with ada.text_io, ada.strings, interfaces.c;
use  ada.text_io, ada.strings, interfaces.c;

package core is

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	type signal_code is (
		signal_none,            signal_space,           signal_zero,            signal_one,             signal_two,             signal_three,
		signal_four,            signal_five,            signal_six,             signal_seven,           signal_eight,           signal_nine,
		signal_a,               signal_b,               signal_c,               signal_d,               signal_e,               signal_f,
		signal_g,               signal_h,               signal_i,               signal_j,               signal_k,               signal_l,
		signal_m,               signal_n,               signal_o,               signal_p,               signal_q,               signal_r,
		signal_s,               signal_t,               signal_u,               signal_v,               signal_w,               signal_x,
		signal_y,               signal_z,               signal_grave,           signal_escape,          signal_enter,           signal_tab,
		signal_backspace,       signal_right,           signal_left,            signal_down,            signal_up,              signal_kp_0,
		signal_kp_1,            signal_kp_2,            signal_kp_3,            signal_kp_4,            signal_kp_5,            signal_kp_6,
		signal_kp_7,            signal_kp_8,            signal_kp_9,            signal_kp_subtract,     signal_kp_add,          signal_left_shift,
		signal_left_control
	);

	subtype short_string is string (1 ..  24);
	subtype long_string  is string (1 .. 160);

	type sprite is
	record
		index, width, height, frames, states : integer;
	end record;

	type vector_2 is
	record
		x, y : integer;
	end record;

                                             ------------------------------------------------------------------------------------------

	-- C

	cursor_x      : integer with import => true, convention => c;
	cursor_y      : integer with import => true, convention => c;
	cursor_mode   : integer with import => true, convention => c;
	signal_mode   : integer with import => true, convention => c;
	engine_active : boolean with import => true, convention => c;
	framerate     : integer with import => true, convention => c;

                                             ------------------------------------------------------------------------------------------

	base                : constant natural := 32;
	gameplay_framerate  : constant natural := 60;
	animation_framerate : constant natural :=  6;

	global_time    : natural := 0;
	gameplay_time  : natural := 0;
	animation_time : natural := 0;

	hexagon_grid_sprite : sprite;
	hexagon_fill_sprite : sprite;

	camera : vector_2 := (0, 0);

                                             ------------------------------------------------------------------------------------------

	-- C

	function random_integer (minimum, maximum : in integer) return integer with import => true, convention => c;

	procedure engine_configure   with import => true, convention => c;
	procedure engine_synchronize with import => true, convention => c;

	function window_width  return integer with import => true, convention => c;
	function window_height return integer with import => true, convention => c;

	procedure render_sprite (sprite, x, y, u, v, width, height : in integer)                      with import => true, convention => c;
	procedure render_string (text : in string; x, y, colour : in integer; monospace : in boolean) with import => true, convention => c;

	function import_sprite (file_path : in string)  return integer with import => true, convention => c;
	function sprite_width  (index     : in integer) return integer with import => true, convention => c;
	function sprite_height (index     : in integer) return integer with import => true, convention => c;

                                             ------------------------------------------------------------------------------------------

	-- Fortran

	procedure fairy_synchronize (level : in integer) with import => true, convention => fortran;

                                             ------------------------------------------------------------------------------------------

	procedure configure;
	procedure synchronize;

	procedure draw_state_box (x, y : in integer);

	function flip_coin                           return integer;
	function roll_dice                           return integer;
	function by_chance (chance     : in integer) return integer;
	function sigmoid   (value      : in boolean) return integer;
	function c_string  (ada_string : in string)  return string;

	function load_sprite (file_path : in string; frames, states : in integer) return sprite;

	procedure crop  (data : in sprite; x, y, u, v, width, height : in integer);
	procedure draw  (data : in sprite; x, y                      : in integer);
	procedure move  (data : in sprite; x, y, frame, state        : in integer);

	procedure write (text : in string; x, y : in integer; colour : in integer := 16#CCCCCC#);

	procedure hexagonal_grid (x, y, width, height : in integer; fill : in boolean);

	function lowercase (text : in string) return string;
	function uppercase (text : in string) return string;

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end core;