#import "modules/std.sx";
#import "build.sx";
#import "modules/compiler.sx";
#import "modules/opengl.sx";
#import "modules/sdl3.sx";
#import "modules/math";
#import "modules/stb.sx";
#import "modules/stb_truetype.sx";
#import "modules/gpu/api.sx";
#import "modules/gpu/types.sx";
#import "modules/gpu/metal.sx";
#import "modules/ui";
#import "modules/platform/api.sx";
#import "modules/platform/sdl3.sx";
#import "modules/platform/uikit.sx";
#import "board.sx";
#import "board_view.sx";
#import "board_anim.sx";

#run configure_build();

// Fixed seed for the rendered board — the same seed tests/board_init.sx locks
// as a snapshot, so the on-screen layout matches that golden gem-for-gem.
BOARD_SEED :: 1337;

g_plat : Platform = ---;
g_pipeline : *UIPipeline = ---;
g_delta_time : f32 = 0.016;
g_viewport_w : f32 = 800.0;
g_viewport_h : f32 = 600.0;
g_safe_insets : EdgeInsets = .{};

// iOS-only concrete handles kept alongside the boxed `g_plat` so the frame loop
// can reach the CAMetalLayer pointer / pixel dims without going through the
// protocol box.
g_uikit_plat : *UIKitPlatform = null;
g_metal_gpu  : *MetalGPU      = null;

// The pure-sx model (board.sx) and its sprites, seeded once in main() and
// rendered every frame. Heap-allocated so the view holds stable pointers to
// the mutable state across frames.
g_board  : *Board       = null;
g_assets : *BoardAssets = null;

// Current cell selection (P4.4). Heap-allocated so it survives BoardView's
// per-frame rebuild; a tap hit-tests a cell and toggles this.
g_sel : *BoardSelection = null;

// In-progress touch drag (P5.2). Heap-allocated for the same reason: the press
// and release that bracket a swipe land on different per-frame BoardView values,
// so the drag start must persist between them.
g_drag : *DragInput = null;

// In-flight move animation (P6.1). Heap-allocated for the same reason: a swipe
// begins the swap/clear/fall timeline, which then plays out over many subsequent
// frames, so the timeline state must persist across BoardView's per-frame rebuild.
g_anim : *BoardAnim = null;

// Rebuilt each frame inside the pipeline's arena; carries the current safe-area
// insets so the grid stays inside the notch / home-indicator region.
build_ui :: () -> View {
    BoardView.{ board = g_board, assets = g_assets, sel = g_sel, drag = g_drag, anim = g_anim, safe = g_safe_insets }
}

frame :: () {
    fc := g_plat.begin_frame();
    g_delta_time = fc.delta_time;
    g_viewport_w = fc.viewport_w;
    g_viewport_h = fc.viewport_h;
    g_safe_insets = g_plat.safe_insets();

    if fc.viewport_w != g_pipeline.screen_width or fc.viewport_h != g_pipeline.screen_height {
        g_pipeline.resize(fc.viewport_w, fc.viewport_h);
    }

    for g_plat.poll_events(): (*ev) {
        inline if OS != .ios {
            if ev == {
                case .key_up: (e) {
                    if e.key == .escape { g_plat.stop(); }
                }
            }
        }
        g_pipeline.dispatch_event(ev);
    }

    // Advance the in-flight move animation by this frame's delta before rendering,
    // so the board view draws the timeline slice for the current wall-clock time.
    if g_anim != null { g_anim.tick(g_delta_time); }

    inline if OS == .ios {
        // Lazy-attach Metal once -[SxAppDelegate didFinishLaunching:] has
        // installed the SxMetalView and its bounds have been measured; both can
        // lag the first CADisplayLink tick, and a zero-sized drawable aborts
        // via XPC.
        if g_uikit_plat.gl_layer == null { return; }
        if g_uikit_plat.pixel_w <= 0 or g_uikit_plat.pixel_h <= 0 { return; }
        if g_metal_gpu.layer == null {
            g_metal_gpu.init(g_uikit_plat.gl_layer, g_uikit_plat.pixel_w, g_uikit_plat.pixel_h);
        } else if g_metal_gpu.pixel_w != g_uikit_plat.pixel_w or g_metal_gpu.pixel_h != g_uikit_plat.pixel_h {
            g_metal_gpu.resize(g_uikit_plat.pixel_w, g_uikit_plat.pixel_h);
        }
        clear : ClearColor = .{ r = 0.05, g = 0.06, b = 0.10, a = 1.0 };
        if !g_metal_gpu.begin_frame(clear) { return; }
        g_pipeline.tick();
        g_metal_gpu.end_frame(fc.target_present_time);
    } else {
        glViewport(0, 0, fc.pixel_w, fc.pixel_h);
        glClearColor(0.05, 0.06, 0.10, 1.0);
        glClear(GL_COLOR_BUFFER_BIT);
        g_pipeline.tick();
    }
    g_plat.end_frame();
}

main :: () -> void {
    inline if OS == .ios {
        u : *UIKitPlatform = xx context.allocator.alloc(size_of(UIKitPlatform));
        u.gpu_mode = .metal;
        if !u.init("m3te", 800, 600) { return; }
        g_plat = xx u;
        g_uikit_plat = u;

        // The CAMetalLayer doesn't exist until didFinishLaunching: runs after we
        // return into UIApplicationMain, so attach lazily on the first frame.
        // init(null, 0, 0) only needs the MTLDevice, which is enough for the
        // texture uploads below.
        g_metal_gpu = xx context.allocator.alloc(size_of(MetalGPU));
        // alloc returns uninitialized memory; struct field defaults are NOT
        // applied, so List caps/lens would be garbage without this memset.
        memset(xx g_metal_gpu, 0, size_of(MetalGPU));
        if !g_metal_gpu.init(null, 0, 0) { return; }
    } else {
        s : *SdlPlatform = xx context.allocator.alloc(size_of(SdlPlatform));
        if !s.init("m3te", 800, 600) { return; }
        g_plat = xx s;
    }

    fc := g_plat.begin_frame();
    g_viewport_w = fc.viewport_w;
    g_viewport_h = fc.viewport_h;
    g_safe_insets = g_plat.safe_insets();

    g_pipeline = xx context.allocator.alloc(size_of(UIPipeline));
    // Same alloc caveat as above: zero so the optional `gpu` reads as null on
    // the desktop path (where set_gpu is not called) and the Lists start empty.
    memset(xx g_pipeline, 0, size_of(UIPipeline));
    inline if OS == .ios {
        g_pipeline.set_gpu(xx g_metal_gpu);
    }
    g_pipeline.init(fc.viewport_w, fc.viewport_h);
    g_pipeline.init_font("assets/fonts/default.ttf", 32.0, fc.dpi_scale);

    g_board = xx context.allocator.alloc(size_of(Board));
    g_board.init(BOARD_SEED);

    g_assets = xx context.allocator.alloc(size_of(BoardAssets));
    g_assets.init();
    g_assets.load(g_pipeline.gpu);

    g_sel = xx context.allocator.alloc(size_of(BoardSelection));
    g_sel.init();

    g_drag = xx context.allocator.alloc(size_of(DragInput));
    g_drag.init();

    g_anim = xx context.allocator.alloc(size_of(BoardAnim));
    g_anim.init();

    g_pipeline.set_body(closure(build_ui));

    g_plat.run_frame_loop(closure(frame));
    g_plat.shutdown();
}
