1 files changed, 74 insertions, 0 deletions
diff --git a/app_expo/services/api/api-problem.ts b/app_expo/services/api/api-problem.ts
new file mode 100644
index 0000000..15ca850
--- /dev/null
+++ b/app_expo/services/api/api-problem.ts
@@ -0,0 +1,74 @@
+import { ApiResponse } from 'apisauce'
+
+export type GeneralApiProblem =
+  /**
+   * Times up.
+   */
+  | { kind: 'timeout'; temporary: true }
+  /**
+   * Cannot connect to the server for some reason.
+   */
+  | { kind: 'cannot-connect'; temporary: true }
+  /**
+   * The server experienced a problem. Any 5xx error.
+   */
+  | { kind: 'server' }
+  /**
+   * We're not allowed because we haven't identified ourself. This is 401.
+   */
+  | { kind: 'unauthorized' }
+  /**
+   * We don't have access to perform that request. This is 403.
+   */
+  | { kind: 'forbidden' }
+  /**
+   * Unable to find that resource.  This is a 404.
+   */
+  | { kind: 'not-found' }
+  /**
+   * All other 4xx series errors.
+   */
+  | { kind: 'rejected' }
+  /**
+   * Something truly unexpected happened. Most likely can try again. This is a catch all.
+   */
+  | { kind: 'unknown'; temporary: true }
+  /**
+   * The data we received is not in the expected format.
+   */
+  | { kind: 'bad-data' }
+
+/**
+ * Attempts to get a common cause of problems from an api response.
+ *
+ * @param response The api response.
+ */
+export function getGeneralApiProblem(response: ApiResponse<any>): GeneralApiProblem | void {
+  switch (response.problem) {
+    case 'CONNECTION_ERROR':
+      return { kind: 'cannot-connect', temporary: true }
+    case 'NETWORK_ERROR':
+      return { kind: 'cannot-connect', temporary: true }
+    case 'TIMEOUT_ERROR':
+      return { kind: 'timeout', temporary: true }
+    case 'SERVER_ERROR':
+      return { kind: 'server' }
+    case 'UNKNOWN_ERROR':
+      return { kind: 'unknown', temporary: true }
+    case 'CLIENT_ERROR':
+      switch (response.status) {
+        case 401:
+          return { kind: 'unauthorized' }
+        case 403:
+          return { kind: 'forbidden' }
+        case 404:
+          return { kind: 'not-found' }
+        default:
+          return { kind: 'rejected' }
+      }
+    case 'CANCEL_ERROR':
+      return null
+  }
+
+  return null
+}