/*
  ==============================================================================

   This file is part of the JUCE framework.
   Copyright (c) Raw Material Software Limited

   JUCE is an open source framework subject to commercial or open source
   licensing.

   By downloading, installing, or using the JUCE framework, or combining the
   JUCE framework with any other source code, object code, content or any other
   copyrightable work, you agree to the terms of the JUCE End User Licence
   Agreement, and all incorporated terms including the JUCE Privacy Policy and
   the JUCE Website Terms of Service, as applicable, which will bind you. If you
   do not agree to the terms of these agreements, we will not license the JUCE
   framework to you, and you must discontinue the installation or download
   process and cease use of the JUCE framework.

   JUCE End User Licence Agreement: https://juce.com/legal/juce-8-licence/
   JUCE Privacy Policy: https://juce.com/juce-privacy-policy
   JUCE Website Terms of Service: https://juce.com/juce-website-terms-of-service/

   Or:

   You may also use this code under the terms of the AGPLv3:
   https://www.gnu.org/licenses/agpl-3.0.en.html

   THE JUCE FRAMEWORK IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL
   WARRANTIES, WHETHER EXPRESSED OR IMPLIED, INCLUDING WARRANTY OF
   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, ARE DISCLAIMED.

  ==============================================================================
*/

namespace juce
{

StretchableLayoutManager::StretchableLayoutManager() {}
StretchableLayoutManager::~StretchableLayoutManager() {}

//==============================================================================
void StretchableLayoutManager::clearAllItems()
{
    items.clear();
    totalSize = 0;
}

void StretchableLayoutManager::setItemLayout (const int itemIndex,
                                              const double minimumSize,
                                              const double maximumSize,
                                              const double preferredSize)
{
    auto* layout = getInfoFor (itemIndex);

    if (layout == nullptr)
    {
        layout = new ItemLayoutProperties();
        layout->itemIndex = itemIndex;

        int i;
        for (i = 0; i < items.size(); ++i)
            if (items.getUnchecked (i)->itemIndex > itemIndex)
                break;

        items.insert (i, layout);
    }

    layout->minSize = minimumSize;
    layout->maxSize = maximumSize;
    layout->preferredSize = preferredSize;
    layout->currentSize = 0;
}

bool StretchableLayoutManager::getItemLayout (const int itemIndex,
                                              double& minimumSize,
                                              double& maximumSize,
                                              double& preferredSize) const
{
    if (auto* layout = getInfoFor (itemIndex))
    {
        minimumSize = layout->minSize;
        maximumSize = layout->maxSize;
        preferredSize = layout->preferredSize;
        return true;
    }

    return false;
}

//==============================================================================
void StretchableLayoutManager::setTotalSize (const int newTotalSize)
{
    totalSize = newTotalSize;

    fitComponentsIntoSpace (0, items.size(), totalSize, 0);
}

int StretchableLayoutManager::getItemCurrentPosition (const int itemIndex) const
{
    int pos = 0;

    for (int i = 0; i < itemIndex; ++i)
        if (auto* layout = getInfoFor (i))
            pos += layout->currentSize;

    return pos;
}

int StretchableLayoutManager::getItemCurrentAbsoluteSize (const int itemIndex) const
{
    if (auto* layout = getInfoFor (itemIndex))
        return layout->currentSize;

    return 0;
}

double StretchableLayoutManager::getItemCurrentRelativeSize (const int itemIndex) const
{
    if (auto* layout = getInfoFor (itemIndex))
        return -layout->currentSize / (double) totalSize;

    return 0;
}

void StretchableLayoutManager::setItemPosition (const int itemIndex,
                                                int newPosition)
{
    for (int i = items.size(); --i >= 0;)
    {
        auto* layout = items.getUnchecked (i);

        if (layout->itemIndex == itemIndex)
        {
            auto realTotalSize = jmax (totalSize, getMinimumSizeOfItems (0, items.size()));
            auto minSizeAfterThisComp = getMinimumSizeOfItems (i, items.size());
            auto maxSizeAfterThisComp = getMaximumSizeOfItems (i + 1, items.size());

            newPosition = jmax (newPosition, totalSize - maxSizeAfterThisComp - layout->currentSize);
            newPosition = jmin (newPosition, realTotalSize - minSizeAfterThisComp);

            auto endPos = fitComponentsIntoSpace (0, i, newPosition, 0);

            endPos += layout->currentSize;

            fitComponentsIntoSpace (i + 1, items.size(), totalSize - endPos, endPos);
            updatePrefSizesToMatchCurrentPositions();
            break;
        }
    }
}

//==============================================================================
void StretchableLayoutManager::layOutComponents (Component** const components,
                                                 int numComponents,
                                                 int x, int y, int w, int h,
                                                 const bool vertically,
                                                 const bool resizeOtherDimension)
{
    setTotalSize (vertically ? h : w);
    int pos = vertically ? y : x;

    for (int i = 0; i < numComponents; ++i)
    {
        if (auto* layout = getInfoFor (i))
        {
            if (auto* c = components[i])
            {
                if (i == numComponents - 1)
                {
                    // if it's the last item, crop it to exactly fit the available space
                    if (resizeOtherDimension)
                    {
                        if (vertically)
                            c->setBounds (x, pos, w, jmax (layout->currentSize, h - pos));
                        else
                            c->setBounds (pos, y, jmax (layout->currentSize, w - pos), h);
                    }
                    else
                    {
                        if (vertically)
                            c->setBounds (c->getX(), pos, c->getWidth(), jmax (layout->currentSize, h - pos));
                        else
                            c->setBounds (pos, c->getY(), jmax (layout->currentSize, w - pos), c->getHeight());
                    }
                }
                else
                {
                    if (resizeOtherDimension)
                    {
                        if (vertically)
                            c->setBounds (x, pos, w, layout->currentSize);
                        else
                            c->setBounds (pos, y, layout->currentSize, h);
                    }
                    else
                    {
                        if (vertically)
                            c->setBounds (c->getX(), pos, c->getWidth(), layout->currentSize);
                        else
                            c->setBounds (pos, c->getY(), layout->currentSize, c->getHeight());
                    }
                }
            }

            pos += layout->currentSize;
        }
    }
}


//==============================================================================
StretchableLayoutManager::ItemLayoutProperties* StretchableLayoutManager::getInfoFor (const int itemIndex) const
{
    for (auto* i : items)
        if (i->itemIndex == itemIndex)
            return i;

    return nullptr;
}

int StretchableLayoutManager::fitComponentsIntoSpace (const int startIndex,
                                                      const int endIndex,
                                                      const int availableSpace,
                                                      int startPos)
{
    // calculate the total sizes
    double totalIdealSize = 0.0;
    int totalMinimums = 0;

    for (int i = startIndex; i < endIndex; ++i)
    {
        auto* layout = items.getUnchecked (i);

        layout->currentSize = sizeToRealSize (layout->minSize, totalSize);

        totalMinimums += layout->currentSize;
        totalIdealSize += sizeToRealSize (layout->preferredSize, totalSize);
   }

    if (totalIdealSize <= 0)
        totalIdealSize = 1.0;

    // now calc the best sizes
    int extraSpace = availableSpace - totalMinimums;

    while (extraSpace > 0)
    {
        int numWantingMoreSpace = 0;
        int numHavingTakenExtraSpace = 0;

        // first figure out how many comps want a slice of the extra space
        for (int i = startIndex; i < endIndex; ++i)
        {
            auto* layout = items.getUnchecked (i);

            auto sizeWanted = sizeToRealSize (layout->preferredSize, totalSize);

            auto bestSize = jlimit (layout->currentSize,
                                    jmax (layout->currentSize,
                                          sizeToRealSize (layout->maxSize, totalSize)),
                                    roundToInt (sizeWanted * availableSpace / totalIdealSize));

            if (bestSize > layout->currentSize)
                ++numWantingMoreSpace;
        }

        // share out the extra space
        for (int i = startIndex; i < endIndex; ++i)
        {
            auto* layout = items.getUnchecked (i);

            auto sizeWanted = sizeToRealSize (layout->preferredSize, totalSize);

            auto bestSize = jlimit (layout->currentSize,
                                    jmax (layout->currentSize, sizeToRealSize (layout->maxSize, totalSize)),
                                    roundToInt (sizeWanted * availableSpace / totalIdealSize));

            auto extraWanted = bestSize - layout->currentSize;

            if (extraWanted > 0)
            {
                auto extraAllowed = jmin (extraWanted,
                                          extraSpace / jmax (1, numWantingMoreSpace));

                if (extraAllowed > 0)
                {
                    ++numHavingTakenExtraSpace;
                    --numWantingMoreSpace;

                    layout->currentSize += extraAllowed;
                    extraSpace -= extraAllowed;
                }
            }
        }

        if (numHavingTakenExtraSpace <= 0)
            break;
    }

    // calculate the end position
    for (int i = startIndex; i < endIndex; ++i)
    {
        auto* layout = items.getUnchecked (i);
        startPos += layout->currentSize;
    }

    return startPos;
}

int StretchableLayoutManager::getMinimumSizeOfItems (const int startIndex,
                                                     const int endIndex) const
{
    int totalMinimums = 0;

    for (int i = startIndex; i < endIndex; ++i)
        totalMinimums += sizeToRealSize (items.getUnchecked (i)->minSize, totalSize);

    return totalMinimums;
}

int StretchableLayoutManager::getMaximumSizeOfItems (const int startIndex, const int endIndex) const
{
    int totalMaximums = 0;

    for (int i = startIndex; i < endIndex; ++i)
        totalMaximums += sizeToRealSize (items.getUnchecked (i)->maxSize, totalSize);

    return totalMaximums;
}

void StretchableLayoutManager::updatePrefSizesToMatchCurrentPositions()
{
    for (int i = 0; i < items.size(); ++i)
    {
        auto* layout = items.getUnchecked (i);

        layout->preferredSize
            = (layout->preferredSize < 0) ? getItemCurrentRelativeSize (i)
                                          : getItemCurrentAbsoluteSize (i);
    }
}

int StretchableLayoutManager::sizeToRealSize (double size, int totalSpace)
{
    if (size < 0)
        size *= -totalSpace;

    return roundToInt (jmax (1.0, size));
}

} // namespace juce
