struct VaTestGroup {
    name string
}

// basic
fn variadic_test(name string, groups ...VaTestGroup) {
    assert groups.len == 2
    assert groups[0].name == 'users'
    assert groups[1].name == 'admins'
}

fn test_fn_variadic() {
    group1 := VaTestGroup{
        name: 'users'
    }
    group2 := VaTestGroup{
        name: 'admins'
    }
    variadic_test('joe', group1, group2)
}

/*
// QTODO
// generic
fn variadic_test_generic[T](a int, b ...T) T {
    b1 := b[0]
    b2 := b[1]
    return '${a} ${b1} ${b2}'
}

fn test_fn_variadic_generic() {
    assert variadic_test_generic(111, 'hello', 'v') == '111 hello v'
}
*/
// forwarding
fn variadic_forward_a(a ...string) string {
    return variadic_fn_a(...a)
}

fn variadic_fn_a(a ...string) string {
    a0 := a[0]
    a1 := a[1]
    a2 := a[2]
    return '${a0}${a1}${a2}'
}

fn test_fn_variadic_forward() {
    assert variadic_forward_a('a', 'b', 'c') == 'abc'
}

fn variadic_fn_head_tail(head string, tail ...string) string {
    return '${head}|${tail.join(',')}'
}

fn variadic_forward_with_fixed_arg(args ...string) string {
    return variadic_fn_head_tail(...args)
}

fn test_fn_variadic_forward_with_fixed_arg() {
    assert variadic_forward_with_fixed_arg('a') == 'a|'
    assert variadic_forward_with_fixed_arg('a', 'b', 'c') == 'a|b,c'
}

fn fn_variadic_with_arg_no_vargs(name string, groups ...VaTestGroup) {
    assert groups.len == 0
}

fn test_fn_variadic_with_arg_no_vargs() {
    fn_variadic_with_arg_no_vargs('marko')
}

fn fn_variadic_only_with_no_vargs(groups ...VaTestGroup) {
    assert groups.len == 0
}

fn test_variadic_only_with_no_vargs() {
    fn_variadic_only_with_no_vargs()
}

fn test_array_decomposition_to_vargs() {
    a := ['a', 'b', 'c']
    assert variadic_fn_a(...a) == 'abc'
}

struct VaTestStruct {
}

fn (a VaTestStruct) variadic_method(name string, groups ...VaTestGroup) {
    assert groups.len == 2
    assert groups[0].name == 'users'
    assert groups[1].name == 'admins'
}

fn (a VaTestStruct) variadic_method_no_args(name string, groups ...VaTestGroup) {
    assert groups.len == 0
}

fn test_fn_variadic_method() {
    a := VaTestStruct{}
    group1 := VaTestGroup{
        name: 'users'
    }
    group2 := VaTestGroup{
        name: 'admins'
    }
    a.variadic_method('marko', group1, group2)
}

fn test_fn_variadic_method_no_args() {
    a := VaTestStruct{}
    a.variadic_method_no_args('marko')
}

// test vargs with pointer type
fn take_variadic_string_ptr(strings ...&string) {
    take_array_string_ptr(strings)
}

fn take_array_string_ptr(strings []&string) {
    assert strings.len == 2
    assert *strings[0] == 'a'
    assert *strings[1] == 'b'
}

fn test_varg_pointer() {
    a := 'a'
    b := 'b'
    take_variadic_string_ptr(&a, &b)
}