#include "RecursiveFileSystemWatcher.h"

#include <QDebug>

RecursiveFileSystemWatcher::RecursiveFileSystemWatcher(QObject* parent) : QObject(parent), m_watcher(new QFileSystemWatcher(this))
{
    connect(m_watcher, &QFileSystemWatcher::fileChanged, this, &RecursiveFileSystemWatcher::fileChange);
    connect(m_watcher, &QFileSystemWatcher::directoryChanged, this, &RecursiveFileSystemWatcher::directoryChange);
}

void RecursiveFileSystemWatcher::setRootDir(const QDir& root)
{
    bool wasEnabled = m_isEnabled;
    disable();
    m_root = root;
    setFiles(scanRecursive(m_root));
    if (wasEnabled) {
        enable();
    }
}
void RecursiveFileSystemWatcher::setWatchFiles(const bool watchFiles)
{
    bool wasEnabled = m_isEnabled;
    disable();
    m_watchFiles = watchFiles;
    if (wasEnabled) {
        enable();
    }
}

void RecursiveFileSystemWatcher::enable()
{
    if (m_isEnabled) {
        return;
    }
    Q_ASSERT(m_root != QDir::root());
    addFilesToWatcherRecursive(m_root);
    m_isEnabled = true;
}
void RecursiveFileSystemWatcher::disable()
{
    if (!m_isEnabled) {
        return;
    }
    m_isEnabled = false;
    m_watcher->removePaths(m_watcher->files());
    m_watcher->removePaths(m_watcher->directories());
}

void RecursiveFileSystemWatcher::setFiles(const QStringList& files)
{
    if (files != m_files) {
        m_files = files;
        emit filesChanged();
    }
}

void RecursiveFileSystemWatcher::addFilesToWatcherRecursive(const QDir& dir)
{
    m_watcher->addPath(dir.absolutePath());
    for (const QString& directory : dir.entryList(QDir::Dirs | QDir::NoDotAndDotDot)) {
        addFilesToWatcherRecursive(dir.absoluteFilePath(directory));
    }
    if (m_watchFiles) {
        for (const QFileInfo& info : dir.entryInfoList(QDir::Files)) {
            m_watcher->addPath(info.absoluteFilePath());
        }
    }
}
QStringList RecursiveFileSystemWatcher::scanRecursive(const QDir& directory)
{
    QStringList ret;
    if (!m_matcher) {
        return {};
    }
    for (const QString& dir : directory.entryList(QDir::Dirs | QDir::NoDotAndDotDot | QDir::Hidden)) {
        ret.append(scanRecursive(directory.absoluteFilePath(dir)));
    }
    for (const QString& file : directory.entryList(QDir::Files | QDir::Hidden)) {
        auto relPath = m_root.relativeFilePath(directory.absoluteFilePath(file));
        if (m_matcher(relPath)) {
            ret.append(relPath);
        }
    }
    return ret;
}

void RecursiveFileSystemWatcher::fileChange(const QString& path)
{
    emit fileChanged(path);
}
void RecursiveFileSystemWatcher::directoryChange([[maybe_unused]] const QString& path)
{
    setFiles(scanRecursive(m_root));
}
