//  SPDX-License-Identifier: MIT
//
//  EmulationStation Desktop Edition
//  ComponentList.cpp
//
//  Used to lay out and navigate lists in GUI menus.
//

#include "components/ComponentList.h"

#include "resources/Font.h"

#define TOTAL_HORIZONTAL_PADDING_PX 20.0f

ComponentList::ComponentList()
    : IList<ComponentListRow, void*> {LIST_SCROLL_STYLE_SLOW, LIST_NEVER_LOOP}
    , mFocused {false}
    , mSetupCompleted {false}
    , mBottomCameraOffset {false}
    , mSingleRowScroll {false}
    , mSelectorBarOffset {0.0f}
    , mCameraOffset {0.0f}
    , mLoopRows {false}
    , mLoopScroll {false}
    , mLoopOffset {0}
    , mLoopOffset2 {0}
    , mLoopTime {0}
    , mScrollIndicatorStatus {SCROLL_NONE}
{
    // Adjust the padding relative to the aspect ratio and screen resolution to make it look
    // coherent regardless of screen type. The 1.778 aspect ratio value is the 16:9 reference.
    float aspectValue {1.778f / Renderer::getScreenAspectRatio()};
    mHorizontalPadding =
        TOTAL_HORIZONTAL_PADDING_PX * aspectValue * Renderer::getScreenWidthModifier();
}

void ComponentList::addRow(const ComponentListRow& row, bool setCursorHere)
{
    IList<ComponentListRow, void*>::Entry e;
    e.name = "";
    e.object = nullptr;
    e.data = row;

    this->add(e);

    for (auto it = mEntries.back().data.elements.cbegin();
         it != mEntries.back().data.elements.cend(); ++it)
        addChild(it->component.get());

    updateElementSize(mEntries.back().data);
    updateElementPosition(mEntries.back().data);

    if (setCursorHere) {
        mCursor = static_cast<int>(mEntries.size()) - 1;
        onCursorChanged(CURSOR_STOPPED);
    }
}

void ComponentList::onSizeChanged()
{
    for (auto it = mEntries.cbegin(); it != mEntries.cend(); ++it) {
        updateElementSize(it->data);
        updateElementPosition(it->data);
    }

    updateCameraOffset();
}

bool ComponentList::input(InputConfig* config, Input input)
{
    if (size() == 0)
        return false;

    mSingleRowScroll = false;

    if (input.value &&
        (config->isMappedTo("a", input) || config->isMappedLike("lefttrigger", input) ||
         config->isMappedLike("righttrigger", input))) {
        stopScrolling();
    }

    // Give it to the current row's input handler.
    if (mEntries.at(mCursor).data.input_handler) {
        if (mEntries.at(mCursor).data.input_handler(config, input))
            return true;
    }
    else {
        // No input handler assigned, do the default, which is to give it
        // to the rightmost element in the row.
        auto& row = mEntries.at(mCursor).data;
        if (row.elements.size()) {
            if (row.elements.back().component->input(config, input))
                return true;
        }
    }

    // Input handler didn't consume the input - try to scroll.
    if (config->isMappedLike("up", input)) {
        mSingleRowScroll = true;
        return listInput(input.value != 0 ? -1 : 0);
    }
    else if (config->isMappedLike("down", input)) {
        mSingleRowScroll = true;
        return listInput(input.value != 0 ? 1 : 0);
    }
    else if (config->isMappedLike("leftshoulder", input)) {
        return listInput(input.value != 0 ? -6 : 0);
    }
    else if (config->isMappedLike("rightshoulder", input)) {
        return listInput(input.value != 0 ? 6 : 0);
    }
    else if (config->isMappedLike("lefttrigger", input)) {
        if (input.value != 0) {
            mSelectorBarOffset = 0;
            return listFirstRow();
        }
    }
    else if (config->isMappedLike("righttrigger", input)) {
        if (input.value != 0) {
            mSelectorBarOffset = mEntries.size() - 1.0f;
            return listLastRow();
        }
    }

    return false;
}

void ComponentList::update(int deltaTime)
{
    if (!mFocused && mLoopRows) {
        mLoopOffset = 0;
        mLoopOffset2 = 0;
        mLoopTime = 0;
    }

    const float totalHeight = getTotalRowHeight();

    // Scroll indicator logic, used by ScrollIndicatorComponent.
    bool scrollIndicatorChanged = false;

    if (totalHeight > mSize.y) {
        if (mCameraOffset == 0) {
            if (mScrollIndicatorStatus != SCROLL_DOWN) {
                mScrollIndicatorStatus = SCROLL_DOWN;
                scrollIndicatorChanged = true;
            }
        }
        else if (mBottomCameraOffset) {
            if (mScrollIndicatorStatus != SCROLL_UP) {
                mScrollIndicatorStatus = SCROLL_UP;
                scrollIndicatorChanged = true;
            }
        }
        else if (mCameraOffset > 0) {
            if (mScrollIndicatorStatus != SCROLL_UP_DOWN) {
                mScrollIndicatorStatus = SCROLL_UP_DOWN;
                scrollIndicatorChanged = true;
            }
        }
    }

    if (scrollIndicatorChanged == true && mScrollIndicatorChangedCallback != nullptr)
        mScrollIndicatorChangedCallback(mScrollIndicatorStatus, mSingleRowScroll);

    listUpdate(deltaTime);

    if (size()) {
        float rowWidth {0.0f};

        // Update our currently selected row.
        for (auto it = mEntries.at(mCursor).data.elements.cbegin();
             it != mEntries.at(mCursor).data.elements.cend(); ++it) {
            it->component->update(deltaTime);
            rowWidth += it->component->getSize().x;
        }

        if (mLoopRows && rowWidth + mHorizontalPadding / 2.0f > mSize.x) {
            // Loop the text.
            const float speed {
                Font::get(FONT_SIZE_MEDIUM)->sizeText("ABCDEFGHIJKLMNOPQRSTUVWXYZ").x * 0.247f};
            const float delay {1500.0f};
            const float scrollLength {rowWidth};
            const float returnLength {speed * 1.5f};
            const float scrollTime {(scrollLength * 1000.0f) / speed};
            const float returnTime {(returnLength * 1000.0f) / speed};
            const int maxTime {static_cast<int>(delay + scrollTime + returnTime)};

            mLoopTime += deltaTime;
            while (mLoopTime > maxTime)
                mLoopTime -= maxTime;

            mLoopOffset = static_cast<int>(Utils::Math::loop(delay, scrollTime + returnTime,
                                                             static_cast<float>(mLoopTime),
                                                             scrollLength + returnLength));

            if (mLoopOffset > (scrollLength - (mSize.x - returnLength)))
                mLoopOffset2 = static_cast<int>(mLoopOffset - (scrollLength + returnLength));
            else if (mLoopOffset2 < 0)
                mLoopOffset2 = 0;
        }
    }
}

void ComponentList::onCursorChanged(const CursorState& state)
{
    mSetupCompleted = true;

    if (mLoopRows) {
        mLoopOffset = 0;
        mLoopOffset2 = 0;
        mLoopTime = 0;
    }

    // Update the selector bar position.
    // In the future this might be animated.
    mSelectorBarOffset = 0;
    for (int i = 0; i < mCursor; ++i)
        mSelectorBarOffset += getRowHeight(mEntries.at(i).data);

    updateCameraOffset();

    // This is terribly inefficient but we don't know what we came from so...
    if (size()) {
        for (auto it = mEntries.cbegin(); it != mEntries.cend(); ++it)
            it->data.elements.back().component->onFocusLost();

        mEntries.at(mCursor).data.elements.back().component->onFocusGained();
    }

    if (mCursorChangedCallback)
        mCursorChangedCallback(state);

    updateHelpPrompts();
}

void ComponentList::updateCameraOffset()
{
    float oldCameraOffset = mCameraOffset;

    // Move the camera to scroll.
    const float totalHeight = getTotalRowHeight();
    if (totalHeight > mSize.y) {
        float target =
            mSelectorBarOffset + getRowHeight(mEntries.at(mCursor).data) / 2.0f - (mSize.y / 2.0f);

        // Clamp the camera to prevent a fraction of a row from being displayed.
        mCameraOffset = 0.0f;
        unsigned int i = 0;
        while (mCameraOffset < target && i < mEntries.size()) {
            mCameraOffset += getRowHeight(mEntries.at(i).data);
            if (mCameraOffset > totalHeight - mSize.y) {
                if (mSetupCompleted) {
                    if (mScrollIndicatorStatus == ComponentList::SCROLL_NONE &&
                        oldCameraOffset == 0.0f)
                        break;
                    if (mScrollIndicatorStatus != ComponentList::SCROLL_NONE &&
                        oldCameraOffset == 0.0f)
                        mBottomCameraOffset = true;
                    else if (mCameraOffset != oldCameraOffset)
                        mBottomCameraOffset = true;
                }
                break;
            }
            ++i;
        }

        if (mCameraOffset < oldCameraOffset &&
            (oldCameraOffset > mSelectorBarOffset ||
             mScrollIndicatorStatus != ComponentList::SCROLL_NONE))
            mBottomCameraOffset = false;

        if (mCameraOffset < 0.0f)
            mCameraOffset = 0.0f;
    }
    else {
        mCameraOffset = 0.0f;
    }
}

void ComponentList::render(const glm::mat4& parentTrans)
{
    if (!size())
        return;

    glm::mat4 trans {parentTrans * getTransform()};

    // Clip everything to be inside our bounds.
    glm::vec3 dim {mSize.x, mSize.y, 0.0f};
    dim.x = (trans[0].x * dim.x + trans[3].x) - trans[3].x;
    dim.y = (trans[1].y * dim.y + trans[3].y) - trans[3].y;

    const int clipRectPosX {static_cast<int>(std::ceil(trans[3].x))};
    const int clipRectPosY {static_cast<int>(std::round(trans[3].y))};
    const int clipRectSizeX {static_cast<int>(std::round(dim.x))};
    const int clipRectSizeY {static_cast<int>(std::round(dim.y))};

    Renderer::pushClipRect(glm::ivec2 {clipRectPosX, clipRectPosY},
                           glm::ivec2 {clipRectSizeX, clipRectSizeY});

    // Scroll the camera.
    trans = glm::translate(trans, glm::vec3 {0.0f, -mCameraOffset, 0.0f});

    glm::mat4 loopTrans {trans};

    // Draw our entries.
    std::vector<GuiComponent*> drawAfterCursor;
    bool drawAll;
    for (size_t i = 0; i < mEntries.size(); ++i) {

        if (mLoopRows && mFocused && mLoopOffset > 0) {
            loopTrans =
                glm::translate(trans, glm::vec3 {static_cast<float>(-mLoopOffset), 0.0f, 0.0f});
        }

        auto& entry = mEntries.at(i);
        drawAll = !mFocused || i != static_cast<unsigned int>(mCursor);
        for (auto it = entry.data.elements.cbegin(); it != entry.data.elements.cend(); ++it) {
            if (drawAll || it->invert_when_selected) {
                auto renderLoopFunc = [&]() {
                    // Needed to avoid flickering when returning to the start position.
                    if (mLoopOffset == 0 && mLoopOffset2 == 0)
                        mLoopScroll = false;
                    it->component->render(loopTrans);
                    // Render row again if text is moved far enough for it to repeat.
                    if (mLoopOffset2 < 0 || mLoopScroll) {
                        mLoopScroll = true;
                        loopTrans = glm::translate(
                            trans, glm::vec3 {static_cast<float>(-mLoopOffset2), 0.0f, 0.0f});
                        it->component->render(loopTrans);
                    }
                };

                // For the row where the cursor is at, we want to remove any hue from the
                // font or image before inverting, as it would otherwise lead to an ugly
                // inverted color (e.g. red inverting to a green hue).
                if (mFocused && i == static_cast<size_t>(mCursor) &&
                    it->component->getValue() != "") {
                    // Check if we're dealing with text or an image component.
                    bool isTextComponent = true;
                    unsigned int origColor = it->component->getColor();
                    if (origColor == 0) {
                        origColor = it->component->getColorShift();
                        isTextComponent = false;
                    }
                    // Check if the color is neutral.
                    unsigned char byteRed = origColor >> 24 & 0xFF;
                    unsigned char byteGreen = origColor >> 16 & 0xFF;
                    unsigned char byteBlue = origColor >> 8 & 0xFF;
                    // If it's neutral, just proceed with normal rendering.
                    if (byteRed == byteGreen && byteGreen == byteBlue) {
                        renderLoopFunc();
                    }
                    else {
                        if (isTextComponent)
                            it->component->setColor(DEFAULT_INVERTED_TEXTCOLOR);
                        else
                            it->component->setColorShift(DEFAULT_INVERTED_IMAGECOLOR);
                        renderLoopFunc();
                        // Revert to the original color after rendering.
                        if (isTextComponent)
                            it->component->setColor(origColor);
                        else
                            it->component->setColorShift(origColor);
                    }
                }
                else {
                    it->component->render(trans);
                }
            }
            else {
                drawAfterCursor.push_back(it->component.get());
            }
        }
    }

    // Custom rendering.
    Renderer::setMatrix(trans);

    float opacity = mOpacity / 255.0f;

    // Draw selector bar.
    if (mFocused) {
        const float selectedRowHeight = getRowHeight(mEntries.at(mCursor).data);

        if (opacity == 1) {
            Renderer::drawRect(0.0f, mSelectorBarOffset, std::ceil(mSize.x), selectedRowHeight,
                               0xFFFFFFFF, 0xFFFFFFFF, false, opacity, trans,
                               Renderer::Blend::ONE_MINUS_DST_COLOR, Renderer::Blend::ZERO);

            Renderer::drawRect(0.0f, mSelectorBarOffset, std::ceil(mSize.x), selectedRowHeight,
                               0x777777FF, 0x777777FF, false, opacity, trans, Renderer::Blend::ONE,
                               Renderer::Blend::ONE);
        }

        for (auto it = drawAfterCursor.cbegin(); it != drawAfterCursor.cend(); ++it)
            (*it)->render(trans);

        // Reset matrix if one of these components changed it.
        if (drawAfterCursor.size())
            Renderer::setMatrix(trans);
    }

    // Draw separators.
    float y = 0;
    for (unsigned int i = 0; i < mEntries.size(); ++i) {
        Renderer::drawRect(0.0f, y, std::ceil(mSize.x), 1.0f * Renderer::getScreenHeightModifier(),
                           0xC6C7C6FF, 0xC6C7C6FF, false, opacity, trans);
        y += getRowHeight(mEntries.at(i).data);
    }

    Renderer::drawRect(0.0f, y, std::ceil(mSize.x), 1.0f * Renderer::getScreenHeightModifier(),
                       0xC6C7C6FF, 0xC6C7C6FF, false, opacity, trans);
    Renderer::popClipRect();
}

float ComponentList::getRowHeight(const ComponentListRow& row) const
{
    // Returns the highest component height found in the row.
    float height = 0;
    for (unsigned int i = 0; i < row.elements.size(); ++i) {
        if (row.elements.at(i).component->getSize().y > height)
            height = row.elements.at(i).component->getSize().y;
    }

    return std::floor(height);
}

float ComponentList::getTotalRowHeight() const
{
    float height = 0;
    for (auto it = mEntries.cbegin(); it != mEntries.cend(); ++it)
        height += getRowHeight(it->data);

    return height;
}

void ComponentList::updateElementPosition(const ComponentListRow& row)
{
    float yOffset = 0;
    for (auto it = mEntries.cbegin(); it != mEntries.cend() && &it->data != &row; ++it)
        yOffset += getRowHeight(it->data);

    // Assumes updateElementSize has already been called.
    float rowHeight = getRowHeight(row);
    float x = mHorizontalPadding / 2.0f;

    for (unsigned int i = 0; i < row.elements.size(); ++i) {
        const auto comp = row.elements.at(i).component;

        // Center vertically.
        comp->setPosition(x, (rowHeight - std::round(comp->getSize().y)) / 2.0f + yOffset);
        x += comp->getSize().x;
    }
}

void ComponentList::updateElementSize(const ComponentListRow& row)
{
    float width = mSize.x - mHorizontalPadding;
    std::vector<std::shared_ptr<GuiComponent>> resizeVec;

    for (auto it = row.elements.cbegin(); it != row.elements.cend(); ++it) {
        if (it->resize_width)
            resizeVec.push_back(it->component);
        else
            width -= it->component->getSize().x;
    }

    // Redistribute the "unused" width equally among the components with resize_width set to true.
    width = width / resizeVec.size();
    for (auto it = resizeVec.cbegin(); it != resizeVec.cend(); ++it)
        (*it)->setSize(width, (*it)->getSize().y);
}

void ComponentList::textInput(const std::string& text)
{
    if (!size())
        return;

    mEntries.at(mCursor).data.elements.back().component->textInput(text);
}

std::vector<HelpPrompt> ComponentList::getHelpPrompts()
{
    if (!size())
        return std::vector<HelpPrompt>();

    std::vector<HelpPrompt> prompts =
        mEntries.at(mCursor).data.elements.back().component->getHelpPrompts();

    if (size() > 1) {
        bool addMovePrompt = true;
        for (auto it = prompts.cbegin(); it != prompts.cend(); ++it) {
            if (it->first == "up/down" || it->first == "up/down/left/right") {
                addMovePrompt = false;
                break;
            }
        }
        if (addMovePrompt)
            prompts.push_back(HelpPrompt("up/down", "choose"));
    }

    return prompts;
}

bool ComponentList::moveCursor(int amt)
{
    bool ret = listInput(amt);
    listInput(0);
    return ret;
}