//
// WASM-4: https://wasm4.org/docs

// ┌───────────────────────────────────────────────────────────────────────────┐
// │                                                                           │
// │ Platform Constants                                                        │
// │                                                                           │
// └───────────────────────────────────────────────────────────────────────────┘

pub const SCREEN_SIZE: u32 = 160;

// ┌───────────────────────────────────────────────────────────────────────────┐
// │                                                                           │
// │ Memory Addresses                                                          │
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// └───────────────────────────────────────────────────────────────────────────┘

pub const PALETTE: *[4]u32 = @intToPtr(*[4]u32, 0x04);
pub const DRAW_COLORS: *u16 = @intToPtr(*u16, 0x14);
pub const GAMEPAD1: *const u8 = @intToPtr(*const u8, 0x16);
pub const GAMEPAD2: *const u8 = @intToPtr(*const u8, 0x17);
pub const GAMEPAD3: *const u8 = @intToPtr(*const u8, 0x18);
pub const GAMEPAD4: *const u8 = @intToPtr(*const u8, 0x19);
pub const MOUSE_X: *const i16 = @intToPtr(*const i16, 0x1a);
pub const MOUSE_Y: *const i16 = @intToPtr(*const i16, 0x1c);
pub const MOUSE_BUTTONS: *const u8 = @intToPtr(*const u8, 0x1e);
pub const SYSTEM_FLAGS: *u8 = @intToPtr(*u8, 0x1f);
pub const NETPLAY: *const u8 = @intToPtr(*const u8, 0x20);
pub const FRAMEBUFFER: *[6400]u8 = @intToPtr(*[6400]u8, 0xA0);

pub const BUTTON_1: u8 = 1;
pub const BUTTON_2: u8 = 2;
pub const BUTTON_LEFT: u8 = 16;
pub const BUTTON_RIGHT: u8 = 32;
pub const BUTTON_UP: u8 = 64;
pub const BUTTON_DOWN: u8 = 128;

pub const MOUSE_LEFT: u8 = 1;
pub const MOUSE_RIGHT: u8 = 2;
pub const MOUSE_MIDDLE: u8 = 4;

pub const SYSTEM_PRESERVE_FRAMEBUFFER: u8 = 1;
pub const SYSTEM_HIDE_GAMEPAD_OVERLAY: u8 = 2;

// ┌───────────────────────────────────────────────────────────────────────────┐
// │                                                                           │
// │ Drawing Functions                                                         │
// │                                                                           │
// └───────────────────────────────────────────────────────────────────────────┘

/// Copies pixels to the framebuffer.
pub extern fn blit(sprite: [*]const u8, x: i32, y: i32, width: u32, height: u32, flags: u32) void;

/// Copies a subregion within a larger sprite atlas to the framebuffer.
pub extern fn blitSub(sprite: [*]const u8, x: i32, y: i32, width: u32, height: u32, src_x: u32, src_y: u32, stride: u32, flags: u32) void;

pub const BLIT_2BPP: u32 = 1;
pub const BLIT_1BPP: u32 = 0;
pub const BLIT_FLIP_X: u32 = 2;
pub const BLIT_FLIP_Y: u32 = 4;
pub const BLIT_ROTATE: u32 = 8;

/// Draws a line between two points.
pub extern fn line(x1: i32, y1: i32, x2: i32, y2: i32) void;

/// Draws an oval (or circle).
pub extern fn oval(x: i32, y: i32, width: u32, height: u32) void;

/// Draws a rectangle.
pub extern fn rect(x: i32, y: i32, width: u32, height: u32) void;

/// Draws text using the built-in system font.
pub fn text(str: []const u8, x: i32, y: i32) void {
    textUtf8(str.ptr, str.len, x, y);
}
extern fn textUtf8(strPtr: [*]const u8, strLen: usize, x: i32, y: i32) void;

/// Draws a vertical line
pub extern fn vline(x: i32, y: i32, len: u32) void;

/// Draws a horizontal line
pub extern fn hline(x: i32, y: i32, len: u32) void;

// ┌───────────────────────────────────────────────────────────────────────────┐
// │                                                                           │
// │ Sound Functions                                                           │
// │                                                                           │
// └───────────────────────────────────────────────────────────────────────────┘

/// Plays a sound tone.
pub extern fn tone(frequency: u32, duration: u32, volume: u32, flags: u32) void;

pub const TONE_PULSE1: u32 = 0;
pub const TONE_PULSE2: u32 = 1;
pub const TONE_TRIANGLE: u32 = 2;
pub const TONE_NOISE: u32 = 3;
pub const TONE_MODE1: u32 = 0;
pub const TONE_MODE2: u32 = 4;
pub const TONE_MODE3: u32 = 8;
pub const TONE_MODE4: u32 = 12;
pub const TONE_PAN_LEFT: u32 = 16;
pub const TONE_PAN_RIGHT: u32 = 32;

// ┌───────────────────────────────────────────────────────────────────────────┐
// │                                                                           │
// │ Storage Functions                                                         │
// │                                                                           │
// └───────────────────────────────────────────────────────────────────────────┘

/// Reads up to `size` bytes from persistent storage into the pointer `dest`.
pub extern fn diskr(dest: [*]u8, size: u32) u32;

/// Writes up to `size` bytes from the pointer `src` into persistent storage.
pub extern fn diskw(src: [*]const u8, size: u32) u32;

// ┌───────────────────────────────────────────────────────────────────────────┐
// │                                                                           │
// │ Other Functions                                                           │
// │                                                                           │
// └───────────────────────────────────────────────────────────────────────────┘

/// Prints a message to the debug console.
pub fn trace(x: []const u8) void {
    traceUtf8(x.ptr, x.len);
}
extern fn traceUtf8(strPtr: [*]const u8, strLen: usize) void;

/// Use with caution, as there's no compile-time type checking.
///
/// * %c, %d, and %x expect 32-bit integers.
/// * %f expects 64-bit floats.
/// * %s expects a *zero-terminated* string pointer.
///
/// See https://github.com/aduros/wasm4/issues/244 for discussion and type-safe
/// alternatives.
pub extern fn tracef(x: [*:0]const u8, ...) void;