#include "MainWindow.h"

#include <QApplication>
#include <QFileDialog>
#include <QMessageBox>
#include <QCloseEvent>
#include <QSettings>
#include <QFileInfo>

#include "AboutDialog.h"
#include "filetree/FileTreePanel.h"
#include "editor/EditorPanel.h"

// ---------------------------------------------------------------------------
// Konstruktor
// ---------------------------------------------------------------------------
MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
    , m_projectManager(std::make_unique<ProjectManager>())
    , m_settings(std::make_unique<Settings>())
    , m_themeManager(std::make_unique<ThemeManager>())
{
    setWindowTitle("BareCode");
    setMinimumSize(900, 600);

    setupUi();
    setupMenuBar();
    setupStatusBar();
    connectSignals();
    restoreWindowState();
    applyInitialTheme();

    // Letztes Projekt wieder öffnen
    const QString lastPath = m_settings->lastProjectPath();
    if (!lastPath.isEmpty())
    {
        m_projectManager->openProject(lastPath);
    }

    // Letzte Session wiederherstellen (geöffnete Dateien + aktiver Tab)
    m_editor->restoreSession(
        m_settings->lastOpenFiles(),
        m_settings->lastActiveFile()
    );
}

MainWindow::~MainWindow() = default;

// ---------------------------------------------------------------------------
// Datei(en) von der Kommandozeile öffnen
// ---------------------------------------------------------------------------
void MainWindow::openFilesFromArguments(const QStringList &filePaths)
{
    for (const QString &path : filePaths)
    {
        const QFileInfo info(path);
        if (info.exists() && info.isFile())
        {
            m_editor->openFile(info.absoluteFilePath());
        }
    }
}

// ---------------------------------------------------------------------------
// UI aufbauen
// ---------------------------------------------------------------------------
void MainWindow::setupUi()
{
    m_splitter = new QSplitter(Qt::Horizontal, this);
    setCentralWidget(m_splitter);

    m_fileTree = new FileTreePanel(m_splitter);
    m_editor   = new EditorPanel(m_settings.get(), m_splitter);

    m_splitter->addWidget(m_fileTree);
    m_splitter->addWidget(m_editor);

    const int treeWidth = m_settings->fileTreeWidth();
    m_splitter->setSizes({treeWidth, width() - treeWidth});
    m_splitter->setStretchFactor(0, 0);
    m_splitter->setStretchFactor(1, 1);
}

// ---------------------------------------------------------------------------
// Menüleiste
// ---------------------------------------------------------------------------
void MainWindow::setupMenuBar()
{
    // ---- Datei ----
    QMenu *mDatei = menuBar()->addMenu(tr("&Datei"));

    m_actNewFile = mDatei->addAction(tr("&Neue Datei…"), this, &MainWindow::onNewFile);
    m_actNewFile->setShortcut(QKeySequence::New);

    mDatei->addSeparator();

    m_actOpenFile = mDatei->addAction(tr("Datei &öffnen…"), this, &MainWindow::onOpenFile);
    m_actOpenFile->setShortcut(QKeySequence::Open);

    m_actOpenProject = mDatei->addAction(tr("&Projekt öffnen…"), this, &MainWindow::onOpenProject);
    m_actOpenProject->setShortcut(Qt::CTRL | Qt::SHIFT | Qt::Key_O);

    m_actClose = mDatei->addAction(tr("Projekt &schließen"), this, &MainWindow::onCloseProject);

    mDatei->addSeparator();

    m_actSave = mDatei->addAction(tr("&Speichern"), this, &MainWindow::onSave);
    m_actSave->setShortcut(QKeySequence::Save);

    m_actSaveAs = mDatei->addAction(tr("Speichern &unter…"), this, &MainWindow::onSaveAs);
    m_actSaveAs->setShortcut(QKeySequence::SaveAs);

    m_actSaveAll = mDatei->addAction(tr("&Alles speichern"), this, &MainWindow::onSaveAll);
    m_actSaveAll->setShortcut(Qt::CTRL | Qt::SHIFT | Qt::Key_S);

    mDatei->addSeparator();

    m_actQuit = mDatei->addAction(tr("&Beenden"), qApp, &QApplication::quit);
    m_actQuit->setShortcut(QKeySequence::Quit);

    // ---- Bearbeiten ----
    QMenu *mBearbeiten = menuBar()->addMenu(tr("&Bearbeiten"));

    m_actUndo = mBearbeiten->addAction(tr("&Rückgängig"), this, &MainWindow::onUndo);
    m_actUndo->setShortcut(QKeySequence::Undo);

    m_actRedo = mBearbeiten->addAction(tr("&Wiederholen"), this, &MainWindow::onRedo);
    m_actRedo->setShortcut(QKeySequence::Redo);

    mBearbeiten->addSeparator();

    m_actSearch = mBearbeiten->addAction(tr("&Suchen / Ersetzen…"), this, &MainWindow::onShowSearch);
    m_actSearch->setShortcut(QKeySequence::Find);

    m_actFileSearch = mBearbeiten->addAction(tr("In &Dateien suchen…"), this, &MainWindow::onShowFileSearch);
    m_actFileSearch->setShortcut(Qt::CTRL | Qt::SHIFT | Qt::Key_F);

    mBearbeiten->addSeparator();

    m_actFuncList = mBearbeiten->addAction(tr("&Projektfunktionen…"), this, &MainWindow::onShowFunctionList);
    m_actFuncList->setShortcut(Qt::CTRL | Qt::SHIFT | Qt::Key_P);

    m_actDeadCode = mBearbeiten->addAction(tr("&Tote Funktionen suchen…"), this, &MainWindow::onShowDeadCode);
    m_actDeadCode->setShortcut(Qt::CTRL | Qt::SHIFT | Qt::Key_T);

    // ---- Ansicht ----
    QMenu *mAnsicht = menuBar()->addMenu(tr("&Ansicht"));

    m_actDarkMode = mAnsicht->addAction(tr("&Dark Mode"));
    m_actDarkMode->setCheckable(true);
    m_actDarkMode->setShortcut(Qt::CTRL | Qt::SHIFT | Qt::Key_D);
    connect(m_actDarkMode, &QAction::toggled, this, &MainWindow::onToggleDarkMode);

    mAnsicht->addSeparator();

    // Sprachauswahl
    QMenu *mSprache = mAnsicht->addMenu(tr("Sprache"));
    m_langGroup = new QActionGroup(this);
    m_langGroup->setExclusive(true);

    const QSettings langSettings(QSettings::IniFormat, QSettings::UserScope,
                                 "BareCode", "BareCode");
    const QString currentLocale = langSettings.value("language/locale",
                                      QLocale::system().name()).toString();

    struct LangEntry { QString locale; QString label; };
    const QList<LangEntry> languages = {
        { "de", "Deutsch" },
        { "en", "English" },
    };

    for (const LangEntry &lang : languages)
    {
        QAction *act = mSprache->addAction(lang.label);
        act->setCheckable(true);
        act->setData(lang.locale);
        act->setChecked(currentLocale.startsWith(lang.locale));
        m_langGroup->addAction(act);
        connect(act, &QAction::triggered, this, [this, lang]()
        {
            onLanguageChanged(lang.locale);
        });
    }

    // ---- Hilfe ----
    QMenu *mHilfe = menuBar()->addMenu(tr("&Hilfe"));
    m_actAbout = mHilfe->addAction(tr("&Über BareCode…"), this, &MainWindow::onAbout);
}

void MainWindow::setupStatusBar()
{
    statusBar()->showMessage(tr("Bereit"));
}

// ---------------------------------------------------------------------------
// Signale verbinden
// ---------------------------------------------------------------------------
void MainWindow::connectSignals()
{
    connect(m_projectManager.get(), &ProjectManager::projectOpened,
            this, &MainWindow::onProjectOpened);

    connect(m_projectManager.get(), &ProjectManager::projectClosed,
            this, &MainWindow::onProjectClosed);

    // Dateibaum → Editor
    connect(m_fileTree, &FileTreePanel::fileActivated,
            m_editor, &EditorPanel::openFile);

    connect(m_fileTree, &FileTreePanel::fileCreated,
            m_editor, &EditorPanel::openFile);

    // Gespeichert → Statusleiste
    connect(m_editor, &EditorPanel::currentFileSaved, this, [this](const QString &path)
    {
        statusBar()->showMessage(tr("Gespeichert: %1").arg(path), 3000);
    });

    // Splitter-Breite merken
    connect(m_splitter, &QSplitter::splitterMoved, this, [this](int pos, int)
    {
        m_settings->setFileTreeWidth(pos);
    });
}

// ---------------------------------------------------------------------------
// Theme beim Start
// ---------------------------------------------------------------------------
void MainWindow::applyInitialTheme()
{
    const bool dark = m_settings->darkMode();
    // Block damit toggled-Signal nicht doppelt feuert
    m_actDarkMode->blockSignals(true);
    m_actDarkMode->setChecked(dark);
    m_actDarkMode->blockSignals(false);

    m_themeManager->applyTheme(dark ? ThemeManager::Theme::Dark
                                    : ThemeManager::Theme::Light);
}

// ---------------------------------------------------------------------------
// Slots – Datei
// ---------------------------------------------------------------------------
void MainWindow::onNewFile()
{
    m_fileTree->triggerNewFile();
}

void MainWindow::onOpenFile()
{
    const QString path = QFileDialog::getOpenFileName(
        this,
        tr("Datei öffnen"),
        m_settings->lastProjectPath()
    );

    if (!path.isEmpty())
    {
        m_editor->openFile(path);
    }
}

void MainWindow::onOpenProject()
{
    const QString path = QFileDialog::getExistingDirectory(
        this,
        tr("Projektverzeichnis öffnen"),
        m_settings->lastProjectPath()
    );

    if (!path.isEmpty())
    {
        m_projectManager->openProject(path);
        m_settings->setLastProjectPath(path);
    }
}

void MainWindow::onCloseProject()
{
    m_projectManager->closeProject();
}

void MainWindow::onSave()
{
    m_editor->saveCurrentFile();
}

void MainWindow::onSaveAs()
{
    m_editor->saveCurrentFileAs();
}

void MainWindow::onSaveAll()
{
    m_editor->saveAllFiles();
    statusBar()->showMessage(tr("Alle Dateien gespeichert"), 3000);
}

// ---------------------------------------------------------------------------
// Slots – Bearbeiten
// ---------------------------------------------------------------------------
void MainWindow::onUndo()
{
    m_editor->undo();
}

void MainWindow::onRedo()
{
    m_editor->redo();
}

void MainWindow::onShowSearch()
{
    m_editor->showSearchPanel();
}

// ---------------------------------------------------------------------------
// Slots – Ansicht
// ---------------------------------------------------------------------------
void MainWindow::onToggleDarkMode(bool checked)
{
    m_themeManager->applyTheme(checked ? ThemeManager::Theme::Dark
                                       : ThemeManager::Theme::Light);
    m_settings->setDarkMode(checked);
}

void MainWindow::onLanguageChanged(const QString &locale)
{
    QSettings s(QSettings::IniFormat, QSettings::UserScope, "BareCode", "BareCode");
    s.setValue("language/locale", locale);

    QMessageBox::information(this,
        tr("Sprache geändert"),
        tr("Die Sprache wird beim nächsten Start von BareCode aktiv.")
    );
}

// ---------------------------------------------------------------------------
// Slots – Hilfe
// ---------------------------------------------------------------------------
void MainWindow::onAbout()
{
    AboutDialog dlg(this);
    dlg.exec();
}

// ---------------------------------------------------------------------------
// Slots – Projekt
// ---------------------------------------------------------------------------
void MainWindow::onShowDeadCode()
{
    m_editor->showDeadCode();
}

void MainWindow::onShowFunctionList()
{
    m_editor->showFunctionList();
}

void MainWindow::onShowFileSearch()
{
    m_editor->showFileSearchPanel();
}

void MainWindow::onProjectOpened(const QString &path)
{
    setWindowTitle(QString("BareCode – %1").arg(path));
    m_fileTree->setRootPath(path);
    m_editor->setSearchRoot(path);
    statusBar()->showMessage(tr("Projekt geöffnet: %1").arg(path), 4000);
}

void MainWindow::onProjectClosed()
{
    setWindowTitle("BareCode");
    m_fileTree->clearRoot();
    m_editor->setSearchRoot(QString());
    statusBar()->showMessage(tr("Projekt geschlossen"), 3000);
}

// ---------------------------------------------------------------------------
// Fenster-Zustand
// ---------------------------------------------------------------------------
void MainWindow::saveWindowState()
{
    QSettings s(QSettings::IniFormat, QSettings::UserScope, "BareCode", "BareCode");
    s.setValue("window/geometry", saveGeometry());
    s.setValue("window/state",    saveState());

    // Session speichern
    m_settings->setLastOpenFiles(m_editor->openFilePaths());
    m_settings->setLastActiveFile(m_editor->activeFilePath());
}

void MainWindow::restoreWindowState()
{
    QSettings s(QSettings::IniFormat, QSettings::UserScope, "BareCode", "BareCode");
    if (s.contains("window/geometry"))
    {
        restoreGeometry(s.value("window/geometry").toByteArray());
    }
    if (s.contains("window/state"))
    {
        restoreState(s.value("window/state").toByteArray());
    }
}

void MainWindow::closeEvent(QCloseEvent *event)
{
    saveWindowState();
    event->accept();
}