#ifndef PIPELINE_H
#define PIPELINE_H

#include "vulkan/vulkan_core.h"
#include "cglm/types.h"
#include "vk_mem_alloc.h"
#include "gpu.h"

#include "ft2build.h"
#include FT_FREETYPE_H

#define ANCHOR_TOP_LEFT 0
#define ANCHOR_TOP_RIGHT 1
#define ANCHOR_BOTTOM_LEFT 2
#define ANCHOR_BOTTOM_RIGHT 3
#define ANCHOR_CENTER 4

#define DRAWABLE_TYPE_RECT 0
#define DRAWABLE_TYPE_GLYPH 1
#define DRAWABLE_TYPE_IMAGE 2
#define DRAWABLE_TYPE_RECT_HSV 3

#define UI_EVENT_CURSOR (1 << 0)
#define UI_EVENT_SCROLL (1 << 1)
#define UI_EVENT_BUTTON (1 << 2)

typedef struct UIPushConstantStruct {
  VkDeviceAddress layer;
  float time;
  uint32_t pad;
} UIPushConstant;

typedef struct GPUFontStruct {
  VkDeviceAddress symbol_list;
  uint32_t num_symbols;
  uint32_t width;
  uint32_t height;
} GPUFont;

typedef struct GPUSymbolStruct {
  float top;
  float left;
  float width;
  float height;
  vec2 advance;
} GPUSymbol;

typedef struct FontStruct {
  VmaAllocation symbol_memory;
  VmaAllocation image_memory;
  VkBuffer      symbols;
  VkImage       image;
  VkImageView   view;
  VkSampler     sampler;
  uint32_t*     charmap;
  uint32_t      num_symbols;
  uint32_t      index;
  char* family;
  char* style;
} Font;

typedef struct TextureStruct {
  VmaAllocation image_memory;
  VkImage image;
  VkImageView view;
  VkSampler sampler;

  char* path;
} Texture;

typedef struct GPUStringStruct {
  vec2 pos;
  vec4 color;
  float size;
  uint32_t offset;
  uint32_t length;
  uint32_t font;
} GPUString;

typedef struct GPUDrawableStruct {
  vec2     pos;
  vec2     size;
  vec4     color[4];
  uint32_t type;
  uint32_t var;
  uint32_t events;
} GPUDrawable;

typedef struct GPULayerStruct {
  DrawCommand     draw;
  DispatchCommand dispatch_strings;

  uint32_t max_drawables;
  uint32_t max_codes;
  uint32_t max_strings;
  uint32_t num_drawables;

  VkDeviceAddress strings;
  VkDeviceAddress codes;
  VkDeviceAddress drawables;
  VkDeviceAddress container;
} GPULayer;

typedef struct LayerStruct {
  VkBuffer        strings[MAX_FRAMES_IN_FLIGHT];
  VkBuffer        codes[MAX_FRAMES_IN_FLIGHT];
  VkBuffer        drawables[MAX_FRAMES_IN_FLIGHT]; 
  VkBuffer        layer[MAX_FRAMES_IN_FLIGHT];

  VmaAllocation strings_memory[MAX_FRAMES_IN_FLIGHT];
  VmaAllocation drawables_memory[MAX_FRAMES_IN_FLIGHT];
  VmaAllocation codes_memory[MAX_FRAMES_IN_FLIGHT];
  VmaAllocation layer_memory[MAX_FRAMES_IN_FLIGHT];

  VkDeviceAddress address[MAX_FRAMES_IN_FLIGHT];

  GPUDrawable* drawables_buffer;
  GPUString* strings_buffer;
  uint32_t* codes_buffer;

  GPULayer data;
} Layer;

typedef struct LayerInputStruct {
  uint32_t num_strings;
  uint32_t num_codes;
  uint32_t num_drawables;

  uint32_t max_codes;
  uint32_t max_strings;
  uint32_t max_drawables;

  GPUString* strings;
  uint32_t* codes;
  GPUDrawable* drawables;
} LayerInput;

typedef struct GPUContainerStruct {
  vec2 offset;
  vec2 size;
  uint32_t anchor;

  VkDeviceAddress context;
} GPUContainer;

typedef struct UIContextStruct UIContext;

typedef bool (*ui_text_callback)(void* data, UIContext* ui, RenderContext* gpu, unsigned int codepoint);
typedef bool (*ui_key_callback)(void* data, UIContext* ui, RenderContext* gpu, int key, int action, int mods);
typedef bool (*ui_button_callback)(void* data, UIContext* ui, RenderContext* gpu, float x, float y, int button, int action, int mods);
typedef bool (*ui_scroll_callback)(void* data, UIContext* ui, RenderContext* gpu, double x, double y);
typedef bool (*ui_cursor_callback)(void* data, UIContext* ui, RenderContext* gpu, float x, float y);
typedef void (*ui_deselect_callback)(void* data, UIContext* ui, RenderContext* gpu);

typedef struct UICallbacksStruct {
  uint32_t layer;
  uint32_t element;
  void*    data;

  ui_text_callback     text;
  ui_key_callback      key;
  ui_button_callback   button;
  ui_scroll_callback   scroll;
  ui_cursor_callback   cursor;
  ui_deselect_callback deselect;
} UICallbacks;

typedef struct ContainerStruct {
  VkBuffer container[MAX_FRAMES_IN_FLIGHT];

  VmaAllocation container_memory[MAX_FRAMES_IN_FLIGHT];

  VkDeviceAddress address[MAX_FRAMES_IN_FLIGHT];

  GPUContainer data;

  uint32_t id;
  uint32_t layer_count;
  Layer* layers;

  uint32_t callback_count;
  UICallbacks* callbacks;
} Container;

typedef struct ContainerInputStruct {
  uint32_t id;
  uint32_t anchor;
  vec2 offset;
  vec2 size;

  uint32_t layer_count;
  LayerInput* layers;

  uint32_t callback_count;
  UICallbacks* callbacks;
} ContainerInput;

typedef struct GPUUIContextStruct {
  VkDeviceAddress font_infos;
  vec2 screen;
  vec2 extent;
  vec2 scale;
} GPUUIContext;

struct UIContextStruct {
  VkDeviceAddress address;

  VkBuffer context;

  VmaAllocation context_memory;

  VkBuffer font_infos;
  VmaAllocation font_infos_memory;

  VkDescriptorSet textures;
  VkDescriptorSet samplers;
  VkDescriptorSet font_samplers;
  VkDescriptorSet font_textures;
  VkDescriptorSetLayout samplers_layout;
  VkDescriptorSetLayout textures_layout;
  VkDescriptorPool fonts_pool;
  VkDescriptorPool textures_pool;
 
  GraphicsPipeline pipeline;
  ComputePipeline string_pipeline;

  uint32_t max_fonts;
  uint32_t max_textures;

  Font* fonts;
  Texture* texture_slots;

  uint32_t max_containers;
  Container* containers;

  GPUUIContext data;

  FT_Library freetype;

  UICallbacks* active_callbacks;
  uint32_t     active_container;
  uint32_t     active_layer;
  uint32_t     active_element;

  double cursor[2];
};

VkResult create_ui_context(
    uint32_t max_fonts,
    uint32_t max_textures,
    uint32_t max_containers,
    RenderContext* gpu,
    UIContext* context);

VkResult load_font(
    uint32_t index,
    const char* ttf_file,
    uint32_t size,
    VkBool32 antialias,
    RenderContext* gpu,
    UIContext* context);

VkResult load_texture(
    const char* png_path,
    RenderContext* gpu,
    UIContext* context,
    uint32_t* index);

VkResult create_container(
    ContainerInput* container,
    RenderContext* gpu,
    UIContext* context);

VkResult create_layer(
    uint32_t index,
    LayerInput* input,
    RenderContext* gpu,
    Container* container);

VkResult map_string(
    const char * text,
    uint32_t* buffer,
    uint32_t offset,
    uint32_t font,
    UIContext* context);

VkResult update_ui_context_resolution(
    UIContext* ui,
    RenderContext* gpu);

VkResult update_ui_string(
    char* string,
    uint32_t container_id,
    uint32_t layer_index,
    uint32_t string_index,
    UIContext* ui,
    RenderContext* gpu);

Container* context_container(uint32_t container_id, UIContext* ui);

bool ui_intersect(
    double cursor[2],
    RenderContext* gpu,
    UIContext* ui,
    uint32_t events,
    uint32_t* container,
    uint32_t* layer,
    uint32_t* element,
    vec2 position); 

void set_active_element(uint32_t container, uint32_t layer, uint32_t element, UIContext* ui);

void clear_active_element(UIContext* ui, RenderContext* gpu);

void anchor_offset(RenderContext* gpu, Container* container, vec2 offset);

#endif