proton-mail-android/app/src/main/java/ch/protonmail/android/activities/messageDetails/MessagePrinter.kt

/*
 * Copyright (c) 2020 Proton Technologies AG
 * 
 * This file is part of ProtonMail.
 * 
 * ProtonMail is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * ProtonMail is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with ProtonMail. If not, see https://www.gnu.org/licenses/.
 */
package ch.protonmail.android.activities.messageDetails

import android.content.Context
import android.content.res.Resources
import android.os.Build
import android.print.PrintAttributes
import android.print.PrintDocumentAdapter
import android.print.PrintManager
import android.webkit.WebView
import android.webkit.WebViewClient
import androidx.annotation.RequiresApi
import androidx.annotation.StringRes
import ch.protonmail.android.R
import ch.protonmail.android.api.models.MessageRecipient
import ch.protonmail.android.api.models.room.messages.Message
import ch.protonmail.android.utils.DateUtil
import ch.protonmail.android.utils.extensions.showToast
import timber.log.Timber

internal class MessagePrinter(
    private val context: Context,
    private val resources: Resources,
    private val printManager: PrintManager,
    private val loadRemoteImages: Boolean
) {

    private fun StringBuilder.appendRecipientsList(recipients: List<MessageRecipient>, @StringRes header: Int) {
        if (recipients.isEmpty()) {
            return
        }
        val first = recipients.first()
        append(String.format(resources.getString(header), first.emailAddress))
        recipients.drop(1).forEach {
            append(String.format(resources.getString(header), it.emailAddress))
            append("<br/>")
        }
    }

    @RequiresApi(Build.VERSION_CODES.KITKAT)
    fun printMessage(message: Message, bodyString: String) {
        val webView = WebView(context)
        webView.webViewClient = PrinterWebViewClient(message)
        webView.settings.blockNetworkImage = !loadRemoteImages
        val messageString = StringBuilder("<p>")
        val imagePath = "file:///android_asset/logo_print.png"
        messageString.append("<img src=\"$imagePath\" height=\"42\"")
        messageString.append("<br/>")
        messageString.append("<br/>")
        messageString.append("<hr>")
        messageString.append(String.format(resources.getString(R.string.print_from_template), message.sender))
        messageString.append("<br/>")
        messageString.appendRecipientsList(message.toList, R.string.print_to_template)
        messageString.appendRecipientsList(message.ccList, R.string.print_cc_template)
        messageString.appendRecipientsList(message.bccList, R.string.print_bcc_template)
        messageString.append(String.format(resources.getString(R.string.print_date_template), DateUtil.formatDetailedDateTime(context, message.timeMs)))
        messageString.append("<br/>")
        val attachmentList = message.Attachments
        val attachmentsCount = attachmentList.size
        messageString.append(resources.getQuantityString(R.plurals.attachments_non_descriptive,
                attachmentsCount, attachmentsCount))
        messageString.append("<br/>")
        attachmentList.forEach { attachment ->
            messageString.append(String.format(resources.getString(R.string.print_attachment_template), attachment.fileName))
            messageString.append("<br/>")
        }
        messageString.append("<br/>")
        messageString.append("</p>")
        messageString.append("<hr>")
        messageString.append(bodyString)
        webView.loadDataWithBaseURL(null, messageString.toString(), "text/HTML", "UTF-8", null)

        // Keep a reference to WebView object until you pass the PrintDocumentAdapter
        // to the PrintManager
    }

    @RequiresApi(Build.VERSION_CODES.KITKAT)
    private inner class PrinterWebViewClient(private val message: Message?) : WebViewClient() {

        override fun onPageFinished(view: WebView, url: String) {
            val printAdapter: PrintDocumentAdapter
            if (message != null) {
                val jobName = resources.getString(R.string.app_name) + message.subject!!
                printAdapter = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
                    view.createPrintDocumentAdapter(jobName)
                } else {
                    view.createPrintDocumentAdapter()
                }
                try {
                    printManager.print(jobName, printAdapter, PrintAttributes.Builder().build())
                } catch (e: Exception) {
                    Timber.e(e)
                    context.showToast(R.string.print_error)
                }
            }
        }
    }
}