#include "main_window.hpp"

#include "config.hpp"

#include <QString>
#include <filesystem>
#include <fud_result.hpp>
#include <fud_status.hpp>
#include <string>
#include <vector>
#include <zip.h>

namespace getsuyomi {

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

constexpr const char* HOME{"HOME"};

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

GetsuyomiApp::GetsuyomiApp() : m_getsuyomi{new Getsuyomi()}
{
    readSettings();
}

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

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

    auto envResult = getEnvironment();
    if (envResult.isError()) {
        return envResult.getError();
    }

    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(QKeySequence::Open);
    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->setShortcut(Qt::CTRL | Qt::ALT | Qt::Key_O);
    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(QKeySequence::Quit);
    m_quitAction->setStatusTip(tr("Quit"));
    connect(m_quitAction, &QAction::triggered, this, &GetsuyomiApp::quit);

    auto nextShortcuts = QList<QKeySequence>{};
    nextShortcuts.append(QKeySequence{Qt::Key_L});
    nextShortcuts.append(QKeySequence{Qt::Key_Right});
    nextShortcuts.append(QKeySequence{Qt::Key_Down});
    m_nextAction = new QAction(QIcon::fromTheme(QIcon::ThemeIcon::GoNext), tr("Next"), this);
    m_nextAction->setShortcuts(nextShortcuts);
    m_nextAction->setStatusTip(tr("Next"));
    connect(m_nextAction, &QAction::triggered, this, &GetsuyomiApp::next);

    auto backShortcuts = QList<QKeySequence>{};
    backShortcuts.append(QKeySequence{Qt::Key_H});
    backShortcuts.append(QKeySequence{Qt::Key_Left});
    backShortcuts.append(QKeySequence{Qt::Key_Up});
    m_backAction = new QAction(QIcon::fromTheme(QIcon::ThemeIcon::GoPrevious), tr("Back"), this);
    m_backAction->setShortcuts(backShortcuts);
    m_backAction->setStatusTip(tr("Back"));
    connect(m_backAction, &QAction::triggered, this, &GetsuyomiApp::back);
}

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

void GetsuyomiApp::createToolBar()
{
    m_toolBar = addToolBar(tr("&Navigation"));
    m_toolBar->addAction(m_backAction);
    m_toolBar->addAction(m_nextAction);
}

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::next()
{
    qDebug("Next");
    m_getsuyomi->next();
}

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

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();
    qDebug("ReadSettings - last directory is %s", qPrintable(m_lastOpenedDirectory));
}

void GetsuyomiApp::writeSettings()
{
    QSettings settings{AppVendor, AppName};
    settings.setValue("geometry", saveGeometry());
    settings.setValue("windowState", saveState());
    settings.setValue("lastOpenedDirectory", m_lastOpenedDirectory);
    settings.sync();
    qDebug() << "Called writeSettings, last dir is " << settings.value("lastOpenedDirectory");
}

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 envVar, std::string& envValue, const char* backup)
{
    auto envValueOpt = getEnvVar(envVar.c_str());
    if (envValueOpt == std::nullopt || envValueOpt->length() == 0) {
        std::filesystem::path envValuePath{HOME};
        envValuePath.append(backup);
        envValue = envValuePath;
    } else {
        envValue = *envValueOpt;
    }
    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(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(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(XdgStateHome, config.stateHome, ".local/state");

    return GetEnvResult::okay(config);
}

} // namespace getsuyomi