package org.commcare.android.mime;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.OutputStream;

import javax.crypto.Cipher;
import javax.crypto.CipherInputStream;

import org.apache.http.entity.mime.MIME;
import org.apache.http.entity.mime.content.AbstractContentBody;
import org.apache.james.mime4j.message.Entity;
import org.javarosa.core.io.StreamsUtil;
import org.javarosa.core.io.StreamsUtil.InputIOException;
import org.javarosa.core.io.StreamsUtil.OutputIOException;


/**
 * @author ctsims
 *
 */
public class EncryptedFileBody extends AbstractContentBody {
    
    Entity entity;
    File file;
    Cipher cipher;
    String contentType;
    
    public EncryptedFileBody(File file, Cipher cipher, String contentType) {
        super(contentType);
        this.file = file;
        this.cipher = cipher;
        this.contentType = contentType;
    }

    public String getFilename() {
        return file.getName();
    }

    public String getCharset() {
        return MIME.DEFAULT_CHARSET.name();
    }

    public long getContentLength() {
        return -1;
    }

    public String getTransferEncoding() {
        return MIME.ENC_BINARY;
    }

    /*
     * (non-Javadoc)
     * @see org.apache.james.mime4j.message.SingleBody#writeTo(java.io.OutputStream)
     */
    @Override
    public void writeTo(OutputStream out) throws IOException {
        //The only time this can cause issues is if the body has disappeared since construction. Don't worry about that, since
        //it'll get caught when we initialize.
        CipherInputStream cis = new CipherInputStream(new FileInputStream(file), cipher);
        
        try {
            StreamsUtil.writeFromInputToOutputSpecific(cis, out);
        } catch(InputIOException iioe) {
            //Here we want to retain the fundamental problem of the _input_ being responsible for the issue
            //so we can differentiate between bad reads and bad network
            throw iioe;
        } catch(OutputIOException oe) {
            //We want the original exception here.
            throw oe.getWrapped();
        }
        cis.close();
    }

}