package DNA.Core;

import java.lang.reflect.Array;

import java.util.Arrays;

import java.util.HashMap;

import java.util.Map;

import java.util.Map.Entry;

import org.bouncycastle.math.ec.ECPoint;

import DNA.Helper;

import DNA.UInt160;

import DNA.Core.Scripts.Program;

import DNA.Core.Scripts.ScriptBuilder;

import DNA.Cryptography.ECC;

import DNA.IO.Json.JArray;

import DNA.IO.Json.JBoolean;

import DNA.IO.Json.JObject;

import DNA.IO.Json.JString;

import DNA.Wallets.Contract;

import DNA.Wallets.ContractParameterType;

/**

* 签名上下文

*

*/

public class SignatureContext {

/**

* 要签名的数据

*/

public final Signable signable;

/**

* 要验证的脚本散列值

*/

public final UInt160[] scriptHashes;

/**

* 合约脚本代码

*/

private final byte[][] redeemScripts;

/**

* 公钥-签名数据

*/

private final Map<ECPoint, byte[]>[] signatures;

private final boolean[] completed;

/**

* 判断签名是否完成

*/

public boolean isCompleted() {

for (boolean b : completed) {

if (!b) {

return false;

}

}

return true;

}

/**

* 对指定的数据构造签名上下文

* <param name="signable">要签名的数据</param>

*/

@SuppressWarnings("unchecked")

public SignatureContext(Signable signable) {

this.signable = signable;

this.scriptHashes = signable.getScriptHashesForVerifying();

this.redeemScripts = new byte[scriptHashes.length][];

this.signatures = (Map<ECPoint, byte[]>[]) Array.newInstance(Map.class, scriptHashes.length);

this.completed = new boolean[scriptHashes.length];

}

/**

* 添加一个签名

* <param name="contract">该签名所对应的合约</param>

* <param name="pubkey">该签名所对应的公钥</param>

* <param name="signature">签名</param>

* <returns>返回签名是否已成功添加</returns>

*/

public boolean add(Contract contract, ECPoint pubkey, byte[] signature) {

for (int i = 0; i < scriptHashes.length; i++) {

if (scriptHashes[i].equals(contract.scriptHash())) {

if (redeemScripts[i] == null) {

redeemScripts[i] = contract.redeemScript;

}

if (signatures[i] == null) {

signatures[i] = new HashMap<ECPoint, byte[]>();

}

signatures[i].put(pubkey, signature);

completed[i] |=

contract.parameterList.length == signatures[i].size()

&& Arrays.stream(contract.parameterList).allMatch(

p -> p == ContractParameterType.Signature);

return true;

}

}

return false;

}

/**

* 从签名上下文中获得完整签名的合约脚本

* <returns>返回合约脚本</returns>

*/

public Program[] getScripts() {

if (!isCompleted()) throw new IllegalStateException();

Program[] scripts = new Program[signatures.length];

for (int i = 0; i < scripts.length; i++) {

try (ScriptBuilder sb = new ScriptBuilder()) {

for (byte[] signature : signatures[i].entrySet().stream()

.sorted((a, b) -> ECC.compare(a.getKey(), b.getKey()))

.map(p -> p.getValue()).toArray(byte[][]::new)) {

sb.push(signature);

}

scripts[i] = new Program();

scripts[i].parameter = sb.toArray(); // sign

scripts[i].code = redeemScripts[i]; // pk

}

}

return scripts;

}

/**

* 把签名上下文转为json对象

* <returns>返回json对象</returns>

*/

public JObject json() {

JObject json = new JObject();

json.set("type", new JString(signable.getClass().getTypeName()));

json.set("hex", new JString(Helper.toHexString(signable.getHashData())));

JArray scripts = new JArray();

for (int i = 0; i < signatures.length; i++) {

if (signatures[i] == null) {

scripts.add(null);

} else {

scripts.add(new JObject());

scripts.get(i).set("redeem_script", new JString(Helper.toHexString(redeemScripts[i])));

JArray sigs = new JArray();

for (Entry<ECPoint, byte[]> pair : signatures[i].entrySet()) {

JObject signature = new JObject();

signature.set("pubkey", new JString(Helper.toHexString(pair.getKey().getEncoded(true))));

signature.set("signature", new JString(Helper.toHexString(pair.getValue())));

sigs.add(signature);

}

scripts.get(i).set("signatures", sigs);

scripts.get(i).set("completed", new JBoolean(completed[i]));

}

}

json.set("scripts", scripts);

return json;

}

@Override

public String toString() {

return json().toString();

}

}