#pragma once
#include "rtt.h"
#include "texture.h"
#include "shader.h"
#include "shape.h"
#include "brush.h"
#include "action.h"

NS_START

class Layer
{
public:
    RTT m_rtt[6];
    bool m_visible = true;
    bool m_locked = false;
    float m_opacity = 1.f;
    std::string m_name;
    struct Snapshot
    {
        std::unique_ptr<uint8_t[]> image[6];
    };
    bool create(int width, int height, std::string name)
    {
        for (int i = 0; i < 6; i++)
        {
            m_rtt[i].create(width, height);
            m_rtt[i].bindFramebuffer();
            m_rtt[i].clear();
            m_rtt[i].unbindFramebuffer();
        }
        return true;
    }
    void clear(const glm::vec4& c)
    {
        // push clear color state
        GLfloat cc[4];
        glGetFloatv(GL_COLOR_CLEAR_VALUE, cc);
        glClearColor(c.r, c.g, c.b, c.a);
        
        for (int i = 0; i < 6; i++)
        {
            m_rtt[i].bindFramebuffer();
            glClear(GL_COLOR_BUFFER_BIT);
            m_rtt[i].unbindFramebuffer();
        }
        
        // restore clear color state
        glClearColor(cc[0], cc[1], cc[2], cc[3]);
    }
    Snapshot snapshot()
    {
        Snapshot snap;
        for (int i = 0; i < 6; i++)
        {
            snap.image[i] = std::make_unique<uint8_t[]>(m_rtt[i].bytes());
            m_rtt[i].readTextureData(snap.image[i].get());
        }
        return snap;
    }
};

class Canvas
{
    Plane m_plane;
    Plane m_plane_brush;
    BrushMesh m_mesh;
    bool m_dirty = false;
public:
    bool m_erase = false;
    glm::mat4 m_mv;
    glm::mat4 m_proj;
    glm::vec4 m_box;
    int m_width;
    int m_height;
    bool m_use_instanced = false;
    int m_current_layer_idx = 0;
    std::unique_ptr<Stroke> m_current_stroke;
    bool m_show_tmp = false;
    std::vector<Layer> m_layers;
    std::vector<int> m_order;
    glm::vec4 m_dirty_box[6];
    bool m_dirty_face[6];
    RTT m_tmp[6];
    Texture2D m_tex[6];
    Texture2D m_tex2[6];
    static glm::vec3 m_plane_origin[6];
    static glm::vec3 m_plane_normal[6];
    static glm::vec3 m_plane_tangent[6];
    static glm::mat4 m_plane_transform[6];
    Sampler m_sampler;
    Sampler m_sampler_bg;
    glm::vec2 m_cam_rot;
    float m_cam_fov = 85;
    
    std::vector<Layer::Snapshot> m_layers_snapshot;

    bool create(int width, int height);
    void resize(int width, int height);
    void layer_add(std::string name);
    void layer_order(int idx, int pos);
    void stroke_start(glm::vec2 point, float pressure, const ui::Brush& brush);
    void stroke_update(glm::vec2 point, float pressure);
    void stroke_draw();
    void stroke_end();
    void stroke_commit();
    void clear(const glm::vec4& color = { 1, 1, 1, 1 });
    void snapshot_save();
    void snapshot_restore();
};


class ActionStroke : public Action
{
public:
    std::unique_ptr<Stroke> m_stroke;
    std::unique_ptr<uint8_t[]> m_image[6];
    glm::ivec4 m_box[6];
    bool m_dirty[6];
    int m_layer_idx;
    Canvas* m_canvas;
    virtual void run() override
    {
        
    }
    virtual void undo() override
    {
        for (int i = 0; i < 6; i++)
        {
            // empty data
            if (!m_image[i])
                continue;

            m_canvas->m_layers[m_layer_idx].m_rtt[i].bindTexture();
            glm::vec2 box_sz = m_box[i].zw() - m_box[i].xy();
            glTexSubImage2D(GL_TEXTURE_2D, 0, m_box[i].x, m_box[i].y, box_sz.x, box_sz.y, GL_RGBA, GL_UNSIGNED_BYTE, m_image[i].get());
            m_canvas->m_layers[m_layer_idx].m_rtt[i].unbindTexture();
        }
    }
};

NS_END