using Microsoft.VisualStudio.TestTools.UnitTesting;
using System;
using System.Security;
using System.Text;

namespace DSInternals.Common.Cryptography.Test
{
    [TestClass]
    public class SecureStringExtensionsTester
    {
        [TestMethod]
        public void SecureStringExtensions_Conversion_TestVector1()
        {
            string pwd = "Pa$$w0rd";
            string result = pwd.ToSecureString().ToUnicodeString();
            Assert.AreEqual(pwd, result);
        }
        [TestMethod]
        public void SecureStringExtensions_ToSecureString_EmptyInput()
        {
            string pwd = string.Empty;
            SecureString result = pwd.ToSecureString();
            Assert.AreEqual(0, result.Length);
        }
        [TestMethod]
        public void SecureStringExtensions_ToSecureString_NullInput()
        {
            string pwd = null;
            SecureString result = pwd.ToSecureString();
            Assert.IsNull(result);
        }
        [TestMethod]
        [ExpectedException(typeof(InvalidOperationException))]
        public void SecureStringExtensions_ToSecureString_ReadOnlyTest()
        {
            SecureString pwd = "Pa$$w0rd".ToSecureString();
            pwd.AppendChar('c');
        }
        [TestMethod]
        public void SecureStringExtensions_Append_Test1()
        {
            SecureString pwd = "Pa$$w0rd".ToSecureString().Copy();
            pwd.Append("Suffix");
            Assert.AreEqual("Pa$$w0rdSuffix", pwd.ToUnicodeString());
        }
        [TestMethod]
        public void SecureStringExtensions_Append_NullInput()
        {
            SecureString pwd = "Pa$$w0rd".ToSecureString().Copy();
            pwd.Append(null);
            Assert.AreEqual("Pa$$w0rd", pwd.ToUnicodeString());
        }
        [TestMethod]
        public void SecureStringExtensions_Append_EmptyInput()
        {
            SecureString pwd = "Pa$$w0rd".ToSecureString().Copy();
            pwd.Append(string.Empty);
            Assert.AreEqual("Pa$$w0rd", pwd.ToUnicodeString());
        }

        [TestMethod]
        public void SecureStringExtensions_ToByteArray_TestInput1()
        {
            string input = "Pa$$w0rd";
            byte[] result = input.ToSecureString().ToByteArray();
            string resultString = UnicodeEncoding.Unicode.GetString(result);
            Assert.AreEqual(input, resultString);
        }
        [TestMethod]
        public void SecureStringExtensions_ToByteArray_EmptyInput()
        {
            SecureString input = new SecureString();
            byte[] output = input.ToByteArray();
            byte[] expected = new byte[0];
            CollectionAssert.AreEqual(expected, output);
        }
    }
}