#ifndef HEX_H
#define HEX_H

#include "gpu.h"
#include "vulkan/vulkan_core.h"

#define MAX_RAYS 10
#define MAX_HIGHLIGHTS 10
#define MAX_POINTS 10

#define MAX_LOADED_REGIONS 2500
#define REGION_SIZE 10
#define REGION_HEX_COUNT (3*REGION_SIZE*(REGION_SIZE-1)+1)
#define HEX_X 0.75
#define SQRT3 1.732050807568877193176604123436845839023590087890625
#define HEX_Z (SQRT3/2)
#define REGION_DIAMETER (2*REGION_SIZE-1)
#define REGION_WIDTH (HEX_X*REGION_DIAMETER)
#define REGION_HEIGHT (HEX_Z*REGION_DIAMETER)

#define max(a, b) ((a > b) ? a : b)
#define min(a, b) ((a < b) ? a : b)

typedef struct HexCoordStruct {
  int32_t q;
  int32_t r;
} HexCoord;

extern vec3 hex_vertices[];
extern vec3 hex_starts[];
extern vec3 hex_directions[];
extern HexCoord hex_starts_qr[];
extern HexCoord hex_directions_qr[];
extern int hex_indices[];

typedef struct GPUHexStruct {
  float    height[6];
  uint32_t color[7];
} GPUHex;

typedef struct GPUHexRegionStruct {
  HexCoord position;
  int32_t y;
  uint32_t map;

  GPUHex hexes[REGION_HEX_COUNT];
} GPUHexRegion;

typedef struct HexRegionStruct {
  VkDeviceAddress address;
  VkBuffer region;
  VmaAllocation region_memory;

  GPUHexRegion data;
} HexRegion;

typedef struct GPURayStruct {
  vec4 start;
  vec4 end;
  vec4 color;
} GPURay;

typedef struct GPUHighlightStruct {
  vec4 color;
  uint32_t region;
  uint32_t hex;
  float offset;
} GPUHighlight;

typedef struct GPUPointStruct {
  vec4 color;
  uint32_t region;
  uint32_t hex;
  uint32_t vertex;
  float size;
  float offset;
} GPUPoint;

typedef struct GPUHexContextStruct {
  mat4 proj;
  mat4 view;
  uint32_t current_map;
  VkDeviceAddress rays;
  VkDeviceAddress points;
  VkDeviceAddress highlights;
  VkDeviceAddress regions[MAX_LOADED_REGIONS];
} GPUHexContext;

typedef struct HexContextStruct {
  VkDeviceAddress address[MAX_FRAMES_IN_FLIGHT];
  VkBuffer        context[MAX_FRAMES_IN_FLIGHT];
  VmaAllocation   context_memory[MAX_FRAMES_IN_FLIGHT]; 

  VkBuffer rays[MAX_FRAMES_IN_FLIGHT];
  VkBuffer points[MAX_FRAMES_IN_FLIGHT];
  VkBuffer highlights[MAX_FRAMES_IN_FLIGHT];
  VmaAllocation rays_memory[MAX_FRAMES_IN_FLIGHT];
  VmaAllocation points_memory[MAX_FRAMES_IN_FLIGHT];
  VmaAllocation highlights_memory[MAX_FRAMES_IN_FLIGHT];

  GPURay rays_buffer[MAX_RAYS];
  GPUHighlight highlights_buffer[MAX_HIGHLIGHTS];
  GPUPoint points_buffer[MAX_POINTS];

  mat4 inverse;

  GraphicsPipeline graphics;
  GraphicsPipeline highlight_pipeline;
  GraphicsPipeline point_pipeline;
  GraphicsPipeline ray_pipeline;

  HexRegion* regions[MAX_LOADED_REGIONS];
  GPUHexContext data;
} HexContext;

typedef struct HexPushConstantStruct {
  VkDeviceAddress context;
  double time;
} HexPushConstant;

VkResult create_hex_context(
    RenderContext* gpu,
    HexContext* context);

VkResult set_hex_region(
    HexRegion* region,
    HexContext* hex,
    RenderContext* gpu);

VkResult allocate_hex_region(
    int32_t q, int32_t r, int32_t y,
    uint32_t map,
    HexRegion** region,
    HexContext* hex,
    RenderContext* gpu);

VkResult free_hex_region(
    uint32_t region_index,
    HexContext* hex,
    RenderContext* gpu);

bool ray_world_intersect(
    float* distance,
    uint32_t* vertex,
    uint32_t* rid,
    uint32_t* hid,
    vec4 ray_start,
    vec4 ray_end,
    HexContext* context);

VkResult update_hex_proj(
    RenderContext* gpu,
    HexContext* hex);

VkResult update_hex_view(
    vec3 position,
    vec2 rotation,
    double distance,
    RenderContext* gpu,
    HexContext* hex);

void hex_qr(uint32_t hex, HexCoord* world);

void region_qr(HexCoord region, HexCoord* world);

void hex_add(HexCoord from, HexCoord* to);

void hex_index(HexCoord world, HexCoord* region, uint32_t* hex);

void hex_vertex_neighbors(
  uint32_t vertex, HexCoord hex,
  uint32_t n_vertex[2], HexCoord n_region[2], uint32_t n_hex[2]);

void first_matching_region(HexCoord coord, int y, uint32_t* region, HexContext* context);

#endif