#pragma once
#include <ReWindow/types/Window.h>

#include <J3ML/LinearAlgebra.hpp>
#include <JGL/JGL.h>

#include "JGL/types/Shader.h"
#include "JUI/JUI.hpp"
#include "JUI/Widgets/Scene.hpp"
#include "JUI/Widgets/TextRect.hpp"

// Our OpenGL wrapper currently targets OpenGL 2.1
// You can specify a different version if you wish to write your own graphics code.
#define GL_VER_MAJOR 2
#define GL_VER_MINOR 1

class RedactedFrameworkAppTemplate : public ReWindow::OpenGLWindow {
public:

    JGL::Texture* logo = nullptr;
    JUI::Scene* scene = nullptr;

    /// Constructs the application class.
    /// @param title
    /// @param width
    /// @param height
    RedactedFrameworkAppTemplate(const std::string& title, int width, int height);


    /// Called after the framework initialization is complete. Loads resources and creates objects.
    bool Load();

    bool Open() override;

    /// Ensure the OpenGL wrapper has the correct canvas size. Good place to update other elements' size as well.
    void PropagateWindowSize() {
        auto size = GetSize();
        Vector2i vSize = Vector2i(size.x, size.y);
        JGL::Update(vSize);

        scene->SetViewportSize(Vector2(vSize));
    }

    void Update(float elapsed) {
        scene->Update(elapsed);
    }

    Vector2 SizeV2() {
        auto size = GetSize();
        return Vector2(size.x, size.y);
    }

    Vector2i SizeV2i() {
        auto size = GetSize();
        return Vector2i(size.x, size.y);
    }

    void DrawBackgroundLogo() {
        Vector2 logo_size = Vector2(logo->GetDimensions());
        float scale_coefficient = 0.75f; // The amount to scale the image by.

        // Computes the percentages [0, 1] of the image size relative to the viewport size.
        Vector2 scale = SizeV2() / logo_size;

        // We pick the best fit and apply it as a uniform scale.
        float best_fit_scale = Math::Min(scale.x, scale.y);

        // The final factor [0, 1] by which to scale the image size.
        scale = Vector2(best_fit_scale, best_fit_scale) * scale_coefficient;

        /// The bounding-box of the image after scaling.
        Vector2 box_size = Vector2(logo->GetDimensions())*scale;

        // Center of the screen.
        Vector2 screen_center = SizeV2() / 2.f;

        // Center of the logo.
        Vector2 logo_center = box_size / 2.f;

        // The point at which to draw the logo such that it always appears centered.
        // TODO: The `origin` parameter in J2D should perform this calculation for us, so we can specify [0.5, 0.5] and it will render from the center.
        Vector2 draw_offset = screen_center - logo_center;

        // Draw the logo's bounding box, as a gradient box.
        J2D::FillGradientRect(Colors::Yellow, Colors::Pinks::HotPink, Direction::Diagonal_SWNE, draw_offset, box_size);
        J2D::DrawSprite(logo, draw_offset, 0, Vector2::Zero, scale);
    }


    void Render() {
        Shader::UseDefault();
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
        glMatrixMode(GL_MODELVIEW);
        glLoadIdentity();

        J2D::Begin();
        DrawBackgroundLogo();
        J2D::End();

        scene->Draw();

    }

    void OnRefresh(float elapsed) override {
        PropagateWindowSize();
        Update(elapsed);
        Render();
        SwapBuffers();
    }

    enum JUI::MouseButton ToJUIEnum(const MouseButton& btn) {

        if (btn == MouseButtons::Left) return JUI::MouseButton::Left;
        if (btn == MouseButtons::Middle) return JUI::MouseButton::Middle;
        if (btn == MouseButtons::Right) return JUI::MouseButton::Right;

        // Default condition.
        return JUI::MouseButton::Left;
    }

    void OnMouseButtonDown(const ReWindow::MouseButtonDownEvent &e) override {
        auto btn = ToJUIEnum(e.Button);

        // Consume mouse clicks that are of interest to the UI scene.
        if (scene->ObserveMouseInput(btn, true))
            return;

        // Listen for mouse clicks.
    }
    void OnMouseButtonUp(const ReWindow::MouseButtonUpEvent &e) override {
        auto btn = ToJUIEnum(e.Button);

        if (scene->ObserveMouseInput(btn, false)) return;
    }
    void OnMouseMove(const ReWindow::MouseMoveEvent &e) override {
        Vector2 nmp = Vector2(e.Position.x, e.Position.y);
        if (scene->ObserveMouseMovement(nmp)) return;
    }
    void OnKeyDown(const ReWindow::KeyDownEvent &e) override {
        if (scene->ObserveKeyInput(e.key, true)) return;
    }

    void OnKeyUp(const ReWindow::KeyUpEvent &e) override {
        if (scene->ObserveKeyInput(e.key, false)) return;
    }
    void OnMouseWheel(const ReWindow::MouseWheelEvent &e) override {
        if (scene->ObserveMouseWheel(e.WheelMovement)) return;
    }
protected:
private:
};