-- Copyright (c) 2024 - Ognjen 'xolatile' Milan Robovic
--
-- GNU General Public Licence (version 3 or later)

with ada.text_io, ada.strings.unbounded;
use  ada.text_io, ada.strings.unbounded;

package core is

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

	type echo_status is (
		failure,                warning,                success,                comment,                import,                 export
	);

	type signal_code is (
		signal_none,            signal_space,           signal_0,               signal_1,               signal_2,               signal_3,
		signal_4,               signal_5,               signal_6,               signal_7,               signal_8,               signal_9,
		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 .. 72);

	type pointer is access procedure;

	type vector is record x, y                                 : integer; end record;
	type sprite is record index, width, height, frames, states : integer; end record;
	type font   is record index, scale, space                  : integer; end record;
	type song   is record index                                : integer; end record;

	type block  is record
		x      :        integer   := 0;
		y      :        integer   := 0;
		width  :        integer   := 0;
		height :        integer   := 0;
		mode   :        integer   := 0;
		action : access procedure := null;
	end record;

	type text_box_data is record
		data : unbounded_string := null_unbounded_string;
		size : vector           := (0, 0);
	end record;

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

	icon                : constant natural := 32;
	base                : constant natural := 16;
	gameplay_framerate  : constant natural := 60;
	animation_framerate : constant natural :=  4;

	echo_mark : constant array (echo_status) of boolean := (
		failure => true,
		warning => true,
		success => true,
		comment => true,
		import  => true,
		export  => true
	);

	engine_active : boolean := false;

	cursor         : vector      := (0, 0);
	camera         : vector      := (0, 0);
	cursor_mode    : integer     := 0;
	signal_mode    : signal_code := signal_none;
	framerate      : integer     := 0;
	global_time    : natural     := 0;
	gameplay_time  : natural     := 0;
	animation_time : natural     := 0;
	zoom           : natural     := 1;

	block_limit : constant natural := 40;
	block_count :          natural := 0;

	block_array : array (0 .. block_limit - 1) of block := (others => (0, 0, 0, 0, 0, null));

	text_box : text_box_data;

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

	procedure echo (status : in echo_status; text : in string);

	procedure dash;
	procedure semi_dash;

	function c_string (ada_string : in string) return string;

	function random (minimum, maximum        : in integer) return integer;
	function clip   (value, minimum, maximum : in integer) return integer;

	function lowercase (text : in string) return string;

	function window_width  return integer;
	function window_height return integer;

	function import_sprite (file_path : in string; frames, states : in integer) return sprite;
	function import_font   (file_path : in string; scale, space   : in integer) return font;
	function import_song   (file_path : in string)                              return song;

	procedure draw (data   : in sprite;
	                x      : in integer := 0;
	                y      : in integer := 0;
	                u      : in integer := 0;
	                v      : in integer := 0;
	                width  : in integer := 0;
	                height : in integer := 0;
	                state  : in integer := 0);

	procedure write (text : in string  := "";
	                 x    : in integer := 0;
	                 y    : in integer := 0;
	                 data : in font);

	procedure play (index : in integer);
	procedure stop (index : in integer);

	procedure overlay;

	procedure block_queue (data : in block);

	function read_text_box return string;

	procedure write_text_box (text : in string);

	procedure increment (value : in out integer);
	procedure decrement (value : in out integer);

	procedure idle;
	procedure move_camera_up;
	procedure move_camera_down;
	procedure move_camera_left;
	procedure move_camera_right;

	procedure initialize;
	procedure deinitialize;
	procedure synchronize;

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end core;