#include "CameraSettings.h"

#include "i18n.h"
#include "ipreferencesystem.h"

#include "registry/registry.h"
#include "util/ScopedBoolLock.h"
#include "CameraWndManager.h"
#include "string/convert.h"
#include "wxutil/dialog/MessageBox.h"

namespace ui
{

CameraSettings::CameraSettings() :
	_callbackActive(false),
	_movementSpeed(registry::getValue<int>(RKEY_MOVEMENT_SPEED)),
	_angleSpeed(registry::getValue<int>(RKEY_ROTATION_SPEED)),
	_invertMouseVerticalAxis(registry::getValue<bool>(RKEY_INVERT_MOUSE_VERTICAL_AXIS)),
	_discreteMovement(registry::getValue<bool>(RKEY_DISCRETE_MOVEMENT)),
	_cameraDrawMode(RENDER_MODE_TEXTURED),
	_cubicScale(registry::getValue<int>(RKEY_CUBIC_SCALE)),
	_farClipEnabled(registry::getValue<bool>(RKEY_ENABLE_FARCLIP)),
	_solidSelectionBoxes(registry::getValue<bool>(RKEY_SOLID_SELECTION_BOXES)),
	_toggleFreelook(registry::getValue<bool>(RKEY_TOGGLE_FREE_MOVE)),
    _gridEnabled(registry::getValue<bool>(RKEY_CAMERA_GRID_ENABLED)),
    _gridSpacing(registry::getValue<int>(RKEY_CAMERA_GRID_SPACING))
{
	// Constrain the cubic scale to a fixed value
	if (_cubicScale > MAX_CUBIC_SCALE) {
		_cubicScale = MAX_CUBIC_SCALE;
	}

    if (_gridSpacing > 512)
    {
        _gridSpacing = 512;
    }
    else if (_gridSpacing < 4)
    {
        _gridSpacing = 4;
    }

	// Initialise the draw mode from the integer value stored in the registry
	importDrawMode(registry::getValue<int>(RKEY_DRAWMODE));

	// Connect self to the according registry keys
	observeKey(RKEY_MOVEMENT_SPEED);
	observeKey(RKEY_ROTATION_SPEED);
	observeKey(RKEY_INVERT_MOUSE_VERTICAL_AXIS);
	observeKey(RKEY_DISCRETE_MOVEMENT);
	observeKey(RKEY_ENABLE_FARCLIP);
	observeKey(RKEY_DRAWMODE);
	observeKey(RKEY_SOLID_SELECTION_BOXES);
	observeKey(RKEY_TOGGLE_FREE_MOVE);
	observeKey(RKEY_CAMERA_GRID_ENABLED);
	observeKey(RKEY_CAMERA_GRID_SPACING);

	// greebo: Add the preference settings
	constructPreferencePage();
}

void CameraSettings::observeKey(const std::string& key)
{
    GlobalRegistry().signalForKey(key).connect(
        sigc::mem_fun(this, &CameraSettings::keyChanged)
    );
}

void CameraSettings::constructPreferencePage()
{
	IPreferencePage& page = GlobalPreferenceSystem().getPage(_("Settings/Camera"));

	// Add the sliders for the movement and angle speed and connect them to the observer
    page.appendSlider(_("Movement Speed (game units)"), RKEY_MOVEMENT_SPEED, 1, MAX_CAMERA_SPEED, 1, 1);
    page.appendSlider(_("Rotation Speed"), RKEY_ROTATION_SPEED, 1, 180, 1, 10);

	// Add the checkboxes and connect them with the registry key and the according observer
	page.appendCheckBox(_("Freelook mode can be toggled"), RKEY_TOGGLE_FREE_MOVE);
	page.appendCheckBox(_("Discrete movement (non-freelook mode)"), RKEY_DISCRETE_MOVEMENT);
	page.appendCheckBox(_("Enable far-clip plane (hides distant objects)"), RKEY_ENABLE_FARCLIP);

	// Add the "inverse mouse vertical axis in free-look mode" preference
	page.appendCheckBox(_("Invert mouse vertical axis (freelook mode)"), RKEY_INVERT_MOUSE_VERTICAL_AXIS);

	// States whether the selection boxes are stippled or not
	page.appendCheckBox(_("Solid selection boxes"), RKEY_SOLID_SELECTION_BOXES);
	page.appendCheckBox(_("Enable drag selections"), RKEY_CAMERA_DRAG_SELECTION_ENABLED);

    // Whether to show the toolbar (to please the screenspace addicts)
    page.appendCheckBox(_("Show camera toolbar"), RKEY_SHOW_CAMERA_TOOLBAR);

    page.appendCheckBox(_("Draw 3D grid"), RKEY_CAMERA_GRID_ENABLED);

    ComboBoxValueList gridSpacings;
    for (int i = 4; i <= 512; i *= 2)
    {
        gridSpacings.push_back(string::to_string(i));
    }
    page.appendCombo(_("Grid spacing"), RKEY_CAMERA_GRID_SPACING, gridSpacings, true);
}

bool CameraSettings::showCameraToolbar() const
{
    // TODO: There must be a less verbose way of introducing a new RKEY with a
    // default behaviour if unset.
    if (!GlobalRegistry().keyExists(RKEY_SHOW_CAMERA_TOOLBAR))
    {
        registry::setValue(RKEY_SHOW_CAMERA_TOOLBAR, true);
    }
    return registry::getValue<bool>(RKEY_SHOW_CAMERA_TOOLBAR);
}

bool CameraSettings::gridEnabled() const
{
    return _gridEnabled;
}

int CameraSettings::gridSpacing() const
{
    return _gridSpacing;
}

void CameraSettings::importDrawMode(const int mode)
{
	switch (mode) {
		case 0:
			_cameraDrawMode = RENDER_MODE_WIREFRAME;
			break;
		case 1:
			_cameraDrawMode = RENDER_MODE_SOLID;
			break;
		case 2:
			_cameraDrawMode = RENDER_MODE_TEXTURED;
			break;
		case 3:
			_cameraDrawMode = RENDER_MODE_LIGHTING;
			break;
		default:
			_cameraDrawMode = RENDER_MODE_TEXTURED;
	}

    // Enabling camera modes may throw an exception if there is a problem with
    // GL shaders.
    try
    {
        GlobalRenderSystem().setShaderProgram(
            _cameraDrawMode == RENDER_MODE_LIGHTING
            ? RenderSystem::SHADER_PROGRAM_INTERACTION
            : RenderSystem::SHADER_PROGRAM_NONE
        );
    }
    catch (const std::runtime_error& e)
    {
        wxutil::Messagebox::ShowError("Failed to enable lighting mode:\n\n"
                                      + std::string(e.what()));
    }

    _sigRenderModeChanged.emit();
}

void CameraSettings::keyChanged()
{
	// Check for iterative loops
	if (_callbackActive) {
		return;
	}

    util::ScopedBoolLock lock(_callbackActive);

	// Load the values from the registry
	_toggleFreelook = registry::getValue<bool>(RKEY_TOGGLE_FREE_MOVE);
	_movementSpeed = registry::getValue<int>(RKEY_MOVEMENT_SPEED);
	_angleSpeed = registry::getValue<int>(RKEY_ROTATION_SPEED);
	_invertMouseVerticalAxis = registry::getValue<bool>(RKEY_INVERT_MOUSE_VERTICAL_AXIS);
	_farClipEnabled = registry::getValue<bool>(RKEY_ENABLE_FARCLIP);
	_solidSelectionBoxes = registry::getValue<bool>(RKEY_SOLID_SELECTION_BOXES);
    _gridEnabled = registry::getValue<bool>(RKEY_CAMERA_GRID_ENABLED);
    _gridSpacing = registry::getValue<int>(RKEY_CAMERA_GRID_SPACING);

	// Determine the draw mode represented by the integer registry value
	importDrawMode(registry::getValue<int>(RKEY_DRAWMODE));

	// Check if a global camwindow is set
    GlobalCamera().foreachCamWnd([&](CamWnd& cam)
    {
        bool freeMovedWasEnabled = cam.freeMoveEnabled();

        // Disable free move if it was enabled during key change (e.g. LightingMode Toggle)
        if (freeMovedWasEnabled)
        {
            cam.disableFreeMove();
        }

        // Disconnect the handlers for the old state and re-connect after reading the registry value
        cam.removeHandlersMove();

        // Check the value and take the according actions
        _discreteMovement = registry::getValue<bool>(RKEY_DISCRETE_MOVEMENT);

        // Reconnect the new handlers
        cam.addHandlersMove();

        cam.setFarClipPlaneEnabled(_farClipEnabled);
        cam.setFarClipPlaneDistance(calculateFarPlaneDistance(_cubicScale));

        if (freeMovedWasEnabled)
        {
            cam.enableFreeMove();
        }
    });

	// Call the update method in case the render mode has changed
	GlobalCamera().update();
}

CameraDrawMode CameraSettings::getRenderMode() const
{
	return _cameraDrawMode;
}

void CameraSettings::setRenderMode(const CameraDrawMode& mode)
{
    // Write the value into the registry, this should trigger the keyChanged()
    // callback that in turn calls the update functions
	registry::setValue(RKEY_DRAWMODE, static_cast<int>(mode));
}

void CameraSettings::toggleLightingMode()
{
	// switch between textured and lighting mode
	setRenderMode(
        (_cameraDrawMode == RENDER_MODE_LIGHTING)
        ? RENDER_MODE_TEXTURED
        : RENDER_MODE_LIGHTING
    );
}

bool CameraSettings::toggleFreelook() const {
	return _toggleFreelook;
}

bool CameraSettings::farClipEnabled() const
{
	return _farClipEnabled;
}

bool CameraSettings::solidSelectionBoxes() const {
	return _solidSelectionBoxes;
}

int CameraSettings::cubicScale() const {
	return _cubicScale;
}

int CameraSettings::movementSpeed() const {
	return _movementSpeed;
}

int CameraSettings::angleSpeed() const {
	return _angleSpeed;
}

bool CameraSettings::invertMouseVerticalAxis() const {
	return _invertMouseVerticalAxis;
}

bool CameraSettings::discreteMovement() const {
	return _discreteMovement;
}

void CameraSettings::setCubicScale(int scale)
{
	// Update the internal value
	_cubicScale = scale;

	// Constrain the value to [1..MAX_CUBIC_SCALE]
	if (_cubicScale>MAX_CUBIC_SCALE) {
		_cubicScale = MAX_CUBIC_SCALE;
	}

	if (_cubicScale < 1) {
		_cubicScale = 1;
	}

    // Store to registry
    registry::setValue(RKEY_CUBIC_SCALE, _cubicScale);
}

void CameraSettings::setFarClip(bool farClipEnabled)
{
    registry::setValue(RKEY_ENABLE_FARCLIP, farClipEnabled);
}

int CameraSettings::fontSize() const
{
    return registry::getValue<int>(RKEY_CAMERA_FONT_SIZE);
}

IGLFont::Style CameraSettings::fontStyle() const
{
    return registry::getValue<std::string>(RKEY_CAMERA_FONT_STYLE) == "Sans" ?
        IGLFont::Style::Sans : IGLFont::Style::Mono;
}

void CameraSettings::toggleFarClip(bool)
{
	setFarClip(!_farClipEnabled);
}

} // namespace

ui::CameraSettings* getCameraSettings()
{
	static ui::CameraSettings _cameraSettings;
	return &_cameraSettings;
}