FUNError.m

//
// Copyright 2017 Google
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#import"Functions/FirebaseFunctions/FUNError.h"

#import"Functions/FirebaseFunctions/FUNSerializer.h"

NS_ASSUME_NONNULL_BEGIN

NSString *const FIRFunctionsErrorDomain = @"com.firebase.functions";
NSString *const FIRFunctionsErrorDetailsKey = @"details";

/**
 * Takes an HTTP status code and returns the corresponding FIRFunctionsErrorCode error code.
 * This is the standard HTTP status code -> error mapping defined in:
 * https://github.com/googleapis/googleapis/blob/master/google/rpc/code.proto
 * @param status An HTTP status code.
 * @return The corresponding error code, or FIRFunctionsErrorCodeUnknown if none.
*/
FIRFunctionsErrorCode FIRFunctionsErrorCodeForHTTPStatus(NSInteger status) {
switch (status) {
case200:
return FIRFunctionsErrorCodeOK;
case400:
return FIRFunctionsErrorCodeInvalidArgument;
case401:
return FIRFunctionsErrorCodeUnauthenticated;
case403:
return FIRFunctionsErrorCodePermissionDenied;
case404:
return FIRFunctionsErrorCodeNotFound;
case409:
return FIRFunctionsErrorCodeAborted;
case429:
return FIRFunctionsErrorCodeResourceExhausted;
case499:
return FIRFunctionsErrorCodeCancelled;
case500:
return FIRFunctionsErrorCodeInternal;
case501:
return FIRFunctionsErrorCodeUnimplemented;
case503:
return FIRFunctionsErrorCodeUnavailable;
case504:
return FIRFunctionsErrorCodeDeadlineExceeded;
 }
return FIRFunctionsErrorCodeInternal;
}

/**
 * Takes the name of an error code and returns the enum value for it.
 * @param name An error name.
 * @return The error code with this name, or FIRFunctionsErrorCodeUnknown if none.
*/
NSNumber *FIRFunctionsErrorCodeForName(NSString *name) {
staticNSDictionary<NSString *, NSNumber *> *errors;
staticdispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
 errors = @{
@"OK" : @(FIRFunctionsErrorCodeOK),
@"CANCELLED" : @(FIRFunctionsErrorCodeCancelled),
@"UNKNOWN" : @(FIRFunctionsErrorCodeUnknown),
@"INVALID_ARGUMENT" : @(FIRFunctionsErrorCodeInvalidArgument),
@"DEADLINE_EXCEEDED" : @(FIRFunctionsErrorCodeDeadlineExceeded),
@"NOT_FOUND" : @(FIRFunctionsErrorCodeNotFound),
@"ALREADY_EXISTS" : @(FIRFunctionsErrorCodeAlreadyExists),
@"PERMISSION_DENIED" : @(FIRFunctionsErrorCodePermissionDenied),
@"RESOURCE_EXHAUSTED" : @(FIRFunctionsErrorCodeResourceExhausted),
@"FAILED_PRECONDITION" : @(FIRFunctionsErrorCodeFailedPrecondition),
@"ABORTED" : @(FIRFunctionsErrorCodeAborted),
@"OUT_OF_RANGE" : @(FIRFunctionsErrorCodeOutOfRange),
@"UNIMPLEMENTED" : @(FIRFunctionsErrorCodeUnimplemented),
@"INTERNAL" : @(FIRFunctionsErrorCodeInternal),
@"UNAVAILABLE" : @(FIRFunctionsErrorCodeUnavailable),
@"DATA_LOSS" : @(FIRFunctionsErrorCodeDataLoss),
@"UNAUTHENTICATED" : @(FIRFunctionsErrorCodeUnauthenticated),
 };
 });
return errors[name];
}

/**
 * Takes a FIRFunctionsErrorCode and returns an English description of it.
 * @param code An error code.
 * @return A description of the code, or "UNKNOWN" if none.
*/
NSString *FUNDescriptionForErrorCode(FIRFunctionsErrorCode code) {
switch (code) {
case FIRFunctionsErrorCodeOK:
return@"OK";
case FIRFunctionsErrorCodeCancelled:
return@"CANCELLED";
case FIRFunctionsErrorCodeUnknown:
return@"UNKNOWN";
case FIRFunctionsErrorCodeInvalidArgument:
return@"INVALID ARGUMENT";
case FIRFunctionsErrorCodeDeadlineExceeded:
return@"DEADLINE EXCEEDED";
case FIRFunctionsErrorCodeNotFound:
return@"NOT FOUND";
case FIRFunctionsErrorCodeAlreadyExists:
return@"ALREADY EXISTS";
case FIRFunctionsErrorCodePermissionDenied:
return@"PERMISSION DENIED";
case FIRFunctionsErrorCodeResourceExhausted:
return@"RESOURCE EXHAUSTED";
case FIRFunctionsErrorCodeFailedPrecondition:
return@"FAILED PRECONDITION";
case FIRFunctionsErrorCodeAborted:
return@"ABORTED";
case FIRFunctionsErrorCodeOutOfRange:
return@"OUT OF RANGE";
case FIRFunctionsErrorCodeUnimplemented:
return@"UNIMPLEMENTED";
case FIRFunctionsErrorCodeInternal:
return@"INTERNAL";
case FIRFunctionsErrorCodeUnavailable:
return@"UNAVAILABLE";
case FIRFunctionsErrorCodeDataLoss:
return@"DATA LOSS";
case FIRFunctionsErrorCodeUnauthenticated:
return@"UNAUTHENTICATED";
 }
return@"UNKNOWN";
}

NSError *_Nullable FUNErrorForCode(FIRFunctionsErrorCode code) {
NSDictionary *userInfo = @{NSLocalizedDescriptionKey : FUNDescriptionForErrorCode(code)};
return [NSErrorerrorWithDomain:FIRFunctionsErrorDomain code:code userInfo:userInfo];
}

NSError *_Nullable FUNErrorForResponse(NSInteger status,
NSData *_Nullable body,
 FUNSerializer *serializer) {
// Start with reasonable defaults from the status code.
 FIRFunctionsErrorCode code = FIRFunctionsErrorCodeForHTTPStatus(status);
NSString *description = FUNDescriptionForErrorCode(code);
id details = nil;

// Then look through the body for explicit details.
if (body) {
NSError *parseError = nil;
id json = [NSJSONSerializationJSONObjectWithData:body options:0error:&parseError];
if (!parseError && [json isKindOfClass:[NSDictionaryclass]]) {
id errorDetails = json[@"error"];
if ([errorDetails isKindOfClass:[NSDictionaryclass]]) {
if ([errorDetails[@"status"] isKindOfClass:[NSStringclass]]) {
NSNumber *codeNumber = FIRFunctionsErrorCodeForName(errorDetails[@"status"]);
if (codeNumber == nil) {
// If the code in the body is invalid, treat the whole response as malformed.
returnFUNErrorForCode(FIRFunctionsErrorCodeInternal);
 }
 code = codeNumber.intValue;
// The default description needs to be updated for the new code.
 description = FUNDescriptionForErrorCode(code);
 }
if ([errorDetails[@"message"] isKindOfClass:[NSStringclass]]) {
 description = (NSString *)errorDetails[@"message"];
 }
 details = errorDetails[@"details"];
if (details) {
NSError *decodeError = nil;
 details = [serializer decode:details error:&decodeError];
// Just ignore the details if there an error decoding them.
 }
 }
 }
 }

if (code == FIRFunctionsErrorCodeOK) {
// Technically, there's an edge case where a developer could explicitly return an error code of
// OK, and we will treat it as success, but that seems reasonable.
returnnil;
 }

NSMutableDictionary *userInfo = [NSMutableDictionarydictionary];
 userInfo[NSLocalizedDescriptionKey] = description;
if (details) {
 userInfo[FIRFunctionsErrorDetailsKey] = details;
 }
return [NSErrorerrorWithDomain:FIRFunctionsErrorDomain code:code userInfo:userInfo];
}

NS_ASSUME_NONNULL_END