// A naive implementation of an immediate mode gui.

#ifndef ED_UI_INCLUDED
#define ED_UI_INCLUDED

#include <stddef.h>
#include <stdint.h>
#include <stdbool.h>
#include "string.h"

typedef enum {
    UI_AXIS_HORIZONTAL,
    UI_AXIS_VERTICAL,
} ui_axis;

typedef enum {
    UI_SEMANTIC_SIZE_FIT_TEXT,
    UI_SEMANTIC_SIZE_CHILDREN_SUM,
    UI_SEMANTIC_SIZE_FILL,
    UI_SEMANTIC_SIZE_EXACT,
    UI_SEMANTIC_SIZE_PERCENT_OF_PARENT,
} ui_semantic_size_t;

typedef struct {
    ui_semantic_size_t type;
    union {
        uint32_t integer;
    };
} ui_semantic_size;

typedef struct {
    ui_axis axis;
    ui_semantic_size semantic_size[2];
    uint32_t computed_size[2];
    uint32_t computed_pos[2]; 
} ui_size;

// UI Element data persisted across frames
typedef struct {
    string label;
    ui_size size;
    size_t last_instantiated_index;
} ui_element_cache_data;

typedef enum {
    UI_FLAG_CLICKABLE         =  0b000000001,
    UI_FLAG_HOVERABLE         =  0b000000010,
    UI_FLAG_SCROLLABLE        =  0b000000100,
    UI_FLAG_DRAW_TEXT         =  0b000001000,
    UI_FLAG_DRAW_BORDER       =  0b000010000,
    UI_FLAG_DRAW_BACKGROUND   =  0b000100000,
    UI_FLAG_ROUNDED_BORDER    =  0b001000000,
    UI_FLAG_FLOATING          =  0b010000000,
    UI_FLAG_CUSTOM_DRAW_FUNC  =  0b100000000,
} ui_flags;

// Ephemeral frame only UI Element data
typedef struct {
    size_t index;
    string key;
    string label;

    ui_size size;
    ui_flags flags;

    // optional types
    size_t first;
    size_t last;
    size_t next;
    size_t prev;
    size_t parent;
} ui_element_frame_data;

typedef struct {
    ed_ht *cached_elements;
} ui_context;

#endif

#ifdef ED_UI_IMPLEMENTATION
#endif