#include <global.h>
#include <ui/uianchorlayout.h>

UIElementPtr Anchor::getAnchorLineElement() const
{
    if(!m_anchoredElement.expired())
        return m_anchoredElement.lock()->backwardsGetElementById(m_anchorLine.getElementId());
    return UIElementPtr();
}

int Anchor::getAnchorLinePoint() const
{
    UIElementPtr anchorLineElement = getAnchorLineElement();
    if(anchorLineElement) {
        switch(m_anchorLine.getEdge()) {
            case UI::AnchorLeft:
                return anchorLineElement->getRect().left();
            case UI::AnchorRight:
                return anchorLineElement->getRect().right();
            case UI::AnchorTop:
                return anchorLineElement->getRect().top();
            case UI::AnchorBottom:
                return anchorLineElement->getRect().bottom();
            case UI::AnchorHorizontalCenter:
                return anchorLineElement->getRect().horizontalCenter();
            case UI::AnchorVerticalCenter:
                return anchorLineElement->getRect().verticalCenter();
            default:
                break;
        }
    }
    return -9999;
}
bool UIAnchorLayout::addAnchor(const UIElementPtr& anchoredElement, UI::AnchorPoint anchoredEdge, const AnchorLine& anchorLine)
{
    Anchor anchor(anchoredElement, anchoredEdge, anchorLine);
    UIElementPtr anchorLineElement = anchor.getAnchorLineElement();

    if(!anchorLineElement) {
        error("ERROR: could not find the element to anchor on, wrong id?");
        return false;
    }

    // we can never anchor with itself
    if(anchoredElement == anchorLineElement) {
        error("ERROR: anchoring with itself is not possible");
        return false;
    }

    // we must never anchor to an anchor child
    if(hasElementInAnchorTree(anchorLineElement, anchoredElement)) {
        error("ERROR: anchors is miss configurated, you must never make anchor chains in loops");
        return false;
    }

    // setup the anchor
    m_anchors.push_back(anchor);

    // recalculate anchored element layout
    recalculateElementLayout(anchoredElement);
    return true;
}

void UIAnchorLayout::recalculateElementLayout(const UIElementPtr& element)
{
    Rect rect = element->getRect();
    bool verticalMoved = false;
    bool horizontalMoved = false;

    foreach(const Anchor& anchor, m_anchors) {
        if(anchor.getAnchoredElement() == element && anchor.getAnchorLineElement()) {
            int point = anchor.getAnchorLinePoint();
            switch(anchor.getAnchoredEdge()) {
                case UI::AnchorHorizontalCenter:
                    rect.moveHorizontalCenter(point + element->getMarginLeft() - element->getMarginRight());
                    horizontalMoved = true;
                    break;
                case UI::AnchorLeft:
                    if(!horizontalMoved) {
                        rect.moveLeft(point + element->getMarginLeft());
                        horizontalMoved = true;
                    } else
                        rect.setLeft(point + element->getMarginLeft());
                    break;
                case UI::AnchorRight:
                    if(!horizontalMoved) {
                        rect.moveRight(point - element->getMarginRight());
                        horizontalMoved = true;
                    } else
                        rect.setRight(point - element->getMarginRight());
                    break;
                case UI::AnchorVerticalCenter:
                    rect.moveVerticalCenter(point + element->getMarginTop() - element->getMarginBottom());
                    verticalMoved = true;
                    break;
                case UI::AnchorTop:
                    if(!verticalMoved) {
                        rect.moveTop(point + element->getMarginTop());
                        verticalMoved = true;
                    } else
                        rect.setTop(point + element->getMarginTop());
                    break;
                case UI::AnchorBottom:
                    if(!verticalMoved) {
                        rect.moveBottom(point - element->getMarginBottom());
                        verticalMoved = true;
                    } else
                        rect.setBottom(point - element->getMarginBottom());
                    break;
                default:
                    break;
            }
        }
    }

    if(rect != element->getRect())
        element->setRect(rect);
}

void UIAnchorLayout::recalculateChildrenLayout(const UIElementPtr& parent)
{
    foreach(const Anchor& anchor, m_anchors) {
        if(anchor.getAnchorLineElement() == parent) {
            UIElementPtr child = anchor.getAnchoredElement();
            if(child)
                recalculateElementLayout(child);
        }
    }
}

bool UIAnchorLayout::hasElementInAnchorTree(const UIElementPtr& element, const UIElementPtr& treeAnchor)
{
    foreach(const Anchor& anchor, m_anchors) {
        if(anchor.getAnchorLineElement() == treeAnchor) {
            if(anchor.getAnchoredElement() == element || hasElementInAnchorTree(element, anchor.getAnchoredElement()))
                return true;
        }
    }
    return false;
}

UI::AnchorPoint UIAnchorLayout::parseAnchorPoint(const std::string& anchorPointStr)
{
    if(anchorPointStr == "left")
        return UI::AnchorLeft;
    else if(anchorPointStr == "right")
        return UI::AnchorRight;
    else if(anchorPointStr == "top")
        return UI::AnchorTop;
    else if(anchorPointStr == "bottom")
        return UI::AnchorBottom;
    else if(anchorPointStr == "horizontalCenter")
        return UI::AnchorHorizontalCenter;
    else if(anchorPointStr == "verticalCenter")
        return UI::AnchorVerticalCenter;
    return UI::AnchorNone;
}