struct CapturedValueReceiver {
    value int
}

fn (r CapturedValueReceiver) get() int {
    return r.value
}

@[heap]
struct CapturedPointerReceiver {
    value int
}

fn (r &CapturedPointerReceiver) get() int {
    return r.value
}

fn stored_anon_closure() fn () int {
    value := 27445
    return fn [value] () int {
        return value
    }
}

fn stored_value_method_closure() fn () int {
    receiver := CapturedValueReceiver{
        value: 27445
    }
    return receiver.get
}

fn stored_pointer_method_closure() fn () int {
    receiver := &CapturedPointerReceiver{
        value: 27445
    }
    return receiver.get
}

fn collect_and_churn() {
    $if gcboehm ? {
        C.GC_gcollect()
    }
    for _ in 0 .. 1000 {
        unsafe {
            p := malloc(16)
            vmemset(p, 0x33, 16)
        }
    }
    $if gcboehm ? {
        C.GC_gcollect()
    }
}

fn test_stored_closure_contexts_survive_boehm_collection() {
    anon_cb := stored_anon_closure()
    value_method_cb := stored_value_method_closure()
    pointer_method_cb := stored_pointer_method_closure()
    collect_and_churn()
    assert anon_cb() == 27445
    assert value_method_cb() == 27445
    assert pointer_method_cb() == 27445
}

fn consume_with_return(n int) int {
    big := []int{len: 200, init: index + n}
    h := fn [big] (x int) int {
        return big[x % big.len]
    }
    if n >= 0 {
        return h(n % 200)
    }
    return 0
}

fn consume_with_call_then_return(n int) int {
    big := []int{len: 200, init: index + n}
    h := fn [big] (x int) int {
        return big[x % big.len]
    }
    _ = h(n % 200)
    return 0
}

fn consume_with_labeled_break(n int) int {
    mut value := 0
    inner: for {
        big := []int{len: 200, init: index + n}
        h := fn [big] (x int) int {
            return big[x % big.len]
        }
        value = h(n % 200)
        break inner
    }
    return value
}

fn consume_with_labeled_continue(n int) int {
    mut value := 0
    outer: for _ in 0 .. 1 {
        big := []int{len: 200, init: index + n}
        h := fn [big] (x int) int {
            return big[x % big.len]
        }
        value = h(n % 200)
        continue outer
    }
    return value
}

fn test_issue_27445_local_closure_contexts_do_not_accumulate() {
    $if gcboehm ? {
        gc_collect()
        start_mb := gc_memory_use() / 1024 / 1024
        for n in 0 .. 80_000 {
            big := []int{len: 200, init: index + n}
            h := fn [big] (x int) int {
                return big[x % big.len]
            }
            _ = h(n % 200)
            if n % 20_000 == 0 {
                gc_collect()
            }
        }
        gc_collect()
        end_mb := gc_memory_use() / 1024 / 1024
        assert end_mb <= start_mb + 24
    }
}

fn test_issue_27445_return_paths_with_local_closure_do_not_accumulate() {
    $if gcboehm ? {
        gc_collect()
        start_mb := gc_memory_use() / 1024 / 1024
        for n in 0 .. 80_000 {
            _ = consume_with_return(n)
            _ = consume_with_call_then_return(n)
            if n % 20_000 == 0 {
                gc_collect()
            }
        }
        gc_collect()
        end_mb := gc_memory_use() / 1024 / 1024
        assert end_mb <= start_mb + 24
    }
}

fn test_issue_27445_labeled_branches_with_local_closure_do_not_accumulate() {
    $if gcboehm ? {
        gc_collect()
        start_mb := gc_memory_use() / 1024 / 1024
        for n in 0 .. 80_000 {
            _ = consume_with_labeled_break(n)
            _ = consume_with_labeled_continue(n)
            if n % 20_000 == 0 {
                gc_collect()
            }
        }
        gc_collect()
        end_mb := gc_memory_use() / 1024 / 1024
        assert end_mb <= start_mb + 24
    }
}