[Shared] Refactors error handling based on ALTLocalizedError protocol (#1115)

* [Shared] Revises ALTLocalizedError protocol

* Refactors errors to conform to revised ALTLocalizedError protocol

* [Missing Commit] Remaining changes for ALTLocalizedError

* [AltServer] Refactors errors to conform to revised ALTLocalizedError protocol

* [Missing Commit] Declares ALTLocalizedTitleErrorKey + ALTLocalizedDescriptionKey

* Updates Objective-C errors to match revised ALTLocalizedError

* [Missing Commit] Unnecessary ALTLocalizedDescription logic

* [Shared] Refactors NSError.withLocalizedFailure to properly support ALTLocalizedError

* [Shared] Supports adding localized titles to errors via NSError.withLocalizedTitle()

* Revises ErrorResponse logic to support arbitrary errors and user info values

* [Missed Commit] Renames CodableServerError to CodableError

* Merges ConnectionError into OperationError

* [Missed Commit] Doesn’t check ALTWrappedError’s userInfo for localizedDescription

* [Missed] Fixes incorrect errorDomain for ALTErrorEnums

* [Missed] Removes nonexistent ALTWrappedError.h

* Includes source file and line number in OperationError.unknown failureReason

* Adds localizedTitle to AppManager operation errors

* Fixes adding localizedTitle + localizedFailure to ALTWrappedError

* Updates ToastView to use error’s localizedTitle as title

* [Shared] Adds NSError.formattedDetailedDescription(with:)

Returns formatted NSAttributedString containing all user info values intended for displaying to the user.

* [Shared] Updates Error.localizedErrorCode to say “code” instead of “error”

* Conforms ALTLocalizedError to CustomStringConvertible

* Adds “View More Details” option to Error Log context menu to view detailed error description

* [Shared] Fixes NSError.formattedDetailedDescription appearing black in dark mode

* [AltServer] Updates error alert to match revised error logic

Uses error’s localizedTitle as alert title.

* [AltServer] Adds “View More Details” button to error alert to view detailed error info

* [AltServer] Renames InstallError to OperationError and conforms to ALTErrorEnum

* [Shared] Removes CodableError support for Date user info values

Not currently used, and we don’t want to accidentally parse a non-Date as a Date in the meantime.

* [Shared] Includes dynamic UserInfoValueProvider values in NSError.formattedDetailedDescription()

* [Shared] Includes source file + line in NSError.formattedDetailedDescription()

Automatically captures source file + line when throwing ALTErrorEnums.

* [Shared] Captures source file + line for unknown errors

* Removes sourceFunction from OperationError

* Adds localizedTitle to AuthenticationViewController errors

* [Shared] Moves nested ALTWrappedError logic to ALTWrappedError initializer

* [AltServer] Removes now-redundant localized failure from JIT errors

All JIT errors now have a localizedTitle which effectively says the same thing.

* Makes OperationError.Code start at 1000

“Connection errors” subsection starts at 1200.

* [Shared] Updates Error domains to revised [Source].[ErrorType] format

* Updates ALTWrappedError.localizedDescription to prioritize using wrapped NSLocalizedDescription as failure reason

* Makes ALTAppleAPIError codes start at 3000

* [AltServer] Adds relevant localizedFailures to ALTDeviceManager.installApplication() errors

* Revises OperationError failureReasons and recovery suggestions

All failure reasons now read correctly when preceded by a failure reason and “because”.

* Revises ALTServerError error messages
All failure reasons now read correctly when preceded by a failure reason and “because”.

* Most failure reasons now read correctly when preceded by a failure reason and “because”.
* ALTServerErrorUnderlyingError forwards all user info provider calls to underlying error.

* Revises error messages for ALTAppleAPIErrorIncorrectCredentials

* [Missed] Removes NSError+AltStore.swift from AltStore target

* [Shared] Updates AltServerErrorDomain to revised [Source].[ErrorType] format

* [Shared] Removes “code” from Error.localizedErrorCode

* [Shared] Makes ALTServerError codes (appear to) start at 2000

We can’t change the actual error codes without breaking backwards compatibility, so instead we just add 2000 whenever we display ALTServerError codes to the user.

* Moves VerificationError.errorFailure to VerifyAppOperation

* Supports custom failure reason for OperationError.unknown

* [Shared] Changes AltServerErrorDomain to “AltServer.ServerError”

* [Shared] Converts ALTWrappedError to Objective-C class

NSError subclasses must be written in ObjC for Swift.Error <-> NSError bridging to work correctly.

# Conflicts:
#	AltStore.xcodeproj/project.pbxproj

* Fixes decoding CodableError nested user info values

Shared/Categories/NSError+ALTServerError.m

@@ -8,9 +8,15 @@
 
 #import "NSError+ALTServerError.h"
 
-NSErrorDomain const AltServerErrorDomain = @"com.rileytestut.AltServer";
-NSErrorDomain const AltServerInstallationErrorDomain = @"com.rileytestut.AltServer.Installation";
-NSErrorDomain const AltServerConnectionErrorDomain = @"com.rileytestut.AltServer.Connection";
+#if TARGET_OS_OSX
+#import "AltServer-Swift.h"
+#else
+#import <AltStoreCore/AltStoreCore-Swift.h>
+#endif
+
+NSErrorDomain const AltServerErrorDomain = @"AltServer.ServerError";
+NSErrorDomain const AltServerInstallationErrorDomain = @"Apple.InstallationError";
+NSErrorDomain const AltServerConnectionErrorDomain = @"AltServer.ConnectionError";
 
 NSErrorUserInfoKey const ALTUnderlyingErrorDomainErrorKey = @"underlyingErrorDomain";
 NSErrorUserInfoKey const ALTUnderlyingErrorCodeErrorKey = @"underlyingErrorCode";
@@ -24,8 +30,16 @@ NSErrorUserInfoKey const ALTOperatingSystemVersionErrorKey = @"ALTOperatingSyste
 
 + (void)load
 {
-    [NSError setUserInfoValueProviderForDomain:AltServerErrorDomain provider:^id _Nullable(NSError * _Nonnull error, NSErrorUserInfoKey  _Nonnull userInfoKey) {
-        if ([userInfoKey isEqualToString:NSLocalizedFailureReasonErrorKey])
+    [NSError alt_setUserInfoValueProviderForDomain:AltServerErrorDomain provider:^id _Nullable(NSError * _Nonnull error, NSErrorUserInfoKey  _Nonnull userInfoKey) {
+        if ([userInfoKey isEqualToString:NSLocalizedDescriptionKey])
+        {
+            return [error altserver_localizedDescription];
+        }
+        else if ([userInfoKey isEqualToString:NSLocalizedFailureErrorKey])
+        {
+            return [error altserver_localizedFailure];
+        }
+        else if ([userInfoKey isEqualToString:NSLocalizedFailureReasonErrorKey])
         {
             return [error altserver_localizedFailureReason];
         }
@@ -41,10 +55,10 @@ NSErrorUserInfoKey const ALTOperatingSystemVersionErrorKey = @"ALTOperatingSyste
         return nil;
     }];
     
-    [NSError setUserInfoValueProviderForDomain:AltServerConnectionErrorDomain provider:^id _Nullable(NSError * _Nonnull error, NSErrorUserInfoKey  _Nonnull userInfoKey) {
-        if ([userInfoKey isEqualToString:NSLocalizedDescriptionKey])
+    [NSError alt_setUserInfoValueProviderForDomain:AltServerConnectionErrorDomain provider:^id _Nullable(NSError * _Nonnull error, NSErrorUserInfoKey  _Nonnull userInfoKey) {
+        if ([userInfoKey isEqualToString:NSLocalizedFailureReasonErrorKey])
         {
-            return [error altserver_connection_localizedDescription];
+            return [error altserver_connection_localizedFailureReason];
         }
         else if ([userInfoKey isEqualToString:NSLocalizedRecoverySuggestionErrorKey])
         {
@@ -55,6 +69,53 @@ NSErrorUserInfoKey const ALTOperatingSystemVersionErrorKey = @"ALTOperatingSyste
     }];
 }
 
+- (nullable NSString *)altserver_localizedDescription
+{
+    switch ((ALTServerError)self.code)
+    {
+        case ALTServerErrorUnderlyingError:
+        {
+            // We're wrapping another error, so return the wrapped error's localized description.
+            NSError *underlyingError = self.userInfo[NSUnderlyingErrorKey];
+            return underlyingError.localizedDescription;
+        }
+            
+        default:
+            return nil;
+    }
+}
+
+- (nullable NSString *)altserver_localizedFailure
+{
+    switch ((ALTServerError)self.code)
+    {
+        case ALTServerErrorUnderlyingError:
+        {
+            NSError *underlyingError = self.userInfo[NSUnderlyingErrorKey];
+            return underlyingError.alt_localizedFailure;
+        }
+        
+        case ALTServerErrorConnectionFailed:
+        {
+            NSError *underlyingError = self.userInfo[NSUnderlyingErrorKey];
+            if (underlyingError.localizedFailureReason != nil)
+            {
+                // Only return localized failure if there is an underlying error with failure reason.
+#if TARGET_OS_OSX
+                return NSLocalizedString(@"There was an error connecting to the device.", @"");
+#else
+                return NSLocalizedString(@"AltServer could not establish a connection to AltStore.", @"");
+#endif
+            }
+            
+            return nil;
+        }
+            
+        default:
+            return nil;
+    }
+}
+
 - (nullable NSString *)altserver_localizedFailureReason
 {
     switch ((ALTServerError)self.code)
@@ -73,6 +134,7 @@ NSErrorUserInfoKey const ALTOperatingSystemVersionErrorKey = @"ALTOperatingSyste
                 return [NSString stringWithFormat:NSLocalizedString(@"Error code: %@", @""), underlyingErrorCode];
             }
             
+            // Return nil because this is a "pass-through" error, so if underlyingError doesn't have failure reason, this doesn't either.
             return nil;
         }
         
@@ -80,20 +142,30 @@ NSErrorUserInfoKey const ALTOperatingSystemVersionErrorKey = @"ALTOperatingSyste
             return NSLocalizedString(@"An unknown error occured.", @"");
             
         case ALTServerErrorConnectionFailed:
+        {
+            NSError *underlyingError = self.userInfo[NSUnderlyingErrorKey];
+            if (underlyingError.localizedFailureReason != nil)
+            {
+                return underlyingError.localizedFailureReason;
+            }
+            
+            // Return fallback failure reason if there isn't an underlying error with failure reason.
+            
 #if TARGET_OS_OSX
             return NSLocalizedString(@"There was an error connecting to the device.", @"");
 #else
-            return NSLocalizedString(@"Could not connect to AltServer.", @"");
+            return NSLocalizedString(@"AltServer could not establish a connection to AltStore.", @"");
 #endif
+        }
             
         case ALTServerErrorLostConnection:
-            return NSLocalizedString(@"Lost connection to AltServer.", @"");
+            return NSLocalizedString(@"The connection to AltServer was lost.", @"");
             
         case ALTServerErrorDeviceNotFound:
             return NSLocalizedString(@"AltServer could not find this device.", @"");
             
         case ALTServerErrorDeviceWriteFailed:
-            return NSLocalizedString(@"Failed to write app data to device.", @"");
+            return NSLocalizedString(@"AltServer could not write data to this device.", @"");
             
         case ALTServerErrorInvalidRequest:
             return NSLocalizedString(@"AltServer received an invalid request.", @"");
@@ -102,13 +174,21 @@ NSErrorUserInfoKey const ALTOperatingSystemVersionErrorKey = @"ALTOperatingSyste
             return NSLocalizedString(@"AltServer sent an invalid response.", @"");
             
         case ALTServerErrorInvalidApp:
-            return NSLocalizedString(@"The app is invalid.", @"");
+            return NSLocalizedString(@"The app is in an invalid format.", @"");
             
         case ALTServerErrorInstallationFailed:
-            return NSLocalizedString(@"An error occured while installing the app.", @"");
+        {
+            NSError *underlyingError = self.userInfo[NSUnderlyingErrorKey];
+            if (underlyingError != nil)
+            {
+                return underlyingError.localizedFailureReason ?: underlyingError.localizedDescription;
+            }
+            
+            return NSLocalizedString(@"An error occurred while installing the app.", @"");
+        }
             
         case ALTServerErrorMaximumFreeAppLimitReached:
-            return NSLocalizedString(@"Cannot activate more than 3 apps with a non-developer Apple ID.", @"");
+            return NSLocalizedString(@"You cannot activate more than 3 apps with a non-developer Apple ID.", @"");
             
         case ALTServerErrorUnsupportediOSVersion:
             return NSLocalizedString(@"Your device must be running iOS 12.2 or later to install AltStore.", @"");
@@ -117,7 +197,7 @@ NSErrorUserInfoKey const ALTOperatingSystemVersionErrorKey = @"ALTOperatingSyste
             return NSLocalizedString(@"AltServer does not support this request.", @"");
             
         case ALTServerErrorUnknownResponse:
-            return NSLocalizedString(@"Received an unknown response from AltServer.", @"");
+            return NSLocalizedString(@"AltStore received an unknown response from AltServer.", @"");
             
         case ALTServerErrorInvalidAnisetteData:
             return NSLocalizedString(@"The provided anisette data is invalid.", @"");
@@ -141,7 +221,7 @@ NSErrorUserInfoKey const ALTOperatingSystemVersionErrorKey = @"ALTOperatingSyste
         case ALTServerErrorIncompatibleDeveloperDisk:
         {
             NSString *osVersion = [self altserver_osVersion] ?: NSLocalizedString(@"this device's OS version", @"");
-            NSString *failureReason = [NSString stringWithFormat:NSLocalizedString(@"The disk is incompatible with %@.", @""), osVersion];
+            NSString *failureReason = [NSString stringWithFormat:NSLocalizedString(@"The disk is incompatible with %@.", @""), osVersion]; // "Developer" disk is included in localizedFailure
             return failureReason;
         }
     }
@@ -153,7 +233,24 @@ NSErrorUserInfoKey const ALTOperatingSystemVersionErrorKey = @"ALTOperatingSyste
 {
     switch ((ALTServerError)self.code)
     {
+        case ALTServerErrorUnderlyingError:
+        {
+            NSError *underlyingError = self.userInfo[NSUnderlyingErrorKey];
+            return underlyingError.localizedRecoverySuggestion;
+        }
+            
         case ALTServerErrorConnectionFailed:
+        {
+            NSError *underlyingError = self.userInfo[NSUnderlyingErrorKey];
+            if (underlyingError.localizedRecoverySuggestion != nil)
+            {
+                return underlyingError.localizedRecoverySuggestion;
+            }
+            
+            // If there is no underlying error, fall through to ALTServerErrorDeviceNotFound.
+            // return nil;
+        }
+            
         case ALTServerErrorDeviceNotFound:
             return NSLocalizedString(@"Make sure you have trusted this device with your computer and WiFi sync is enabled.", @"");
             
@@ -182,6 +279,12 @@ NSErrorUserInfoKey const ALTOperatingSystemVersionErrorKey = @"ALTOperatingSyste
 {
     switch ((ALTServerError)self.code)
     {
+        case ALTServerErrorUnderlyingError:
+        {
+            NSError *underlyingError = self.userInfo[NSUnderlyingErrorKey];
+            return underlyingError.alt_localizedDebugDescription;
+        }
+            
         case ALTServerErrorIncompatibleDeveloperDisk:
         {
             NSString *path = self.userInfo[NSFilePathErrorKey];
@@ -191,7 +294,7 @@ NSErrorUserInfoKey const ALTOperatingSystemVersionErrorKey = @"ALTOperatingSyste
             }
 
             NSString *osVersion = [self altserver_osVersion] ?: NSLocalizedString(@"this device's OS version", @"");
-            NSString *debugDescription = [NSString stringWithFormat:NSLocalizedString(@"The Developer disk located at\n\n%@\n\nis incompatible with %@.", @""), path, osVersion];
+            NSString *debugDescription = [NSString stringWithFormat:NSLocalizedString(@"The Developer disk located at %@ is incompatible with %@.", @""), path, osVersion];
             return debugDescription;
         }
             
@@ -232,7 +335,7 @@ NSErrorUserInfoKey const ALTOperatingSystemVersionErrorKey = @"ALTOperatingSyste
 
 #pragma mark - AltServerConnectionErrorDomain -
 
-- (nullable NSString *)altserver_connection_localizedDescription
+- (nullable NSString *)altserver_connection_localizedFailureReason
 {
     switch ((ALTServerConnectionError)self.code)
     {