#include "buffer16.h"

typedef struct ui_code_loc_t ui_code_loc_t;
struct ui_code_loc_t {
    char *file;
    int line;
    int counter;
};

typedef struct ui_id_t ui_id_t;
struct ui_id_t {
    u64 value;
};

typedef struct ui_box_flags_t ui_box_flags_t;
struct ui_box_flags_t {
    b8 draw_rect: 1;
    b8 draw_border: 1;
    b8 draw_text: 1;
    b8 clip_rect: 1;

    b8 animate_appear: 1;

    b8 children_sum_x: 1;
    b8 children_sum_y: 1;
    b8 keyboard_nav: 1;

    b8 sim_even_if_no_focus: 1;
};

typedef enum {
    ui_text_align_left,
    ui_text_align_center,
} ui_text_align_t;

typedef enum {
    ui_axis2_invalid = -1,
    ui_axis2_x,
    ui_axis2_y,
    ui_axis2_count,
} ui_axis2_t;

typedef enum {
    ui_lop_cut_top,
    ui_lop_cut_bottom,
    ui_lop_cut_left,
    ui_lop_cut_right,
    ui_lop_idle,
} ui_lop_t;

#include "ui.gen.h"

typedef struct ui_caret_t ui_caret_t;
struct ui_caret_t {
    union {
        i32 e[2];
        struct { r1i32_t range; };
    };
    i32 ifront;
};

typedef struct ui_text_input_t ui_text_input_t;
struct ui_text_input_t {
    union {
        struct { char *str; i64 len; };
        s8_t string;
    };

    i32 cap;
    ui_caret_t caret;
};

typedef struct ui_box_t ui_box_t;
typedef void ui_custom_draw_t(ui_box_t *);

struct ui_box_t {
    ui_box_t *next;
    ui_box_t *prev;
    ui_box_t *first;
    ui_box_t *last;
    ui_box_t *parent;
    i32       node_count;

    ui_code_loc_t loc;
    s8_t          string;
    v2f32_t       string_size;

    ui_box_flags_t flags;
    b8                created_new;
    ui_custom_draw_t *custom_draw;
    ui_lop_t          lop;
    UI_DECL_BOX_MEMBERS

    // state
    ui_id_t   id;
    ui_box_t *hash_next;
    ui_box_t *hash_prev;
    u64       last_touched_event_id;

    f32 appear_t;
    f32 hot_t;
    f32 active_t;

    r2f32_t final_rect;
    b32     expanded;

    ui_text_input_t *text_input;
    view_id_t view;
};

typedef struct ui_signal_t ui_signal_t;
struct ui_signal_t {
    ui_box_t *box;
    v2f32_t drag;
    struct {
        b8 clicked:  1;
        b8 dragging: 1;

        b8 text_changed: 1;
        b8 text_commit: 1;
    };
};

typedef struct ui_t ui_t;
struct ui_t {
    app_frame_t *frame;

    // building
    ui_box_t root;
    ui_box_t *top;
    app_event_t *event;
    ui_box_t *reverse_order_ref;

    UI_DECL_STACKS

    // allocation
    ma_arena_t *box_arena;
    i32 allocated_boxes;
    ui_box_t *free_first;
    ui_box_t *hash_first;
    ui_box_t *hash_last;

    // interaction
    ui_id_t hot;
    ui_id_t active;
    ui_id_t focus;

    // drawing
    r2f32_t clip_rect;
};

gb ui_t *ui;

gb_read_only ui_id_t ui_null_id;
gb_read_only ui_box_t ui_null_box;
gb_read_only ui_box_flags_t ui_null_flags;

fn b32 ui_is_null_id(ui_id_t id) { return id.value == 0; }
fn b32 ui_is_null_box(ui_box_t *box) { return box->id.value == 0; }
fn b32 ui_is_hot_box(ui_box_t *box) { return !ui_is_null_box(box) && box->id.value == ui->hot.value; }
fn b32 ui_is_active_box(ui_box_t *box) { return !ui_is_null_box(box) && box->id.value == ui->active.value; }
fn b32 ui_is_focused_box(ui_box_t *box) { return !ui_is_null_box(box) && box->id.value == ui->focus.value; }

#define ev_left(ev) ((ev)->mouse_button == app_mouse_button_left)
#define ev_left_up(ev) ((ev)->kind == app_event_kind_mouse_up && ev_left(ev))
#define ev_left_down(ev) ((ev)->kind == app_event_kind_mouse_down && ev_left(ev))

#define ev_right(ev) ((ev)->mouse_button == app_mouse_button_right)
#define ev_right_up(ev) ((ev)->kind == app_event_kind_mouse_up && ev_right(ev))
#define ev_right_down(ev) ((ev)->kind == app_event_kind_mouse_down && ev_right(ev))

#define UILOC (ui_code_loc_t){.file = __FILE__, .line = __LINE__, .counter = __COUNTER__}
#define ui_em(x) ((x) * rn->main_font->size)
#define ui_dm(V) ((V) * rn->main_font->computed_xchar_size)
#define ui_max 200000000.f
#define ui_children_sum 0

fn ui_id_t ui_id(s8_t string);
fn ui_id_t ui_idf(char *str, ...);

fn r2f32_t window_rect_from_frame(app_frame_t *frame);