package stable_test

import (
	"runtime"
	"testing"

	"git.brut.systems/judah/xx/stable"
)

func TestArray_StableWithGC(t *testing.T) {
	type valuewithptr struct {
		value int
		ptr   *int
	}

	var arr stable.Array[valuewithptr]
	aptr := arr.Append(valuewithptr{value: 10, ptr: nil})
	bptr := arr.Append(valuewithptr{value: 20, ptr: &aptr.value})

	const N = 1000
	for i := range N {
		arr.Append(valuewithptr{value: i})
		runtime.GC()
	}

	expect(t, arr.Get(0) == aptr)
	expect(t, arr.Get(1) == bptr)
	expect(t, arr.Len() == N+2, "len was %d", arr.Len())
	expect(t, bptr.ptr != nil && bptr.value == 20)
	expect(t, bptr.ptr == &aptr.value, "%p vs. %p", bptr.ptr, &aptr.value)
}

func BenchmarkArray_RandomAccess(b *testing.B) {
	var arr stable.Array[int]
	for i := range b.N {
		arr.Append(i * i)
	}

	b.ResetTimer()
	for i := range b.N {
		arr.Get(i % 10000)
	}
}

func BenchmarkArray_Append(b *testing.B) {
	var arr stable.Array[int]
	for i := range b.N {
		arr.Append(i * i)
	}

	arr.Reset()
	for i := range b.N {
		arr.Append(i * i)
	}
}

func BenchmarkArray_Iteration(b *testing.B) {
	var arr stable.Array[int]
	for i := range b.N {
		arr.Append(i * i)
	}

	b.ResetTimer()

	sum := 0
	for _, v := range arr.Values() {
		sum += v
	}
}

func expect(t *testing.T, cond bool, message ...any) {
	t.Helper()

	if !cond {
		if len(message) == 0 {
			message = append(message, "assertion failed")
		}

		str := message[0].(string)
		t.Fatalf(str, message[1:]...)
	}
}