#include "core/DocumentManager.h"

#include <QCoreApplication>
#include <QFile>
#include <QFileInfo>
#include <QSaveFile>
#include <QTextStream>

DocumentManager::DocumentManager(QObject *parent)
    : QObject(parent)
{
    QTimer *autosave = new QTimer(this);
    autosave->setInterval(m_autosaveMs);
    autosave->setSingleShot(false);
    connect(autosave, &QTimer::timeout, this, &DocumentManager::saveAll);
    autosave->start();

    // Защита при выходе
    connect(qApp, &QCoreApplication::aboutToQuit, this, &DocumentManager::saveAll);
}

QStringList DocumentManager::openTabs() const
{
    QStringList list;
    list.reserve(m_docs.size());
    for (const Doc &d : m_docs)
        list.append(d.path);
    return list;
}

int DocumentManager::activeIndex() const { return m_active; }
void DocumentManager::setActiveIndex(int index)
{
    qDebug("setActiveIndex: from %d to %d", m_active, index);
    if (m_active == index)
        return;
    m_active = index;
    emit activeIndexChanged();
}

int DocumentManager::secondaryIndex() const { return m_secondary; }
void DocumentManager::setSecondaryIndex(int index)
{
    if (m_secondary == index)
        return;
    m_secondary = index;
    emit secondaryIndexChanged();
}

bool DocumentManager::sideBySide() const { return m_sideBySide; }
void DocumentManager::setSideBySide(bool on)
{
    if (m_sideBySide == on)
        return;
    m_sideBySide = on;
    emit sideBySideChanged();
}

int DocumentManager::autosaveIntervalMs() const { return m_autosaveMs; }
void DocumentManager::setAutosaveIntervalMs(int ms)
{
    if (m_autosaveMs == ms)
        return;
    m_autosaveMs = ms;
    emit autosaveIntervalChanged();
}

QString DocumentManager::lastStatus() const { return m_lastStatus; }

int DocumentManager::openDocument(const QString &path)
{
    const QString clean = QFileInfo(path).absoluteFilePath();
    for (int i = 0; i < m_docs.size(); ++i) {
        if (m_docs[i].path == clean) {
            setActiveIndex(i);
            return i;
        }
    }

    bool ok = false;
    const QString content = readFile(clean, &ok);
    if (!ok) {
        m_lastStatus = QStringLiteral("Не удалось открыть файл: %1").arg(clean);
        emit lastStatusChanged();
        return -1;
    }

    Doc doc;
    doc.path = clean;
    doc.content = content;
    doc.dirty = false;
    m_docs.append(doc);

    const int idx = m_docs.size() - 1;
    qDebug("openDocument: path=%s idx=%d content_len=%d",
           qPrintable(clean), idx, content.length());
    setActiveIndex(idx);
    emit openTabsChanged();
    return idx;
}

QString DocumentManager::readFile(const QString &path, bool *ok) const
{
    QFile f(path);
    if (!f.open(QIODevice::ReadOnly)) {
        if (ok) *ok = false;
        return QString();
    }
    const QByteArray bytes = f.readAll();
    if (ok) *ok = true;
    return QString::fromUtf8(bytes);
}

QString DocumentManager::contentAt(int index) const
{
    if (index < 0 || index >= m_docs.size())
        return QString();
    return m_docs[index].content;
}

QString DocumentManager::titleAt(int index) const
{
    if (index < 0 || index >= m_docs.size())
        return QString();
    return QFileInfo(m_docs[index].path).fileName();
}

QString DocumentManager::pathAt(int index) const
{
    if (index < 0 || index >= m_docs.size())
        return QString();
    return m_docs[index].path;
}

bool DocumentManager::isDirty(int index) const
{
    return index >= 0 && index < m_docs.size() && m_docs[index].dirty;
}

void DocumentManager::updateContent(int index, const QString &text)
{
    if (index < 0 || index >= m_docs.size())
        return;
    Doc &d = m_docs[index];
    if (d.content == text)
        return;
    d.content = text;
    d.dirty = true;
    emit dirtyFlagChanged(index);
    emit contentChanged(index);
}

bool DocumentManager::isTextForEditor(const QString &path) const
{
    const QString ext = QFileInfo(path).suffix().toLower();
    static const QStringList textExts = {
        "md", "markdown", "txt", "log", "json", "yaml", "yml",
        "c", "h", "cpp", "hpp", "cc", "cxx", "py", "go", "rs",
        "js", "ts", "css", "sh", "bash", "xml", "ini", "csv", "svg"
    };
    return ext.isEmpty() || textExts.contains(ext);
}

void DocumentManager::saveDocument(int index)
{
    if (index < 0 || index >= m_docs.size())
        return;
    Doc &d = m_docs[index];
    if (!d.dirty)
        return;

    QSaveFile f(d.path);
    if (f.open(QIODevice::WriteOnly)) {
        f.write(d.content.toUtf8());
        if (f.commit()) {
            d.dirty = false;
            emit dirtyFlagChanged(index);
            emit documentSaved(index, d.path);
            return;
        }
    }
    m_lastStatus = QStringLiteral("Не удалось сохранить: %1").arg(d.path);
    emit lastStatusChanged();
}

void DocumentManager::saveAll()
{
    for (int i = 0; i < m_docs.size(); ++i)
        saveDocument(i);
}

bool DocumentManager::closeTab(int index)
{
    if (index < 0 || index >= m_docs.size())
        return false;
    // При закрытии тоже сохраняем (защита от потери текста).
    saveDocument(index);

    m_docs.removeAt(index);

    if (m_active > index)
        --m_active;
    else if (m_active == index)
        m_active = m_docs.isEmpty() ? -1 : qMin(index, m_docs.size() - 1);

    if (m_secondary > index)
        --m_secondary;
    else if (m_secondary == index)
        m_secondary = -1;

    emit openTabsChanged();
    emit activeIndexChanged();
    emit secondaryIndexChanged();
    return true;
}