//
//  GTMSystemVersion.m
//
//  Copyright 2007-2008 Google Inc.
//
//  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 "SystemVersion.h"
#if GTM_MACOS_SDK
#import <CoreServices/CoreServices.h>
#endif

static SInt32 sGTMSystemVersionMajor = 0;
static SInt32 sGTMSystemVersionMinor = 0;
static SInt32 sGTMSystemVersionBugFix = 0;
static NSString *sBuild = nil;

NSString *const kGTMArch_iPhone = @"iPhone";
NSString *const kGTMArch_ppc = @"ppc";
NSString *const kGTMArch_ppc64 = @"ppc64";
NSString *const kGTMArch_x86_64 = @"x86_64";
NSString *const kGTMArch_i386 = @"i386";

static NSString *const kSystemVersionPlistPath = @"/System/Library/CoreServices/SystemVersion.plist";

@implementation SystemVersion
+ (void)initialize {
	if (self == [SystemVersion class]) {
		// Gestalt is the recommended way of getting the OS version (despite a
		// comment to the contrary in the 10.4 headers and docs; see
		// <http://lists.apple.com/archives/carbon-dev/2007/Aug/msg00089.html>).
		// The iPhone doesn't have Gestalt though, so use the plist there.
#if GTM_MACOS_SDK
		require_noerr(Gestalt(gestaltSystemVersionMajor, &sGTMSystemVersionMajor), failedGestalt);
		require_noerr(Gestalt(gestaltSystemVersionMinor, &sGTMSystemVersionMinor), failedGestalt);
		require_noerr(Gestalt(gestaltSystemVersionBugFix, &sGTMSystemVersionBugFix), failedGestalt);
		
		return;
		
	failedGestalt:
		;
#if MAC_OS_X_VERSION_MIN_REQUIRED <= MAC_OS_X_VERSION_10_3
		// gestaltSystemVersionMajor et al are only on 10.4 and above, so they
		// could fail when running on 10.3.
		SInt32 binaryCodedDec;
		OSStatus err = err = Gestalt(gestaltSystemVersion, &binaryCodedDec);
		
		// Note that this code will return x.9.9 for any system rev parts that are
		// greater than 9 (i.e., 10.10.10 will be 10.9.9). This shouldn't ever be a
		// problem as the code above takes care of 10.4+.
		SInt32 msb = (binaryCodedDec & 0x0000F000L) >> 12;
		msb *= 10;
		SInt32 lsb = (binaryCodedDec & 0x00000F00L) >> 8;
		sGTMSystemVersionMajor = msb + lsb;
		sGTMSystemVersionMinor = (binaryCodedDec & 0x000000F0L) >> 4;
		sGTMSystemVersionBugFix = (binaryCodedDec & 0x0000000FL);
#endif // MAC_OS_X_VERSION_MIN_REQUIRED <= MAC_OS_X_VERSION_10_3
		
#else // GTM_MACOS_SDK
		@autoreleasepool {
			NSDictionary *systemVersionPlist
			= [NSDictionary dictionaryWithContentsOfFile:kSystemVersionPlistPath];
			NSString *version = systemVersionPlist[@"ProductVersion"];
			NSArray *versionInfo = [version componentsSeparatedByString:@"."];
			int length = [versionInfo count];
			sGTMSystemVersionMajor = [versionInfo[0] intValue];
			sGTMSystemVersionMinor = [versionInfo[1] intValue];
			if (length == 3) {
				sGTMSystemVersionBugFix = [versionInfo[2] intValue];
			}
		}
#endif // GTM_MACOS_SDK
	}
}

+ (void)getMajor:(SInt32*)major minor:(SInt32*)minor bugFix:(SInt32*)bugFix {
	if (major) {
		*major = sGTMSystemVersionMajor;
	}
	if (minor) {
		*minor = sGTMSystemVersionMinor;
	}
	if (bugFix) {
		*bugFix = sGTMSystemVersionBugFix;
	}
}

+ (NSString*)build {
	@synchronized(self) {
		// Not cached at initialization time because we don't expect "real"
		// software to want this, and it costs a bit to get at startup.
		// This will mainly be for unit test cases.
		if (!sBuild) {
			NSDictionary *systemVersionPlist
			= [NSDictionary dictionaryWithContentsOfFile:kSystemVersionPlistPath];
			sBuild = systemVersionPlist[@"ProductBuildVersion"];
		}
	}
	return sBuild;
}

+ (BOOL)isBuildLessThan:(NSString*)build {
	NSComparisonResult result
    = [[self build] compare:build
                    options:NSNumericSearch | NSCaseInsensitiveSearch];
	return result == NSOrderedAscending;
}

+ (BOOL)isBuildLessThanOrEqualTo:(NSString*)build {
	NSComparisonResult result
    = [[self build] compare:build
                    options:NSNumericSearch | NSCaseInsensitiveSearch];
	return result != NSOrderedDescending;
}

+ (BOOL)isBuildGreaterThan:(NSString*)build {
	NSComparisonResult result
    = [[self build] compare:build
                    options:NSNumericSearch | NSCaseInsensitiveSearch];
	return result == NSOrderedDescending;
}

+ (BOOL)isBuildGreaterThanOrEqualTo:(NSString*)build {
	NSComparisonResult result
    = [[self build] compare:build
                    options:NSNumericSearch | NSCaseInsensitiveSearch];
	return result != NSOrderedAscending;
}

+ (BOOL)isBuildEqualTo:(NSString *)build {
	NSComparisonResult result
    = [[self build] compare:build
                    options:NSNumericSearch | NSCaseInsensitiveSearch];
	return result == NSOrderedSame;
}

+ (BOOL)isPanther {
	return sGTMSystemVersionMajor == 10 && sGTMSystemVersionMinor == 3;
}

+ (BOOL)isTiger {
	return sGTMSystemVersionMajor == 10 && sGTMSystemVersionMinor == 4;
}

+ (BOOL)isLeopard {
	return sGTMSystemVersionMajor == 10 && sGTMSystemVersionMinor == 5;
}

+ (BOOL)isSnowLeopard {
	return sGTMSystemVersionMajor == 10 && sGTMSystemVersionMinor == 6;
}

+ (BOOL)isPantherOrGreater {
	return (sGTMSystemVersionMajor > 10) ||
	(sGTMSystemVersionMajor == 10 && sGTMSystemVersionMinor >= 3);
}

+ (BOOL)isTigerOrGreater {
	return (sGTMSystemVersionMajor > 10) ||
	(sGTMSystemVersionMajor == 10 && sGTMSystemVersionMinor >= 4);
}

+ (BOOL)isLeopardOrGreater {
	return (sGTMSystemVersionMajor > 10) ||
	(sGTMSystemVersionMajor == 10 && sGTMSystemVersionMinor >= 5);
}

+ (BOOL)isSnowLeopardOrGreater {
	return (sGTMSystemVersionMajor > 10) ||
	(sGTMSystemVersionMajor == 10 && sGTMSystemVersionMinor >= 6);
}


+ (NSString *)runtimeArchitecture {
	NSString *architecture = nil;
#if GTM_IPHONE_SDK
	architecture = kGTMArch_iPhone;
#else // !GTM_IPHONE_SDK
	// In reading arch(3) you'd thing this would work:
	//
	// const NXArchInfo *localInfo = NXGetLocalArchInfo();
	// _GTMDevAssert(localInfo && localInfo->name, @"Couldn't get NXArchInfo");
	// const NXArchInfo *genericInfo = NXGetArchInfoFromCpuType(localInfo->cputype, 0);
	// _GTMDevAssert(genericInfo && genericInfo->name, @"Couldn't get generic NXArchInfo");
	// extensions[0] = [NSString stringWithFormat:@".%s", genericInfo->name];
	//
	// but on 64bit it returns the same things as on 32bit, so...
#if __POWERPC__
#if __LP64__
	architecture = kGTMArch_ppc64;
#else // !__LP64__
	architecture = kGTMArch_ppc;
#endif // __LP64__
#else // !__POWERPC__
#if __LP64__
	architecture = kGTMArch_x86_64;
#else // !__LP64__
	architecture = kGTMArch_i386;
#endif // __LP64__
#endif // !__POWERPC__
	
#endif // GTM_IPHONE_SDK
	return architecture;
}

@end