[pos] refactor configuration fetching and validation

5 files changed, 34 insertions, 13 deletions

diff --git a/merchant-lib/build.gradle b/merchant-lib/build.gradle
index 93e2d4d..128f4c1 100644
--- a/merchant-lib/build.gradle
+++ b/merchant-lib/build.gradle
@@ -45,14 +45,13 @@ android {
 }
 
 dependencies {
-    implementation project(":taler-kotlin-common")
+    api project(":taler-kotlin-common")
 
     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:$ktor_version"
+    api "io.ktor:ktor-client:$ktor_version"
+    api "io.ktor:ktor-client-okhttp:$ktor_version"
+    api "io.ktor:ktor-client-serialization-jvm:$ktor_version"
 
     testImplementation 'junit:junit:4.13'
     testImplementation "io.ktor:ktor-client-mock-jvm:$ktor_version"
diff --git a/merchant-lib/src/main/java/net/taler/merchantlib/MerchantApi.kt b/merchant-lib/src/main/java/net/taler/merchantlib/MerchantApi.kt
index 06388f4..e995724 100644
--- a/merchant-lib/src/main/java/net/taler/merchantlib/MerchantApi.kt
+++ b/merchant-lib/src/main/java/net/taler/merchantlib/MerchantApi.kt
@@ -37,8 +37,8 @@ import net.taler.merchantlib.Response.Companion.response
 
 class MerchantApi(private val httpClient: HttpClient) {
 
-    suspend fun getConfig(baseUrl: String): ConfigResponse {
-        return httpClient.get("$baseUrl/config")
+    suspend fun getConfig(baseUrl: String): Response<ConfigResponse> = response {
+        httpClient.get("$baseUrl/config") as ConfigResponse
     }
 
     suspend fun postOrder(
@@ -77,6 +77,11 @@ class MerchantApi(private val httpClient: HttpClient) {
 }
 
 fun getDefaultHttpClient(): HttpClient = HttpClient(OkHttp) {
+    engine {
+        config {
+            retryOnConnectionFailure(true)
+        }
+    }
     install(JsonFeature) {
         serializer = getSerializer()
     }
diff --git a/merchant-lib/src/main/java/net/taler/merchantlib/MerchantConfig.kt b/merchant-lib/src/main/java/net/taler/merchantlib/MerchantConfig.kt
index 71185b9..a01624e 100644
--- a/merchant-lib/src/main/java/net/taler/merchantlib/MerchantConfig.kt
+++ b/merchant-lib/src/main/java/net/taler/merchantlib/MerchantConfig.kt
@@ -23,11 +23,12 @@ import kotlinx.serialization.Serializable
 data class MerchantConfig(
     @SerialName("base_url")
     val baseUrl: String,
-    val instance: String,
+    // TODO remove instance when it is part of baseURL
+    val instance: String? = null,
     @SerialName("api_key")
     val apiKey: String
 ) {
-    fun urlFor(endpoint: String, params: Map<String, String>? = null): String {
+    fun urlFor(endpoint: String): String {
         val sb = StringBuilder(baseUrl)
         if (sb.last() != '/') sb.append('/')
         sb.append("instances/$instance/")
diff --git a/merchant-lib/src/main/java/net/taler/merchantlib/Response.kt b/merchant-lib/src/main/java/net/taler/merchantlib/Response.kt
index eb1ef27..1b49d78 100644
--- a/merchant-lib/src/main/java/net/taler/merchantlib/Response.kt
+++ b/merchant-lib/src/main/java/net/taler/merchantlib/Response.kt
@@ -50,14 +50,29 @@ class Response<out T> private constructor(
         }
     }
 
+    suspend fun handleSuspend(
+        onFailure: ((String) -> Any)? = null,
+        onSuccess: (suspend (T) -> Any)? = null
+    ) {
+        if (value is Failure) onFailure?.let { it(getFailureString(value)) }
+        else onSuccess?.let {
+            @Suppress("UNCHECKED_CAST")
+            it(value as T)
+        }
+    }
+
     private suspend fun getFailureString(failure: Failure): String = when (failure.exception) {
         is ClientRequestException -> getExceptionString(failure.exception)
         else -> failure.exception.toString()
     }
 
     private suspend fun getExceptionString(e: ClientRequestException): String {
-        val error: Error = e.response.receive()
-        return "Error ${error.code}: ${error.hint}"
+        return try {
+            val error: Error = e.response.receive()
+            "Error ${error.code}: ${error.hint}"
+        } catch (ex: Exception) {
+            "Status code: ${e.response.status.value}"
+        }
     }
 
     private class Failure(val exception: Throwable)
diff --git a/merchant-lib/src/test/java/net/taler/merchantlib/MerchantApiTest.kt b/merchant-lib/src/test/java/net/taler/merchantlib/MerchantApiTest.kt
index de1ca33..ea5a12a 100644
--- a/merchant-lib/src/test/java/net/taler/merchantlib/MerchantApiTest.kt
+++ b/merchant-lib/src/test/java/net/taler/merchantlib/MerchantApiTest.kt
@@ -46,8 +46,9 @@ class MerchantApiTest {
             }
             """.trimIndent()
         }
-        val response = api.getConfig("https://backend.int.taler.net")
-        assertEquals(ConfigResponse("0:0:0", "INTKUDOS"), response)
+        api.getConfig("https://backend.int.taler.net").assertSuccess {
+            assertEquals(ConfigResponse("0:0:0", "INTKUDOS"), it)
+        }
     }
 
     @Test