package ots

import "crypto/sha256"

type Operation struct {
	Name   string
	Tag    byte
	Binary bool // it's an operation that takes one argument, otherwise takes none
	Apply  func(curr []byte, arg []byte) []byte
}

var Tags = map[byte]*Operation{
	0xf0: {"append", 0xf0, true, func(curr []byte, arg []byte) []byte {
		result := make([]byte, len(curr)+len(arg))
		copy(result[0:], curr)
		copy(result[len(curr):], arg)
		return result
	}},
	0xf1: {"prepend", 0xf1, true, func(curr []byte, arg []byte) []byte {
		result := make([]byte, len(curr)+len(arg))
		copy(result[0:], arg)
		copy(result[len(arg):], curr)
		return result
	}},
	0xf2: {"reverse", 0xf2, false, func(curr []byte, arg []byte) []byte { panic("reverse not implemented") }},
	0xf3: {"hexlify", 0xf3, false, func(curr []byte, arg []byte) []byte { panic("hexlify not implemented") }},
	0x02: {"sha1", 0x02, false, func(curr []byte, arg []byte) []byte { panic("sha1 not implemented") }},
	0x03: {"ripemd160", 0x03, false, ripemd160},
	0x08: {"sha256", 0x08, false, func(curr []byte, arg []byte) []byte {
		v := sha256.Sum256(curr)
		return v[:]
	}},
	0x67: {"keccak256", 0x67, false, func(curr []byte, arg []byte) []byte { panic("keccak256 not implemented") }},
}