/*
 * Copyright 2005-2009, Haiku Inc.
 * Distributed under the terms of the MIT License.
 *
 * Authors:
 *		Axel Dörfler, axeld@pinc-software.de
 *		Stephan Aßmus <superstippi@gmx.de>
 */


#include "WorkspacesView.h"

#include "AppServer.h"
#include "Decorator.h"
#include "Desktop.h"
#include "DrawingEngine.h"
#include "DrawState.h"
#include "InterfaceDefs.h"
#include "ServerApp.h"
#include "Window.h"
#include "Workspace.h"

#include <WindowPrivate.h>


WorkspacesView::WorkspacesView(BRect frame, BPoint scrollingOffset,
		const char* name, int32 token, uint32 resizeMode, uint32 flags)
	:
	View(frame, scrollingOffset, name, token, resizeMode, flags),
	fSelectedWindow(NULL),
	fSelectedWorkspace(-1),
	fHasMoved(false)
{
	fDrawState->SetLowColor((rgb_color){ 255, 255, 255, 255 });
	fDrawState->SetHighColor((rgb_color){ 0, 0, 0, 255 });
}


WorkspacesView::~WorkspacesView()
{
}


void
WorkspacesView::AttachedToWindow(::Window* window)
{
	View::AttachedToWindow(window);

	window->AddWorkspacesView();
	window->Desktop()->AddWorkspacesView(this);
}


void
WorkspacesView::DetachedFromWindow()
{
	fWindow->Desktop()->RemoveWorkspacesView(this);
	fWindow->RemoveWorkspacesView();

	View::DetachedFromWindow();
}


void
WorkspacesView::_GetGrid(int32& columns, int32& rows)
{
	DesktopSettings settings(Window()->Desktop());

	columns = settings.WorkspacesColumns();
	rows = settings.WorkspacesRows();
}


/*!	\brief Returns the frame of the screen for the specified workspace.
*/
BRect
WorkspacesView::_ScreenFrame(int32 i)
{
	return Window()->Desktop()->WorkspaceFrame(i);
}


/*!	\brief Returns the frame of the specified workspace within the
		workspaces view.
*/
BRect
WorkspacesView::_WorkspaceAt(int32 i)
{
	int32 columns, rows;
	_GetGrid(columns, rows);

	BRect frame = Bounds();
	LocalToScreenTransform().Apply(&frame);

	int32 width = frame.IntegerWidth() / columns;
	int32 height = frame.IntegerHeight() / rows;

	int32 column = i % columns;
	int32 row = i / columns;

	BRect rect(column * width, row * height, (column + 1) * width,
		(row + 1) * height);

	rect.OffsetBy(frame.LeftTop());

	// make sure there is no gap anywhere
	if (column == columns - 1)
		rect.right = frame.right;
	if (row == rows - 1)
		rect.bottom = frame.bottom;

	return rect;
}


/*!	\brief Returns the workspace frame and index of the workspace
		under \a where.

	If, for some reason, there is no workspace located under \where,
	an empty rectangle is returned, and \a index is set to -1.
*/
BRect
WorkspacesView::_WorkspaceAt(BPoint where, int32& index)
{
	int32 columns, rows;
	_GetGrid(columns, rows);

	for (index = columns * rows; index-- > 0;) {
		BRect workspaceFrame = _WorkspaceAt(index);

		if (workspaceFrame.Contains(where))
			return workspaceFrame;
	}

	return BRect();
}


BRect
WorkspacesView::_WindowFrame(const BRect& workspaceFrame,
	const BRect& screenFrame, const BRect& windowFrame,
	BPoint windowPosition)
{
	BRect frame = windowFrame;
	frame.OffsetTo(windowPosition);

	// scale down the rect
	float factor = workspaceFrame.Width() / screenFrame.Width();
	frame.left = frame.left * factor;
	frame.right = frame.right * factor;

	factor = workspaceFrame.Height() / screenFrame.Height();
	frame.top = frame.top * factor;
	frame.bottom = frame.bottom * factor;

	// offset by the workspace fame position
	// and snap to integer coordinates without distorting the size too much
	frame.OffsetTo(rintf(frame.left + workspaceFrame.left),
		rintf(frame.top + workspaceFrame.top));
	frame.right = rintf(frame.right);
	frame.bottom = rintf(frame.bottom);

	return frame;
}


void
WorkspacesView::_DrawWindow(DrawingEngine* drawingEngine,
	const BRect& workspaceFrame, const BRect& screenFrame, ::Window* window,
	BPoint windowPosition, BRegion& backgroundRegion, bool workspaceActive)
{
	if (window->Feel() == kDesktopWindowFeel || window->IsHidden())
		return;

	BPoint offset = window->Frame().LeftTop() - windowPosition;
	BRect frame = _WindowFrame(workspaceFrame, screenFrame, window->Frame(),
		windowPosition);
	Decorator *decorator = window->Decorator();
	BRect tabFrame(0, 0, 0, 0);
	if (decorator != NULL)
		tabFrame = decorator->TitleBarRect();

	tabFrame = _WindowFrame(workspaceFrame, screenFrame,
		tabFrame, tabFrame.LeftTop() - offset);
	if (!workspaceFrame.Intersects(frame)
		&& !workspaceFrame.Intersects(tabFrame))
		return;

	rgb_color activeTabColor = (rgb_color){ 255, 203, 0, 255 };
	rgb_color inactiveTabColor = (rgb_color){ 232, 232, 232, 255 };
	rgb_color navColor = (rgb_color){ 0, 0, 229, 255 };
	rgb_color activeFrameColor = (rgb_color){ 180, 180, 180, 255 };
	rgb_color inactiveFrameColor = (rgb_color){ 180, 180, 180, 255 };
	if (decorator != NULL) {
		activeTabColor = decorator->UIColor(B_WINDOW_TAB_COLOR);
		inactiveTabColor = decorator->UIColor(B_WINDOW_INACTIVE_TAB_COLOR);
		navColor = decorator->UIColor(B_NAVIGATION_BASE_COLOR);
		activeFrameColor = decorator->UIColor(B_WINDOW_BORDER_COLOR);
		inactiveFrameColor = decorator->UIColor(B_WINDOW_INACTIVE_BORDER_COLOR);
	}

	rgb_color white = (rgb_color){ 255, 255, 255, 255 };

	rgb_color tabColor = inactiveTabColor;
	rgb_color frameColor = inactiveFrameColor;
	if (window->IsFocus()) {
		tabColor = activeTabColor;
		frameColor = activeFrameColor;
	}

	if (!workspaceActive) {
		_DarkenColor(tabColor);
		_DarkenColor(frameColor);
		_DarkenColor(white);
	}

	if (tabFrame.Height() > 0 && tabFrame.Width() > 0) {
		float width = tabFrame.Width();
		if (tabFrame.left < frame.left) {
			// Shift the tab right
			tabFrame.left = frame.left;
			tabFrame.right = tabFrame.left + width;
		}
		if (tabFrame.right > frame.right) {
			// Shift the tab left
			tabFrame.right = frame.right;
			tabFrame.left = tabFrame.right - width;
		}

		if (tabFrame.bottom >= tabFrame.top) {
			// Shift the tab up
			float tabHeight = tabFrame.Height();
			tabFrame.bottom = frame.top - 1;
			tabFrame.top = tabFrame.bottom - tabHeight;
		}

		tabFrame = tabFrame & workspaceFrame;

		if (decorator != NULL && tabFrame.IsValid()) {
			drawingEngine->FillRect(tabFrame, tabColor);
			backgroundRegion.Exclude(tabFrame);
		}
	}

	drawingEngine->StrokeRect(frame, frameColor);

	BRect fillFrame = frame.InsetByCopy(1, 1) & workspaceFrame;
	frame = frame & workspaceFrame;
	if (!frame.IsValid())
		return;

	// fill the window itself
	drawingEngine->FillRect(fillFrame, white);

	// draw title

	// TODO: the mini-window functionality should probably be moved into the
	// Window class, so that it has only to be recalculated on demand. With
	// double buffered windows, this would also open up the door to have a
	// more detailed preview.
	BString title(window->Title());

	const ServerFont& font = fDrawState->Font();

	font.TruncateString(&title, B_TRUNCATE_END, fillFrame.Width() - 4);
	font_height fontHeight;
	font.GetHeight(fontHeight);
	float height = ceilf(fontHeight.ascent) + ceilf(fontHeight.descent);
	if (title.Length() > 0 && height < frame.Height() - 2) {
		rgb_color textColor = tint_color(white, B_DARKEN_4_TINT);
		drawingEngine->SetHighColor(textColor);
		drawingEngine->SetLowColor(white);

		float width = font.StringWidth(title.String(), title.Length());

		BPoint textOffset;
		textOffset.x = rintf(frame.left + (frame.Width() - width) / 2);
		textOffset.y = rintf(frame.top + (frame.Height() - height) / 2
			+ fontHeight.ascent);
		drawingEngine->DrawString(title.String(), title.Length(), textOffset);
	}

	// prevent the next window down from drawing over this window
	backgroundRegion.Exclude(frame);
}


void
WorkspacesView::_DrawWorkspace(DrawingEngine* drawingEngine,
	BRegion& redraw, int32 index)
{
	BRect rect = _WorkspaceAt(index);

	Workspace workspace(*Window()->Desktop(), index, true);
	bool workspaceActive = workspace.IsCurrent();
	if (workspaceActive) {
		// draw active frame
		rgb_color black = (rgb_color){ 0, 0, 0, 255 };
		drawingEngine->StrokeRect(rect, black);
	} else if (index == fSelectedWorkspace) {
		rgb_color gray = (rgb_color){ 80, 80, 80, 255 };
		drawingEngine->StrokeRect(rect, gray);
	}

	rect.InsetBy(1, 1);

	rgb_color color = workspace.Color();
	if (!workspaceActive)
		_DarkenColor(color);

	// draw windows

	BRegion backgroundRegion = redraw;

	// TODO: would be nice to get the real update region here

	BRect screenFrame = _ScreenFrame(index);

	BRegion workspaceRegion(rect);
	backgroundRegion.IntersectWith(&workspaceRegion);
	drawingEngine->ConstrainClippingRegion(&backgroundRegion);

	ServerFont font = fDrawState->Font();
	font.SetSize(fWindow->ServerWindow()->App()->PlainFont().Size());
	float reducedSize = ceilf(max_c(8.0f,
		min_c(Frame().Height(), Frame().Width()) / 15));
	if (font.Size() > reducedSize)
		font.SetSize(reducedSize);
	fDrawState->SetFont(font);
	drawingEngine->SetFont(font);

	// We draw from top down and cut the window out of the clipping region
	// which reduces the flickering
	::Window* window;
	BPoint leftTop;
	while (workspace.GetPreviousWindow(window, leftTop) == B_OK) {
		_DrawWindow(drawingEngine, rect, screenFrame, window,
			leftTop, backgroundRegion, workspaceActive);
	}

	// draw background
	drawingEngine->FillRect(rect, color);

	drawingEngine->ConstrainClippingRegion(&redraw);
}


void
WorkspacesView::_DarkenColor(rgb_color& color) const
{
	color = tint_color(color, B_DARKEN_2_TINT);
}


void
WorkspacesView::_Invalidate() const
{
	BRect frame = Bounds();
	LocalToScreenTransform().Apply(&frame);

	BRegion region(frame), expose;
	Window()->MarkContentDirty(region, expose);
}


void
WorkspacesView::Draw(DrawingEngine* drawingEngine, const BRegion* effectiveClipping,
	const BRegion* windowContentClipping, bool deep)
{
	// we can only draw within our own area
	BRegion redraw(ScreenAndUserClipping(windowContentClipping));
	// add the current clipping
	redraw.IntersectWith(effectiveClipping);

	int32 columns, rows;
	_GetGrid(columns, rows);

	// draw grid

	// make sure the grid around the active workspace is not drawn
	// to reduce flicker
	BRect activeRect = _WorkspaceAt(Window()->Desktop()->CurrentWorkspace());
	BRegion gridRegion(redraw);
	gridRegion.Exclude(activeRect);
	drawingEngine->ConstrainClippingRegion(&gridRegion);

	BRect frame = Bounds();
	LocalToScreenTransform().Apply(&frame);

	// horizontal lines

	drawingEngine->StrokeLine(BPoint(frame.left, frame.top),
		BPoint(frame.right, frame.top), ViewColor());

	for (int32 row = 0; row < rows; row++) {
		BRect rect = _WorkspaceAt(row * columns);
		drawingEngine->StrokeLine(BPoint(frame.left, rect.bottom),
			BPoint(frame.right, rect.bottom), ViewColor());
	}

	// vertical lines

	drawingEngine->StrokeLine(BPoint(frame.left, frame.top),
		BPoint(frame.left, frame.bottom), ViewColor());

	for (int32 column = 0; column < columns; column++) {
		BRect rect = _WorkspaceAt(column);
		drawingEngine->StrokeLine(BPoint(rect.right, frame.top),
			BPoint(rect.right, frame.bottom), ViewColor());
	}

	drawingEngine->ConstrainClippingRegion(&redraw);

	// draw workspaces

	for (int32 i = rows * columns; i-- > 0;) {
		_DrawWorkspace(drawingEngine, redraw, i);
	}
	fWindow->ServerWindow()->ResyncDrawState();
}


void
WorkspacesView::MouseDown(BMessage* message, BPoint where)
{
	// reset tracking variables
	fSelectedWorkspace = -1;
	fSelectedWindow = NULL;
	fHasMoved = false;

	// check if the correct mouse button is pressed
	int32 buttons;
	if (message->FindInt32("buttons", &buttons) != B_OK
		|| (buttons & B_PRIMARY_MOUSE_BUTTON) == 0)
		return;

	int32 index;
	BRect workspaceFrame = _WorkspaceAt(where, index);
	if (index < 0)
		return;

	Workspace workspace(*Window()->Desktop(), index);
	workspaceFrame.InsetBy(1, 1);

	BRect screenFrame = _ScreenFrame(index);

	::Window* window;
	BRect windowFrame;
	BPoint leftTop;
	while (workspace.GetPreviousWindow(window, leftTop) == B_OK) {
		if (window->IsMinimized() || window->IsHidden())
			continue;

		BRect frame = _WindowFrame(workspaceFrame, screenFrame, window->Frame(),
			leftTop);
		if (frame.Contains(where) && window->Feel() != kDesktopWindowFeel
			&& window->Feel() != kWindowScreenFeel) {
			fSelectedWindow = window;
			windowFrame = frame;
			break;
		}
	}

	// Some special functionality (clicked with modifiers)

	int32 modifiers;
	if (fSelectedWindow != NULL
		&& message->FindInt32("modifiers", &modifiers) == B_OK) {
		if ((modifiers & B_CONTROL_KEY) != 0) {
			// Activate window if clicked with the control key pressed,
			// minimize it if control+shift - this mirrors Deskbar
			// shortcuts (when pressing a team menu item).
			if ((modifiers & B_SHIFT_KEY) != 0)
				fSelectedWindow->ServerWindow()->NotifyMinimize(true);
			else
				Window()->Desktop()->ActivateWindow(fSelectedWindow);
			fSelectedWindow = NULL;
		} else if ((modifiers & B_OPTION_KEY) != 0) {
			// Also, send window to back if clicked with the option
			// key pressed.
			Window()->Desktop()->SendWindowBehind(fSelectedWindow);
			fSelectedWindow = NULL;
		}
	}

	// If this window is movable, we keep it selected
	// (we prevent our own window from being moved, too)

	if ((fSelectedWindow != NULL
			&& (fSelectedWindow->Flags() & B_NOT_MOVABLE) != 0)
		|| fSelectedWindow == Window()) {
		fSelectedWindow = NULL;
	}

	fLeftTopOffset = where - windowFrame.LeftTop();
	fSelectedWorkspace = index;
	fClickPoint = where;

	if (index >= 0)
		_Invalidate();
}


void
WorkspacesView::MouseUp(BMessage* message, BPoint where)
{
	if (!fHasMoved && fSelectedWorkspace >= 0) {
		int32 index;
		_WorkspaceAt(where, index);
		if (index >= 0)
			Window()->Desktop()->SetWorkspaceAsync(index);
	}

	if (fSelectedWindow != NULL) {
		// We need to hide the selection frame again
		_Invalidate();
	}

	fSelectedWindow = NULL;
	fSelectedWorkspace = -1;
}


void
WorkspacesView::MouseMoved(BMessage* message, BPoint where)
{
	if (fSelectedWindow == NULL && fSelectedWorkspace < 0)
		return;

	// check if the correct mouse button is pressed
	int32 buttons;
	if (message->FindInt32("buttons", &buttons) != B_OK
		|| (buttons & B_PRIMARY_MOUSE_BUTTON) == 0)
		return;

	if (!fHasMoved) {
		Window()->Desktop()->SetMouseEventWindow(Window());
			// don't let us off the mouse
	}

	int32 index;
	BRect workspaceFrame = _WorkspaceAt(where, index);

	if (fSelectedWindow == NULL) {
		if (fSelectedWorkspace >= 0 && fSelectedWorkspace != index) {
			fSelectedWorkspace = index;
			_Invalidate();
		}
		return;
	}

	workspaceFrame.InsetBy(1, 1);

	if (index != fSelectedWorkspace) {
		if (fSelectedWindow->IsNormal() && !fSelectedWindow->InWorkspace(index)) {
			// move window to this new workspace
			uint32 newWorkspaces = (fSelectedWindow->Workspaces()
				& ~(1UL << fSelectedWorkspace)) | (1UL << index);

			Window()->Desktop()->SetWindowWorkspaces(fSelectedWindow,
				newWorkspaces);
		}
		fSelectedWorkspace = index;
	}

	BRect screenFrame = _ScreenFrame(index);
	float left = rintf((where.x - workspaceFrame.left - fLeftTopOffset.x)
		* screenFrame.Width() / workspaceFrame.Width());
	float top = rintf((where.y - workspaceFrame.top - fLeftTopOffset.y)
		* screenFrame.Height() / workspaceFrame.Height());

	BPoint leftTop;
	if (fSelectedWorkspace == Window()->Desktop()->CurrentWorkspace())
		leftTop = fSelectedWindow->Frame().LeftTop();
	else {
		if (fSelectedWindow->Anchor(fSelectedWorkspace).position
				== kInvalidWindowPosition) {
			fSelectedWindow->Anchor(fSelectedWorkspace).position
				= fSelectedWindow->Frame().LeftTop();
		}
		leftTop = fSelectedWindow->Anchor(fSelectedWorkspace).position;
	}

	// Don't treat every little mouse move as a window move - this would
	// make it too hard to activate a workspace.
	float diff = max_c(fabs(fClickPoint.x - where.x),
		fabs(fClickPoint.y - where.y));
	if (!fHasMoved && diff > 2)
		fHasMoved = true;

	if (fHasMoved) {
		Window()->Desktop()->MoveWindowBy(fSelectedWindow, left - leftTop.x,
			top - leftTop.y, fSelectedWorkspace);
	}
}


void
WorkspacesView::WindowChanged(::Window* window)
{
	// TODO: be smarter about this!
	_Invalidate();
}


void
WorkspacesView::WindowRemoved(::Window* window)
{
	if (fSelectedWindow == window)
		fSelectedWindow = NULL;
}