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

NS_START

class Layer
{
public:
    RTT m_rtt[6];
    glm::vec4 m_dirty_box[6];
    bool m_dirty_face[6];
    bool m_visible = true;
    bool m_alpha_locked = false;
    float m_opacity = 1.f;
    bool m_hightlight = false;
    std::string m_name;
    int w, h;
    struct Snapshot
    {
        std::unique_ptr<uint8_t[]> image[6];
        glm::vec4 m_dirty_box[6];
        bool m_dirty_face[6];
        void create(int w, int h)
        {
            for (int i = 0; i < 6; i++)
                image[i] = std::make_unique<uint8_t[]>(w*h*4);
        }
    };
    bool create(int width, int height, std::string name);
    void clear(const glm::vec4& c);
    Snapshot snapshot(std::string data_path);
    void restore(const Snapshot& snap);
    void destroy();
};

class Canvas
{
public:
    Plane m_plane;
    Plane m_plane_brush;
    BrushMesh m_mesh;
    bool m_dirty = false;
    bool m_commit_delayed = false;

    static Canvas* I;
    bool m_alpha_lock = false;
    bool m_touch_lock = true;
    glm::mat4 m_mv;
    glm::mat4 m_proj;
    glm::vec4 m_box;
    glm::vec2 m_pan;
    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];
    Layer m_smask; // selection mask
    bool m_smask_active = false;
    RTT m_tmp[6];
    Texture2D m_brush_mix;
    Texture2D m_tex[6];
    Texture2D m_tex2[6];
    bool m_pick_ready[6];
    std::unique_ptr<glm::u8vec4[]> m_pick_data[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_brush;
    Sampler m_sampler_bg;
    Sampler m_sampler_mask;
    Sampler m_sampler_stencil;
    glm::vec2 m_cam_rot;
    glm::vec3 m_cam_pos;
    float m_cam_fov = 85;

    enum class kCanvasMode { Draw, Erase, Line, Camera, Grid, Fill, COUNT };
    kCanvasMode m_state{ kCanvasMode::Draw };
    static std::vector<CanvasMode*> modes[];
    std::vector<CanvasMode*>* m_mode = nullptr;
    kCanvasMode m_current_mode = kCanvasMode::Draw;
    static void set_mode(kCanvasMode mode)
    {
        if (I->m_mode)
            for (auto& m : *I->m_mode)
                m->leave();
        I->m_mode = &modes[(int)mode];
        I->m_state = mode;
        I->m_current_mode = mode;
        if (I->m_mode)
            for (auto& m : *I->m_mode)
                m->enter();
    }

    std::vector<Layer::Snapshot> m_layers_snapshot;

    Canvas() { I = this; }
    bool create(int width, int height);
    void resize(int width, int height);
    void layer_remove(int idx);
    void layer_add(std::string name);
    void layer_order(int idx, int pos);
    void layer_merge(int source_idx, int dest_idx);
    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_cancel();
    void stroke_commit();
    void clear(const glm::vec4& color = { 1, 1, 1, 0 });
    void pick_start();
    void pick_update(int plane);
    glm::vec4 pick_get(glm::vec2 canvas_loc);
    void snapshot_save(std::string data_path);
    void snapshot_restore();
    void snap_history(const std::vector<int>& planes);
    void clear_context();
    void export_equirectangular(std::string data_path);
    void export_equirectangular_thread(std::string data_path);
    void export_anim(std::string data_path);
    void project_save(std::string data_path);
    void project_save_thread(std::string data_path);
    void project_open(std::string data_path);
    void project_open_thread(std::string data_path);
    void inject_xmp(std::string jpg_path);
    ui::Image thumbnail_generate(int w, int h);
    ui::Image thumbnail_read(std::string data_path);
    void preview_generate();
    void draw_objects(std::function<void(const glm::mat4& camera, const glm::mat4& proj)>);
    void draw_objects(std::function<void(const glm::mat4& camera, const glm::mat4& proj)>, Layer& layer);
    bool ray_intersect(glm::vec3 ray_origin, glm::vec3 ray_dir, glm::vec3 plane_origin,
                          glm::vec3 plane_normal, glm::vec3 plane_tangent, glm::vec3 &out_hit);
    void point_unproject(glm::vec2 loc, glm::vec4 vp, glm::mat4 camera, glm::mat4 proj,
                         glm::vec3 &out_origin, glm::vec3 &out_dir);
    bool point_trace(glm::vec2 loc, glm::vec3& ray_origin, glm::vec3& ray_dir,
                     glm::vec3& hit_pos, glm::vec2& fb_pos, glm::vec3& hit_normal, int& out_plane_id);
    bool point_trace_plane(glm::vec2 loc, glm::vec3& ray_origin, glm::vec3& ray_dir,
                     glm::vec3& hit_pos, glm::vec3& hit_normal, glm::vec2& hit_fb_pos, int plane_id);
};

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

            m_canvas->m_layers[m_layer_idx].m_dirty_box[i] = m_old_box[i];
            m_canvas->m_layers[m_layer_idx].m_dirty_face[i] = m_old_dirty[i];

            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, (int)m_box[i].x, (int)m_box[i].y, (int)box_sz.x, (int)box_sz.y, GL_RGBA, GL_UNSIGNED_BYTE, m_image[i].get());
            m_canvas->m_layers[m_layer_idx].m_rtt[i].unbindTexture();
        }
    }
    virtual size_t memory() override
    {
        size_t mem = 0;
        for (int i = 0; i < 6; i++)
        {
            glm::ivec2 sz = m_box[i].zw() - m_box[i].xy();
            mem += sz.x * sz.y * 4 + sizeof(*this);
        }
        return mem;
    }
    virtual ~ActionStroke()
    {
    }
};

NS_END