Meshtastic-Android/app/src/main/java/com/geeksville/mesh/model/ChannelSet.kt
2025-01-02 07:00:51 -03:00

101 lines
3.8 KiB
Kotlin

/*
* Copyright (c) 2025 Meshtastic LLC
*
* This program 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.
*
* This program 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 this program. If not, see <https://www.gnu.org/licenses/>.
*/
package com.geeksville.mesh.model
import android.graphics.Bitmap
import android.net.Uri
import android.util.Base64
import com.geeksville.mesh.AppOnlyProtos.ChannelSet
import com.geeksville.mesh.android.BuildUtils.errormsg
import com.google.zxing.BarcodeFormat
import com.google.zxing.MultiFormatWriter
import com.journeyapps.barcodescanner.BarcodeEncoder
import java.net.MalformedURLException
import kotlin.jvm.Throws
private const val MESHTASTIC_HOST = "meshtastic.org"
private const val MESHTASTIC_PATH = "/e/"
internal const val URL_PREFIX = "https://$MESHTASTIC_HOST$MESHTASTIC_PATH#"
private const val BASE64FLAGS = Base64.URL_SAFE + Base64.NO_WRAP + Base64.NO_PADDING
/**
* Return a [ChannelSet] that represents the ChannelSet encoded by the URL.
* @throws MalformedURLException when not recognized as a valid Meshtastic URL
*/
@Throws(MalformedURLException::class)
fun Uri.toChannelSet(): ChannelSet {
if (fragment.isNullOrBlank() ||
!host.equals(MESHTASTIC_HOST, true) ||
!path.equals(MESHTASTIC_PATH, true)
) {
throw MalformedURLException("Not a valid Meshtastic URL: ${toString().take(40)}")
}
// Older versions of Meshtastic clients (Apple/web) included `?add=true` within the URL fragment.
// This gracefully handles those cases until the newer version are generally available/used.
val url = ChannelSet.parseFrom(Base64.decode(fragment!!.substringBefore('?'), BASE64FLAGS))
val shouldAdd = fragment?.substringAfter('?', "")
?.takeUnless { it.isBlank() }
?.equals("add=true")
?: getBooleanQueryParameter("add", false)
return url.toBuilder().apply { if (shouldAdd) clearLoraConfig() }.build()
}
/**
* @return A list of globally unique channel IDs usable with MQTT subscribe()
*/
val ChannelSet.subscribeList: List<String>
get() = settingsList.filter { it.downlinkEnabled }.map { Channel(it, loraConfig).name }
fun ChannelSet.getChannel(index: Int): Channel? =
if (settingsCount > index) Channel(getSettings(index), loraConfig) else null
/**
* Return the primary channel info
*/
val ChannelSet.primaryChannel: Channel? get() = getChannel(0)
/**
* Return a URL that represents the [ChannelSet]
* @param upperCasePrefix portions of the URL can be upper case to make for more efficient QR codes
*/
fun ChannelSet.getChannelUrl(upperCasePrefix: Boolean = false): Uri {
val channelBytes = this.toByteArray() ?: ByteArray(0) // if unset just use empty
val enc = Base64.encodeToString(channelBytes, BASE64FLAGS)
val p = if (upperCasePrefix) URL_PREFIX.uppercase() else URL_PREFIX
return Uri.parse("$p$enc")
}
val ChannelSet.qrCode: Bitmap?
get() = try {
val multiFormatWriter = MultiFormatWriter()
val bitMatrix =
multiFormatWriter.encode(
getChannelUrl(false).toString(),
BarcodeFormat.QR_CODE,
960,
960
)
val barcodeEncoder = BarcodeEncoder()
barcodeEncoder.createBitmap(bitMatrix)
} catch (ex: Throwable) {
errormsg("URL was too complex to render as barcode")
null
}