Move some repo classes to :core:data (#3214)

core/model/src/main/kotlin/org/meshtastic/core/model/util/ChannelSet.kt

@@ -0,0 +1,91 @@
+/*
+ * 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 org.meshtastic.core.model.util
+
+import android.graphics.Bitmap
+import android.net.Uri
+import android.util.Base64
+import com.geeksville.mesh.AppOnlyProtos.ChannelSet
+import com.google.zxing.BarcodeFormat
+import com.google.zxing.MultiFormatWriter
+import com.journeyapps.barcodescanner.BarcodeEncoder
+import org.meshtastic.core.model.Channel
+import timber.log.Timber
+import java.net.MalformedURLException
+import kotlin.jvm.Throws
+
+private const val MESHTASTIC_HOST = "meshtastic.org"
+private const val CHANNEL_PATH = "/e/"
+const val URL_PREFIX = "https://$MESHTASTIC_HOST$CHANNEL_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(CHANNEL_PATH, true)) {
+        throw MalformedURLException("Not a valid Meshtastic URL: ${toString().take(40)}")
+    }
+
+    // Older versions of Meshtastic clients (Apple/web) included `?add=true` within the URL fragment.
+    // This gracefully handles those cases until the newer version are generally available/used.
+    val url = ChannelSet.parseFrom(Base64.decode(fragment!!.substringBefore('?'), BASE64FLAGS))
+    val shouldAdd =
+        fragment?.substringAfter('?', "")?.takeUnless { it.isBlank() }?.equals("add=true")
+            ?: getBooleanQueryParameter("add", false)
+
+    return url.toBuilder().apply { if (shouldAdd) clearLoraConfig() }.build()
+}
+
+/** @return A list of globally unique channel IDs usable with MQTT subscribe() */
+val ChannelSet.subscribeList: List<String>
+    get() = settingsList.filter { it.downlinkEnabled }.map { Channel(it, loraConfig).name }
+
+fun ChannelSet.getChannel(index: Int): Channel? =
+    if (settingsCount > index) Channel(getSettings(index), loraConfig) else null
+
+/** Return the primary channel info */
+val ChannelSet.primaryChannel: Channel?
+    get() = getChannel(0)
+
+/**
+ * Return a URL that represents the [ChannelSet]
+ *
+ * @param upperCasePrefix portions of the URL can be upper case to make for more efficient QR codes
+ */
+fun ChannelSet.getChannelUrl(upperCasePrefix: Boolean = false, shouldAdd: Boolean = false): Uri {
+    val channelBytes = this.toByteArray() ?: ByteArray(0) // if unset just use empty
+    val enc = Base64.encodeToString(channelBytes, BASE64FLAGS)
+    val p = if (upperCasePrefix) URL_PREFIX.uppercase() else URL_PREFIX
+    val query = if (shouldAdd) "?add=true" else ""
+    return Uri.parse("$p$query#$enc")
+}
+
+fun ChannelSet.qrCode(shouldAdd: Boolean): Bitmap? = try {
+    val multiFormatWriter = MultiFormatWriter()
+    val bitMatrix =
+        multiFormatWriter.encode(getChannelUrl(false, shouldAdd).toString(), BarcodeFormat.QR_CODE, 960, 960)
+    val barcodeEncoder = BarcodeEncoder()
+    barcodeEncoder.createBitmap(bitMatrix)
+} catch (ex: Throwable) {
+    Timber.e("URL was too complex to render as barcode")
+    null
+}