new: extract logging module into standalone core library

core/logging/build.gradle.kts

@@ -0,0 +1,49 @@
+import org.jetbrains.kotlin.gradle.ExperimentalWasmDsl
+import org.jetbrains.kotlin.gradle.dsl.JvmTarget
+
+plugins {
+    alias(libs.plugins.kotlinMultiplatform)
+    alias(libs.plugins.androidMultiplatformLibrary)
+}
+
+kotlin {
+    iosArm64()
+    iosSimulatorArm64()
+
+    jvm()
+
+    js {
+        browser()
+    }
+
+    @OptIn(ExperimentalWasmDsl::class)
+    wasmJs {
+        browser()
+    }
+
+    androidLibrary {
+        namespace = "fr.ajaury.gwenedeg.core.logging"
+        compileSdk =
+            libs.versions.androidCompileSdk
+                .get()
+                .toInt()
+        minSdk =
+            libs.versions.androidMinSdk
+                .get()
+                .toInt()
+
+        compilerOptions {
+            jvmTarget = JvmTarget.JVM_11
+        }
+    }
+
+    sourceSets {
+        commonMain.dependencies {
+            // Logging
+            implementation(libs.kermit)
+        }
+        commonTest.dependencies {
+            implementation(libs.kotlin.test)
+        }
+    }
+}

core/logging/src/commonMain/kotlin/fr/ajaury/gwenedeg/core/logging/KermitLogger.kt

@@ -0,0 +1,26 @@
+package fr.ajaury.gwenedeg.core.logging
+
+import co.touchlab.kermit.Logger as Kermit
+
+/**
+ * Kermit-backed implementation (adapter) of the [Logger] port.
+ */
+class KermitLogger(
+    private val tag: String = "Gwenedeg",
+) : Logger {
+    override fun debug(message: String, throwable: Throwable?) {
+        Kermit.d(throwable = throwable, tag = tag) { message }
+    }
+
+    override fun info(message: String, throwable: Throwable?) {
+        Kermit.i(throwable = throwable, tag = tag) { message }
+    }
+
+    override fun warning(message: String, throwable: Throwable?) {
+        Kermit.w(throwable = throwable, tag = tag) { message }
+    }
+
+    override fun error(message: String, throwable: Throwable?) {
+        Kermit.e(throwable = throwable, tag = tag) { message }
+    }
+}

core/logging/src/commonMain/kotlin/fr/ajaury/gwenedeg/core/logging/Logger.kt

@@ -0,0 +1,27 @@
+package fr.ajaury.gwenedeg.core.logging
+
+/**
+ * Logging abstraction so the rest of the app depends on this interface
+ * rather than on a concrete logging library.
+ */
+interface Logger {
+    fun debug(
+        message: String,
+        throwable: Throwable? = null,
+    )
+
+    fun info(
+        message: String,
+        throwable: Throwable? = null,
+    )
+
+    fun warning(
+        message: String,
+        throwable: Throwable? = null,
+    )
+
+    fun error(
+        message: String,
+        throwable: Throwable? = null,
+    )
+}