import os

const c_variadic_vexe = @VEXE
const c_variadic_tests_dir = os.dir(@FILE)
const c_variadic_v3_dir = os.dir(c_variadic_tests_dir)
const c_variadic_vlib_dir = os.dir(c_variadic_v3_dir)
const c_variadic_v3_src = os.join_path(c_variadic_v3_dir, 'v3.v')

fn c_variadic_build_v3() string {
    v3_bin := os.join_path(os.temp_dir(), 'v3_c_variadic_test_${os.getpid()}')
    os.rm(v3_bin) or {}
    build :=
        os.execute('${c_variadic_vexe} -gc none -path "${c_variadic_vlib_dir}|@vlib|@vmodules" -o ${v3_bin} ${c_variadic_v3_src}')
    assert build.exit_code == 0, build.output
    return v3_bin
}

fn c_variadic_call_lines(generated string, names []string) []string {
    mut lines := []string{}
    for line in generated.split_into_lines() {
        for name in names {
            if line.contains('${name}(') {
                lines << line
                break
            }
        }
    }
    return lines
}

fn test_c_variadic_calls_emit_real_args_without_v_pack_array() {
    v3_bin := c_variadic_build_v3()
    src := os.join_path(os.temp_dir(), 'v3_c_variadic_${os.getpid()}.v')
    os.write_file(src, "module main

struct C.FILE {}

fn C.printf(fmt &char, args ...voidptr) int
fn C.fprintf(stream &C.FILE, fmt &char, args ...voidptr) int
fn C.sscanf(input &char, fmt &char, args ...voidptr) int
fn C.fflush(stream &C.FILE) int

__global C.stderr &C.FILE

fn sum(xs ...int) int {
    mut total := 0
    for x in xs {
        total += x
    }
    return total
}

fn main() {
    C.printf(&c'plain\\n')
    C.printf(&c'name=%s count=%d\\n', &c'ok', 7)
    C.fprintf(C.stderr, &c'err=%d\\n', 9)
    C.fflush(C.stderr)
    mut a := 0
    mut b := 0
    C.sscanf(&c'12 34', &c'%d %d', &a, &b)
    println(int_str(a + b + sum(1, 2, 3)))
}
") or {
        panic(err)
    }
    bin := os.join_path(os.temp_dir(), 'v3_c_variadic_${os.getpid()}')
    compile := os.execute('${v3_bin} ${src} -b c -o ${bin}')
    assert compile.exit_code == 0, compile.output
    run := os.execute(bin)
    assert run.exit_code == 0, run.output
    assert run.output.contains('plain'), run.output
    assert run.output.contains('name=ok count=7'), run.output
    assert run.output.trim_space().ends_with('52'), run.output

    generated := os.read_file(bin + '.c') or { panic(err) }
    c_lines := c_variadic_call_lines(generated, ['printf', 'fprintf', 'sscanf'])
    assert c_lines.len >= 4, generated
    for line in c_lines {
        assert !line.contains('__varargs_'), line
    }
    assert generated.contains('printf("plain\\n");'), generated
    assert generated.contains('printf("name=%s count=%d\\n", "ok", 7);'), generated
    assert generated.contains('fprintf(stderr, "err=%d\\n", 9);'), generated
    assert generated.contains('sscanf("12 34", "%d %d", &a, &b);'), generated
    assert generated.contains('__varargs_'), generated
}