#include <OS.h>
#include <Region.h>
#include <Rect.h>
#include <stdio.h>
#include <strings.h>

#include <Window.h>

#include "Layer.h"
#include "MyView.h"

extern BWindow* wind;

Layer::Layer(BRect frame, const char* name, uint32 rm, uint32 flags, rgb_color c)
{
        fFrame = frame;
        fOrigin.Set(0.0f, 0.0f);
        fResizeMode = rm;
        fFlags = flags;
        fColor = c;

        fBottom = NULL;
        fUpper = NULL;
        fLower = NULL;
        fTop = NULL;
        fParent = NULL;
        fView = NULL;
        fCurrent = NULL;
        fHidden = false;

        strcpy(fName, name);
}

Layer::~Layer()
{
        Layer   *c = fBottom;
        Layer   *toast;
        while (c) {
                toast = c;
                c = c->fUpper;
                delete toast;
        }
}

void
Layer::ConvertToScreen2(BRect* rect) const
{
        if (GetRootLayer())
                if (fParent) {
                        rect->OffsetBy(-fOrigin.x, -fOrigin.y);
                        rect->OffsetBy(fFrame.left, fFrame.top);

                        fParent->ConvertToScreen2(rect);
                }
}

void
Layer::ConvertToScreen2(BRegion* reg) const
{
        if (GetRootLayer())
                if (fParent) {
                        reg->OffsetBy(-fOrigin.x, -fOrigin.y);
                        reg->OffsetBy(fFrame.left, fFrame.top);

                        fParent->ConvertToScreen2(reg);
                }
}

MyView*
Layer::GetRootLayer() const // we already have

{
        if (fView)
                return fView;
        else
                if (fParent)
                        return fParent->GetRootLayer();
                else
                        return NULL;
}

Layer*
Layer::BottomChild() const // we already have

{
        fCurrent = fBottom;
        return fCurrent;
}

Layer*
Layer::TopChild() const// we already have

{
        fCurrent = fTop;
        return fCurrent;
}

Layer*
Layer::UpperSibling() const// we already have

{
        fCurrent = fCurrent->fUpper;
        return fCurrent;
}

Layer*
Layer::LowerSibling() const// we already have

{
        fCurrent = fCurrent->fLower;
        return fCurrent;
}

void
Layer::AddLayer(Layer* layer)// we already have

{
        if( layer->fParent != NULL ) {
                printf("ERROR: Layer already has a parent\n");
                return;
        }
        
        layer->fParent = this;
        
        if (!fBottom) {
                fBottom = layer;
                fTop = layer;
                return;
        }
        fBottom->fLower = layer;
        layer->fUpper = fBottom;
        fBottom = layer;
}

bool
Layer::RemLayer(Layer* layer)// we already have

{
        if(!layer->fParent || layer->fParent != this) {
                printf("ERROR: Rem: Layer doesn't have a fParent or !=this\n");
                return false;
        }
        
        layer->fParent = NULL;
        
        if(fTop == layer)
                fTop = layer->fLower;
        
        if(fBottom == layer )
                fBottom = layer->fUpper;
        
        if(layer->fUpper != NULL)
                layer->fUpper->fLower = layer->fLower;
        
        if(layer->fLower != NULL)
                layer->fLower->fUpper = layer->fUpper;
        
        layer->fUpper = NULL;
        layer->fLower = NULL;

        layer->clear_visible_regions(); // TAKE


        return true;
}

bool
Layer::IsHidden() const
{
        if (fHidden)
                return true;

// TODO: remove the following 2 lines when for real.

        if (fView)
                return false;

        if (fParent)
                return fParent->IsHidden();
                
        return fHidden;
}

void
Layer::Hide()
{
        fHidden = true;

        if (fParent && !fParent->IsHidden() && GetRootLayer()) {
                // save fullVisible so we know what to invalidate

                BRegion invalid(fFullVisible);

                clear_visible_regions();

                if (invalid.Frame().IsValid())
                        fParent->Invalidate(invalid, this);
        }
}

void
Layer::Show()
{
        fHidden = false;

        if (fParent && !fParent->IsHidden() && GetRootLayer()) {
                BRegion invalid;

                get_user_regions(invalid);

                if (invalid.CountRects() > 0)
                        fParent->Invalidate(invalid, this);
        }
}

void
Layer::Invalidate(const BRegion &invalid, const Layer *startFrom)
{
        BRegion         localVisible(fFullVisible);
        localVisible.IntersectWith(&invalid);
        rebuild_visible_regions(invalid, localVisible,
                startFrom? startFrom: BottomChild());

        // add localVisible to our RootLayer's redraw region.

        GetRootLayer()->fRedrawReg.Include(&localVisible);
        GetRootLayer()->RequestRedraw(); // TODO: what if we pass (fParent, startFromTHIS, &redrawReg)?

}

inline void
Layer::resize_layer_frame_by(float x, float y)
{
        uint16          rm = fResizeMode & 0x0000FFFF;
        BRect           newFrame = fFrame;

        if ((rm & 0x0F00U) == _VIEW_LEFT_ << 8)
                newFrame.left += 0.0f;
        else if ((rm & 0x0F00U) == _VIEW_RIGHT_ << 8)
                newFrame.left += x;
        else if ((rm & 0x0F00U) == _VIEW_CENTER_ << 8)
                newFrame.left += x/2;

        if ((rm & 0x000FU) == _VIEW_LEFT_)
                newFrame.right += 0.0f;
        else if ((rm & 0x000FU) == _VIEW_RIGHT_)
                newFrame.right += x;
        else if ((rm & 0x000FU) == _VIEW_CENTER_)
                newFrame.right += x/2;

        if ((rm & 0xF000U) == _VIEW_TOP_ << 12)
                newFrame.top += 0.0f;
        else if ((rm & 0xF000U) == _VIEW_BOTTOM_ << 12)
                newFrame.top += y;
        else if ((rm & 0xF000U) == _VIEW_CENTER_ << 12)
                newFrame.top += y/2;

        if ((rm & 0x00F0U) == _VIEW_TOP_ << 4)
                newFrame.bottom += 0.0f;
        else if ((rm & 0x00F0U) == _VIEW_BOTTOM_ << 4)
                newFrame.bottom += y;
        else if ((rm & 0x00F0U) == _VIEW_CENTER_ << 4)
                newFrame.bottom += y/2;

        if (newFrame != fFrame) {
                float           dx, dy;

                dx      = newFrame.Width() - fFrame.Width();
                dy      = newFrame.Height() - fFrame.Height();

                fFrame  = newFrame;

                if (dx != 0.0f || dy != 0.0f) {
                        // call hook function

                        ResizedByHook(dx, dy, true); // automatic


                        for (Layer *lay = BottomChild(); lay; lay = UpperSibling())
                                lay->resize_layer_frame_by(dx, dy);
                }
                else
                        MovedByHook(dx, dy);
        }
}

inline void
Layer::rezize_layer_redraw_more(BRegion &reg, float dx, float dy)
{
        if (dx == 0 && dy == 0)
                return;

        for (Layer *lay = BottomChild(); lay; lay = UpperSibling()) {
                uint16          rm = lay->fResizeMode & 0x0000FFFF;

                if ((rm & 0x0F0F) == (uint16)B_FOLLOW_LEFT_RIGHT || (rm & 0xF0F0) == (uint16)B_FOLLOW_TOP_BOTTOM) {
                        // NOTE: this is not exactly corect, but it works :-)

                        // Normaly we shoud've used the lay's old, required region - the one returned

                        // from get_user_region() with the old frame, and the current one. lay->Bounds()

                        // works for the moment so we leave it like this.


                        // calculate the old bounds.

                        BRect   oldBounds(lay->Bounds());               
                        if ((rm & 0x0F0F) == (uint16)B_FOLLOW_LEFT_RIGHT)
                                oldBounds.right -=dx;
                        if ((rm & 0xF0F0) == (uint16)B_FOLLOW_TOP_BOTTOM)
                                oldBounds.bottom -=dy;
                        
                        // compute the region that became visible because we got bigger OR smaller.

                        BRegion regZ(lay->Bounds());
                        regZ.Include(oldBounds);
                        regZ.Exclude(oldBounds&lay->Bounds());

                        lay->ConvertToScreen2(&regZ);

                        // intersect that with this'(not lay's) fullVisible region

                        regZ.IntersectWith(&fFullVisible);
                        reg.Include(&regZ);

                        lay->rezize_layer_redraw_more(reg,
                                (rm & 0x0F0F) == (uint16)B_FOLLOW_LEFT_RIGHT? dx: 0,
                                (rm & 0xF0F0) == (uint16)B_FOLLOW_TOP_BOTTOM? dy: 0);

                        // above, OR this:

                        // reg.Include(&lay->fFullVisible);

                }
                else
                if (((rm & 0x0F0F) == (uint16)B_FOLLOW_RIGHT && dx != 0) ||
                        ((rm & 0x0F0F) == (uint16)B_FOLLOW_H_CENTER && dx != 0) ||
                        ((rm & 0xF0F0) == (uint16)B_FOLLOW_BOTTOM && dy != 0)||
                        ((rm & 0xF0F0) == (uint16)B_FOLLOW_V_CENTER && dy != 0))
                {
                        reg.Include(&lay->fFullVisible);
                }
        }
}

inline void
Layer::resize_layer_full_update_on_resize(BRegion &reg, float dx, float dy)
{
        if (dx == 0 && dy == 0)
                return;

        for (Layer *lay = BottomChild(); lay; lay = UpperSibling()) {
                uint16          rm = lay->fResizeMode & 0x0000FFFF;             

                if ((rm & 0x0F0F) == (uint16)B_FOLLOW_LEFT_RIGHT || (rm & 0xF0F0) == (uint16)B_FOLLOW_TOP_BOTTOM) {
                        if (lay->fFlags & B_FULL_UPDATE_ON_RESIZE && lay->fVisible.CountRects() > 0)
                                reg.Include(&lay->fVisible);

                        lay->resize_layer_full_update_on_resize(reg,
                                (rm & 0x0F0F) == (uint16)B_FOLLOW_LEFT_RIGHT? dx: 0,
                                (rm & 0xF0F0) == (uint16)B_FOLLOW_TOP_BOTTOM? dy: 0);
                }
        }
}

void
Layer::ResizeBy(float dx, float dy)
{
        fFrame.Set(fFrame.left, fFrame.top, fFrame.right+dx, fFrame.bottom+dy);

        // resize children using their resize_mask.

        for (Layer *lay = BottomChild(); lay; lay = UpperSibling())
                        lay->resize_layer_frame_by(dx, dy);

        // call hook function

        if (dx != 0.0f || dy != 0.0f)
                ResizedByHook(dx, dy, false); // manual


        if (!IsHidden() && GetRootLayer()) {
                BRegion oldFullVisible(fFullVisible);
                // this is required to invalidate the old border

                BRegion oldVisible(fVisible);

                // in case they moved, bottom, right and center aligned layers must be redrawn

                BRegion redrawMore;
                rezize_layer_redraw_more(redrawMore, dx, dy);

                // we'll invalidate the old area and the new, maxmial one.

                BRegion invalid;
                get_user_regions(invalid);
                invalid.Include(&fFullVisible);

                clear_visible_regions();

                fParent->RebuildVisibleRegions(invalid, this);

                // done rebuilding regions, now redraw regions that became visible


                // what's invalid, are the differences between to old and the new fullVisible region

                // 1) in case we grow.

                BRegion         redrawReg(fFullVisible);
                redrawReg.Exclude(&oldFullVisible);
                // 2) in case we shrink

                BRegion         redrawReg2(oldFullVisible);
                redrawReg2.Exclude(&fFullVisible);
                // 3) combine.

                redrawReg.Include(&redrawReg2);

                // for center, right and bottom alligned layers, redraw their old positions

                redrawReg.Include(&redrawMore);

                // layers that had their frame modified must be entirely redrawn.

                rezize_layer_redraw_more(redrawReg, dx, dy);

                // add redrawReg to our RootLayer's redraw region.

                GetRootLayer()->fRedrawReg.Include(&redrawReg);
                // include layer's visible region in case we want a full update on resize

                if (fFlags & B_FULL_UPDATE_ON_RESIZE && fVisible.Frame().IsValid()) {
                        resize_layer_full_update_on_resize(GetRootLayer()->fRedrawReg, dx, dy);

                        GetRootLayer()->fRedrawReg.Include(&fVisible);
                        GetRootLayer()->fRedrawReg.Include(&oldVisible);
                }
                // clear canvas and set invalid regions for affected WinBorders

                GetRootLayer()->RequestRedraw(); // TODO: what if we pass (fParent, startFromTHIS, &redrawReg)?

        }
}

void Layer::MoveBy(float dx, float dy)
{
        if (dx == 0.0f && dy == 0.0f)
                return;

//      fFrame.Set(fFrame.left+dx, fFrame.top+dy, fFrame.right+dx, fFrame.bottom+dy);

        fFrame.OffsetBy(dx, dy);

        // call hook function

        MovedByHook(dx, dy);

        if (!IsHidden() && GetRootLayer()) {
                BRegion oldFullVisible(fFullVisible);

                // we'll invalidate the old position and the new, maxmial one.

                BRegion invalid;
                get_user_regions(invalid);
                invalid.Include(&fFullVisible);

                clear_visible_regions();

                fParent->RebuildVisibleRegions(invalid, this);

                // done rebuilding regions, now copy common parts and redraw regions that became visible


                // include the actual and the old fullVisible regions. later, we'll exclude the common parts.

                BRegion         redrawReg(fFullVisible);
                redrawReg.Include(&oldFullVisible);

                // offset to layer's new location so that we can calculate the common region.

                oldFullVisible.OffsetBy(dx, dy);

                // finally we have the region that needs to be redrawn.

                redrawReg.Exclude(&oldFullVisible);

                // by intersecting the old fullVisible offseted to layer's new location, with the current

                // fullVisible, we'll have the common region which can be copied using HW acceleration.

                oldFullVisible.IntersectWith(&fFullVisible);

                // offset back and instruct the HW to do the actual copying.

                oldFullVisible.OffsetBy(-dx, -dy);
                GetRootLayer()->CopyRegion(&oldFullVisible, dx, dy);

                // add redrawReg to our RootLayer's redraw region.

                GetRootLayer()->fRedrawReg.Include(&redrawReg);
                GetRootLayer()->RequestRedraw(); // TODO: what if we pass (fParent, startFromTHIS, &redrawReg)?

        }
}

void
Layer::ScrollBy(float dx, float dy)
{
        fOrigin.Set(fOrigin.x + dx, fOrigin.y + dy);

        if (!IsHidden() && GetRootLayer()) {
                // set the region to be invalidated.

                BRegion         invalid(fFullVisible);

                clear_visible_regions();

                rebuild_visible_regions(invalid, invalid, BottomChild());

                // for the moment we say that the whole surface needs to be redraw.

                BRegion         redrawReg(fFullVisible);

                // offset old region so that we can start comparing.

                invalid.OffsetBy(dx, dy);

                // compute the common region. we'll use HW acc to copy this to the new location.

                invalid.IntersectWith(&fFullVisible);
                GetRootLayer()->CopyRegion(&invalid, -dx, -dy);

                // common region goes back to its original location. then, by excluding

                // it from curent fullVisible we'll obtain the region that needs to be redrawn.

                invalid.OffsetBy(-dx, -dy);
                redrawReg.Exclude(&invalid);

                GetRootLayer()->fRedrawReg.Include(&redrawReg);
                GetRootLayer()->RequestRedraw(); // TODO: what if we pass (fParent, startFromTHIS, &redrawReg)?

        }

        if (dx != 0.0f || dy != 0.0f)
                ScrolledByHook(dx, dy);
}





void
Layer::GetWantedRegion(BRegion &reg) // TAKE?

{
        get_user_regions(reg);
}

void
Layer::get_user_regions(BRegion &reg)
{
        // 1) set to frame in screen coords

        BRect                   screenFrame(Bounds());
        ConvertToScreen2(&screenFrame);
        reg.Set(screenFrame);

        // 2) intersect with screen region

// TODO: remove locking when for real

wind->Lock();
        BRegion                 screenReg(GetRootLayer()->Bounds());
wind->Unlock();
        reg.IntersectWith(&screenReg);

// TODO: you MUST at some point uncomment this block!

/*

        // 3) impose user constrained regions

        LayerData               *stackData = fLayerData;

        while (stackData)

        {

                // transform in screen coords

                BRegion         screenReg(stackData->ClippingRegion());

                ConvertToScreen2(&screenReg);

                reg.IntersectWith(&screenReg);

                stackData       = stackData->prevState;

        }

*/
}

void
Layer::RebuildVisibleRegions(const BRegion &invalid, const Layer *startFrom)
{
        BRegion         localVisible(fFullVisible);
        localVisible.IntersectWith(&invalid);
        rebuild_visible_regions(invalid, localVisible, startFrom);
}

void
Layer::rebuild_visible_regions(const BRegion &invalid,
                                                                const BRegion &parentLocalVisible,
                                                                const Layer *startFrom)
{
        // no point in continuing if this layer is hidden. starting from here, all

        // descendants have (and will have) invalid visible regions.

        if (fHidden)
                return;

        // no need to go deeper if the parent doesn't have a visible region anymore

        // and our fullVisible region is also empty.

        if (!parentLocalVisible.Frame().IsValid() && !(fFullVisible.CountRects() > 0))
                return;

        bool fullRebuild = false;

        // intersect maximum wanted region with the invalid region

        BRegion common;
        get_user_regions(common);
        common.IntersectWith(&invalid);

        // if the resulted region is not valid, this layer is not in the catchment area

        // of the region being invalidated

        if (!common.CountRects() > 0)
                return;

        // now intersect with parent's visible part of the region that was/is invalidated

        common.IntersectWith(&parentLocalVisible);

        // exclude the invalid region

        fFullVisible.Exclude(&invalid);
        fVisible.Exclude(&invalid);

        // put in what's really visible

        fFullVisible.Include(&common);

        // this is to allow a layer to hide some parts of itself so children

        // won't take them.

        BRegion unalteredVisible(common);
        bool altered = alter_visible_for_children(common);

        for (Layer *lay = BottomChild(); lay; lay = UpperSibling()) {
                if (lay == startFrom)
                        fullRebuild = true;

                if (fullRebuild)
                        lay->rebuild_visible_regions(invalid, common, lay->BottomChild());

                // to let children know much they can take from parent's visible region

                common.Exclude(&lay->fFullVisible);
                // we've hidden some parts of our visible region from our children,

                // and we must be in sysnc with this region too...

                if (altered)
                        unalteredVisible.Exclude(&lay->fFullVisible);
        }

        // the visible region of this layer is what left after all its children took

        // what they could.

        if (altered)
                fVisible.Include(&unalteredVisible);
        else
                fVisible.Include(&common);
}

bool
Layer::alter_visible_for_children(BRegion &reg)
{
        // Empty Hook function

        return false;
}

void
Layer::clear_visible_regions()
{
        // OPT: maybe we should uncomment these lines for performance

        //if (fFullVisible.CountRects() <= 0)

        //      return;


        fVisible.MakeEmpty();
        fFullVisible.MakeEmpty();
        for (Layer *child = BottomChild(); child; child = UpperSibling())
                child->clear_visible_regions();
}

void
Layer::PrintToStream() const
{
        printf("-> %s\n", fName);
        fVisible.PrintToStream();
        fFullVisible.PrintToStream();
        for (Layer *child = BottomChild(); child; child = UpperSibling())
                child->PrintToStream();
}