package aes

import (
	"testing"
)

// See const.go for overview of math here.

// Test that powx is initialized correctly.
// (Can adapt this code to generate it too.)
func TestPowx(t *testing.T) {
	p := 1
	for i := 0; i < len(powx); i++ {
		if powx[i] != byte(p) {
			t.Errorf("powx[%d] = %#x, want %#x", i, powx[i], p)
		}
		p <<= 1
		if p&0x100 != 0 {
			p ^= poly
		}
	}
}

// Their rcon[i] is our powx[i-1] << 24.
func expandKeyGo(key []byte, enc, dec []uint32) {
	// Encryption key setup.
	var i int
	nk := len(key) / 4
	for i = 0; i < nk; i++ {
		enc[i] = byteorder.BeUint32(key[4*i:])
	}
	for ; i < len(enc); i++ {
		t := enc[i-1]
		if i%nk == 0 {
			t = subw(rotw(t)) ^ (uint32(powx[i/nk-1]) << 24)
		} else if nk > 6 && i%nk == 4 {
			t = subw(t)

// Reducing mod poly corresponds to binary xor with poly every
// time a 0x100 bit appears.
const poly = 1<<8 | 1<<4 | 1<<3 | 1<<1 | 1<<0 // x⁸ + x⁴ + x³ + x + 1

// Powers of x mod poly in GF(2).
var powx = [16]byte{
	0x01,
	0x02,
	0x04,
	0x08,
	0x10,
	0x20,
	0x40,
	0x80,
	0x1b,
	0x36,
	0x6c,
	0xd8,
	0xab,
	0x4d,
	0x9a,
	0x2f,
}

//	Pow(±0, y) = +0 for finite y > 0 and not an odd integer
//	Pow(-1, ±Inf) = 1
//	Pow(x, +Inf) = +Inf for |x| > 1
//	Pow(x, -Inf) = +0 for |x| > 1
//	Pow(x, +Inf) = +0 for |x| < 1
//	Pow(x, -Inf) = +Inf for |x| < 1
//	Pow(+Inf, y) = +Inf for y > 0
//	Pow(+Inf, y) = +0 for y < 0
//	Pow(-Inf, y) = Pow(-0, -y)
//	Pow(x, y) = NaN for finite x < 0 and finite non-integer y
func Pow(x, y float64) float64 {

//    IEEE      -10,+10     30000       9.4e-15     1.5e-15

// Pow returns x**y, the base-x exponential of y.
// For generalized compatibility with [math.Pow]:
//
//	Pow(0, ±0) returns 1+0i
//	Pow(0, c) for real(c)<0 returns Inf+0i if imag(c) is zero, otherwise Inf+Inf i.
func Pow(x, y complex128) complex128 {
	if x == 0 { // Guaranteed also true for x == -0.
		if IsNaN(y) {
			return NaN()

		}
		v := float64(n)
		// We expect that v*pow2(e) fits in a float64,
		// but pow2(e) by itself may not. Be careful.
		if e <= -1000 {
			v *= pow2(-1000)
			e += 1000
			for e < 0 {
				v /= 2
				e++
			}
			return v, true
		}
		if e >= 1000 {
			v *= pow2(1000)
			e -= 1000
			for e > 0 {
				v *= 2
				e--
			}
			return v, true
		}
		return v * pow2(e), true
	}

//      Pow(±0, y) = ±0 for y an odd integer > 0
//      Pow(±0, y) = +0 for finite y > 0 and not an odd integer
//      Pow(-1, ±Inf) = 1
//      Pow(x, +Inf) = +Inf for |x| > 1
//      Pow(x, -Inf) = +0 for |x| > 1
//      Pow(x, +Inf) = +0 for |x| < 1
//      Pow(x, -Inf) = +Inf for |x| < 1
//      Pow(+Inf, y) = +Inf for y > 0
//      Pow(+Inf, y) = +0 for y < 0
//      Pow(-Inf, y) = Pow(-0, -y)

        .roundUnnecessaryShouldThrow()
        .test();
  }

  public void testRoundToDouble_negativeTwoToThe54MinusOne() {
    new RoundToDoubleTester(BigDecimal.valueOf((-1L << 54) - 1))
        .setExpectation(-Math.pow(2, 54), DOWN, CEILING, HALF_DOWN, HALF_UP, HALF_EVEN)
        .setExpectation(DoubleUtils.nextDown(-Math.pow(2, 54)), FLOOR, UP)

	hash := uint32(0)
	for i := 0; i < len(sep); i++ {
		hash = hash*PrimeRK + uint32(sep[i])
	}
	var pow, sq uint32 = 1, PrimeRK
	for i := len(sep); i > 0; i >>= 1 {
		if i&1 != 0 {
			pow *= sq
		}
		sq *= sq
	}
	return hash, pow
}

// HashStrRev returns the hash of the reverse of sep and the
// appropriate multiplicative factor for use in Rabin-Karp algorithm.

      BigInteger x2 = x.pow(2);
      // x^2 < 10^(2 * result + 1), or else we would have rounded up
      assertTrue(TEN.pow(2 * result + 1).compareTo(x2) > 0);
      // x^2 >= 10^(2 * result - 1), or else we would have rounded down
      assertTrue(result == 0 || TEN.pow(2 * result - 1).compareTo(x2) <= 0);
    }
  }

  @GwtIncompatible // TODO
  public void testLog10HalfDown() {