionType::DualPage);
    binder(config.mangaPageShortcuts, ActionType::MangaPage);

    return GetConfigResult::okay(config);
}

GetsuyomiApp::GetsuyomiApp() : QMainWindow(nullptr), m_getsuyomi{new Getsuyomi(this)}
{
    readSettings();
}

FudStatus GetsuyomiApp::setup()
{
    setCentralWidget(m_getsuyomi);

    QCoreApplication::setApplicationName(AppName);
    QCoreApplication::setApplicationVersion(AppVersionString);
    setWindowTitle(AppName);

    auto envResult = getUserConfig();
    if (envResult.isError()) {
        qCritical("Failure %s", fud::FudStatusToString(envResult.getError()));
        return envResult.getError();
    }
    m_config = envResult.getOkay();

    createActions();
    createMenus();
    createToolBar();

    constexpr int minimumWidth = 640;
    constexpr int minimumHeight = 480;
    setMinimumSize(minimumWidth, minimumHeight);

    show();

    return FudStatus::Success;
}

void GetsuyomiApp::createActions()
{
    m_openFile = new QAction(QIcon::fromTheme(QIcon::ThemeIcon::DocumentOpen), tr("&Open File"), this);
    m_openFile->setShortcuts(m_config.openFileShortcuts);
    m_openFile->setStatusTip(tr("Open a file"));
    connect(m_openFile, &QAction::triggered, this, &GetsuyomiApp::openFile);

    m_openDirectory = new QAction(QIcon::fromTheme(QIcon::ThemeIcon::FolderOpen), tr("Open &Directory"), this);
    m_openDirectory->setShortcuts(m_config.openDirectoryShortcuts);
    m_openDirectory->setStatusTip(tr("Open a directory"));
    connect(m_openDirectory, &QAction::triggered, this, &GetsuyomiApp::openDirectory);

    m_quitAction = new QAction(QIcon::fromTheme(QIcon::ThemeIcon::ApplicationExit), tr("&Quit"), this);
    m_quitAction->setShortcuts(m_config.quitShortcuts);
    m_quitAction->setStatusTip(tr("Quit"));
    connect(m_quitAction, &QAction::triggered, this, &GetsuyomiApp::quit);

    m_settingsAction = new QAction(QIcon("resources/gear.svg"), tr("&Settings"), this);
    m_settingsAction->setShortcuts(m_config.settingsShortcuts);
    m_settingsAction->setStatusTip(tr("Configure getsuyomi"));
    connect(m_settingsAction, &QAction::triggered, this, &GetsuyomiApp::configure);

    m_nextAction = new QAction(QIcon::fromTheme(QIcon::ThemeIcon::GoNext), tr("Next"), this);
    m_nextAction->setShortcuts(m_config.nextShortcuts);
    m_nextAction->setStatusTip(tr("Next"));
    connect(m_nextAction, &QAction::triggered, this, &GetsuyomiApp::next);

    m_backAction = new QAction(QIcon::fromTheme(QIcon::ThemeIcon::GoPrevious), tr("Back"), this);
    m_backAction->setShortcuts(m_config.backShortcuts);
    m_backAction->setStatusTip(tr("Back"));
    connect(m_backAction, &QAction::triggered, this, &GetsuyomiApp::back);

    m_setSinglePageLayout = new QAction(QIcon("../resources/pageSingle.png"), tr("Single Page Layout"), this);
    m_setSinglePageLayout->setShortcuts(m_config.singlePageShortcuts);
    m_setSinglePageLayout->setStatusTip(tr("Set Single Page Layout"));
    connect(m_setSinglePageLayout, &QAction::triggered, this, &GetsuyomiApp::setSinglePageLayout);

    m_setDualPageLayout = new QAction(QIcon("../resources/pageDual.png"), tr("Dual Page Layout"), this);
    m_setDualPageLayout->setShortcuts(m_config.dualPageShortcuts);
    m_setDualPageLayout->setStatusTip(tr("Set Dual Page Layout"));
    connect(m_setDualPageLayout, &QAction::triggered, this, &GetsuyomiApp::setDualPageLayout);

    m_setMangaLayout = new QAction(QIcon("../resources/pageManga.png"), tr("Manga Page Layout"), this);
    m_setMangaLayout->setShortcuts(m_config.mangaPageShortcuts);
    m_setMangaLayout->setStatusTip(tr("Set Manga Page Layout"));
    connect(m_setMangaLayout, &QAction::triggered, this, &GetsuyomiApp::setMangaLayout);

    m_setPageLayoutGroup = new QActionGroup(this);
    m_setPageLayoutGroup->addAction(m_setSinglePageLayout);
    m_setPageLayoutGroup->addAction(m_setDualPageLayout);
    m_setPageLayoutGroup->addAction(m_setMangaLayout);
    m_setPageLayoutGroup->setExclusionPolicy(QActionGroup::ExclusionPolicy::Exclusive);
}

void GetsuyomiApp::createMenus()
{
    m_fileMenu = menuBar()->addMenu(tr("&File"));
    m_fileMenu->addAction(m_openFile);
    m_fileMenu->addAction(m_openDirectory);
    m_fileMenu->addAction(m_quitAction);

    m_SettingsMenu = menuBar()->addMenu(tr("&Settings"));
    m_SettingsMenu->addAction(m_settingsAction);
}

void GetsuyomiApp::createToolBar()
{
    m_toolBar = addToolBar(tr("&Navigation"));
    m_toolBar->setObjectName("Navigation");

    // goto first
    m_toolBar->addAction(m_backAction);
    m_toolBar->addAction(m_nextAction);
    // goto last

    m_toolBar->addSeparator();

    m_toolBar->addAction(m_setSinglePageLayout);
    m_toolBar->addAction(m_setDualPageLayout);
    m_toolBar->addAction(m_setMangaLayout);
}

void GetsuyomiApp::openFile()
{
    auto dialog = QFileDialog(
        this,
        tr("Open Archive"),
        m_lastOpenedDirectory,
        tr("Archive types (*.zip *.cbz *.cbr *.gz)"));
    dialog.setFileMode(QFileDialog::ExistingFile);
    QString filename;
    if (dialog.exec()) {
        auto filenames = dialog.selectedFiles();
        if (filenames.length() == 0) {
            qWarning("No files selected.");
            return;
        } else if (filenames.length() > 1) {
            qWarning("Too many files selected %llu.", filenames.length());
            return;
        }
        filename = filenames[0];
        m_lastOpenedDirectory = dialog.directory().absolutePath();
        qDebug("Last opened directory is %s", qPrintable(m_lastOpenedDirectory));
    } else {
        qWarning("File dialog did not execute");
        return;
    }

    if (filename.endsWith(".zip")) {
        auto* archive = new ZipArchive(filename);
        if (!archive->valid()) {
            qCritical("Failed to change archive");
        } else {
            m_getsuyomi->setArchive(archive);
        }
    } else {
        qCritical("Unsupported file extension");
    }
}

void GetsuyomiApp::openDirectory()
{
    auto dialog = QFileDialog(this, tr("Open Directory"), m_lastOpenedDirectory);
    dialog.setFileMode(QFileDialog::Directory);
    QString directoryName;
    if (dialog.exec()) {
        auto filenames = dialog.selectedFiles();
        if (filenames.length() == 0) {
            qWarning("No files selected.");
            return;
        } else if (filenames.length() > 1) {
            qWarning("Too many files selected %llu.", filenames.length());
            return;
        }
        directoryName = filenames[0];
        m_lastOpenedDirectory = dialog.directory().absolutePath();
    } else {
        qWarning("File dialog did not execute");
        return;
    }
    qDebug("Opened directory %s", qPrintable(directoryName));
}

void GetsuyomiApp::quit()
{
    QCoreApplication::quit();
}

void GetsuyomiApp::configure()
{
    Settings settings(this, m_config.shortcuts());
    if (!settings.valid()) {
        qCritical("Invalid settings");
        return;
    }
    settings.exec();
}

void GetsuyomiApp::next()
{
    m_getsuyomi->next();
}

void GetsuyomiApp::back()
{
    m_getsuyomi->back();
}

void GetsuyomiApp::setSinglePageLayout()
{
    m_getsuyomi->setPageLayout(PageLayout::Single);
    m_setSinglePageLayout->setEnabled(false);
    m_setDualPageLayout->setEnabled(true);
    m_setMangaLayout->setEnabled(true);
}

void GetsuyomiApp::setDualPageLayout()
{
    m_getsuyomi->setPageLayout(PageLayout::Dual);
    m_setSinglePageLayout->setEnabled(true);
    m_setDualPageLayout->setEnabled(false);
    m_setMangaLayout->setEnabled(true);
}

void GetsuyomiApp::setMangaLayout()
{
    m_getsuyomi->setPageLayout(PageLayout::Manga);
    m_setSinglePageLayout->setEnabled(true);
    m_setDualPageLayout->setEnabled(true);
    m_setMangaLayout->setEnabled(false);
}

void GetsuyomiApp::closeEvent(QCloseEvent* event)
{
    writeSettings();
    QMainWindow::closeEvent(event);
}

void GetsuyomiApp::readSettings()
{

    QSettings settings{AppVendor, AppName};
    restoreGeometry(settings.value("geometry").toByteArray());
    restoreState(settings.value("windowState").toByteArray());
    m_lastOpenedDirectory = settings.value("lastOpenedDirectory", QDir::homePath()).toString();
}

void GetsuyomiApp::writeSettings()
{
    QSettings settings{AppVendor, AppName};
    settings.setValue("geometry", saveGeometry());
    settings.setValue("windowState", saveState());
    settings.setValue("lastOpenedDirectory", m_lastOpenedDirectory);
    settings.sync();
}

std::optional<std::string> getEnvVar(const char* envVar)
{
    const QByteArray defaultArray{};
    if (envVar == nullptr) {
        return std::nullopt;
    }
    QByteArray varArray = qgetenv(envVar);
    if (varArray == defaultArray) {
        return std::nullopt;
    }
    return varArray.toStdString();
}

void getEnvVar(const std::string& homeVar, const std::string& envVar, std::string& envValue, const char* backup)
{
    auto envValueOpt = getEnvVar(envVar.c_str());
    std::filesystem::path envValuePath{homeVar};
    if (envValueOpt == std::nullopt || envValueOpt->length() == 0) {
        envValuePath.append(backup);
    } else {
        envValuePath = *envValueOpt;
    }
    envValuePath.append(AppName);
    envValue = envValuePath;
    // qDebug("%s is %s", envVar.c_str(), envValue.c_str());
}

GetEnvResult getEnvironment()
{
    GetsuyomiConfig config{};

    auto homeOpt = getEnvVar(HOME);
    if (homeOpt == std::nullopt || homeOpt->length() == 0) {
        qCritical("Error getting home");
        return GetEnvResult::error(FudStatus::Failure);
    }
    config.home = *homeOpt;
    // qDebug("Home is %s", config.home.c_str());

    /* If $XDG_DATA_HOME is either not set or empty, a default equal to $HOME/.local/share should be used. */
    const std::string XdgDataHome{"XDG_DATA_HOME"};
    getEnvVar(config.home, XdgDataHome, config.dataHome, ".local/share");

    /* If $XDG_CONFIG_HOME is either not set or empty, a default equal to $HOME/.config should be used. */
    const std::string XdgConfigHome{"XDG_CONFIG_HOME"};
    getEnvVar(config.home, XdgConfigHome, config.configHome, ".config");

    /* If $XDG_STATE_HOME is either not set or empty, a default equal to $HOME/.local/state should be used. */
    const std::string XdgStateHome{"XDG_STATE_HOME"};
    getEnvVar(config.home, XdgStateHome, config.stateHome, ".local/state");

    return GetEnvResult::okay(config);
}

} // namespace getsuyomi