package mathutil

import (
	"testing"
)

func TestIntegerSquareRoot(t *testing.T) {
	tt := []struct {
		number uint64
		root   uint64
	}{
		{
			number: 20,
			root:   4,
		},
		{
			number: 200,
			root:   14,
		},
		{
			number: 1987,
			root:   44,
		},
		{
			number: 34989843,
			root:   5915,
		},
		{
			number: 97282,
			root:   311,
		},
	}

	for _, testVals := range tt {
		root := IntegerSquareRoot(testVals.number)
		if testVals.root != root {
			t.Fatalf("expected root and computed root are not equal %d, %d", testVals.root, root)
		}
	}
}

func TestCeilDiv8(t *testing.T) {
	tests := []struct {
		number int
		div8   int
	}{
		{
			number: 20,
			div8:   3,
		},
		{
			number: 200,
			div8:   25,
		},
		{
			number: 1987,
			div8:   249,
		},
		{
			number: 1,
			div8:   1,
		},
		{
			number: 97282,
			div8:   12161,
		},
	}

	for _, tt := range tests {
		div8 := CeilDiv8(tt.number)
		if tt.div8 != div8 {
			t.Fatalf("Div8 was not an expected value. Wanted: %d, got: %d", tt.div8, div8)
		}
	}
}

func TestIsPowerOf2(t *testing.T) {
	tests := []struct {
		a uint64
		b bool
	}{
		{
			a: 2,
			b: true,
		},
		{
			a: 64,
			b: true,
		},
		{
			a: 100,
			b: false,
		},
		{
			a: 1024,
			b: true,
		},
	}
	for _, tt := range tests {
		if tt.b != IsPowerOf2(tt.a) {
			t.Fatalf("IsPowerOf2(%d) = %v, wanted: %v", tt.a, IsPowerOf2(tt.a), tt.b)
		}
	}
}

func TestPowerOf2(t *testing.T) {
	tests := []struct {
		a uint64
		b uint64
	}{
		{
			a: 3,
			b: 8,
		},
		{
			a: 20,
			b: 1048576,
		},
		{
			a: 11,
			b: 2048,
		},
		{
			a: 8,
			b: 256,
		},
	}
	for _, tt := range tests {
		if tt.b != PowerOf2(tt.a) {
			t.Fatalf("PowerOf2(%d) = %d, wanted: %d", tt.a, PowerOf2(tt.a), tt.b)
		}
	}
}