10 files changed, 292 insertions, 0 deletions
diff --git a/merchant-lib/.gitignore b/merchant-lib/.gitignore
new file mode 100644
index 0000000..42afabf
--- /dev/null
+++ b/merchant-lib/.gitignore
@@ -0,0 +1 @@
+/build
+\ No newline at end of file
diff --git a/merchant-lib/.gitlab-ci.yml b/merchant-lib/.gitlab-ci.yml
new file mode 100644
index 0000000..62a7516
--- /dev/null
+++ b/merchant-lib/.gitlab-ci.yml
@@ -0,0 +1,11 @@
+merchant_lib_test:
+  stage: test
+  only:
+    changes:
+      - merchant-lib/**/*
+      - build.gradle
+  script: ./gradlew :merchant-lib:check
+  artifacts:
+    paths:
+      - merchant-lib/build/reports/lint-results.html
+    expire_in: 1 week
diff --git a/merchant-lib/build.gradle b/merchant-lib/build.gradle
new file mode 100644
index 0000000..08da35d
--- /dev/null
+++ b/merchant-lib/build.gradle
@@ -0,0 +1,58 @@
+/*
+ * This file is part of GNU Taler
+ * (C) 2020 Taler Systems S.A.
+ *
+ * GNU Taler 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, or (at your option) any later version.
+ *
+ * GNU Taler 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
+ * GNU Taler; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
+ */
+
+plugins {
+    id 'org.jetbrains.kotlin.plugin.serialization' version "$kotlin_version"
+}
+
+apply plugin: 'com.android.library'
+apply plugin: 'kotlin-android'
+apply plugin: 'kotlin-android-extensions'
+
+android {
+    compileSdkVersion 29
+    //noinspection GradleDependency
+    buildToolsVersion "$build_tools_version"
+
+    defaultConfig {
+        minSdkVersion 21
+        targetSdkVersion 29
+        versionCode 1
+        versionName "0.1"
+
+        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
+        consumerProguardFiles "consumer-rules.pro"
+    }
+
+    buildTypes {
+        release {
+            minifyEnabled false
+            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
+        }
+    }
+}
+
+dependencies {
+    implementation "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
+
+    def ktor_version = "1.3.2"
+    implementation "io.ktor:ktor-client:$ktor_version"
+    implementation "io.ktor:ktor-client-okhttp:$ktor_version"
+    implementation "io.ktor:ktor-client-serialization-jvm:$ktor_version"
+
+    testImplementation 'junit:junit:4.13'
+    testApi "io.ktor:ktor-client-mock-jvm:$ktor_version"
+}
diff --git a/merchant-lib/consumer-rules.pro b/merchant-lib/consumer-rules.pro
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/merchant-lib/consumer-rules.pro
diff --git a/merchant-lib/proguard-rules.pro b/merchant-lib/proguard-rules.pro
new file mode 100644
index 0000000..481bb43
--- /dev/null
+++ b/merchant-lib/proguard-rules.pro
@@ -0,0 +1,21 @@
+# Add project specific ProGuard rules here.
+# You can control the set of applied configuration files using the
+# proguardFiles setting in build.gradle.
+#
+# For more details, see
+#   http://developer.android.com/guide/developing/tools/proguard.html
+
+# If your project uses WebView with JS, uncomment the following
+# and specify the fully qualified class name to the JavaScript interface
+# class:
+#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
+#   public *;
+#}
+
+# Uncomment this to preserve the line number information for
+# debugging stack traces.
+#-keepattributes SourceFile,LineNumberTable
+
+# If you keep the line number information, uncomment this to
+# hide the original source file name.
+#-renamesourcefileattribute SourceFile
+\ No newline at end of file
diff --git a/merchant-lib/src/main/AndroidManifest.xml b/merchant-lib/src/main/AndroidManifest.xml
new file mode 100644
index 0000000..7318c07
--- /dev/null
+++ b/merchant-lib/src/main/AndroidManifest.xml
@@ -0,0 +1,23 @@
+<!--
+  ~ This file is part of GNU Taler
+  ~ (C) 2020 Taler Systems S.A.
+  ~
+  ~ GNU Taler 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, or (at your option) any later version.
+  ~
+  ~ GNU Taler 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
+  ~ GNU Taler; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
+  -->
+
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    package="net.taler.merchantlib">
+
+    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
+    <uses-permission android:name="android.permission.INTERNET" />
+
+</manifest>
diff --git a/merchant-lib/src/main/java/net/taler/merchantlib/ConfigResponse.kt b/merchant-lib/src/main/java/net/taler/merchantlib/ConfigResponse.kt
new file mode 100644
index 0000000..49164e6
--- /dev/null
+++ b/merchant-lib/src/main/java/net/taler/merchantlib/ConfigResponse.kt
@@ -0,0 +1,34 @@
+/*
+ * This file is part of GNU Taler
+ * (C) 2020 Taler Systems S.A.
+ *
+ * GNU Taler 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, or (at your option) any later version.
+ *
+ * GNU Taler 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
+ * GNU Taler; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
+ */
+
+package net.taler.merchantlib
+
+import kotlinx.serialization.Serializable
+
+@Serializable
+data class ConfigResponse(
+    /**
+     * libtool-style representation of the Merchant protocol version, see
+     * https://www.gnu.org/software/libtool/manual/html_node/Versioning.html#Versioning
+     * The format is "current:revision:age".
+     */
+    val version: String,
+
+    /**
+    Currency supported by this backend.
+     */
+    val currency: String
+)
diff --git a/merchant-lib/src/main/java/net/taler/merchantlib/MerchantApi.kt b/merchant-lib/src/main/java/net/taler/merchantlib/MerchantApi.kt
new file mode 100644
index 0000000..656b093
--- /dev/null
+++ b/merchant-lib/src/main/java/net/taler/merchantlib/MerchantApi.kt
@@ -0,0 +1,43 @@
+/*
+ * This file is part of GNU Taler
+ * (C) 2020 Taler Systems S.A.
+ *
+ * GNU Taler 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, or (at your option) any later version.
+ *
+ * GNU Taler 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
+ * GNU Taler; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
+ */
+
+package net.taler.merchantlib
+
+import io.ktor.client.HttpClient
+import io.ktor.client.engine.okhttp.OkHttp
+import io.ktor.client.features.json.JsonFeature
+import io.ktor.client.features.json.serializer.KotlinxSerializer
+import io.ktor.client.request.get
+import io.ktor.client.request.header
+import io.ktor.http.HttpHeaders.Authorization
+
+class MerchantApi(private val httpClient: HttpClient) {
+
+    constructor() : this(getDefaultHttpClient())
+
+    suspend fun getConfig(baseUrl: String, apiKey: String = "sandbox"): ConfigResponse {
+        return httpClient.get("$baseUrl/config") {
+            header(Authorization, "ApiKey $apiKey")
+        }
+    }
+
+}
+
+private fun getDefaultHttpClient(): HttpClient = HttpClient(OkHttp) {
+    install(JsonFeature) {
+        serializer = KotlinxSerializer()
+    }
+}
diff --git a/merchant-lib/src/test/java/net/taler/merchantlib/MerchantApiTest.kt b/merchant-lib/src/test/java/net/taler/merchantlib/MerchantApiTest.kt
new file mode 100644
index 0000000..6b2199b
--- /dev/null
+++ b/merchant-lib/src/test/java/net/taler/merchantlib/MerchantApiTest.kt
@@ -0,0 +1,43 @@
+/*
+ * This file is part of GNU Taler
+ * (C) 2020 Taler Systems S.A.
+ *
+ * GNU Taler 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, or (at your option) any later version.
+ *
+ * GNU Taler 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
+ * GNU Taler; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
+ */
+
+package net.taler.merchantlib
+
+import kotlinx.coroutines.runBlocking
+import net.taler.merchantlib.MockHttpClient.giveJsonResponse
+import net.taler.merchantlib.MockHttpClient.httpClient
+import org.junit.Assert.assertEquals
+import org.junit.Test
+
+class MerchantApiTest {
+
+    private val api = MerchantApi(httpClient)
+
+    @Test
+    fun testGetConfig() = runBlocking {
+        httpClient.giveJsonResponse("https://backend.int.taler.net/config") {
+            """
+            {
+              "currency": "INTKUDOS",
+              "version": "0:0:0"
+            }
+            """.trimIndent()
+        }
+        val response = api.getConfig("https://backend.int.taler.net")
+        assertEquals(ConfigResponse("0:0:0", "INTKUDOS"), response)
+    }
+
+}
diff --git a/merchant-lib/src/test/java/net/taler/merchantlib/MockHttpClient.kt b/merchant-lib/src/test/java/net/taler/merchantlib/MockHttpClient.kt
new file mode 100644
index 0000000..076b77e
--- /dev/null
+++ b/merchant-lib/src/test/java/net/taler/merchantlib/MockHttpClient.kt
@@ -0,0 +1,58 @@
+/*
+ * This file is part of GNU Taler
+ * (C) 2020 Taler Systems S.A.
+ *
+ * GNU Taler 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, or (at your option) any later version.
+ *
+ * GNU Taler 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
+ * GNU Taler; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
+ */
+
+package net.taler.merchantlib
+
+import io.ktor.client.HttpClient
+import io.ktor.client.engine.mock.MockEngine
+import io.ktor.client.engine.mock.MockEngineConfig
+import io.ktor.client.engine.mock.respond
+import io.ktor.client.features.json.JsonFeature
+import io.ktor.client.features.json.serializer.KotlinxSerializer
+import io.ktor.http.ContentType.Application.Json
+import io.ktor.http.Url
+import io.ktor.http.fullPath
+import io.ktor.http.headersOf
+import io.ktor.http.hostWithPort
+
+object MockHttpClient {
+
+    val httpClient = HttpClient(MockEngine) {
+        install(JsonFeature) {
+            serializer = KotlinxSerializer()
+        }
+        engine {
+            addHandler { error("No response handler set") }
+        }
+    }
+
+    fun HttpClient.giveJsonResponse(url: String, jsonProducer: () -> String) {
+        val httpConfig = engineConfig as MockEngineConfig
+        httpConfig.requestHandlers.removeAt(0)
+        httpConfig.requestHandlers.add { request ->
+            if (request.url.fullUrl == url) {
+                val headers = headersOf("Content-Type" to listOf(Json.toString()))
+                respond(jsonProducer(), headers = headers)
+            } else {
+                error("Unexpected URL: ${request.url.fullUrl}")
+            }
+        }
+    }
+
+    private val Url.hostWithPortIfRequired: String get() = if (port == protocol.defaultPort) host else hostWithPort
+    private val Url.fullUrl: String get() = "${protocol.name}://$hostWithPortIfRequired$fullPath"
+
+}