const std = @import("std");
const sys = @import("system.zig");
const sdl = @import("SDL3");

const palette = [_]u32{
    0x000000ff, // black
    0xffffffff, // white
    0xff0000ff, // red
    // ...
};

pub fn main() !void {
    var system: sys.System = .{};

    _ = sdl.SDL_SetAppMetadata("ZigCon", "0.0.1", "com.cityboundforest.zigcon");

    if (!sdl.SDL_Init(sdl.SDL_INIT_VIDEO)) {
        std.debug.print("SDL Init Errror: {s}\n", .{sdl.SDL_GetError()});
        return error.SDLInitializationFailed;
    }

    defer sdl.SDL_Quit();

    var window: *sdl.SDL_Window = undefined;
    var renderer: *sdl.SDL_Renderer = undefined;

    if (!sdl.SDL_CreateWindowAndRenderer("ZigCon", 600, 600, 0, @ptrCast(&window), @ptrCast(&renderer))) {
        std.debug.print("SDL Window Error: {s}\n", .{sdl.SDL_GetError()});
        return error.WindowCreationError;
    }

    defer sdl.SDL_DestroyWindow(@ptrCast(window));

    _ = sdl.SDL_SetRenderLogicalPresentation(@ptrCast(renderer), 600, 600, sdl.SDL_LOGICAL_PRESENTATION_LETTERBOX);

    var run = true;

    const texture = sdl.SDL_CreateTexture(@ptrCast(renderer), sdl.SDL_PIXELFORMAT_RGBA32, sdl.SDL_TEXTUREACCESS_STREAMING, sys.System.WIDTH, sys.System.HEIGHT);
    defer sdl.SDL_DestroyTexture(@ptrCast(texture));

    const format_details = sdl.SDL_GetPixelFormatDetails(sdl.SDL_PIXELFORMAT_RGBA32);
    var r: u8 = undefined;
    var g: u8 = undefined;
    var b: u8 = undefined;
    var a: u8 = undefined;

    while (run) {
        var event: sdl.SDL_Event = undefined;
        var surface: *sdl.SDL_Surface = undefined;

        while (sdl.SDL_PollEvent(@ptrCast(&event))) {
            if (event.type == sdl.SDL_EVENT_QUIT) {
                run = false;
            }
        }

        try system.step();

        if (sdl.SDL_LockTextureToSurface(@ptrCast(texture), null, @ptrCast(&surface))) {
            for (0..sys.System.HEIGHT) |y| {
                for (0..sys.System.WIDTH) |x| {
                    const idx = system.ram[sys.System.VRAM_START + y * sys.System.HEIGHT + x];
                    const color = palette[idx];
                    sdl.SDL_GetRGBA(color, @ptrCast(format_details), null, @ptrCast(&r), @ptrCast(&g), @ptrCast(&b), @ptrCast(&a));
                    _ = sdl.SDL_WriteSurfacePixel(@ptrCast(surface), @intCast(x), @intCast(y), r, g, b, a);
                }
            }

            sdl.SDL_UnlockTexture(@ptrCast(texture));
        }

        const dst_rect: sdl.SDL_FRect = .{
            .x = 0.0,
            .y = 0.0,
            .w = 600.0,
            .h = 600.0,
        };

        _ = sdl.SDL_SetRenderDrawColorFloat(@ptrCast(renderer), 0.0, 0.0, 0.0, sdl.SDL_ALPHA_OPAQUE_FLOAT);
        _ = sdl.SDL_RenderClear(@ptrCast(renderer));
        _ = sdl.SDL_RenderTexture(@ptrCast(renderer), @ptrCast(texture), null, @ptrCast(&dst_rect));
        _ = sdl.SDL_RenderPresent(@ptrCast(renderer));
    }
}