improve error codes

Pocket Poster/Error Codes/ApplyError.swift

@@ -0,0 +1,30 @@
+//
+//  ApplyError.swift
+//  Pocket Poster
+//
+//  Created by lemin on 6/18/25.
+//
+
+import Foundation
+
+enum ApplyError: LocalizedError {
+    // Throw when the app hash is incorrect
+    case wrongAppHash
+    
+    // Throw when the collections need to be reset
+    case collectionsNeedsReset
+    
+    // Throw in all other cases
+    case unexpected(info: String)
+    
+    public var errorDescription: String? {
+        switch self {
+        case .wrongAppHash:
+            return "Your app hash is incorrect. Please set it again."
+        case .collectionsNeedsReset:
+            return "The folder is improperly set up. Please tap \"Reset Collections\" and try again."
+        case .unexpected(let info):
+            return info
+        }
+    }
+}