var Bitcoin = {};


function makeKeypair()
{
	// Generate private key
	var n = ecparams.getN();
	var n1 = n.subtract(BigInteger.ONE);
	var r = new BigInteger(n.bitLength(), rng);
	
	var privateKey = r.mod(n1).add(BigInteger.ONE);
	
	// Generate public key
	var G = ecparams.getG();
	var publicPoint = G.multiply(privateKey);

	return {priv: privateKey, pubkey: publicPoint};
};

function serializeTransaction(tx)
{
	var buffer = [];
	buffer = buffer.concat(Crypto.util.wordsToBytes([parseInt(tx.version)]));
	buffer = buffer.concat(numToVarInt(tx.ins.length));
	for (var i = 0; i < tx.ins.length; i++) {
		var txin = tx.ins[i];
		buffer = buffer.concat(Crypto.util.base64ToBytes(txin.outpoint.hash));
		buffer = buffer.concat(Crypto.util.wordsToBytes([parseInt(txin.index)]));
		var scriptBytes = Crypto.util.base64ToBytes(txin.script);
		buffer = buffer.concat(numToVarInt(scriptBytes.length));
		buffer = buffer.concat(scriptBytes);
		buffer = buffer.concat(Crypto.util.wordsToBytes([parseInt(txin.sequence)]));
	}
	buffer = buffer.concat(numToVarInt(tx.outs.length));
	for (var i = 0; i < tx.outs.length; i++) {
		var txout = tx.outs[i];
		var valueHex = (new BigInteger(txout.value, 10)).toString(16);
		while (valueHex.length < 16) valueHex = "0" + valueHex;
		buffer = buffer.concat(Crypto.util.hexToBytes(valueHex));
		var scriptBytes = Crypto.util.base64ToBytes(txout.script);
		buffer = buffer.concat(numToVarInt(scriptBytes.length));
		buffer = buffer.concat(scriptBytes);
	}
	buffer = buffer.concat(Crypto.util.wordsToBytes([parseInt(tx.lock_time)]));
	
	return buffer;
};

var OP_CODESEPARATOR = 171;

var SIGHASH_ALL = 1;
var SIGHASH_NONE = 2;
var SIGHASH_SINGLE = 3;
var SIGHASH_ANYONECANPAY = 80;

function hashTransactionForSignature(scriptCode, tx, inIndex, hashType)
{
	// TODO: We need to actually deep copy here
	var txTmp = tx;

	// In case concatenating two scripts ends up with two codeseparators,
    // or an extra one at the end, this prevents all those possible incompatibilities.
	scriptCode = scriptCode.filter(function (val) {
		return val !== OP_CODESEPARATOR;
	});
	
    // Blank out other inputs' signatures
    for (var i = 0; i < txTmp.ins.length; i++) {
    	txTmp.ins[i].script = Crypto.util.bytesToBase64([]);
    }
    txTmp.ins[inIndex].script = Crypto.util.bytesToBase64(scriptCode);

    // Blank out some of the outputs
    if ((hashType & 0x1f) == SIGHASH_NONE) {
    	txTmp.outs = [];

        // Let the others update at will
        for (var i = 0; i < txTmp.ins.length; i++)
            if (i != inIndex)
                txTmp.ins[i].sequence = 0;
    } else if ((hashType & 0x1f) == SIGHASH_SINGLE) {
        // TODO: Implement
    }

    // Blank out other inputs completely, not recommended for open transactions
    if (hashType & SIGHASH_ANYONECANPAY) {
        txTmp.ins = [txTmp.ins[inIndex]];
    }
    
	var buffer = serializeTransaction(txTmp);
	
	buffer.concat(Crypto.util.wordsToBytes([parseInt(hashType)]));
	
	return Crypto.SHA256(Crypto.SHA256(buffer, {asBytes: true}), {asBytes: true});
};

function verifyTransactionSignature(tx) {
	var hash = hashTransactionForSignature([], tx, 0, 0);
	return Crypto.util.bytesToHex(hash);
};

function numToVarInt(i)
{
	// TODO: THIS IS TOTALLY UNTESTED!
	if (i < 0xfd) {
		// unsigned char
		return [i];
	} else if (i <= 1<<16) {
		// unsigned short (LE)
		return [0xfd, i >>> 8, i & 255];
	} else if (i <= 1<<32) {
		// unsigned int (LE)
		return [0xfe].concat(Crypto.util.wordsToBytes([i]));
    } else {
		// unsigned long long (LE)
		return [0xff].concat(Crypto.util.wordsToBytes([i >>> 32, i]));
    }
};

var testTx = {
	"version":"1",
	"lock_time":"0",
	"block": {
		"hash":"N/A",
		"height":115806
	},
	"index":6,
	"hash":"WUFzjKubG1kqfJWMb4qZdlhU2F3l5NGXN7AUg8Jwl14=",
	"ins":[{
		"outpoint":{
			"hash":"nqcbMM1oRhfLdZga11q7x0CpUMujm+vtxHXO9V0gnwE=",
			"index":0
		},
		"script":"RzBEAiB2XXkx1pca9SlfCmCGNUVf+h2sAFBttcxG1VnypIcvEgIgXrOp7LSdYBYp3nPsQAz8BOLD3K4pAlXfZImP1rkzk2EBQQRi7NcODzNfnVqLtG79Axp5UF6EhFIhCmzqKqssfKpfCIOmzCuXEeDFUFvFzeGLJx5N+wp2qRS1TqYezGD3yERk",
		"sequence":4294967295
	}],
	"outs":[{
		"value":"3000000000",
		"script":"dqkUBLZwqhAPRVgZvwI8MN5gLHbU8NOIrA=="
	},{
		"value":"25937000000",
		"script":"dqkUQ82gJ0O5vOBg6yK5/yorLLV5zLKIrA=="
	}]
};

/* TODO: Make this stuff into test cases ;)
$(function () {
	var key = new Bitcoin.ECKey(Crypto.util.hexToBytes("5c0b98e524ad188ddef35dc6abba13c34a351a05409e5d285403718b93336a4a"));
	key = new Bitcoin.ECKey(Crypto.util.hexToBytes("180cb41c7c600be951b5d3d0a7334acc7506173875834f7a6c4c786a28fcbb19"));
	//console.log(key.getBitcoinAddress().toString());
	var message = Crypto.util.hexToBytes("2aec28d323ee7b06a799d540d224b351161fe48967174ca5e43164e86137da11");
	message = [0];
	//var out = key.sign(message);
	//console.log("pubkey: "+Crypto.util.bytesToHex(key.getPub()));
	//console.log("sig: "+Crypto.util.bytesToHex(out));

	//console.log(key.verify(message, out));

	//console.log(Bitcoin.ECDSA.verify(message, Crypto.util.hexToBytes("3046022100dffbc26774fc841bbe1c1362fd643609c6e42dcb274763476d87af2c0597e89e022100c59e3c13b96b316cae9fa0ab0260612c7a133a6fe2b3445b6bf80b3123bf274d"), Crypto.util.hexToBytes("0401de173aa944eacf7e44e5073baca93fb34fe4b7897a1c82c92dfdc8a1f75ef58cd1b06e8052096980cb6e1ad6d3df143c34b3d7394bae2782a4df570554c2fb")));

	//console.log(Bitcoin.ECDSA.verify(Crypto.util.hexToBytes("230aba77ccde46bb17fcb0295a92c0cc42a6ea9f439aaadeb0094625f49e6ed8"), Crypto.util.hexToBytes("3046022100a3ee5408f0003d8ef00ff2e0537f54ba09771626ff70dca1f01296b05c510e85022100d4dc70a5bb50685b65833a97e536909a6951dd247a2fdbde6688c33ba6d6407501"),Crypto.util.hexToBytes("04a19c1f07c7a0868d86dbb37510305843cc730eb3bea8a99d92131f44950cecd923788419bfef2f635fad621d753f30d4b4b63b29da44b4f3d92db974537ad5a4")));
	//console.log(Bitcoin.ECDSA.verify(Crypto.util.hexToBytes("c2c75bb77d7a5acddceb1d45ceef58e7451fd0d3abc9d4c16df7848eefafe00d"), Crypto.util.hexToBytes("3045022100ff9362dadcbf1f6ef954bc8eb27144bbb4f49abd32be1eb04c311151dcf4bcf802205112c2ca6a25aefb8be98bf460c5a9056c01253f31e118d80b81ec9604e3201a01"),Crypto.util.hexToBytes("04fe62ce7892ec209310c176ef7f06565865e286e8699e884603657efa9aa51086785099d544d4e04f1f7b4b065205c1783fade8daf4ba1e0d1962292e8eb722cd")));
});
*/