var expect = require("chai").expect;
var createHash = require("crypto").createHash;
var bufferEqual = require("buffer-equal");
var eccrypto = require("./");

var msg = createHash("sha256").update("test").digest();
var otherMsg = createHash("sha256").update("test2").digest();
var shortMsg = createHash("sha1").update("test").digest();

var privateKey = Buffer.alloc(32);
privateKey.fill(1);
var publicKey = eccrypto.getPublic(privateKey);
var publicKeyCompressed = eccrypto.getPublicCompressed(privateKey);

var privateKeyA = Buffer.alloc(32);
privateKeyA.fill(2);
var publicKeyA = eccrypto.getPublic(privateKeyA);
var publicKeyACompressed = eccrypto.getPublicCompressed(privateKeyA);

var privateKeyB = Buffer.alloc(32);
privateKeyB.fill(3);
var publicKeyB = eccrypto.getPublic(privateKeyB);
var publicKeyBCompressed = eccrypto.getPublicCompressed(privateKeyB);

describe("Hashes", function() {
  it("should comply to the Spec", function() {
    const sample_sha512 = "9b71d224bd62f3785d96d46ad3ea3d73319bfbc2890caadae2dff72519673ca72323c3d99ba5c11d7c7acc6e14b8c5da0c4663475c2e5c3adef46f73bcdec043",
	  sample_double_sha512 = "0592a10584ffabf96539f3d780d776828c67da1ab5b169e9e8aed838aaecc9ed36d49ff1423c55f019e050c66c6324f53588be88894fef4dcffdb74b98e2b200",
	  sample_bm160 = "79a324faeebcbf9849f310545ed531556882487e";
    var sha512 = createHash("sha512").update("hello").digest(),
	double_sha512 = createHash("sha512").update(sha512).digest(),
	bm160 = createHash("ripemd160").update(sha512).digest();
    expect(sha512.toString("hex")).to.equal(sample_sha512);
    expect(double_sha512.toString("hex")).to.equal(sample_double_sha512);
    expect(bm160.toString("hex")).to.equal(sample_bm160);
  });
});

describe("Key conversion", function() {
  it("should allow to convert private key to public", function() {
    expect(Buffer.isBuffer(publicKey)).to.be.true;
    expect(publicKey.toString("hex")).to.equal("041b84c5567b126440995d3ed5aaba0565d71e1834604819ff9c17f5e9d5dd078f70beaf8f588b541507fed6a642c5ab42dfdf8120a7f639de5122d47a69a8e8d1");
  });

  it("should allow to convert private key to compressed public", function() {
	expect(Buffer.isBuffer(publicKeyCompressed)).to.be.true;
	expect(publicKeyCompressed.toString("hex")).to.equal("031b84c5567b126440995d3ed5aaba0565d71e1834604819ff9c17f5e9d5dd078f");
  });

  it("should throw on invalid private key", function() {
    expect(eccrypto.getPublic.bind(null, Buffer.from("00", "hex"))).to.throw(Error);
    expect(eccrypto.getPublic.bind(null, Buffer.from("test"))).to.throw(Error);
  });
});

describe("ECDSA", function() {
  it("should allow to sign and verify message", function() {
    return eccrypto.sign(privateKey, msg).then(function(sig) {
      expect(Buffer.isBuffer(sig)).to.be.true;
      expect(sig.toString("hex")).to.equal("3044022078c15897a34de6566a0d396fdef660698c59fef56d34ee36bef14ad89ee0f6f8022016e02e8b7285d93feafafbe745702f142973a77d5c2fa6293596357e17b3b47c");
      return eccrypto.verify(publicKey, msg, sig);
    });
  });

  it("should allow to sign and verify message using a compressed public key", function() {
    return eccrypto.sign(privateKey, msg).then(function(sig) {
      expect(Buffer.isBuffer(sig)).to.be.true;
      expect(sig.toString("hex")).to.equal("3044022078c15897a34de6566a0d396fdef660698c59fef56d34ee36bef14ad89ee0f6f8022016e02e8b7285d93feafafbe745702f142973a77d5c2fa6293596357e17b3b47c");
      return eccrypto.verify(publicKeyCompressed, msg, sig);
    });
  });

  it("shouldn't verify incorrect signature", function(done) {
    eccrypto.sign(privateKey, msg).then(function(sig) {
      expect(Buffer.isBuffer(sig)).to.be.true;
      eccrypto.verify(publicKey, otherMsg, sig).catch(function() {
        done();
      });
    });
  });

  it("should reject promise on invalid key when signing", function(done) {
    var k4 = Buffer.from("test");
    var k192 = Buffer.from("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa", "hex");
    var k384 = Buffer.from("bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb", "hex");
    eccrypto.sign(k4, msg).catch(function() {
      eccrypto.sign(k192, msg).catch(function() {
        eccrypto.sign(k384, msg).catch(function() {
          done();
        });
      });
    });
  });

  it("should reject promise on invalid key when verifying", function(done) {
    eccrypto.sign(privateKey, msg).then(function(sig) {
      expect(Buffer.isBuffer(sig)).to.be.true;
      eccrypto.verify(Buffer.from("test"), msg, sig).catch(function() {
        var badKey = Buffer.alloc(65);
        publicKey.copy(badKey);
        badKey[0] ^= 1;
        eccrypto.verify(badKey, msg, sig).catch(function() {
          done();
        });
      });
    });
  });

  it("should reject promise on invalid sig when verifying", function(done) {
    eccrypto.sign(privateKey, msg).then(function(sig) {
      expect(Buffer.isBuffer(sig)).to.be.true;
      sig[0] ^= 1;
      eccrypto.verify(publicKey, msg, sig).catch(function() {
        done();
      });
    });
  });

  it("should allow to sign and verify messages less than 32 bytes", function() {
    return eccrypto.sign(privateKey, shortMsg).then(function(sig) {
      expect(Buffer.isBuffer(sig)).to.be.true;
      expect(sig.toString("hex")).to.equal("304402204737396b697e5a3400e3aedd203d8be89879f97708647252bd0c17752ff4c8f302201d52ef234de82ce0719679fa220334c83b80e21b8505a781d32d94a27d9310aa");
      return eccrypto.verify(publicKey, shortMsg, sig);
    });
  });

  it("shouldn't sign and verify messages longer than 32 bytes", function(done) {
    var longMsg = Buffer.alloc(40);
    var someSig = Buffer.from("304402204737396b697e5a3400e3aedd203d8be89879f97708647252bd0c17752ff4c8f302201d52ef234de82ce0719679fa220334c83b80e21b8505a781d32d94a27d9310aa", "hex");
    eccrypto.sign(privateKey, longMsg).catch(function() {
      eccrypto.verify(privateKey, longMsg, someSig).catch(function(e) {
        expect(e.message).to.not.match(/bad signature/i);
        done();
      });
    });
  });

  it("shouldn't sign and verify empty messages", function(done) {
    var emptyMsg = Buffer.alloc(0);
    var someSig = Buffer.from("304402204737396b697e5a3400e3aedd203d8be89879f97708647252bd0c17752ff4c8f302201d52ef234de82ce0719679fa220334c83b80e21b8505a781d32d94a27d9310aa", "hex");
    eccrypto.sign(privateKey, emptyMsg).catch(function() {
      eccrypto.verify(publicKey, emptyMsg, someSig).catch(function(e) {
        expect(e.message).to.not.match(/bad signature/i);
        done();
      });
    });
  });
});

describe("ECDH", function() {
  it("should derive shared secret from privkey A and pubkey B", function() {
    return eccrypto.derive(privateKeyA, publicKeyB).then(function(Px) {
      expect(Buffer.isBuffer(Px)).to.be.true;
      expect(Px.length).to.equal(32);
      expect(Px.toString("hex")).to.equal("aca78f27d5f23b2e7254a0bb8df128e7c0f922d47ccac72814501e07b7291886");
      return eccrypto.derive(privateKeyB, publicKeyA).then(function(Px2) {
        expect(Buffer.isBuffer(Px2)).to.be.true;
        expect(Px2.length).to.equal(32);
        expect(bufferEqual(Px, Px2)).to.be.true;
      });
    });
  });

  it("should derive shared secret from  privkey A and compressed pubkey B", function() {
    return eccrypto.derive(privateKeyA, publicKeyBCompressed).then(function(Px) {
      expect(Buffer.isBuffer(Px)).to.be.true;
      expect(Px.length).to.equal(32);
      expect(Px.toString("hex")).to.equal("aca78f27d5f23b2e7254a0bb8df128e7c0f922d47ccac72814501e07b7291886");
      return eccrypto.derive(privateKeyB, publicKeyA).then(function(Px2) {
        expect(Buffer.isBuffer(Px2)).to.be.true;
        expect(Px2.length).to.equal(32);
        expect(bufferEqual(Px, Px2)).to.be.true;
      });
    });
  });

  it("should reject promise on bad keys", function(done) {
    eccrypto.derive(Buffer.from("test"), publicKeyB).catch(function() {
      eccrypto.derive(publicKeyB, publicKeyB).catch(function() {
        eccrypto.derive(privateKeyA, privateKeyA).catch(function() {
          eccrypto.derive(privateKeyB, Buffer.from("test")).catch(function() {
            done();
          });
        });
      });
    });
  });

  it("should reject promise on bad arguments", function(done) {
    eccrypto.derive({}, {}).catch(function(e) {
      expect(e.message).to.match(/Bad private key/i);
      done();
    });
  });
});

describe("ECIES", function() {
  // To comply to the Spec
  const samplePrivateKey = Buffer.from(
    "5be6facd941b76e9d3ead03029fbdb6b6e0809293f7fb197d0c51f84e96b8ba4",
    "hex"),
	sampleIV = Buffer.from("bddb7c2829b08038753084a2f3991681", "hex"),
	// notice the simple (not encoded) pubkey here
	samplePublicKey = Buffer.from(
	  "0409d4e5c0ab3d25fe048c64c9da1a242c7f19417e9517cd266950d72c755713585c6178e97fe092fc897c9a1f1720d5770ae8eaad2fa8fcbd08e9324a5dde1857", "hex"),
	sampleData = "The quick brown fox jumps over the lazy dog.",
	sampleCiphertext = Buffer.from(
	  "64203d5b24688e2547bba345fa139a5a1d962220d4d48a0cf3b1572c0d95b61643a6f9a0d75af7eacc1bd957147bf723", "hex"),
	// a pubkey encoded with curve number and length
	sampleEphemPublicKey = Buffer.from(
	  "02ca00200293213dcf1388b61c2ae5cf80fee6ffffc049a2f9fe7365fe3867813ca812920020df94686c6afb565ac6149b153d61b3b287ee2c7f997c14238796c12b43a3865a",
	  "hex"),
	sampleMAC = Buffer.from(
	  "f2526d61b4851fb23409863826fd206165edc021368c7946571cead69046e619",
	  "hex"),
	encOpts = {ephemPrivateKey: samplePrivateKey, iv: sampleIV};
  const data = Buffer.from("test"),
	ciphertext = Buffer.from("dd2e0b29bd31f9b6c1f9b49c5eda29c9", "hex"),
	mac = Buffer.from(
	  "109603cc4568edd10c9a3850d82846c4610dc1d11cfc84da64161025a47147b7",
	  "hex");

  var decOpts = {
    iv: sampleIV, ephemPublicKey: sampleEphemPublicKey,
    ciphertext: ciphertext, mac: mac};


  it("should comply to the Spec and the network", function() {
    return eccrypto.encrypt(samplePublicKey, sampleData, encOpts)
    .then(function(enc) {
      expect(bufferEqual(enc.iv, sampleIV)).to.be.true;
      expect(bufferEqual(enc.ciphertext, sampleCiphertext)).to.be.true;
      expect(bufferEqual(enc.ephemPublicKey, sampleEphemPublicKey)).to.be.true;
      expect(bufferEqual(enc.mac, sampleMAC)).to.be.true;
    });
  });

  it("should encrypt", function() {
    return eccrypto.encrypt(publicKeyB, data, encOpts)
    .then(function(enc) {
      expect(bufferEqual(enc.iv, sampleIV)).to.be.true;
      expect(bufferEqual(enc.ciphertext, ciphertext)).to.be.true;
      expect(bufferEqual(enc.ephemPublicKey, sampleEphemPublicKey)).to.be.true;
      expect(bufferEqual(enc.mac, mac)).to.be.true;
      });
   });

  it("should decrypt", function() {
    return eccrypto.decrypt(privateKeyB, decOpts)
    .then(function(msg) {
      expect(bufferEqual(msg, data)).to.be.true;
    });
  });

  it("should encrypt and decrypt", function() {
    return eccrypto.encrypt(publicKeyA, Buffer.from("to a")).then(function(enc) {
      return eccrypto.decrypt(privateKeyA, enc);
    }).then(function(msg) {
      expect(msg.toString()).to.equal("to a");
    });
  });

  it("should encrypt and decrypt with message size > 15", function() {
    return eccrypto.encrypt(publicKeyA, Buffer.from("message size that is greater than 15 for sure =)")).then(function(enc) {
      return eccrypto.decrypt(privateKeyA, enc);
    }).then(function(msg) {
      expect(msg.toString()).to.equal("message size that is greater than 15 for sure =)");
    });
  });

  it("should encrypt with compressed public key", function() {
    return eccrypto.encrypt(publicKeyBCompressed, Buffer.from("test"), encOpts)
    .then(function(enc) {
      expect(bufferEqual(enc.iv, sampleIV)).to.be.true;
      expect(bufferEqual(enc.ephemPublicKey, sampleEphemPublicKey)).to.be.true;
      expect(bufferEqual(enc.ciphertext, ciphertext)).to.be.true;
      expect(bufferEqual(enc.mac, mac)).to.be.true;
    });
  });

  it("should encrypt and decrypt with compressed public key", function() {
    return eccrypto.encrypt(publicKeyACompressed, Buffer.from("to a")).then(function(enc) {
      return eccrypto.decrypt(privateKeyA, enc);
    }).then(function(msg) {
      expect(msg.toString()).to.equal("to a");
    });
  });

  it("should encrypt and decrypt with generated private and public key", function () {
    var privateKey = eccrypto.generatePrivate();
    var publicKey = eccrypto.getPublic(privateKey);
    return eccrypto.encrypt(publicKey, Buffer.from("generated private key"))
        .then(function(enc) { return eccrypto.decrypt(privateKey, enc); })
        .then(function(msg) {
          expect(msg.toString()).to.equal("generated private key");
        });
  });

  // To comply to the Spec and the network
  it("should comply to the Spec", function() {
    return eccrypto.encrypt(samplePublicKey, sampleData, {
      iv: sampleIV, ephemPrivateKey: samplePrivateKey
    }).then(
      function(enc) {
	expect(bufferEqual(enc.iv, sampleIV)).to.be.true;
	expect(bufferEqual(enc.ciphertext, sampleCiphertext)).to.be.true;
	expect(bufferEqual(enc.ephemPublicKey, sampleEphemPublicKey)).to.be.true;
	expect(bufferEqual(enc.mac, sampleMAC)).to.be.true;
      });
  });

  it("should reject promise on bad private key when decrypting", function(done) {
    eccrypto.encrypt(publicKeyA, Buffer.from("test")).then(function(enc) {
      eccrypto.decrypt(privateKeyB, enc).catch(function() {
        done();
      });
    });
  });

  it("should reject promise on bad IV when decrypting", function(done) {
    eccrypto.encrypt(publicKeyA, Buffer.from("test")).then(function(enc) {
      enc.iv[0] ^= 1;
      eccrypto.decrypt(privateKeyA, enc).catch(function() {
        done();
      });
    });
  });

  // it("should reject promise on bad R when decrypting", function(done) {
  //   eccrypto.encrypt(publicKeyA, Buffer.from("test")).then(function(enc) {
  //     enc.ephemPublicKey[0] ^= 1;
  //     eccrypto.decrypt(privateKeyA, enc).catch(function() {
  //       done();
  //     });
  //   });
  // });

  it("should reject promise on bad ciphertext when decrypting", function(done) {
    eccrypto.encrypt(publicKeyA, Buffer.from("test")).then(function(enc) {
      enc.ciphertext[0] ^= 1;
      eccrypto.decrypt(privateKeyA, enc).catch(function() {
        done();
      });
    });
  });

  it("should reject promise on bad MAC when decrypting", function(done) {
    eccrypto.encrypt(publicKeyA, Buffer.from("test")).then(function(enc) {
      var origMac = enc.mac;
      enc.mac = mac.slice(1);
      eccrypto.decrypt(privateKeyA, enc).catch(function() {
        enc.mac = origMac;
        enc.mac[10] ^= 1;
        eccrypto.decrypt(privateKeyA, enc).catch(function() {
          done();
        });
      });
    });
  });
});