package vm

import (
	"math/big"
	"testing"

	"github.com/ethereum/go-ethereum/common"
	"github.com/ethereum/go-ethereum/params"
)

func TestByteOp(t *testing.T) {
	var (
		env   = NewEVM(Context{}, nil, params.TestChainConfig, Config{EnableJit: false, ForceJit: false})
		stack = newstack()
	)
	tests := []struct {
		v        string
		th       uint64
		expected *big.Int
	}{
		{"ABCDEF0908070605040302010000000000000000000000000000000000000000", 0, big.NewInt(0xAB)},
		{"ABCDEF0908070605040302010000000000000000000000000000000000000000", 1, big.NewInt(0xCD)},
		{"00CDEF090807060504030201ffffffffffffffffffffffffffffffffffffffff", 0, big.NewInt(0x00)},
		{"00CDEF090807060504030201ffffffffffffffffffffffffffffffffffffffff", 1, big.NewInt(0xCD)},
		{"0000000000000000000000000000000000000000000000000000000000102030", 31, big.NewInt(0x30)},
		{"0000000000000000000000000000000000000000000000000000000000102030", 30, big.NewInt(0x20)},
		{"ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", 32, big.NewInt(0x0)},
		{"ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", 0xFFFFFFFFFFFFFFFF, big.NewInt(0x0)},
	}
	pc := uint64(0)
	for _, test := range tests {
		val := new(big.Int).SetBytes(common.Hex2Bytes(test.v))
		th := new(big.Int).SetUint64(test.th)
		stack.push(val)
		stack.push(th)
		opByte(&pc, env, nil, nil, stack)
		actual := stack.pop()
		if actual.Cmp(test.expected) != 0 {
			t.Fatalf("Expected  [%v] %v:th byte to be %v, was %v.", test.v, test.th, test.expected, actual)
		}
	}
}