/// <summary>
/// Embeds the message.
/// </summary>
/// @Precondition this.messageFile != null && this.sourceFile != null
/// @Postcondition message is embedded and shown in the program
/// <param name="encryptionSelected">if set to <c>true</c> [encryption selected].</param>
/// <param name="bpcc">The BPCC.</param>
/// <param name="encryptionKey">The encryption key.</param>
public async Task EmbedMessage(bool encryptionSelected, int bpcc, string encryptionKey)
{
if (this.messageFile.FileType == FileTypeConstants.TextFileType)
{
string formattedText;
if (encryptionSelected)
{
formattedText =
EmbedTextFormatter.FormatEncryptedTextForEmbedding(encryptionKey, this.TextFromFile);
}
else
{
formattedText = EmbedTextFormatter.FormatTextForEmbedding(this.TextFromFile);
}
var binaryText = BinaryStringConverter.ConvertStringToBinary(formattedText);
var messageLength = binaryText.Length;
await this.messageEmbedder.EmbedMessageInImage(binaryText, (uint)messageLength, 0,
this.sourceImageWidth, this.sourceImageHeight, encryptionSelected, bpcc);
}
else
{
var messageDecoder =
await BitmapDecoder.CreateAsync(await this.messageFile.OpenAsync(FileAccessMode.Read));
var messagePixels = await PixelExtracter.ExtractPixelDataFromFile(this.messageFile);
var messageImageWidth = messageDecoder.PixelWidth;
var messageImageHeight = messageDecoder.PixelHeight;
await this.messageEmbedder.EmbedMessageInImage(messagePixels, messageImageWidth, messageImageHeight,
this.sourceImageWidth, this.sourceImageHeight, encryptionSelected, bpcc);
}
}
private void handleExtractLetter(int count)
{
if (count % 8 != 7)
{
return;
}
var currIndex = 0;
var peekBits = new BitArray(this.numberOfBitsInByte);
for (var k = count; k >= count - 7; k--)
{
peekBits.Set(currIndex, this.embeddedBits.Get(k));
currIndex++;
}
var extractedLetter = BinaryStringConverter.BitArrayToString(peekBits);
if (this.peek.Length == this.numberOfBitsInByte && this.endOfEncryptionKeyReached)
{
this.embeddedMessage.Append(this.peek.ToString().Substring(0, 1));
this.peek.Remove(0, 1);
}
else if (this.peek.Length == this.numberOfBitsInByte)
{
this.encryptionKey.Append(this.peek.ToString().Substring(0, 1));
this.peek.Remove(0, 1);
}
this.peek.Append(extractedLetter);
if (this.endOfEncryptionKeyReached)
{
this.checkForEndOfMessage();
}
else
{
this.checkForEndOfEncryptionKey();
}
}
public void Setup() => _converter = new BinaryStringConverter();