//  SPDX-License-Identifier: MIT
//
//  EmulationStation Desktop Edition
//  OptionListComponent.h
//
//  Provides a list of option components.
//  Supports various types using templates.
//

#ifndef ES_CORE_COMPONENTS_OPTION_LIST_COMPONENT_H
#define ES_CORE_COMPONENTS_OPTION_LIST_COMPONENT_H

#define CHECKED_PATH ":/graphics/checkbox_checked.svg"
#define UNCHECKED_PATH ":/graphics/checkbox_unchecked.svg"

#include "GuiComponent.h"
#include "Log.h"
#include "Window.h"

#include <algorithm>

// Used to display a list of options.
// Can select one or multiple options.

// if !multiSelect
// * <- curEntry ->
// Always
// * press a -> open full list.

template<typename T>
class OptionListComponent : public GuiComponent
{
public:
    OptionListComponent(
            Window* window,
            const HelpStyle& helpstyle,
            const std::string& name,
            bool multiSelect = false)
            : GuiComponent(window),
            mHelpStyle(helpstyle),
            mMultiSelect(multiSelect),
            mName(name),
             mText(window),
            mLeftArrow(window),
            mRightArrow(window)
    {
        auto font = Font::get(FONT_SIZE_MEDIUM, FONT_PATH_LIGHT);
        mText.setFont(font);
        mText.setColor(0x777777FF);
        mText.setHorizontalAlignment(ALIGN_CENTER);
        addChild(&mText);

        mLeftArrow.setResize(0, mText.getFont()->getLetterHeight());
        mRightArrow.setResize(0, mText.getFont()->getLetterHeight());

        if (mMultiSelect) {
            mRightArrow.setImage(":/graphics/arrow.svg");
            addChild(&mRightArrow);
        }
        else {
            mLeftArrow.setImage(":/graphics/option_arrow.svg");
            mLeftArrow.setFlipX(true);
            addChild(&mLeftArrow);

            mRightArrow.setImage(":/graphics/option_arrow.svg");
            addChild(&mRightArrow);
        }

        setSize(mLeftArrow.getSize().x() + mRightArrow.getSize().x(), font->getHeight());
    }

    // Handles positioning/resizing of text and arrows.
    void onSizeChanged() override
    {
        mLeftArrow.setResize(0, mText.getFont()->getLetterHeight());
        mRightArrow.setResize(0, mText.getFont()->getLetterHeight());

        if (mSize.x() < (mLeftArrow.getSize().x() + mRightArrow.getSize().x())) {
            LOG(LogWarning) << "OptionListComponent too narrow!";
        }

        mText.setSize(mSize.x() - mLeftArrow.getSize().x() -
                mRightArrow.getSize().x(), mText.getFont()->getHeight());

        // Position.
        mLeftArrow.setPosition(0, (mSize.y() - mLeftArrow.getSize().y()) / 2);
        mText.setPosition(mLeftArrow.getPosition().x() + mLeftArrow.getSize().x(),
                (mSize.y() - mText.getSize().y()) / 2);
        mRightArrow.setPosition(mText.getPosition().x() + mText.getSize().x(),
                (mSize.y() - mRightArrow.getSize().y()) / 2);
    }

    bool input(InputConfig* config, Input input) override
    {
        if (input.value != 0) {
            if (config->isMappedTo("a", input)) {
                // Ignore input if the component has been disabled.
                if (!mEnabled)
                    return true;
                open();
                return true;
            }
            if (!mMultiSelect) {
                if (config->isMappedLike("left", input)) {
                    // Ignore input if the component has been disabled.
                    if (!mEnabled)
                        return true;
                    // Move selection to previous.
                    unsigned int i = getSelectedId();
                    int next = static_cast<int>(i) - 1;
                    if (next < 0)
                        next += static_cast<int>(mEntries.size());

                    mEntries.at(i).selected = false;
                    mEntries.at(next).selected = true;
                    onSelectedChanged();
                    return true;

                }
                else if (config->isMappedLike("right", input)) {
                    // Ignore input if the component has been disabled.
                    if (!mEnabled)
                        return true;
                    // Move selection to next.
                    unsigned int i = getSelectedId();
                    int next = (i + 1) % mEntries.size();
                    mEntries.at(i).selected = false;
                    mEntries.at(next).selected = true;
                    onSelectedChanged();
                    return true;
                }
            }
        }
        return GuiComponent::input(config, input);
    }

    std::vector<T> getSelectedObjects()
    {
        std::vector<T> ret;
        for (auto it = mEntries.cbegin(); it != mEntries.cend(); it++) {
            if (it->selected)
                ret.push_back(it->object);
        }

        return ret;
    }

    T getSelected()
    {
        assert(mMultiSelect == false);
        auto selected = getSelectedObjects();
        assert(selected.size() == 1);
        return selected.at(0);
    }

    void add(const std::string& name, const T& obj, bool selected)
    {
        OptionListData e;
        e.name = name;
        e.object = obj;
        e.selected = selected;

        mEntries.push_back(e);
        onSelectedChanged();
    }

    bool selectEntry(unsigned int entry)
    {
        if (entry > mEntries.size()) {
            return false;
        }
        else {
            mEntries.at(entry).selected = true;
            onSelectedChanged();
            return true;
        }
    }

    bool unselectEntry(unsigned int entry)
    {
        if (entry > mEntries.size()) {
            return false;
        }
        else {
            mEntries.at(entry).selected = false;
            onSelectedChanged();
            return true;
        }
    }

    void selectAll()
    {
        for (unsigned int i = 0; i < mEntries.size(); i++)
            mEntries.at(i).selected = true;
        onSelectedChanged();
    }

    void selectNone()
    {
        for (unsigned int i = 0; i < mEntries.size(); i++)
            mEntries.at(i).selected = false;
        onSelectedChanged();
    }

    void sortEntriesByName()
    {
        std::sort(std::begin(mEntries), std::end(mEntries),
                [](OptionListData a, OptionListData b) { return a.name < b.name; });
    }

    HelpStyle getHelpStyle() override { return mHelpStyle; };

private:
    struct OptionListData {
        std::string name;
        T object;
        bool selected;
    };

    HelpStyle mHelpStyle;

    unsigned int getSelectedId()
    {
        assert(mMultiSelect == false);
        for (unsigned int i = 0; i < mEntries.size(); i++) {
            if (mEntries.at(i).selected)
                return i;
        }

        LOG(LogWarning) << "OptionListComponent::getSelectedId() - "
                "no selected element found, defaulting to 0";
        return 0;
    }

    void open()
    {
        mWindow->pushGui(new OptionListPopup(mWindow, getHelpStyle(), this, mName));
    }

    void onSelectedChanged()
    {
        if (mMultiSelect) {
            // Display # selected.
            std::stringstream ss;
            ss << getSelectedObjects().size() << " SELECTED";
            mText.setText(ss.str());
            mText.setSize(0, mText.getSize().y());
            setSize(mText.getSize().x() + mRightArrow.getSize().x() + 24, mText.getSize().y());
            if (mParent) // Hack since theres no "on child size changed" callback atm...
                mParent->onSizeChanged();
        }
        else {
            // Display currently selected + l/r cursors.
            for (auto it = mEntries.cbegin(); it != mEntries.cend(); it++) {
                if (it->selected) {
                    mText.setText(Utils::String::toUpper(it->name));
                    mText.setSize(0, mText.getSize().y());
                    setSize(mText.getSize().x() + mLeftArrow.getSize().x() +
                            mRightArrow.getSize().x() + 24, mText.getSize().y());
                    if (mParent) // Hack since theres no "on child size changed" callback atm...
                        mParent->onSizeChanged();
                    break;
                }
            }
        }
    }

    std::vector<HelpPrompt> getHelpPrompts() override
    {
        std::vector<HelpPrompt> prompts;
        if (!mMultiSelect)
            prompts.push_back(HelpPrompt("left/right", "change value"));

        prompts.push_back(HelpPrompt("a", "select"));
        return prompts;
    }

    bool mMultiSelect;

    std::string mName;
    TextComponent mText;
    ImageComponent mLeftArrow;
    ImageComponent mRightArrow;

    std::vector<OptionListData> mEntries;

    // Subclass to OptionListComponent.
    class OptionListPopup : public GuiComponent
    {
    public:
        OptionListPopup(
                Window* window,
                const HelpStyle& helpstyle,
                OptionListComponent<T>* parent,
                const std::string& title)
                : GuiComponent(window),
                mHelpStyle(helpstyle),
                mMenu(window, title.c_str()),
                mParent(parent)
        {
            auto font = Font::get(FONT_SIZE_MEDIUM);
            ComponentListRow row;

            // For select all/none.
            std::vector<ImageComponent*> checkboxes;

            for (auto it = mParent->mEntries.begin(); it != mParent->mEntries.end(); it++) {
                row.elements.clear();
                row.addElement(std::make_shared<TextComponent>
                        (mWindow, Utils::String::toUpper(it->name), font, 0x777777FF), true);

                OptionListData& e = *it;

                if (mParent->mMultiSelect) {
                    // Add checkbox.
                    auto checkbox = std::make_shared<ImageComponent>(mWindow);
                    checkbox->setImage(it->selected ? CHECKED_PATH : UNCHECKED_PATH);
                    checkbox->setResize(0, font->getLetterHeight());
                    row.addElement(checkbox, false);

                    // Input handler.
                    // Update checkbox state & selected value.
                    row.makeAcceptInputHandler([this, &e, checkbox] {
                        e.selected = !e.selected;
                        checkbox->setImage(e.selected ? CHECKED_PATH : UNCHECKED_PATH);
                        mParent->onSelectedChanged();
                    });

                    // For select all/none.
                    checkboxes.push_back(checkbox.get());
                }
                else {
                    // Input handler for non-multiselect.
                    // Update selected value and close.
                    row.makeAcceptInputHandler([this, &e] {
                        mParent->mEntries.at(mParent->getSelectedId()).selected = false;
                        e.selected = true;
                        mParent->onSelectedChanged();
                        delete this;
                    });
                }

                // Also set cursor to this row if we're not multi-select and this row is selected.
                mMenu.addRow(row, (!mParent->mMultiSelect && it->selected));
            }

            mMenu.addButton("BACK", "back", [this] { delete this; });

            if (mParent->mMultiSelect) {
                mMenu.addButton("SELECT ALL", "select all", [this, checkboxes] {
                    for (unsigned int i = 0; i < mParent->mEntries.size(); i++) {
                        mParent->mEntries.at(i).selected = true;
                        checkboxes.at(i)->setImage(CHECKED_PATH);
                    }
                    mParent->onSelectedChanged();
                });

                mMenu.addButton("SELECT NONE", "select none", [this, checkboxes] {
                    for (unsigned int i = 0; i < mParent->mEntries.size(); i++) {
                        mParent->mEntries.at(i).selected = false;
                        checkboxes.at(i)->setImage(UNCHECKED_PATH);
                    }
                    mParent->onSelectedChanged();
                });
            }

            mMenu.setPosition((Renderer::getScreenWidth() - mMenu.getSize().x()) / 2,
                    Renderer::getScreenHeight() * 0.15f);
            addChild(&mMenu);
        }

        bool input(InputConfig* config, Input input) override
        {
            if (config->isMappedTo("b", input) && input.value != 0) {
                delete this;
                return true;
            }

            return GuiComponent::input(config, input);
        }

        std::vector<HelpPrompt> getHelpPrompts() override
        {
            auto prompts = mMenu.getHelpPrompts();
            prompts.push_back(HelpPrompt("a", "select"));
            prompts.push_back(HelpPrompt("b", "back"));
            return prompts;
        }

        HelpStyle getHelpStyle() override { return mHelpStyle; };

    private:
        MenuComponent mMenu;
        OptionListComponent<T>* mParent;
        HelpStyle mHelpStyle;
    };
};

#endif // ES_CORE_COMPONENTS_OPTION_LIST_COMPONENT_H