session-android/src/org/thoughtcrime/securesms/loki/redesign/activities/QRCodeActivity.kt

package org.thoughtcrime.securesms.loki.redesign.activities

import android.Manifest
import android.content.Intent
import android.graphics.Bitmap
import android.graphics.Typeface
import android.os.Bundle
import android.os.Environment
import android.support.v4.app.Fragment
import android.support.v4.app.FragmentPagerAdapter
import android.text.Spannable
import android.text.SpannableStringBuilder
import android.text.style.StyleSpan
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.Toast
import com.tbruyelle.rxpermissions2.RxPermissions
import kotlinx.android.synthetic.main.activity_qr_code.*
import kotlinx.android.synthetic.main.fragment_view_my_qr_code.*
import network.loki.messenger.R
import org.thoughtcrime.securesms.PassphraseRequiredActionBarActivity
import org.thoughtcrime.securesms.conversation.ConversationActivity
import org.thoughtcrime.securesms.database.Address
import org.thoughtcrime.securesms.database.DatabaseFactory
import org.thoughtcrime.securesms.database.ThreadDatabase
import org.thoughtcrime.securesms.loki.redesign.fragments.ScanQRCodeWrapperFragment
import org.thoughtcrime.securesms.loki.redesign.fragments.ScanQRCodeWrapperFragmentDelegate
import org.thoughtcrime.securesms.loki.redesign.utilities.QRCodeUtilities
import org.thoughtcrime.securesms.loki.toPx
import org.thoughtcrime.securesms.recipients.Recipient
import org.thoughtcrime.securesms.util.FileProviderUtil
import org.thoughtcrime.securesms.util.TextSecurePreferences
import org.whispersystems.signalservice.loki.utilities.PublicKeyValidation
import java.io.File
import java.io.FileOutputStream

class QRCodeActivity : PassphraseRequiredActionBarActivity(), ScanQRCodeWrapperFragmentDelegate {
    private val adapter = QRCodeActivityAdapter(this)

    // region Lifecycle
    override fun onCreate(savedInstanceState: Bundle?, isReady: Boolean) {
        super.onCreate(savedInstanceState, isReady)
        // Set content view
        setContentView(R.layout.activity_qr_code)
        // Set title
        supportActionBar!!.title = "QR Code"
        // Set up view pager
        viewPager.adapter = adapter
        tabLayout.setupWithViewPager(viewPager)
    }
    // endregion

    // region Interaction
    override fun handleQRCodeScanned(hexEncodedPublicKey: String) {
        createPrivateChatIfPossible(hexEncodedPublicKey)
    }

    fun createPrivateChatIfPossible(hexEncodedPublicKey: String) {
        if (!PublicKeyValidation.isValid(hexEncodedPublicKey)) { return Toast.makeText(this, "Invalid Session ID", Toast.LENGTH_SHORT).show() }
        val masterHexEncodedPublicKey = TextSecurePreferences.getMasterHexEncodedPublicKey(this)
        val userHexEncodedPublicKey = TextSecurePreferences.getLocalNumber(this)
        val targetHexEncodedPublicKey = if (hexEncodedPublicKey == masterHexEncodedPublicKey) userHexEncodedPublicKey else hexEncodedPublicKey
        val recipient = Recipient.from(this, Address.fromSerialized(targetHexEncodedPublicKey), true)
        val intent = Intent(this, ConversationActivity::class.java)
        intent.putExtra(ConversationActivity.ADDRESS_EXTRA, recipient.address)
        intent.putExtra(ConversationActivity.TEXT_EXTRA, getIntent().getStringExtra(ConversationActivity.TEXT_EXTRA))
        intent.setDataAndType(getIntent().data, getIntent().type)
        val existingThread = DatabaseFactory.getThreadDatabase(this).getThreadIdIfExistsFor(recipient)
        intent.putExtra(ConversationActivity.THREAD_ID_EXTRA, existingThread)
        intent.putExtra(ConversationActivity.DISTRIBUTION_TYPE_EXTRA, ThreadDatabase.DistributionTypes.DEFAULT)
        startActivity(intent)
        finish()
    }
    // endregion
}

// region Adapter
private class QRCodeActivityAdapter(val activity: QRCodeActivity) : FragmentPagerAdapter(activity.supportFragmentManager) {

    override fun getCount(): Int {
        return 2
    }

    override fun getItem(index: Int): Fragment {
        return when (index) {
            0 -> ViewMyQRCodeFragment()
            1 -> {
                val result = ScanQRCodeWrapperFragment()
                result.delegate = activity
                result.message = "Scan someone\'s QR code to start a conversation with them"
                result
            }
            else -> throw IllegalStateException()
        }
    }

    override fun getPageTitle(index: Int): CharSequence? {
        return when (index) {
            0 -> "View My QR Code"
            1 -> "Scan QR Code"
            else -> throw IllegalStateException()
        }
    }
}
// endregion

// region View My QR Code Fragment
class ViewMyQRCodeFragment : Fragment() {

    private val hexEncodedPublicKey: String
        get() {
            val masterHexEncodedPublicKey = TextSecurePreferences.getMasterHexEncodedPublicKey(context!!)
            val userHexEncodedPublicKey = TextSecurePreferences.getLocalNumber(context!!)
            return masterHexEncodedPublicKey ?: userHexEncodedPublicKey
        }

    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View {
        return inflater.inflate(R.layout.fragment_view_my_qr_code, container, false)
    }

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)
        val size = toPx(280, resources)
        val qrCode = QRCodeUtilities.encode(hexEncodedPublicKey, size)
        qrCodeImageView.setImageBitmap(qrCode)
        val explanation = SpannableStringBuilder("This is your unique public QR code. Other users can scan this to start a conversation with you.")
        explanation.setSpan(StyleSpan(Typeface.BOLD), 8, 34, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE)
        explanationTextView.text = explanation
        shareButton.setOnClickListener { shareQRCode() }
    }

    private fun shareQRCode() {
        fun proceed() {
            val directory = File(Environment.getExternalStorageDirectory(), Environment.DIRECTORY_PICTURES)
            val fileName = "$hexEncodedPublicKey.png"
            val file = File(directory, fileName)
            file.createNewFile()
            val fos = FileOutputStream(file)
            val size = toPx(280, resources)
            val qrCode = QRCodeUtilities.encode(hexEncodedPublicKey, size, false)
            qrCode.compress(Bitmap.CompressFormat.PNG, 100, fos)
            fos.flush()
            fos.close()
            val intent = Intent(Intent.ACTION_SEND)
            intent.putExtra(Intent.EXTRA_STREAM, FileProviderUtil.getUriFor(activity!!, file))
            intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION)
            intent.type = "image/png"
            startActivity(Intent.createChooser(intent, "Share QR Code"))
        }
        if (RxPermissions(this).isGranted(Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
            proceed()
        } else {
            @SuppressWarnings("unused")
            val unused = RxPermissions(this).request(Manifest.permission.WRITE_EXTERNAL_STORAGE).subscribe { isGranted ->
                if (isGranted) {
                    proceed()
                }
            }
        }
    }
}
// endregion