// Phase 0 baseline (PLAN-FFI.md step 0.2): small structs (≤16 bytes)
// passed by value into a C `#foreign` fn and returned by value. Two
// shapes that exercise different aggregate ABI paths today:
//   Vec2  — 8 bytes,  two f32        (float register pair on AAPCS64)
//   Vec4f — 16 bytes, four f32       (HFA — homogeneous float aggregate)
//
// 16-byte integer-only structs (e.g. `{ s64, s64 }`, `{ s32, s32, s32, s32 }`)
// are *not* covered here: sx's `#foreign` decl currently lowers them
// as `[2 x i64]` while the call site uses the struct type, tripping
// the LLVM verifier. Repro pinned in `examples/issue-0036.sx`; once
// that bug closes, fold those shapes back into this baseline.

#import "modules/std.sx";

// `#source` only — c_import would rewrite struct-typed params/returns
// in the .h to *void (its "struct/opaque pointer → *void" default),
// which would link but pass through the wrong ABI. The sx declarations
// below match the C signatures exactly.
#import c {
    #source "vendors/ffi_structs/ffi_structs.c";
};

Vec2  :: struct { x: f32; y: f32; }
Vec4f :: struct { x: f32; y: f32; z: f32; w: f32; }

ffi_vec2_make :: (x: f32, y: f32) -> Vec2 #foreign;
ffi_vec2_swap :: (v: Vec2)        -> Vec2 #foreign;
ffi_vec2_sum  :: (v: Vec2)        -> f32  #foreign;

ffi_vec4f_make    :: (x: f32, y: f32, z: f32, w: f32) -> Vec4f #foreign;
ffi_vec4f_reverse :: (v: Vec4f)                       -> Vec4f #foreign;
ffi_vec4f_sum     :: (v: Vec4f)                       -> f32   #foreign;

main :: () -> s32 {
    // ── Vec2 (8 bytes, float pair) ─────────────────────────────────
    v := ffi_vec2_make(1.5, 2.5);
    print("vec2 make = ({}, {})\n", v.x, v.y);
    w := ffi_vec2_swap(v);
    print("vec2 swap = ({}, {})\n", w.x, w.y);
    print("vec2 sum  = {}\n", ffi_vec2_sum(v));

    // ── Vec4f (16 bytes, HFA) ──────────────────────────────────────
    f := ffi_vec4f_make(1.0, 2.0, 3.0, 4.0);
    print("vec4f make = ({}, {}, {}, {})\n", f.x, f.y, f.z, f.w);
    g := ffi_vec4f_reverse(f);
    print("vec4f rev  = ({}, {}, {}, {})\n", g.x, g.y, g.z, g.w);
    print("vec4f sum  = {}\n", ffi_vec4f_sum(f));

    0;
}