#pragma once
#include <QWidget>
#include <QImage>
#include <QSize>
#include <QLabel>
#include <QPushButton>
#include <QComboBox>
#include <QHBoxLayout>
#include <QVBoxLayout>
#include <QThread>
#include <QProcess>

#include "v4l2worker.h"

// VideoWidget shows the live V4L2 preview and can additionally record it
// to an MP4 file. Recording works by piping raw BGRA frames into an
// external `ffmpeg` process (via QProcess/stdin), which encodes them to
// H.264/MP4 - this avoids reimplementing video encoding and just needs
// ffmpeg to be installed and on PATH.
class VideoWidget : public QWidget
{
    Q_OBJECT

public:
    explicit VideoWidget(QWidget *parent = nullptr);
    ~VideoWidget();

public:
    void shutdown();   // safe to call multiple times, called from MainWindow::closeEvent

public slots:
    void onNewFrame(const QImage &frame);
    void clearFrame();   // blanks the preview (used on ANSI clear-screen)

private slots:
    void onStartStop();
    void onFreeze(bool frozen);
    void onScreenshot();
    void onRecordToggled(bool checked);
    void refreshDeviceList();

protected:
    void paintEvent(QPaintEvent *event) override;
    void resizeEvent(QResizeEvent *event) override;

private:
    void setupUi();
    void startCapture();
    void stopCapture();
    void updateScaled();
    void startRecording();
    void stopRecording();
    void writeRecordingFrame(const QImage &frame);

    QThread     *m_thread = nullptr;
    V4l2Worker  *m_worker = nullptr;

    QImage  m_frame;
    QImage  m_scaled;
    bool    m_frozen       = false;
    bool    m_running      = false;
    bool    m_shutdownDone = false;

    QComboBox   *m_deviceCombo   = nullptr;
    QPushButton *m_startBtn      = nullptr;
    QPushButton *m_freezeBtn     = nullptr;
    QPushButton *m_screenshotBtn = nullptr;
    QPushButton *m_recordBtn     = nullptr;
    QLabel      *m_infoLabel     = nullptr;

    // Recording state. m_recordProcess is the running ffmpeg instance (or
    // nullptr when not recording); m_recordSize is the frame size the
    // recording was started with, so a mid-stream resolution change (which
    // ffmpeg's raw pipe can't handle) can be detected and the recording
    // stopped cleanly instead of corrupting the output file.
    QProcess *m_recordProcess = nullptr;
    bool      m_recording     = false;
    QSize     m_recordSize;
};