#pragma once

#include <map>
#include <optional>
#include <vector>

#include <QWidget>

#include "BuilderModeExitedEvent.h"
#include "BuildHotkeyPressedEvent.h"
#include "BuildingBlocksChangedEvent.h"
#include "BuildingType.h"
#include "DemolishModeChangedEvent.h"
#include "EventHandler.h"
#include "GameConfig.h"

class QPushButton;
class Simulation;

class BuildButtonGrid : public QWidget,
                        public CombinedEventHandler<BuilderModeExitedEvent,
                                                    DemolishModeChangedEvent,
                                                    BuildHotkeyPressedEvent,
                                                    BuildingBlocksChangedEvent>
{
    Q_OBJECT

public:
    BuildButtonGrid(Simulation* sim, const GameConfig* config, QWidget* parent = nullptr);
    ~BuildButtonGrid() override;

    void clearActiveButton();

private:
    // Re-evaluates which build buttons are enabled from the current building block
    // stock (read from the simulation). If the currently selected tool can no longer
    // be afforded, it exits builder mode so the button does not stay selected.
    void updateAffordability();

    void handleEvent(std::shared_ptr<const BuilderModeExitedEvent> event) override;
    void handleEvent(std::shared_ptr<const DemolishModeChangedEvent> event) override;
    void handleEvent(std::shared_ptr<const BuildHotkeyPressedEvent> event) override;
    void handleEvent(std::shared_ptr<const BuildingBlocksChangedEvent> event) override;

private slots:
    void onBuildButton(int index);

private:
    Simulation*                      m_sim;
    const GameConfig*                m_config;
    std::vector<BuildingType>        m_types;
    std::vector<QPushButton*>        m_buttons;
    std::map<BuildingType, int>      m_costs;
    std::optional<std::size_t>       m_activeIndex;
    QPushButton*                     m_demolishButton;
};