const std = @import("std");

// ============================================================================
// Types & Enums
// ============================================================================

/// RGB565 Color Format (16-bit)
pub const Color = u16;

/// Transformation flags for hardware-accelerated sprite operations.
pub const Transform = packed struct(u32) {
    flip_h: bool = false,
    flip_v: bool = false,
    rot_90: bool = false,
    rot_180: bool = false,
    rot_270: bool = false,
    _padding: u27 = 0,
};

// Common Transform Constants
pub const TRANSFORM_NONE = Transform{};
pub const TRANSFORM_FLIP_H = Transform{ .flip_h = true };
pub const TRANSFORM_FLIP_V = Transform{ .flip_v = true };

// ============================================================================
// Low-Level C-Imports (Raw WAMR Native Symbol Bindings)
// ============================================================================

pub extern "nova64" fn nova64_yield(timeout_ms: u32) void;
pub extern "nova64" fn nova64_log(message: [*:0]const u8) void;

// Framebuffer Controls
pub extern "nova64" fn nova64_ppu_clear(color: u32) void;
pub extern "nova64" fn nova64_framebuffer_swap() void;

// PPU Drawing Primitives
pub extern "nova64" fn nova64_ppu_fill_rect(x: i32, y: i32, w: i32, h: i32, color: u32) void;
pub extern "nova64" fn nova64_ppu_blit(
    src_ptr: [*]const Color,
    src_stride: u32,
    src_x: i32,
    src_y: i32,
    dst_x: i32,
    dst_y: i32,
    w: i32,
    h: i32,
) void;
pub extern "nova64" fn nova64_ppu_blit_colorkey(
    src_ptr: [*]const Color,
    src_stride: u32,
    src_x: i32,
    src_y: i32,
    dst_x: i32,
    dst_y: i32,
    w: i32,
    h: i32,
    key_color: u32,
) void;
pub extern "nova64" fn nova64_ppu_blend(
    src_ptr: [*]const Color,
    src_stride: u32,
    src_x: i32,
    src_y: i32,
    dst_x: i32,
    dst_y: i32,
    w: i32,
    h: i32,
    global_alpha: u32,
) void;
pub extern "nova64" fn nova64_ppu_blit_transform(
    src_ptr: [*]const Color,
    src_stride: u32,
    src_x: i32,
    src_y: i32,
    dst_x: i32,
    dst_y: i32,
    w: i32,
    h: i32,
    transform: Transform,
) void;
pub extern "nova64" fn nova64_ppu_blit_scale(
    src_ptr: [*]const Color,
    src_stride: u32,
    src_w: i32,
    src_h: i32,
    dst_x: i32,
    dst_y: i32,
    dst_w: i32,
    dst_h: i32,
) void;

// Hardware Sync
pub extern "nova64" fn nova64_ppu_wait_idle() void;
pub extern "nova64" fn nova64_ppu_is_busy() u32;

// ============================================================================
// High-Level Idiomatic Zig API
// ============================================================================

pub fn log(message: [*:0]const u8) void {
    nova64_log(message);
}

pub fn sleep(timeout_ms: u32) void {
    nova64_yield(timeout_ms);
}

pub fn yield() void {
    nova64_yield(0);
}

/// Swaps the front and back buffer to display the rendered frame.
pub fn ppuSwapBuffers() void {
    nova64_framebuffer_swap();
}

/// Clears the back buffer with a solid RGB565 color.
pub fn ppuClear(color: Color) void {
    nova64_ppu_clear(@as(u32, color));
}

/// Fills a rectangle on the back buffer with a solid RGB565 color.
pub fn ppuFillRect(x: i32, y: i32, w: i32, h: i32, color: Color) void {
    nova64_ppu_fill_rect(x, y, w, h, @as(u32, color));
}

/// Opaque block image transfer from a pixel buffer to the back buffer.
pub fn ppuBlit(
    src: []const Color,
    src_stride: u32,
    src_x: i32,
    src_y: i32,
    dst_x: i32,
    dst_y: i32,
    w: i32,
    h: i32,
) void {
    nova64_ppu_blit(src.ptr, src_stride, src_x, src_y, dst_x, dst_y, w, h);
}

/// Transparent sprite blitting using color keying.
pub fn ppuBlitColorKey(
    src: []const Color,
    src_stride: u32,
    src_x: i32,
    src_y: i32,
    dst_x: i32,
    dst_y: i32,
    w: i32,
    h: i32,
    key_color: Color,
) void {
    nova64_ppu_blit_colorkey(src.ptr, src_stride, src_x, src_y, dst_x, dst_y, w, h, @as(u32, key_color));
}

/// Alpha-blended sprite composition (alpha: 0 = transparent, 255 = opaque).
pub fn ppuBlend(
    src: []const Color,
    src_stride: u32,
    src_x: i32,
    src_y: i32,
    dst_x: i32,
    dst_y: i32,
    w: i32,
    h: i32,
    alpha: u8,
) void {
    nova64_ppu_blend(src.ptr, src_stride, src_x, src_y, dst_x, dst_y, w, h, @as(u32, alpha));
}

/// Transformed image transfer (rotation & flipping).
pub fn ppuBlitTransform(
    src: []const Color,
    src_stride: u32,
    src_x: i32,
    src_y: i32,
    dst_x: i32,
    dst_y: i32,
    w: i32,
    h: i32,
    transform: Transform,
) void {
    nova64_ppu_blit_transform(src.ptr, src_stride, src_x, src_y, dst_x, dst_y, w, h, transform);
}

/// Hardware-accelerated image scaling/resizing.
pub fn ppuBlitScale(
    src: []const Color,
    src_stride: u32,
    src_w: i32,
    src_h: i32,
    dst_x: i32,
    dst_y: i32,
    dst_w: i32,
    dst_h: i32,
) void {
    nova64_ppu_blit_scale(src.ptr, src_stride, src_w, src_h, dst_x, dst_y, dst_w, dst_h);
}

/// Blocks execution until the PPU/DMA2D hardware engine finishes all operations.
pub fn ppuWaitIdle() void {
    nova64_ppu_wait_idle();
}

/// Checks if the PPU hardware engine is currently busy.
pub fn ppuIsBusy() bool {
    return nova64_ppu_is_busy() != 0;
}