Meshtastic-Android/app/src/main/java/com/geeksville/mesh/ui/ChannelFragment.kt

package com.geeksville.mesh.ui

import android.content.ActivityNotFoundException
import android.content.Intent
import android.graphics.ColorMatrix
import android.graphics.ColorMatrixColorFilter
import android.net.Uri
import android.os.Bundle
import android.os.RemoteException
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.view.inputmethod.EditorInfo
import android.widget.ArrayAdapter
import android.widget.ImageView
import androidx.activity.result.contract.ActivityResultContracts
import androidx.fragment.app.activityViewModels
import androidx.lifecycle.asLiveData
import com.geeksville.mesh.analytics.DataPair
import com.geeksville.mesh.android.GeeksvilleApplication
import com.geeksville.mesh.android.Logging
import com.geeksville.mesh.android.hideKeyboard
import com.geeksville.mesh.ChannelProtos
import com.geeksville.mesh.ConfigProtos
import com.geeksville.mesh.R
import com.geeksville.mesh.android.getCameraPermissions
import com.geeksville.mesh.android.hasCameraPermission
import com.geeksville.mesh.channelSet
import com.geeksville.mesh.copy
import com.geeksville.mesh.databinding.ChannelFragmentBinding
import com.geeksville.mesh.model.Channel
import com.geeksville.mesh.model.ChannelOption
import com.geeksville.mesh.model.ChannelSet
import com.geeksville.mesh.model.UIViewModel
import com.google.android.material.dialog.MaterialAlertDialogBuilder
import com.google.android.material.snackbar.Snackbar
import com.google.protobuf.ByteString
import com.journeyapps.barcodescanner.ScanContract
import com.journeyapps.barcodescanner.ScanOptions
import dagger.hilt.android.AndroidEntryPoint
import java.security.SecureRandom


// Make an image view dim
fun ImageView.setDim() {
    val matrix = ColorMatrix()
    matrix.setSaturation(0f) //0 means grayscale
    val cf = ColorMatrixColorFilter(matrix)
    colorFilter = cf
    imageAlpha = 64 // 128 = 0.5
}

/// Return image view to normal
fun ImageView.setOpaque() {
    colorFilter = null
    imageAlpha = 255
}

@AndroidEntryPoint
class ChannelFragment : ScreenFragment("Channel"), Logging {

    private var _binding: ChannelFragmentBinding? = null

    // This property is only valid between onCreateView and onDestroyView.
    private val binding get() = _binding!!

    private val model: UIViewModel by activityViewModels()

    override fun onCreateView(
        inflater: LayoutInflater, container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View {
        _binding = ChannelFragmentBinding.inflate(inflater, container, false)
        return binding.root
    }

    /// Called when the lock/unlock icon has changed
    private fun onEditingChanged() {
        val isEditing = binding.editableCheckbox.isChecked

        binding.channelOptions.isEnabled = isEditing
        binding.shareButton.isEnabled = !isEditing
        binding.resetButton.isEnabled = isEditing
        binding.scanButton.isEnabled = isEditing
        binding.channelNameView.isEnabled = isEditing
        if (isEditing) // Dim the (stale) QR code while editing...
            binding.qrView.setDim()
        else
            binding.qrView.setOpaque()
    }

    /// Pull the latest data from the model (discarding any user edits)
    private fun setGUIfromModel() {
        val channels = model.channels.value
        val channel = channels.primaryChannel
        val connected = model.isConnected()

        // Only let buttons work if we are connected to the radio
        binding.editableCheckbox.isChecked = false // start locked
        onEditingChanged() // we just locked the gui
        binding.shareButton.isEnabled = connected

        if (channel != null) {
            binding.qrView.visibility = View.VISIBLE
            binding.channelNameEdit.visibility = View.VISIBLE
            binding.channelNameEdit.setText(channel.humanName)

            // For now, we only let the user edit/save channels while the radio is awake - because the service
            // doesn't cache DeviceConfig writes.
            binding.editableCheckbox.isEnabled = connected

            val bitmap = channels.qrCode
            if (bitmap != null)
                binding.qrView.setImageBitmap(bitmap)

            val modemPreset = channel.loraConfig.modemPreset
            val channelOption = ChannelOption.fromConfig(modemPreset)
            binding.filledExposedDropdown.setText(
                getString(
                    channelOption?.configRes ?: R.string.modem_config_unrecognized
                ), false
            )

        } else {
            binding.qrView.visibility = View.INVISIBLE
            binding.channelNameEdit.visibility = View.INVISIBLE
            binding.editableCheckbox.isEnabled = false
        }

        val modemPresets = ChannelOption.values()
        val modemPresetList = modemPresets.map { getString(it.configRes) }
        val adapter = ArrayAdapter(
            requireContext(),
            R.layout.dropdown_menu_popup_item,
            modemPresetList
        )

        binding.filledExposedDropdown.setAdapter(adapter)
    }

    private fun shareChannel() {
        model.channels.value.let { channels ->

            GeeksvilleApplication.analytics.track(
                "share",
                DataPair("content_type", "channel")
            ) // track how many times users share channels

            val sendIntent: Intent = Intent().apply {
                action = Intent.ACTION_SEND
                putExtra(Intent.EXTRA_TEXT, channels.getChannelUrl().toString())
                putExtra(
                    Intent.EXTRA_TITLE,
                    getString(R.string.url_for_join)
                )
                type = "text/plain"
            }

            try {
                val shareIntent = Intent.createChooser(sendIntent, null)
                requireActivity().startActivity(shareIntent)
            } catch (ex: ActivityNotFoundException) {
                Snackbar.make(
                    requireView(),
                    R.string.no_app_found,
                    Snackbar.LENGTH_SHORT
                ).show()
            }
        }
    }

    /// Send new channel settings to the device
    private fun installSettings(
        newChannel: ChannelProtos.ChannelSettings,
        newLoRaConfig: ConfigProtos.Config.LoRaConfig
    ) {
        val newSet = ChannelSet(
            channelSet {
                settings.add(newChannel)
                loraConfig = newLoRaConfig
            })
        // Try to change the radio, if it fails, tell the user why and throw away their edits
        try {
            model.setChannels(newSet)
            // Since we are writing to DeviceConfig, that will trigger the rest of the GUI update (QR code etc)
        } catch (ex: RemoteException) {
            errormsg("ignoring channel problem", ex)

            setGUIfromModel() // Throw away user edits

            // Tell the user to try again
            Snackbar.make(
                requireView(),
                R.string.radio_sleeping,
                Snackbar.LENGTH_SHORT
            ).show()
        }
    }

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)

        val barcodeLauncher = registerForActivityResult(ScanContract()) { result ->
            if (result.contents != null) {
                model.setRequestChannelUrl(Uri.parse(result.contents))
            }
        }

        fun zxingScan() {
            debug("Starting zxing QR code scanner")
            val zxingScan = ScanOptions()
            zxingScan.setCameraId(0)
            zxingScan.setPrompt("")
            zxingScan.setBeepEnabled(false)
            zxingScan.setDesiredBarcodeFormats(ScanOptions.QR_CODE)
            barcodeLauncher.launch(zxingScan)
        }

        val requestPermissionAndScanLauncher =
            registerForActivityResult(ActivityResultContracts.RequestMultiplePermissions()) { permissions ->
                if (permissions.entries.all { it.value }) zxingScan()
            }

        fun requestPermissionAndScan() {
            MaterialAlertDialogBuilder(requireContext())
                .setTitle(R.string.camera_required)
                .setMessage(R.string.why_camera_required)
                .setNeutralButton(R.string.cancel) { _, _ ->
                    debug("Camera permission denied")
                }
                .setPositiveButton(getString(R.string.accept)) { _, _ ->
                    requestPermissionAndScanLauncher.launch(requireContext().getCameraPermissions())
                }
                .show()
        }

        binding.channelNameEdit.on(EditorInfo.IME_ACTION_DONE) {
            requireActivity().hideKeyboard()
        }

        binding.resetButton.setOnClickListener {
            // User just locked it, we should warn and then apply changes to radio
            MaterialAlertDialogBuilder(requireContext())
                .setTitle(R.string.reset_to_defaults)
                .setMessage(R.string.are_you_sure_change_default)
                .setNeutralButton(R.string.cancel) { _, _ ->
                    setGUIfromModel() // throw away any edits
                }
                .setPositiveButton(R.string.apply) { _, _ ->
                    debug("Switching back to default channel")
                    installSettings(
                        Channel.default.settings,
                        Channel.default.loraConfig.copy {
                            region = model.region
                            txEnabled = model.txEnabled
                        }
                    )
                }
                .show()
        }

        binding.scanButton.setOnClickListener {
            if (requireContext().hasCameraPermission()) zxingScan()
            else requestPermissionAndScan()
        }

        // Note: Do not use setOnCheckedChanged here because we don't want to be called when we programmatically disable editing
        binding.editableCheckbox.setOnClickListener {

            /// We use this to determine if the user tried to install a custom name
            var originalName = ""

            val checked = binding.editableCheckbox.isChecked
            if (checked) {
                // User just unlocked for editing - remove the # goo around the channel name
                model.channels.value.primaryChannel?.let { ch ->
                    // Note: We are careful to show the empty string here if the user was on a default channel, so the user knows they should it for any changes
                    originalName = ch.settings.name
                    binding.channelNameEdit.setText(originalName)
                }
            } else {
                // User just locked it, we should warn and then apply changes to radio

                model.channels.value.primaryChannel?.let { oldPrimary ->
                    var newSettings = oldPrimary.settings
                    val newName = binding.channelNameEdit.text.toString().trim()

                    // Find the new modem config
                    val selectedModemPresetString =
                        binding.filledExposedDropdown.editableText.toString()
                    var newModemPreset = getModemPreset(selectedModemPresetString)
                    if (newModemPreset == ConfigProtos.Config.LoRaConfig.ModemPreset.UNRECOGNIZED) // Huh? didn't find it - keep same
                        newModemPreset = oldPrimary.loraConfig.modemPreset

                    // Generate a new AES256 key if the user changes channel name or the name is non-default and the settings changed
                    val shouldUseRandomKey =
                        newName != originalName || (newName.isNotEmpty() && newModemPreset != oldPrimary.loraConfig.modemPreset)
                    if (shouldUseRandomKey) {

                        // Install a new customized channel
                        debug("ASSIGNING NEW AES256 KEY")
                        val random = SecureRandom()
                        val bytes = ByteArray(32)
                        random.nextBytes(bytes)
                        newSettings = newSettings.copy {
                            name = newName.take(11) // proto max_size:12
                            psk = ByteString.copyFrom(bytes)
                        }
                    } else {
                        debug("Switching back to default channel")
                        newSettings = Channel.default.settings
                    }

                    // No matter what apply the speed selection from the user
                    val newLoRaConfig = model.config.lora.copy {
                        usePreset = true
                        modemPreset = newModemPreset
                        bandwidth = 0
                        spreadFactor = 0
                        codingRate = 0
                    }

                    val humanName = Channel(newSettings, newLoRaConfig).humanName
                    binding.channelNameEdit.setText(humanName)

                    val message = buildString {
                        append(getString(R.string.are_you_sure_channel))
                        if (!shouldUseRandomKey)
                            append("\n\n" + getString(R.string.warning_default_psk).format(humanName))
                    }

                    MaterialAlertDialogBuilder(requireContext())
                        .setTitle(R.string.change_channel)
                        .setMessage(message)
                        .setNeutralButton(R.string.cancel) { _, _ ->
                            setGUIfromModel()
                        }
                        .setPositiveButton(getString(R.string.accept)) { _, _ ->
                            // Generate a new channel with only the changes the user can change in the GUI

                            installSettings(newSettings, newLoRaConfig)
                        }
                        .show()
                }
            }

            onEditingChanged() // update GUI on what user is allowed to edit/share
        }

        // Share this particular channel if someone clicks share
        binding.shareButton.setOnClickListener {
            shareChannel()
        }

        model.channels.asLiveData().observe(viewLifecycleOwner) {
            setGUIfromModel()
        }

        // If connection state changes, we might need to enable/disable buttons
        model.connectionState.observe(viewLifecycleOwner) {
            setGUIfromModel()
        }
    }

    private fun getModemPreset(selectedChannelOptionString: String): ConfigProtos.Config.LoRaConfig.ModemPreset {
        for (item in ChannelOption.values()) {
            if (getString(item.configRes) == selectedChannelOptionString)
                return item.modemPreset
        }
        return ConfigProtos.Config.LoRaConfig.ModemPreset.UNRECOGNIZED
    }
}