Meshtastic-Android/app/src/main/java/com/geeksville/mesh/model/Channel.kt
2020-09-08 12:05:19 -07:00

90 lines
3.4 KiB
Kotlin

package com.geeksville.mesh.model
import android.graphics.Bitmap
import android.net.Uri
import android.util.Base64
import com.geeksville.mesh.MeshProtos
import com.google.zxing.BarcodeFormat
import com.google.zxing.MultiFormatWriter
import com.journeyapps.barcodescanner.BarcodeEncoder
import java.net.MalformedURLException
/** Utility function to make it easy to declare byte arrays - FIXME move someplace better */
fun byteArrayOfInts(vararg ints: Int) = ByteArray(ints.size) { pos -> ints[pos].toByte() }
data class Channel(
val settings: MeshProtos.ChannelSettings = MeshProtos.ChannelSettings.getDefaultInstance()
) {
companion object {
// Note: this string _SHOULD NOT BE LOCALIZED_ because it directly hashes to values used on the device for the default channel name.
val defaultChannelName = "Default"
// These bytes must match the well known and not secret bytes used the default channel AES128 key device code
val channelDefaultKey = byteArrayOfInts(
0xd4, 0xf1, 0xbb, 0x3a, 0x20, 0x29, 0x07, 0x59,
0xf0, 0xbc, 0xff, 0xab, 0xcf, 0x4e, 0x69, 0xbf
)
// Placeholder when emulating
val emulated = Channel(
MeshProtos.ChannelSettings.newBuilder().setName(defaultChannelName)
.setModemConfig(MeshProtos.ChannelSettings.ModemConfig.Bw125Cr45Sf128).build()
)
private const val prefixRoot = "https://www.meshtastic.org/c/"
const val prefix = "$prefixRoot#"
private const val base64Flags = Base64.URL_SAFE + Base64.NO_WRAP
private fun urlToSettings(url: Uri): MeshProtos.ChannelSettings {
val urlStr = url.toString()
// Let the path optionally include the # character (or not) so we can work with old URLs generated by old versions of the app
val pathRegex = Regex("$prefixRoot#?(.*)")
val (base64) = pathRegex.find(urlStr)?.destructured
?: throw MalformedURLException("Not a meshtastic URL: ${urlStr.take(40)}")
val bytes = Base64.decode(base64, base64Flags)
return MeshProtos.ChannelSettings.parseFrom(bytes)
}
}
constructor(url: Uri) : this(urlToSettings(url))
val name: String get() = settings.name
val modemConfig: MeshProtos.ChannelSettings.ModemConfig get() = settings.modemConfig
/**
* Return a name that is formatted as #channename-suffix
*
* Where suffix indicates the hash of the PSK
*/
val humanName: String
get() {
val code = settings.psk.fold(0, { acc, x -> acc xor (x.toInt() and 0xff) })
return "#${settings.name}-${'A' + (code % 26)}"
}
/// Can this channel be changed right now?
var editable = false
/// Return an URL that represents the current channel values
fun getChannelUrl(): Uri {
// If we have a valid radio config use it, othterwise use whatever we have saved in the prefs
val channelBytes = settings.toByteArray() ?: ByteArray(0) // if unset just use empty
val enc = Base64.encodeToString(channelBytes, base64Flags)
return Uri.parse("$prefix$enc")
}
fun getChannelQR(): Bitmap {
val multiFormatWriter = MultiFormatWriter()
val bitMatrix =
multiFormatWriter.encode(getChannelUrl().toString(), BarcodeFormat.QR_CODE, 192, 192);
val barcodeEncoder = BarcodeEncoder()
return barcodeEncoder.createBitmap(bitMatrix)
}
}