Convert 'TextQuoteCreator' to Kotlin

import com.fsck.k9.mail.Message

internal class QuoteHelper(private val resources: Resources) {

class QuoteHelper(private val resources: Resources) {

    /**

     * Extract the date from a message and convert it into a locale-specific

package com.fsck.k9.message.quote;

package com.fsck.k9.message.quote

import java.util.regex.Matcher;

import com.fsck.k9.Account.QuoteStyle

import com.fsck.k9.CoreResourceProvider

import com.fsck.k9.mail.Address

import com.fsck.k9.mail.Message

import com.fsck.k9.mail.Message.RecipientType

import com.fsck.k9.message.quote.QuoteHelper.Companion.QUOTE_BUFFER_LENGTH

import com.fsck.k9.Account.QuoteStyle;

import com.fsck.k9.CoreResourceProvider;

import com.fsck.k9.mail.Address;

import com.fsck.k9.mail.Message;

import com.fsck.k9.mail.Message.RecipientType;

import static com.fsck.k9.message.quote.QuoteHelper.QUOTE_BUFFER_LENGTH;

class TextQuoteCreator(private val quoteHelper: QuoteHelper, private val resourceProvider: CoreResourceProvider) {

    private val prefixInsertionRegex = Regex("(?m)^")

public class TextQuoteCreator {

    private final QuoteHelper quoteHelper;

    private final CoreResourceProvider resourceProvider;

    public TextQuoteCreator(QuoteHelper quoteHelper, CoreResourceProvider resourceProvider) {

        this.quoteHelper = quoteHelper;

        this.resourceProvider = resourceProvider;

    fun quoteOriginalTextMessage(

            originalMessage: Message,

            messageBody: String?,

            quoteStyle: QuoteStyle,

            prefix: String

    ): String {

        val body = messageBody ?: ""

        return when (quoteStyle) {

            QuoteStyle.PREFIX -> prefixQuoteText(body, originalMessage, prefix)

            QuoteStyle.HEADER -> headerQuoteText(body, originalMessage)

        }

    }

    /**

     * Add quoting markup to a text message.

     * @param originalMessage Metadata for message being quoted.

     * @param messageBody Text of the message to be quoted.

     * @param quoteStyle Style of quoting.

     * @return Quoted text.

     */

    public String quoteOriginalTextMessage(Message originalMessage, String messageBody, QuoteStyle quoteStyle,

            String prefix) {

        String body = messageBody == null ? "" : messageBody;

        String sentDate = quoteHelper.getSentDateText(originalMessage);

        if (quoteStyle == QuoteStyle.PREFIX) {

            String sender = Address.toString(originalMessage.getFrom());

            StringBuilder quotedText = new StringBuilder(body.length() + QUOTE_BUFFER_LENGTH);

            if (sentDate.length() != 0) {

                String replyHeader = resourceProvider.replyHeader(sender, sentDate);

                quotedText.append(replyHeader);

    private fun prefixQuoteText(body: String, originalMessage: Message, prefix: String): String {

        val sentDate = quoteHelper.getSentDateText(originalMessage)

        val sender = Address.toString(originalMessage.from)

        return StringBuilder(body.length + QUOTE_BUFFER_LENGTH).apply {

            val replyHeader = if (sentDate.isEmpty()) {

                resourceProvider.replyHeader(sender)

            } else {

                String replyHeader = resourceProvider.replyHeader(sender);

                quotedText.append(replyHeader);

                resourceProvider.replyHeader(sender, sentDate)

            }

            quotedText.append("\r\n");

            final String escapedPrefix = Matcher.quoteReplacement(prefix);

            quotedText.append(body.replaceAll("(?m)^", escapedPrefix));

            return quotedText.toString();

        } else if (quoteStyle == QuoteStyle.HEADER) {

            StringBuilder quotedText = new StringBuilder(body.length() + QUOTE_BUFFER_LENGTH);

            quotedText.append("\r\n");

            quotedText.append(resourceProvider.messageHeaderSeparator()).append("\r\n");

            if (originalMessage.getFrom() != null && Address.toString(originalMessage.getFrom()).length() != 0) {

                quotedText.append(resourceProvider.messageHeaderFrom()).append(" ").append(Address.toString(originalMessage.getFrom())).append("\r\n");

            append(replyHeader)

            append(CRLF)

            val escapedPrefix = Regex.escapeReplacement(prefix)

            val prefixedText = body.replace(prefixInsertionRegex, escapedPrefix)

            append(prefixedText)

        }.toString()

    }

            if (sentDate.length() != 0) {

                quotedText.append(resourceProvider.messageHeaderDate()).append(" ").append(sentDate).append("\r\n");

    private fun headerQuoteText(body: String, originalMessage: Message): String {

        val sentDate = quoteHelper.getSentDateText(originalMessage)

        return StringBuilder(body.length + QUOTE_BUFFER_LENGTH).apply {

            append(CRLF)

            append(resourceProvider.messageHeaderSeparator())

            append(CRLF)

            originalMessage.from.displayString()?.let { fromAddresses ->

                append(resourceProvider.messageHeaderFrom())

                append(" ")

                append(fromAddresses)

                append(CRLF)

            }

            if (originalMessage.getRecipients(RecipientType.TO) != null && originalMessage.getRecipients(RecipientType.TO).length != 0) {

                quotedText.append(resourceProvider.messageHeaderTo()).append(" ").append(Address.toString(originalMessage.getRecipients(RecipientType.TO))).append("\r\n");

            if (sentDate.isNotEmpty()) {

                append(resourceProvider.messageHeaderDate())

                append(" ")

                append(sentDate)

                append(CRLF)

            }

            if (originalMessage.getRecipients(RecipientType.CC) != null && originalMessage.getRecipients(RecipientType.CC).length != 0) {

                quotedText.append(resourceProvider.messageHeaderCc()).append(" ").append(Address.toString(originalMessage.getRecipients(RecipientType.CC))).append("\r\n");

            originalMessage.getRecipients(RecipientType.TO).displayString()?.let { toAddresses ->

                append(resourceProvider.messageHeaderTo())

                append(" ")

                append(toAddresses)

                append(CRLF)

            }

            if (originalMessage.getSubject() != null) {

                quotedText.append(resourceProvider.messageHeaderSubject()).append(" ").append(originalMessage.getSubject()).append("\r\n");

            originalMessage.getRecipients(RecipientType.CC).displayString()?.let { ccAddresses ->

                append(resourceProvider.messageHeaderCc())

                append(" ")

                append(ccAddresses)

                append(CRLF)

            }

            quotedText.append("\r\n");

            quotedText.append(body);

            originalMessage.subject?.let { subject ->

                append(resourceProvider.messageHeaderSubject())

                append(" ")

                append(subject)

                append(CRLF)

            }

            return quotedText.toString();

        } else {

            // Shouldn't ever happen.

            return body;

            append(CRLF)

            append(body)

        }.toString()

    }

    private fun Array<Address>.displayString() = Address.toString(this)?.let { if (it.isEmpty()) null else it }

    companion object {

        private const val CRLF = "\r\n"

    }

}