package keccak

import (
	"bytes"
	"fmt"
	"testing"
)

func TestShake(t *testing.T) {
	tests := []struct {
		function string
		F, S     []byte
		input    string
		digest   string
	}{
		{
			function: "shake128",
			digest:   "027cfb9e61ea1419dfce3b48e6bcb0b6b692fa2904751e5391c9ed468e010d5946f6f7c2be344c3ac2d722d96cf2a9a115681e22fcb43fd162a830b2079b527b",
		},
		{
			function: "shake256",
			digest:   "f08a3125f880d9a58e0603ed5ae3778d33b8ccc795e0c18c9b9d735caa079440c6ab577eca4e0d898d966c4b730aee69307af26e459a0332367129476c381817",
		},

		{
			function: "shake256",
			input:    "odd output",
			digest:   "678cc171bbc31a40c50d5e",
		},

		{
			function: "cshake256",
			F:        []byte("FunctionName"),
			S:        []byte("CustomizationString"),
			digest:   "e80473cc7466ed4de29611752502ab9c5597818d",
		},
	}
	for _, tt := range tests {
		want := tt.digest
		var sh *Shake
		switch tt.function {
		case "shake128":
			sh = NewShake128(nil, nil)
		case "shake256":
			sh = NewShake256(nil, nil)
		case "cshake256":
			sh = NewShake256(tt.F, tt.S)
		}
		if tt.input == "" {
			sh.Write([]byte("hello keccak"))
		} else {
			sh.Write([]byte(tt.input))
		}
		out := make([]byte, len(want)/2)
		sh.Read(out)
		got := fmt.Sprintf("%x", out)
		if want != got {
			t.Errorf("%s: got %s want %s", tt.function, got, want)
		}
	}
}

func TestShakeNIST(t *testing.T) {
	sh := NewShake256(nil, nil)
	want := shake256_digest_m0[:]
	out := make([]byte, len(want))
	n, err := sh.Read(out)
	if n != len(out) || err != nil {
		t.Errorf("unexpected return value: want (0, nil) got (%v,%v)", n, err)
	}
	if !bytes.Equal(want, out) {
		t.Errorf("hash output:\nwant %x\ngot %x", want, out)
		for i := range want {
			if want[i] != out[i] {
				t.Logf("note: first difference is at index %d", i)
				break
			}
		}
	}
}

// NIST test vector
var shake256_digest_m0 = [...]byte{
	0x46, 0xB9, 0xDD, 0x2B, 0x0B, 0xA8, 0x8D, 0x13, 0x23, 0x3B, 0x3F, 0xEB, 0x74,
	0x3E, 0xEB, 0x24, 0x3F, 0xCD, 0x52, 0xEA, 0x62, 0xB8, 0x1B, 0x82, 0xB5, 0x0C,
	0x27, 0x64, 0x6E, 0xD5, 0x76, 0x2F, 0xD7, 0x5D, 0xC4, 0xDD, 0xD8, 0xC0, 0xF2,
	0x00, 0xCB, 0x05, 0x01, 0x9D, 0x67, 0xB5, 0x92, 0xF6, 0xFC, 0x82, 0x1C, 0x49,
	0x47, 0x9A, 0xB4, 0x86, 0x40, 0x29, 0x2E, 0xAC, 0xB3, 0xB7, 0xC4, 0xBE, 0x14,
	0x1E, 0x96, 0x61, 0x6F, 0xB1, 0x39, 0x57, 0x69, 0x2C, 0xC7, 0xED, 0xD0, 0xB4,
	0x5A, 0xE3, 0xDC, 0x07, 0x22, 0x3C, 0x8E, 0x92, 0x93, 0x7B, 0xEF, 0x84, 0xBC,
	0x0E, 0xAB, 0x86, 0x28, 0x53, 0x34, 0x9E, 0xC7, 0x55, 0x46, 0xF5, 0x8F, 0xB7,
	0xC2, 0x77, 0x5C, 0x38, 0x46, 0x2C, 0x50, 0x10, 0xD8, 0x46, 0xC1, 0x85, 0xC1,
	0x51, 0x11, 0xE5, 0x95, 0x52, 0x2A, 0x6B, 0xCD, 0x16, 0xCF, 0x86, 0xF3, 0xD1,
	0x22, 0x10, 0x9E, 0x3B, 0x1F, 0xDD, 0x94, 0x3B, 0x6A, 0xEC, 0x46, 0x8A, 0x2D,
	0x62, 0x1A, 0x7C, 0x06, 0xC6, 0xA9, 0x57, 0xC6, 0x2B, 0x54, 0xDA, 0xFC, 0x3B,
	0xE8, 0x75, 0x67, 0xD6, 0x77, 0x23, 0x13, 0x95, 0xF6, 0x14, 0x72, 0x93, 0xB6,
	0x8C, 0xEA, 0xB7, 0xA9, 0xE0, 0xC5, 0x8D, 0x86, 0x4E, 0x8E, 0xFD, 0xE4, 0xE1,
	0xB9, 0xA4, 0x6C, 0xBE, 0x85, 0x47, 0x13, 0x67, 0x2F, 0x5C, 0xAA, 0xAE, 0x31,
	0x4E, 0xD9, 0x08, 0x3D, 0xAB, 0x4B, 0x09, 0x9F, 0x8E, 0x30, 0x0F, 0x01, 0xB8,
	0x65, 0x0F, 0x1F, 0x4B, 0x1D, 0x8F, 0xCF, 0x3F, 0x3C, 0xB5, 0x3F, 0xB8, 0xE9,
	0xEB, 0x2E, 0xA2, 0x03, 0xBD, 0xC9, 0x70, 0xF5, 0x0A, 0xE5, 0x54, 0x28, 0xA9,
	0x1F, 0x7F, 0x53, 0xAC, 0x26, 0x6B, 0x28, 0x41, 0x9C, 0x37, 0x78, 0xA1, 0x5F,
	0xD2, 0x48, 0xD3, 0x39, 0xED, 0xE7, 0x85, 0xFB, 0x7F, 0x5A, 0x1A, 0xAA, 0x96,
	0xD3, 0x13, 0xEA, 0xCC, 0x89, 0x09, 0x36, 0xC1, 0x73, 0xCD, 0xCD, 0x0F, 0xAB,
	0x88, 0x2C, 0x45, 0x75, 0x5F, 0xEB, 0x3A, 0xED, 0x96, 0xD4, 0x77, 0xFF, 0x96,
	0x39, 0x0B, 0xF9, 0xA6, 0x6D, 0x13, 0x68, 0xB2, 0x08, 0xE2, 0x1F, 0x7C, 0x10,
	0xD0, 0x4A, 0x3D, 0xBD, 0x4E, 0x36, 0x06, 0x33, 0xE5, 0xDB, 0x4B, 0x60, 0x26,
	0x01, 0xC1, 0x4C, 0xEA, 0x73, 0x7D, 0xB3, 0xDC, 0xF7, 0x22, 0x63, 0x2C, 0xC7,
	0x78, 0x51, 0xCB, 0xDD, 0xE2, 0xAA, 0xF0, 0xA3, 0x3A, 0x07, 0xB3, 0x73, 0x44,
	0x5D, 0xF4, 0x90, 0xCC, 0x8F, 0xC1, 0xE4, 0x16, 0x0F, 0xF1, 0x18, 0x37, 0x8F,
	0x11, 0xF0, 0x47, 0x7D, 0xE0, 0x55, 0xA8, 0x1A, 0x9E, 0xDA, 0x57, 0xA4, 0xA2,
	0xCF, 0xB0, 0xC8, 0x39, 0x29, 0xD3, 0x10, 0x91, 0x2F, 0x72, 0x9E, 0xC6, 0xCF,
	0xA3, 0x6C, 0x6A, 0xC6, 0xA7, 0x58, 0x37, 0x14, 0x30, 0x45, 0xD7, 0x91, 0xCC,
	0x85, 0xEF, 0xF5, 0xB2, 0x19, 0x32, 0xF2, 0x38, 0x61, 0xBC, 0xF2, 0x3A, 0x52,
	0xB5, 0xDA, 0x67, 0xEA, 0xF7, 0xBA, 0xAE, 0x0F, 0x5F, 0xB1, 0x36, 0x9D, 0xB7,
	0x8F, 0x3A, 0xC4, 0x5F, 0x8C, 0x4A, 0xC5, 0x67, 0x1D, 0x85, 0x73, 0x5C, 0xDD,
	0xDB, 0x09, 0xD2, 0xB1, 0xE3, 0x4A, 0x1F, 0xC0, 0x66, 0xFF, 0x4A, 0x16, 0x2C,
	0xB2, 0x63, 0xD6, 0x54, 0x12, 0x74, 0xAE, 0x2F, 0xCC, 0x86, 0x5F, 0x61, 0x8A,
	0xBE, 0x27, 0xC1, 0x24, 0xCD, 0x8B, 0x07, 0x4C, 0xCD, 0x51, 0x63, 0x01, 0xB9,
	0x18, 0x75, 0x82, 0x4D, 0x09, 0x95, 0x8F, 0x34, 0x1E, 0xF2, 0x74, 0xBD, 0xAB,
	0x0B, 0xAE, 0x31, 0x63, 0x39, 0x89, 0x43, 0x04, 0xE3, 0x58, 0x77, 0xB0, 0xC2,
	0x8A, 0x9B, 0x1F, 0xD1, 0x66, 0xC7, 0x96, 0xB9, 0xCC, 0x25, 0x8A, 0x06, 0x4A,
	0x8F, 0x57, 0xE2, 0x7F, 0x2A,
}