// Protocol Buffers - Google's data interchange format
// Copyright 2015 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

// Importing sources here to force the linker to include our category methods in
// the static library. If these were compiled separately, the category methods
// below would be stripped by the linker.

#import "GPBWellKnownTypes.h"

#import "GPBUtilities.h"
#import "GPBUtilities_PackagePrivate.h"

NSString *const GPBWellKnownTypesErrorDomain = GPBNSStringifySymbol(GPBWellKnownTypesErrorDomain);

static NSString *kTypePrefixGoogleApisCom = @"type.googleapis.com/";

static NSTimeInterval TimeIntervalFromSecondsAndNanos(int64_t seconds, int32_t nanos) {
  return seconds + (NSTimeInterval)nanos / 1e9;
}

static int32_t SecondsAndNanosFromTimeInterval(NSTimeInterval time, int64_t *outSeconds,
                                               BOOL nanosMustBePositive) {
  NSTimeInterval seconds;
  NSTimeInterval nanos = modf(time, &seconds);

  if (nanosMustBePositive && (nanos < 0)) {
    // Per Timestamp.proto, nanos is non-negative and "Negative second values with
    // fractions must still have non-negative nanos values that count forward in
    // time. Must be from 0 to 999,999,999 inclusive."
    --seconds;
    nanos = 1.0 + nanos;
  }

  nanos *= 1e9;
  *outSeconds = (int64_t)seconds;
  return (int32_t)nanos;
}

static NSString *BuildTypeURL(NSString *typeURLPrefix, NSString *fullName) {
  if (typeURLPrefix.length == 0) {
    return fullName;
  }

  if ([typeURLPrefix hasSuffix:@"/"]) {
    return [typeURLPrefix stringByAppendingString:fullName];
  }

  return [NSString stringWithFormat:@"%@/%@", typeURLPrefix, fullName];
}

static NSString *ParseTypeFromURL(NSString *typeURLString) {
  NSRange range = [typeURLString rangeOfString:@"/" options:NSBackwardsSearch];
  if ((range.location == NSNotFound) || (NSMaxRange(range) == typeURLString.length)) {
    return nil;
  }
  NSString *result = [typeURLString substringFromIndex:range.location + 1];
  return result;
}

#pragma mark - GPBTimestamp

@implementation GPBTimestamp (GBPWellKnownTypes)

- (instancetype)initWithDate:(NSDate *)date {
  return [self initWithTimeIntervalSince1970:date.timeIntervalSince1970];
}

- (instancetype)initWithTimeIntervalSince1970:(NSTimeInterval)timeIntervalSince1970 {
  if ((self = [super init])) {
    int64_t seconds;
    int32_t nanos = SecondsAndNanosFromTimeInterval(timeIntervalSince1970, &seconds, YES);
    self.seconds = seconds;
    self.nanos = nanos;
  }
  return self;
}

- (NSDate *)date {
  return [NSDate dateWithTimeIntervalSince1970:self.timeIntervalSince1970];
}

- (void)setDate:(NSDate *)date {
  self.timeIntervalSince1970 = date.timeIntervalSince1970;
}

- (NSTimeInterval)timeIntervalSince1970 {
  return TimeIntervalFromSecondsAndNanos(self.seconds, self.nanos);
}

- (void)setTimeIntervalSince1970:(NSTimeInterval)timeIntervalSince1970 {
  int64_t seconds;
  int32_t nanos = SecondsAndNanosFromTimeInterval(timeIntervalSince1970, &seconds, YES);
  self.seconds = seconds;
  self.nanos = nanos;
}

@end

#pragma mark - GPBDuration

@implementation GPBDuration (GBPWellKnownTypes)

- (instancetype)initWithTimeInterval:(NSTimeInterval)timeInterval {
  if ((self = [super init])) {
    int64_t seconds;
    int32_t nanos = SecondsAndNanosFromTimeInterval(timeInterval, &seconds, NO);
    self.seconds = seconds;
    self.nanos = nanos;
  }
  return self;
}

- (NSTimeInterval)timeInterval {
  return TimeIntervalFromSecondsAndNanos(self.seconds, self.nanos);
}

- (void)setTimeInterval:(NSTimeInterval)timeInterval {
  int64_t seconds;
  int32_t nanos = SecondsAndNanosFromTimeInterval(timeInterval, &seconds, NO);
  self.seconds = seconds;
  self.nanos = nanos;
}

@end

#pragma mark - GPBAny

@implementation GPBAny (GBPWellKnownTypes)

+ (instancetype)anyWithMessage:(GPBMessage *)message error:(NSError **)errorPtr {
  return [self anyWithMessage:message typeURLPrefix:kTypePrefixGoogleApisCom error:errorPtr];
}

+ (instancetype)anyWithMessage:(GPBMessage *)message
                 typeURLPrefix:(NSString *)typeURLPrefix
                         error:(NSError **)errorPtr {
  return [[[self alloc] initWithMessage:message typeURLPrefix:typeURLPrefix
                                  error:errorPtr] autorelease];
}

- (instancetype)initWithMessage:(GPBMessage *)message error:(NSError **)errorPtr {
  return [self initWithMessage:message typeURLPrefix:kTypePrefixGoogleApisCom error:errorPtr];
}

- (instancetype)initWithMessage:(GPBMessage *)message
                  typeURLPrefix:(NSString *)typeURLPrefix
                          error:(NSError **)errorPtr {
  self = [self init];
  if (self) {
    if (![self packWithMessage:message typeURLPrefix:typeURLPrefix error:errorPtr]) {
      [self release];
      self = nil;
    }
  }
  return self;
}

- (BOOL)packWithMessage:(GPBMessage *)message error:(NSError **)errorPtr {
  return [self packWithMessage:message typeURLPrefix:kTypePrefixGoogleApisCom error:errorPtr];
}

- (BOOL)packWithMessage:(GPBMessage *)message
          typeURLPrefix:(NSString *)typeURLPrefix
                  error:(NSError **)errorPtr {
  NSString *fullName = [message descriptor].fullName;
  if (fullName.length == 0) {
    if (errorPtr) {
      *errorPtr = [NSError errorWithDomain:GPBWellKnownTypesErrorDomain
                                      code:GPBWellKnownTypesErrorCodeFailedToComputeTypeURL
                                  userInfo:nil];
    }
    return NO;
  }
  if (errorPtr) {
    *errorPtr = nil;
  }
  self.typeURL = BuildTypeURL(typeURLPrefix, fullName);
  self.value = message.data;
  return YES;
}

- (GPBMessage *)unpackMessageClass:(Class)messageClass error:(NSError **)errorPtr {
  return [self unpackMessageClass:messageClass extensionRegistry:nil error:errorPtr];
}

- (nullable GPBMessage *)unpackMessageClass:(Class)messageClass
                          extensionRegistry:(nullable id<GPBExtensionRegistry>)extensionRegistry
                                      error:(NSError **)errorPtr {
  NSString *fullName = [messageClass descriptor].fullName;
  if (fullName.length == 0) {
    if (errorPtr) {
      *errorPtr = [NSError errorWithDomain:GPBWellKnownTypesErrorDomain
                                      code:GPBWellKnownTypesErrorCodeFailedToComputeTypeURL
                                  userInfo:nil];
    }
    return nil;
  }

  NSString *expectedFullName = ParseTypeFromURL(self.typeURL);
  if ((expectedFullName == nil) || ![expectedFullName isEqual:fullName]) {
    if (errorPtr) {
      *errorPtr = [NSError errorWithDomain:GPBWellKnownTypesErrorDomain
                                      code:GPBWellKnownTypesErrorCodeTypeURLMismatch
                                  userInfo:nil];
    }
    return nil;
  }

  return [messageClass parseFromData:self.value extensionRegistry:extensionRegistry error:errorPtr];
}

@end
