// Protocol Buffers - Google's data interchange format
// Copyright 2008 Google Inc.  All rights reserved.
//
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file or at
// https://developers.google.com/open-source/licenses/bsd

#import "GPBUnknownFieldSet_PackagePrivate.h"

#import "GPBCodedInputStream_PackagePrivate.h"
#import "GPBCodedOutputStream.h"
#import "GPBUnknownField_PackagePrivate.h"
#import "GPBUtilities.h"
#import "GPBWireFormat.h"

#pragma mark Helpers

static void checkNumber(int32_t number) {
  if (number == 0) {
    [NSException raise:NSInvalidArgumentException format:@"Zero is not a valid field number."];
  }
}

@implementation GPBUnknownFieldSet {
 @package
  CFMutableDictionaryRef fields_;
}

static void CopyWorker(__unused const void *key, const void *value, void *context) {
  GPBUnknownField *field = value;
  GPBUnknownFieldSet *result = context;

  GPBUnknownField *copied = [field copy];
  [result addField:copied];
  [copied release];
}

// Direct access is use for speed, to avoid even internally declaring things
// read/write, etc. The warning is enabled in the project to ensure code calling
// protos can turn on -Wdirect-ivar-access without issues.
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wdirect-ivar-access"

- (id)copyWithZone:(NSZone *)zone {
  GPBUnknownFieldSet *result = [[GPBUnknownFieldSet allocWithZone:zone] init];
  if (fields_) {
    CFDictionaryApplyFunction(fields_, CopyWorker, result);
  }
  return result;
}

- (void)dealloc {
  if (fields_) {
    CFRelease(fields_);
  }
  [super dealloc];
}

- (BOOL)isEqual:(id)object {
  BOOL equal = NO;
  if ([object isKindOfClass:[GPBUnknownFieldSet class]]) {
    GPBUnknownFieldSet *set = (GPBUnknownFieldSet *)object;
    if ((fields_ == NULL) && (set->fields_ == NULL)) {
      equal = YES;
    } else if ((fields_ != NULL) && (set->fields_ != NULL)) {
      equal = CFEqual(fields_, set->fields_);
    }
  }
  return equal;
}

- (NSUInteger)hash {
  // Return the hash of the fields dictionary (or just some value).
  if (fields_) {
    return CFHash(fields_);
  }
  return (NSUInteger)[GPBUnknownFieldSet class];
}

#pragma mark - Public Methods

- (BOOL)hasField:(int32_t)number {
  ssize_t key = number;
  return fields_ ? (CFDictionaryGetValue(fields_, (void *)key) != nil) : NO;
}

- (GPBUnknownField *)getField:(int32_t)number {
  ssize_t key = number;
  GPBUnknownField *result = fields_ ? CFDictionaryGetValue(fields_, (void *)key) : nil;
  return result;
}

- (NSUInteger)countOfFields {
  return fields_ ? CFDictionaryGetCount(fields_) : 0;
}

- (NSArray *)sortedFields {
  if (!fields_) return [NSArray array];
  size_t count = CFDictionaryGetCount(fields_);
  ssize_t keys[count];
  GPBUnknownField *values[count];
  CFDictionaryGetKeysAndValues(fields_, (const void **)keys, (const void **)values);
  struct GPBFieldPair {
    ssize_t key;
    GPBUnknownField *value;
  } pairs[count];
  for (size_t i = 0; i < count; ++i) {
    pairs[i].key = keys[i];
    pairs[i].value = values[i];
  };
  qsort_b(pairs, count, sizeof(struct GPBFieldPair), ^(const void *first, const void *second) {
    const struct GPBFieldPair *a = first;
    const struct GPBFieldPair *b = second;
    return (a->key > b->key) ? 1 : ((a->key == b->key) ? 0 : -1);
  });
  for (size_t i = 0; i < count; ++i) {
    values[i] = pairs[i].value;
  };
  return [NSArray arrayWithObjects:values count:count];
}

#pragma mark - Internal Methods

- (void)writeToCodedOutputStream:(GPBCodedOutputStream *)output {
  if (!fields_) return;
  size_t count = CFDictionaryGetCount(fields_);
  ssize_t keys[count];
  GPBUnknownField *values[count];
  CFDictionaryGetKeysAndValues(fields_, (const void **)keys, (const void **)values);
  if (count > 1) {
    struct GPBFieldPair {
      ssize_t key;
      GPBUnknownField *value;
    } pairs[count];

    for (size_t i = 0; i < count; ++i) {
      pairs[i].key = keys[i];
      pairs[i].value = values[i];
    };
    qsort_b(pairs, count, sizeof(struct GPBFieldPair), ^(const void *first, const void *second) {
      const struct GPBFieldPair *a = first;
      const struct GPBFieldPair *b = second;
      return (a->key > b->key) ? 1 : ((a->key == b->key) ? 0 : -1);
    });
    for (size_t i = 0; i < count; ++i) {
      GPBUnknownField *value = pairs[i].value;
      [value writeToOutput:output];
    }
  } else {
    [values[0] writeToOutput:output];
  }
}

- (NSString *)description {
  NSMutableString *description =
      [NSMutableString stringWithFormat:@"<%@ %p>: TextFormat: {\n", [self class], self];
  NSString *textFormat = GPBTextFormatForUnknownFieldSet(self, @"  ");
  [description appendString:textFormat];
  [description appendString:@"}"];
  return description;
}

static void GPBUnknownFieldSetSerializedSize(__unused const void *key, const void *value,
                                             void *context) {
  GPBUnknownField *field = value;
  size_t *result = context;
  *result += [field serializedSize];
}

- (size_t)serializedSize {
  size_t result = 0;
  if (fields_) {
    CFDictionaryApplyFunction(fields_, GPBUnknownFieldSetSerializedSize, &result);
  }
  return result;
}

static void GPBUnknownFieldSetWriteAsMessageSetTo(__unused const void *key, const void *value,
                                                  void *context) {
  GPBUnknownField *field = value;
  GPBCodedOutputStream *output = context;
  [field writeAsMessageSetExtensionToOutput:output];
}

- (void)writeAsMessageSetTo:(GPBCodedOutputStream *)output {
  if (fields_) {
    CFDictionaryApplyFunction(fields_, GPBUnknownFieldSetWriteAsMessageSetTo, output);
  }
}

static void GPBUnknownFieldSetSerializedSizeAsMessageSet(__unused const void *key,
                                                         const void *value, void *context) {
  GPBUnknownField *field = value;
  size_t *result = context;
  *result += [field serializedSizeAsMessageSetExtension];
}

- (size_t)serializedSizeAsMessageSet {
  size_t result = 0;
  if (fields_) {
    CFDictionaryApplyFunction(fields_, GPBUnknownFieldSetSerializedSizeAsMessageSet, &result);
  }
  return result;
}

- (NSData *)data {
  NSMutableData *data = [NSMutableData dataWithLength:self.serializedSize];
  GPBCodedOutputStream *output = [[GPBCodedOutputStream alloc] initWithData:data];
  [self writeToCodedOutputStream:output];
  [output release];
  return data;
}

+ (BOOL)isFieldTag:(int32_t)tag {
  return GPBWireFormatGetTagWireType(tag) != GPBWireFormatEndGroup;
}

- (void)addField:(GPBUnknownField *)field {
  int32_t number = [field number];
  checkNumber(number);
  if (!fields_) {
    // Use a custom dictionary here because the keys are numbers and conversion
    // back and forth from NSNumber isn't worth the cost.
    fields_ =
        CFDictionaryCreateMutable(kCFAllocatorDefault, 0, NULL, &kCFTypeDictionaryValueCallBacks);
  }
  ssize_t key = number;
  CFDictionarySetValue(fields_, (const void *)key, field);
}

- (GPBUnknownField *)mutableFieldForNumber:(int32_t)number create:(BOOL)create {
  ssize_t key = number;
  GPBUnknownField *existing = fields_ ? CFDictionaryGetValue(fields_, (const void *)key) : nil;
  if (!existing && create) {
    existing = [[GPBUnknownField alloc] initWithNumber:number];
    // This retains existing.
    [self addField:existing];
    [existing release];
  }
  return existing;
}

static void GPBUnknownFieldSetMergeUnknownFields(__unused const void *key, const void *value,
                                                 void *context) {
  GPBUnknownField *field = value;
  GPBUnknownFieldSet *self = context;

  int32_t number = [field number];
  checkNumber(number);
  GPBUnknownField *oldField = [self mutableFieldForNumber:number create:NO];
  if (oldField) {
    [oldField mergeFromField:field];
  } else {
    // Merge only comes from GPBMessage's mergeFrom:, so it means we are on
    // mutable message and are an mutable instance, so make sure we need
    // mutable fields.
    GPBUnknownField *fieldCopy = [field copy];
    [self addField:fieldCopy];
    [fieldCopy release];
  }
}

- (void)mergeUnknownFields:(GPBUnknownFieldSet *)other {
  if (other && other->fields_) {
    CFDictionaryApplyFunction(other->fields_, GPBUnknownFieldSetMergeUnknownFields, self);
  }
}

- (void)mergeVarintField:(int32_t)number value:(int32_t)value {
  checkNumber(number);
  [[self mutableFieldForNumber:number create:YES] addVarint:value];
}

- (BOOL)mergeFieldFrom:(int32_t)tag input:(GPBCodedInputStream *)input {
  NSAssert(GPBWireFormatIsValidTag(tag), @"Got passed an invalid tag");
  int32_t number = GPBWireFormatGetTagFieldNumber(tag);
  GPBCodedInputStreamState *state = &input->state_;
  switch (GPBWireFormatGetTagWireType(tag)) {
    case GPBWireFormatVarint: {
      GPBUnknownField *field = [self mutableFieldForNumber:number create:YES];
      [field addVarint:GPBCodedInputStreamReadInt64(state)];
      return YES;
    }
    case GPBWireFormatFixed64: {
      GPBUnknownField *field = [self mutableFieldForNumber:number create:YES];
      [field addFixed64:GPBCodedInputStreamReadFixed64(state)];
      return YES;
    }
    case GPBWireFormatLengthDelimited: {
      NSData *data = GPBCodedInputStreamReadRetainedBytes(state);
      GPBUnknownField *field = [self mutableFieldForNumber:number create:YES];
      [field addLengthDelimited:data];
      [data release];
      return YES;
    }
    case GPBWireFormatStartGroup: {
      GPBUnknownFieldSet *unknownFieldSet = [[GPBUnknownFieldSet alloc] init];
      GPBUnknownField *field = [self mutableFieldForNumber:number create:YES];
      [field addGroup:unknownFieldSet];
      // The field will now retain unknownFieldSet, so go ahead and release it in case
      // -readUnknownGroup:message: throws so it won't be leaked.
      [unknownFieldSet release];
      [input readUnknownGroup:number message:unknownFieldSet];
      return YES;
    }
    case GPBWireFormatEndGroup:
      return NO;
    case GPBWireFormatFixed32: {
      GPBUnknownField *field = [self mutableFieldForNumber:number create:YES];
      [field addFixed32:GPBCodedInputStreamReadFixed32(state)];
      return YES;
    }
  }
}

- (void)mergeMessageSetMessage:(int32_t)number data:(NSData *)messageData {
  [[self mutableFieldForNumber:number create:YES] addLengthDelimited:messageData];
}

- (void)addUnknownMapEntry:(int32_t)fieldNum value:(NSData *)data {
  GPBUnknownField *field = [self mutableFieldForNumber:fieldNum create:YES];
  [field addLengthDelimited:data];
}

- (void)mergeFromCodedInputStream:(GPBCodedInputStream *)input {
  while (YES) {
    int32_t tag = GPBCodedInputStreamReadTag(&input->state_);
    if (tag == 0 || ![self mergeFieldFrom:tag input:input]) {
      break;
    }
  }
}

- (void)getTags:(int32_t *)tags {
  if (!fields_) return;
  size_t count = CFDictionaryGetCount(fields_);
  ssize_t keys[count];
  CFDictionaryGetKeysAndValues(fields_, (const void **)keys, NULL);
  for (size_t i = 0; i < count; ++i) {
    tags[i] = (int32_t)keys[i];
  }
}

#pragma clang diagnostic pop

@end