

#import "OCMethodTrace.h"
#import <UIKit/UIKit.h>
#import <objc/runtime.h>
#import <objc/message.h>
#import <execinfo.h>
#import <dlfcn.h>
#import <pthread.h>
#import "OCSelectorTrampolines.h"

#define OMT_LOG(_level_, _fmt_, ...) do { \
        if ((_level_) <= [OCMethodTrace sharedInstance].logLevel) { \
            if ([OCMethodTrace sharedInstance].delegate && [[OCMethodTrace sharedInstance].delegate respondsToSelector:@selector(log:format:)]) { \
                [[OCMethodTrace sharedInstance].delegate log:OMTLogLevelDebug format:(_fmt_), ## __VA_ARGS__]; \
            } else { \
                NSLog((_fmt_), ## __VA_ARGS__); \
            } \
        } \
    } while(0)

#define OMT_LOGE(_fmt_, ...)  OMT_LOG(OMTLogLevelError, (_fmt_), ## __VA_ARGS__)
#define OMT_LOGD(_fmt_, ...)  OMT_LOG(OMTLogLevelDebug, (_fmt_), ## __VA_ARGS__)

static NSString *const OMTMessageTempPrefix                 = @"__OMTMessageTemp_";
static NSString *const OMTMessageFinalPrefix                = @"__OMTMessageFinal_";
static NSString *const OMTBlockRunBeforeSelector            = @"runBefore:";
static NSString *const OMTBlockRunAfterSelector             = @"runAfter:";
static NSString *const OMTDescriptionWithTargetSelector     = @"descriptionWithTarget:";

// trace位置
typedef NS_ENUM(NSUInteger, OMTTracePosition) {
    OMTTracePositionBefore  = 1 << 0,   // before
    OMTTracePositionAfter   = 1 << 1,   // after
};

// 错误码，对内使用，便于调试
typedef NS_ENUM(NSUInteger, OMTErrorCode) {
    OMTErrorNoError,                            // NERR 没有错误
    OMTErrorSelectorPassThrough,                // SPTH 透传不处理
    OMTErrorSelectorAlreadyHooked,              // SAHK 已经hook过
    OMTErrorSelectorInUserBlacklist,            // SIUB 在用户的黑名单里
    OMTErrorClassInSelfBlacklist,               // CISB 在内部的类黑名单里
    OMTErrorSelectorInSelfBlacklist,            // SISB 在内部的sel黑名单里
    OMTErrorSelectorUnsuppotedMethodSignature,  // SUMS 无法支持的方法签名(导致crash的异常签名)
    OMTErrorSelectorUnsuppotedEncodeType,       // SUEY 无法支持的编码类型(局部无法识别的签名)
    OMTErrorDoesNotRespondToMethod,             // NMTD 无此method
    OMTErrorDoesNotRespondToSelector,           // NSEL 无此sel
    OMTErrorDoesNotRespondToIMP,                // NIMP 无此IMP
    OMTErrorSwizzleMethodFailed,                // SMDF 替换方法失败
};

#define LOG_LEVEL_4_ERROR_CODE(_errorCode_) (((_errorCode_) >= OMTErrorSelectorUnsuppotedMethodSignature) ? OMTLogLevelError : OMTLogLevelDebug)

////////////////////////////////////////////////////////////////////////////////
#pragma mark - C Helper Define

// 替换实例方法
static void swizzle_instance_method(Class cls, SEL originSel, SEL newSel);
// 替换类方法
static void swizzle_class_method(Class cls, SEL originSel, SEL newSel);

// 是否支持某类型限定符
static BOOL omt_isTypeQualifier(const char argumentType);
// 是否是struct类型
static BOOL omt_isStructType(const char *argumentType);
// 获取struct类型名
static NSString *omt_structName(const char *argumentType);
// 是否是union类型
static BOOL omt_isUnionType(const char *argumentType);
// 获取union类型名
static NSString *omt_unionName(const char *argumentType);
static BOOL isCGRect           (const char *type);
static BOOL isCGPoint          (const char *type);
static BOOL isCGSize           (const char *type);
static BOOL isCGVector         (const char *type);
static BOOL isUIOffset         (const char *type);
static BOOL isUIEdgeInsets     (const char *type);
static BOOL isCGAffineTransform(const char *type);

////////////////////////////////////////////////////////////////////////////////
#pragma mark - Class Define

@interface OMTBlock : NSObject

@property (nonatomic, strong) NSString *className;
@property (nonatomic, copy) OMTConditionBlock condition;
@property (nonatomic, copy) OMTBeforeBlock before;
@property (nonatomic, copy) OMTAfterBlock after;

- (BOOL)runCondition:(SEL)sel;
- (void)runBefore:(id)target class:(Class)cls sel:(SEL)sel args:(NSArray *)args deep:(int)deep;
- (void)runAfter:(id)target class:(Class)cls sel:(SEL)sel ret:(id)ret deep:(int)deep interval:(NSTimeInterval)interval;

@end

@interface OMTMessageStub : NSObject

@property (nonatomic, unsafe_unretained) id target;
@property (nonatomic, assign) SEL selector;

- (instancetype)initWithTarget:(id)target selector:(SEL)aSelector;

@end

@interface NSObject (OCMethodTrace)

// 类转发方法
+ (id)omt_forwardingTargetForSelector:(SEL)aSelector;
// 实例转发方法
- (id)omt_forwardingTargetForSelector:(SEL)aSelector;

@end

@interface NSInvocation (OCMethodTrace)

// 获取原始的类名
- (Class)omt_originClass;
// 获取原始的方法名
- (SEL)omt_originSelector;
// 获取方法返回值
- (id)omt_getReturnValue;
// 获取方法参数
- (NSArray *)omt_getArguments;

@end

@interface OCMethodTrace() {
    pthread_mutex_t _blockMutex;
    pthread_mutex_t _deepMutex;
}

@property (nonatomic, strong) NSArray *defaultClassBlackList;
@property (nonatomic, strong) NSArray *defaultMethodBlackList;
@property (nonatomic, strong) NSDictionary *supportedTypeDict;
@property (nonatomic, strong) NSDictionary *tracePositionDict;
@property (nonatomic, strong) NSMutableDictionary *blockCache;
@property (nonatomic, assign) int deep;

// 初始化内部默认黑名单
- (void)initDefaultClassBlackList;
- (void)initDefaultMethodBlackList;
// 初始化所支持类型编码的字典
- (void)initSupportedTypeDict;
// 初始化trace位置字典
- (void)initTracePositionDict;
// 根据错误码返回错误描述
+ (NSString *)errorString:(OMTErrorCode)errorCode;
// 判断函数数组里任意函数是否存在递归循环调用
+ (BOOL)detectInfiniteLoopAtSelectorArray:(NSArray *)selectorArray;
// 获取target的description
- (NSString *)descriptionWithTarget:(id)target class:(Class)cls selector:(SEL)sel targetPosition:(OMTTargetPosition)targetPosition;
// 判断类是否在内部默认黑名单中
- (BOOL)isClassInBlackList:(NSString *)className;
// 判断方法是否在内部默认黑名单中
- (BOOL)isSelectorInBlackList:(NSString *)methodName;
// 判断类型编码是否可以处理
- (BOOL)isSupportedType:(NSString *)typeEncode;
// 获取方法名对应的trace位置
- (OMTTracePosition)tracePosition:(NSString *)methodName;
// block相关
- (void)setBlock:(OMTBlock *)block forKey:(NSString *)key;
- (OMTBlock *)blockforKey:(NSString *)key;
- (OMTBlock *)blockWithTarget:(id)target;
// 原子操作deep++，返回原值
- (int)atomicAddDeep;
// 原子操作deep--
- (void)atomicIncDeep;
// 根据条件跟踪目标类的方法
- (void)traceMethodWithClass:(Class)cls condition:(OMTConditionBlock)condition;
// 判断方法是否支持跟踪
- (OMTErrorCode)isTraceSupportedWithClass:(Class)cls method:(Method)method;
// 替换方法
- (OMTErrorCode)swizzleMethodWithClass:(Class)cls selector:(SEL)selector;
// 转发实现
- (void)omt_forwardInvocation:(NSInvocation *)invocation;

@end

////////////////////////////////////////////////////////////////////////////////

#pragma mark - C Helper

static void swizzle_instance_method(Class cls, SEL originSel, SEL newSel)
{
    Method originMethod = class_getInstanceMethod(cls, originSel);
    Method newMethod = class_getInstanceMethod(cls, newSel);
    
    if (class_addMethod(cls, originSel, method_getImplementation(newMethod), method_getTypeEncoding(newMethod))) {
        class_replaceMethod(cls, newSel, method_getImplementation(originMethod), method_getTypeEncoding(originMethod));
    } else {
        method_exchangeImplementations(originMethod, newMethod);
    }
}

static void swizzle_class_method(Class cls, SEL originSel, SEL newSel)
{
    Class metaClass = objc_getMetaClass([NSStringFromClass(cls) UTF8String]);
    
    Method originMethod = class_getInstanceMethod(metaClass, originSel);
    Method newMethod = class_getInstanceMethod(metaClass, newSel);
    
    if (class_addMethod([metaClass class], originSel, method_getImplementation(newMethod), method_getTypeEncoding(newMethod))) {
        class_replaceMethod([metaClass class], newSel, method_getImplementation(originMethod), method_getTypeEncoding(originMethod));
    } else {
        method_exchangeImplementations(originMethod, newMethod);
    }
}

static BOOL omt_isTypeQualifier(const char argumentType)
{
    // Table 6-2 Objective-C method encodings
    static const char supportedTypeQualifierList[] = { 'r', 'n', 'N', 'o', 'O', 'R', 'V' };
    static const size_t kNumSupportedTypeQualifier = sizeof(supportedTypeQualifierList) / sizeof(supportedTypeQualifierList[0]);
    
    size_t i;
    for (i = 0; i < kNumSupportedTypeQualifier; i++) {
        if (argumentType == supportedTypeQualifierList[i]) {
            return YES;
        }
    }
    return NO;
}

static BOOL omt_isStructType(const char *argumentType)
{
    NSString *typeString = [NSString stringWithUTF8String:argumentType];
    return ([typeString hasPrefix:@"{"] && [typeString hasSuffix:@"}"]);
}

static NSString *omt_structName(const char *argumentType)
{
    NSString *typeString = [NSString stringWithUTF8String:argumentType];
    NSUInteger start = [typeString rangeOfString:@"{"].location;
    NSUInteger end = [typeString rangeOfString:@"="].location;
    if (end > start) {
        return [typeString substringWithRange:NSMakeRange(start + 1, end - start - 1)];
    } else {
        return nil;
    }
}

static BOOL omt_isUnionType(const char *argumentType)
{
    NSString *typeString = [NSString stringWithUTF8String:argumentType];
    return ([typeString hasPrefix:@"("] && [typeString hasSuffix:@")"]);
}

static NSString *omt_unionName(const char *argumentType)
{
    NSString *typeString = [NSString stringWithUTF8String:argumentType];
    NSUInteger start = [typeString rangeOfString:@"("].location;
    NSUInteger end = [typeString rangeOfString:@"="].location;
    if (end > start) {
        return [typeString substringWithRange:NSMakeRange(start + 1, end - start - 1)];
    } else {
        return nil;
    }
}

static BOOL isCGRect           (const char *type) {return [omt_structName(type) isEqualToString:@"CGRect"];}
static BOOL isCGPoint          (const char *type) {return [omt_structName(type) isEqualToString:@"CGPoint"];}
static BOOL isCGSize           (const char *type) {return [omt_structName(type) isEqualToString:@"CGSize"];}
static BOOL isCGVector         (const char *type) {return [omt_structName(type) isEqualToString:@"CGVector"];}
static BOOL isUIOffset         (const char *type) {return [omt_structName(type) isEqualToString:@"UIOffset"];}
static BOOL isUIEdgeInsets     (const char *type) {return [omt_structName(type) isEqualToString:@"UIEdgeInsets"];}
static BOOL isCGAffineTransform(const char *type) {return [omt_structName(type) isEqualToString:@"CGAffineTransform"];}

////////////////////////////////////////////////////////////////////////////////
#pragma mark - OCMethodTrace

@implementation OCMethodTrace

////////////////////////////////////////////////////////////////////////////////

#pragma mark - Public OCMethodTrace API

+ (OCMethodTrace *)sharedInstance
{
    static OCMethodTrace *instance = nil;
    static dispatch_once_t pred;
    dispatch_once(&pred, ^{
        instance = [[OCMethodTrace alloc] init];
    });
    return instance;
}

- (void)traceMethodWithClass:(Class)cls
                   condition:(OMTConditionBlock)condition
                      before:(OMTBeforeBlock)before
                       after:(OMTAfterBlock)after
{
#ifndef DEBUG
    return;
#endif
    
    // 黑名单的类不跟踪
    if ([self isClassInBlackList:NSStringFromClass(cls)]) {
        OMT_LOG(OMTLogLevelDebug, @"[%@] trace class: %@",
                [self.class errorString:OMTErrorClassInSelfBlacklist],
                NSStringFromClass(cls));
        return;
    }
    
    // 处理一个类被添加到blockCache多次的情况
    if (cls && ![self blockforKey:NSStringFromClass(cls)]) {
        OMTBlock *block = [[OMTBlock alloc] init];
        block.className = NSStringFromClass(cls);
        block.condition = condition;
        block.before = before;
        block.after = after;
        [self setBlock:block forKey:block.className];
    }
    
    // 处理实例方法
    [self traceMethodWithClass:cls condition:condition];
    
    // 处理类方法
    Class metaCls = object_getClass(cls);
    if (class_isMetaClass(metaCls)) {
        [self traceMethodWithClass:metaCls condition:condition];
    }
}

////////////////////////////////////////////////////////////////////////////////
#pragma mark - Private OCMethodTrace API

- (instancetype)init
{
    self = [super init];
    if (self) {
        // 参考ANYMethodLog的处理
        [self initDefaultClassBlackList];
        [self initDefaultMethodBlackList];
        [self initSupportedTypeDict];
        [self initTracePositionDict];

        self.disableTrace = NO;
        self.logLevel = OMTLogLevelDebug;
        self.blockCache = [NSMutableDictionary dictionary];
        self.deep = 0;
        
        pthread_mutex_init(&_blockMutex, NULL);
        pthread_mutex_init(&_deepMutex, NULL);
        
    }
    return self;
}

- (void)dealloc
{
    pthread_mutex_destroy(&_blockMutex);
    pthread_mutex_destroy(&_deepMutex);
}

- (void)initDefaultClassBlackList
{
    self.defaultClassBlackList = @[@"OCMethodTrace",
                                   @"OMTBlock",
                                   @"OMTMessageStub",
                                   @"NSMethodSignature",
                                   @"NSInvocation",
                                   ];
}

- (void)initDefaultMethodBlackList
{
    self.defaultMethodBlackList = @[@".cxx_destruct",
                                    @"_isDeallocating",
                                    @"release",
                                    @"autorelease",
                                    @"recycle",
                                    @"retain",
                                    @"Retain",
                                    @"_tryRetain",
                                    @"copy",
                                    @"copyWithZone:",
                                    @"mutableCopyWithZone:",
                                    @"nsis_descriptionOfVariable:",
                                    @"respondsToSelector:",
                                    @"class",
                                    @"methodSignatureForSelector:",
                                    @"allowsWeakReference",
                                    @"retainWeakReference",
                                    @"forwardInvocation:",
                                    @"description",
                                    @"sharedInstance",
                                    @"SharedInstance",
                                    @"getInstance",
                                    @"GetInstance",
                                    ];
}

- (void)initSupportedTypeDict
{
    // https://developer.apple.com/library/archive/documentation/Cocoa/Conceptual/ObjCRuntimeGuide/Articles/ocrtTypeEncodings.html#//apple_ref/doc/uid/TP40008048-CH100-SW1

    // Table 6-1  Objective-C type encodings
    self.supportedTypeDict = @{[NSString stringWithUTF8String:@encode(char)] : @"(char)",
                               [NSString stringWithUTF8String:@encode(int)] : @"(int)",
                               [NSString stringWithUTF8String:@encode(short)] : @"(short)",
                               [NSString stringWithUTF8String:@encode(long)] : @"(long)",
                               [NSString stringWithUTF8String:@encode(long long)] : @"(long long)",
                               [NSString stringWithUTF8String:@encode(unsigned char)] : @"(unsigned char))",
                               [NSString stringWithUTF8String:@encode(unsigned int)] : @"(unsigned int)",
                               [NSString stringWithUTF8String:@encode(unsigned short)] : @"(unsigned short)",
                               [NSString stringWithUTF8String:@encode(unsigned long)] : @"(unsigned long)",
                               [NSString stringWithUTF8String:@encode(unsigned long long)] : @"(unsigned long long)",
                               [NSString stringWithUTF8String:@encode(float)] : @"(float)",
                               [NSString stringWithUTF8String:@encode(double)] : @"(double)",
                               [NSString stringWithUTF8String:@encode(BOOL)] : @"(BOOL)",
                               [NSString stringWithUTF8String:@encode(void)] : @"(void)",
                               [NSString stringWithUTF8String:@encode(char *)] : @"(char *)",
                               [NSString stringWithUTF8String:@encode(id)] : @"(id)",
                               [NSString stringWithUTF8String:@encode(Class)] : @"(Class)",
                               [NSString stringWithUTF8String:@encode(SEL)] : @"(SEL)",
                               [NSString stringWithUTF8String:@encode(CGRect)] : @"(CGRect)",
                               [NSString stringWithUTF8String:@encode(CGPoint)] : @"(CGPoint)",
                               [NSString stringWithUTF8String:@encode(CGSize)] : @"(CGSize)",
                               [NSString stringWithUTF8String:@encode(CGVector)] : @"(CGVector)",
                               [NSString stringWithUTF8String:@encode(CGAffineTransform)] : @"(CGAffineTransform)",
                               [NSString stringWithUTF8String:@encode(UIOffset)] : @"(UIOffset)",
                               [NSString stringWithUTF8String:@encode(UIEdgeInsets)] : @"(UIEdgeInsets)",
                               @"@?" : @"(block)", // block类型
                               }; // 添加更多类型
}

- (void)initTracePositionDict
{
    // @interface NSObject
    self.tracePositionDict = @{@"initialize" : @(OMTTracePositionBefore | OMTTracePositionAfter),
                               @"init" : @(OMTTracePositionBefore | OMTTracePositionAfter),
                               @"new" : @(OMTTracePositionBefore | OMTTracePositionAfter),
                               @"allocWithZone:" : @(OMTTracePositionBefore | OMTTracePositionAfter),
                               @"alloc" : @(OMTTracePositionBefore | OMTTracePositionAfter),
                               @"dealloc" : @(OMTTracePositionBefore),
                               @"finalize" : @(OMTTracePositionBefore),
                               }; // 添加更多类型
}

+ (NSString *)errorString:(OMTErrorCode)errorCode
{
    struct CodeToString {
        OMTErrorCode errorCode;
        const char *errorString;
    };
    static const struct CodeToString kCodeToString[] = {
        { OMTErrorNoError,                          "NERR" },
        { OMTErrorSelectorPassThrough,              "SPTH" },
        { OMTErrorSelectorAlreadyHooked,            "SAHK" },
        { OMTErrorSelectorInUserBlacklist,          "SIUB" },
        { OMTErrorClassInSelfBlacklist,             "CISB" },
        { OMTErrorSelectorInSelfBlacklist,          "SISB" },
        { OMTErrorSelectorUnsuppotedMethodSignature,"SUMS" },
        { OMTErrorSelectorUnsuppotedEncodeType,     "SUEY" },
        { OMTErrorDoesNotRespondToMethod,           "NMTD" },
        { OMTErrorDoesNotRespondToSelector,         "NSEL" },
        { OMTErrorDoesNotRespondToIMP,              "NIMP" },
        { OMTErrorSwizzleMethodFailed,              "SMDF" },
    };
    
    static const size_t kNumCodeToString = sizeof(kCodeToString) / sizeof(kCodeToString[0]);
    
    size_t i;
    for (i = 0; i < kNumCodeToString; i++) {
        if (errorCode == kCodeToString[i].errorCode) {
            break;
        }
    }
    NSAssert(i != kNumCodeToString, @"Unknown errorCode???");
    
    return [NSString stringWithUTF8String:kCodeToString[i].errorString];
}

+ (BOOL)detectInfiniteLoopAtSelectorArray:(NSArray *)selectorArray
{
    void *callstack[128];
    int frames = backtrace(callstack, 128);
    char **strs = backtrace_symbols(callstack, frames);
    
    BOOL exists = NO;
    // 跳过自身方法，所以从1开始
    for (int i = 1; i < frames && strs && !exists; i++) {
        NSString *frame = [NSString stringWithUTF8String:strs[i]];
        // OMT_LOGD(@"frame[%d]: %@", i, frame);
        for (NSString *selector in selectorArray) {
            if ([frame containsString:selector]) {
                exists = YES;
                break;
            }
        }
    }
    if (strs) {
        free(strs);
    }
    return exists;
}

- (NSString *)descriptionWithTarget:(id)target class:(Class)cls selector:(SEL)sel targetPosition:(OMTTargetPosition)targetPosition
{
    if (nil != self.delegate && [self.delegate respondsToSelector:@selector(descriptionWithTarget:class:selector:targetPosition:)]) {
        return [self.delegate descriptionWithTarget:target class:cls selector:sel targetPosition:targetPosition];
    } else {
        return [target description];
    }
}

- (BOOL)isClassInBlackList:(NSString *)className
{
    return [self.defaultClassBlackList containsObject:className];
}

- (BOOL)isSelectorInBlackList:(NSString *)methodName
{
    return [self.defaultMethodBlackList containsObject:methodName];
}

- (BOOL)isSupportedType:(NSString *)typeEncode
{
    return [self.supportedTypeDict.allKeys containsObject:typeEncode];
}

- (OMTTracePosition)tracePosition:(NSString *)methodName
{
    OMTTracePosition defaultPostion = OMTTracePositionBefore | OMTTracePositionAfter;
    return [self.tracePositionDict.allKeys containsObject:methodName] ? [self.tracePositionDict[methodName] intValue]: defaultPostion;
}

- (void)setBlock:(OMTBlock *)block forKey:(NSString *)key
{
    pthread_mutex_lock(&_blockMutex);
    [self.blockCache setObject:block forKey:key];
    pthread_mutex_unlock(&_blockMutex);
}

- (OMTBlock *)blockforKey:(NSString *)key
{
    pthread_mutex_lock(&_blockMutex);
    OMTBlock *block = [self.blockCache objectForKey:key];
    pthread_mutex_unlock(&_blockMutex);
    return block;
}

- (OMTBlock *)blockWithTarget:(id)target
{
    pthread_mutex_lock(&_blockMutex);
    Class cls = [target class];
    OMTBlock *block = [self.blockCache objectForKey:NSStringFromClass(cls)];
    while (nil == block) {
        cls = [cls superclass];
        if (nil == cls) {
            break;
        }
        block = [self.blockCache objectForKey:NSStringFromClass(cls)];
    }
    pthread_mutex_unlock(&_blockMutex);
    return block;
}

- (int)atomicAddDeep
{
    pthread_mutex_lock(&_deepMutex);
    int deep = _deep++;
    pthread_mutex_unlock(&_deepMutex);
    return deep;
}

- (void)atomicIncDeep
{
    pthread_mutex_lock(&_deepMutex);
    _deep--;
    pthread_mutex_unlock(&_deepMutex);
}

- (void)traceMethodWithClass:(Class)cls condition:(OMTConditionBlock)condition
{
    unsigned int outCount;
    Method *methods = class_copyMethodList(cls, &outCount);
    for (unsigned int i = 0; i < outCount; i++) {
        Method method = *(methods + i);
        SEL selector = method_getName(method);
        
        OMTErrorCode errorCode = [self isTraceSupportedWithClass:cls method:method];
        if (errorCode == OMTErrorNoError && condition) {
            // 用户只有两种选择：跟踪，不跟踪
            if (!condition(selector)) {
                errorCode = OMTErrorSelectorInUserBlacklist;
            }
        }
        
        if (errorCode == OMTErrorNoError) {
            errorCode = [self swizzleMethodWithClass:cls selector:selector];
        }
        
        OMT_LOG(LOG_LEVEL_4_ERROR_CODE(errorCode), @"[%@] trace class: %@ method: %@ types: %s",
                 [self.class errorString:errorCode],
                 NSStringFromClass(cls),
                 NSStringFromSelector(selector),
                 method_getDescription(method)->types);
    }
    free(methods);
}

- (OMTErrorCode)isTraceSupportedWithClass:(Class)cls method:(Method)method
{
    char returnTypeCString[1024];
    memset(returnTypeCString, 0, sizeof(returnTypeCString));
    method_getReturnType(method, returnTypeCString, sizeof(returnTypeCString));
    const char *returnType = returnTypeCString;
    
    
    NSString *selectorName = NSStringFromSelector(method_getName(method));
    if ([selectorName hasPrefix:@"omt_"]) {
        // 1 内部方法不处理
        return OMTErrorSelectorPassThrough;
    } else if ([selectorName hasPrefix:OMTMessageFinalPrefix]) {
        // 2 处理过的方法不处理
        return OMTErrorSelectorAlreadyHooked;
    }
    
    // 3 内部黑名单中的方法不处理
    if ([self isSelectorInBlackList:selectorName]) {
        return OMTErrorSelectorInSelfBlacklist;
    }
    
    // 4 签名异常的方法不处理。模拟器下有一些奇葩的方法(系统方法居多)签名异常，会导致[NSMethodSignature signatureWithObjCTypes:] crash，所以需捕捉异常
    BOOL hasSignatureException = NO;
    @try {
        __unused NSMethodSignature *methodSignature = [NSMethodSignature signatureWithObjCTypes:method_getTypeEncoding(method)];
    } @catch (__unused NSException *e) {
        hasSignatureException = YES;
    }
    if (hasSignatureException) {
        return OMTErrorSelectorUnsuppotedMethodSignature;
    }
    
    // 5 处理返回值类型
    // 跳过类型限定符
    if (omt_isTypeQualifier(returnType[0])) {
        returnType++;
    }
    
    // 支持指针类型
    if (returnType[0] != _C_PTR) {
        // struct和union有可能无法解析，但是也通过，解释不出的用NSValue输出，便于打印函数调用链
        if (!(omt_isStructType(returnType) || omt_isUnionType(returnType))) {
            if (![self isSupportedType:[NSString stringWithUTF8String:returnType]]) {
                return OMTErrorSelectorUnsuppotedEncodeType;
            }
        }
    }
    
    // 6 处理参数类型。需注意：发送消息时，第0个参数是self, 第1个参数是sel，第2个参数才是真正意义上的第一个方法参数，所以从2开始算
    for (int k = 2 ; k < method_getNumberOfArguments(method); k++) {
        char argumentTypeCString[1024];
        memset(argumentTypeCString, 0, sizeof(argumentTypeCString));
        method_getArgumentType(method, k, argumentTypeCString, sizeof(argumentTypeCString));
        const char *argumentType = argumentTypeCString;

        // 跳过类型限定符
        if (omt_isTypeQualifier(argumentType[0])) {
            argumentType++;
        }
        // 支持指针类型
        if (argumentType[0] == _C_PTR) {
            continue;
        }

        // struct和union有可能无法解析，但是也通过，解释不出的用NSValue输出，便于打印函数调用链
        if (!(omt_isStructType(argumentType) || omt_isUnionType(argumentType))) {
            if (![self isSupportedType:[NSString stringWithUTF8String:argumentType]]) {
                return OMTErrorSelectorUnsuppotedEncodeType;
            }
        }
    }
    
    return OMTErrorNoError;
}

- (OMTErrorCode)swizzleMethodWithClass:(Class)cls selector:(SEL)selector
{
    // 1 检查该selector是否已经hook过
    SEL newSelector = NSSelectorFromString([NSString stringWithFormat:@"%@%@->%@",
                                            OMTMessageFinalPrefix,
                                            NSStringFromClass(cls),
                                            NSStringFromSelector(selector)]);
    if (class_respondsToSelector(cls, newSelector)) {
        return OMTErrorSelectorAlreadyHooked;
    }
    
    // 2 原方法相关校验
    Method originMethod = class_getInstanceMethod(cls, selector);
    if (!originMethod) {
        return OMTErrorDoesNotRespondToMethod;
    }
    IMP originIMP = method_getImplementation(originMethod);
    if (!originIMP) {
        return OMTErrorDoesNotRespondToIMP;
    }
    const char *originTypes = method_getTypeEncoding(originMethod);

    // 3 转发：旧方法跳转到转发IMP
    // 使用比较另类的"类与方法间隔符"，如"->"。如果使用"_"，有可能会导致冲突，如系统内部类"__CFNotification"就会异常
    SEL forwardingSEL = NSSelectorFromString([NSString stringWithFormat:@"%@%@->%@",
                                              OMTMessageTempPrefix,
                                              NSStringFromClass(cls),
                                              NSStringFromSelector(selector)]);
    IMP forwardingIMP = imp_implementationWithSelector(forwardingSEL, originTypes);
    NSAssert(originIMP != forwardingIMP, @"originIMP != forwardingIMP");
    method_setImplementation(originMethod, forwardingIMP);
    
    // 4 还原：新SEL跳转回旧IMP
    if (!class_addMethod(cls, newSelector, originIMP, originTypes)) {
        return OMTErrorSwizzleMethodFailed;
    }
    
    return OMTErrorNoError;
}

- (void)omt_forwardInvocation:(NSInvocation *)invocation
{
    if (self.disableTrace) {
        [invocation invoke];
        return;
    }
    
    Class originClass = [invocation omt_originClass];
    SEL originSelector = [invocation omt_originSelector];
    // XXX 通过堆栈搜索递归调用会有挺大的性能损耗。但确实不知道怎么处理比较好，了解的麻烦知会email一下我
    // 其实主要是因为description调用，当遇到description则用加递归锁，直接跳过runBefore和runAfer，但是如果description内部有条件等待，可能会死锁.
    BOOL disableTrace = [[self class] detectInfiniteLoopAtSelectorArray:@[OMTBlockRunBeforeSelector,
                                                                          OMTBlockRunAfterSelector,
                                                                          OMTDescriptionWithTargetSelector]];
    int deep = [self atomicAddDeep];
    
    if (!disableTrace) {
        OMTBlock *block = [self blockWithTarget:invocation.target];
        OMTTracePosition postion = [self tracePosition:NSStringFromSelector(originSelector)];
        NSDate *start;
        
        // 1 原方法调用前回调
        if (postion & OMTTracePositionBefore) {
            [block runBefore:invocation.target class:originClass sel:originSelector args:[invocation omt_getArguments] deep:deep];
        }
        if (postion & OMTTracePositionAfter) {
            start = [NSDate date];
        }
        
        // 2 调用原方法
        [invocation invoke];
        
        // 3 原方法调用后回调
        if (postion & OMTTracePositionAfter) {
            NSTimeInterval interval = [[NSDate date] timeIntervalSinceDate:start];
            [block runAfter:invocation.target class:originClass sel:originSelector ret:[invocation omt_getReturnValue] deep:deep interval:interval];
        }
    } else {
        // 直接调用原方法
        [invocation invoke];
    }
    
    [self atomicIncDeep];
}

@end

////////////////////////////////////////////////////////////////////////////////
#pragma mark - OMTBlock

@implementation OMTBlock

- (BOOL)runCondition:(SEL)sel
{
    if (self.condition) {
        return self.condition(sel);
    } else {
        return YES;
    }
}

- (void)runBefore:(id)target class:(Class)cls sel:(SEL)sel args:(NSArray *)args deep:(int)deep
{
    if (self.before) {
        self.before(target, cls, sel, args, deep);
    }
}

- (void)runAfter:(id)target class:(Class)cls sel:(SEL)sel ret:(id)ret deep:(int)deep interval:(NSTimeInterval)interval
{
    if (self.after) {
        self.after(target, cls, sel, ret, deep, interval);
    }
}

@end

////////////////////////////////////////////////////////////////////////////////
#pragma mark - OMTMessageStub

@implementation OMTMessageStub

- (instancetype)initWithTarget:(id)target selector:(SEL)aSelector
{
    self = [super init];
    if (self) {
        self.target = target;
        NSString *finalSelectorName = [NSStringFromSelector(aSelector) stringByReplacingOccurrencesOfString:OMTMessageTempPrefix withString:OMTMessageFinalPrefix];
        self.selector = NSSelectorFromString(finalSelectorName);
    }
    return self;
}

- (NSMethodSignature *)methodSignatureForSelector:(SEL)aSelector
{
    Method method = class_getInstanceMethod(object_getClass(self.target), self.selector);
    if (NULL == method) {
        OMT_LOGE(@"No Method, target: %@ selector: %@", self.target, NSStringFromSelector(self.selector));
        assert(NULL != method);
    }
    
    const char *types = method_getTypeEncoding(method);
    if (NULL == types) {
        OMT_LOGE(@"No Types, target: %@ selector: %@", self.target, NSStringFromSelector(self.selector));
        assert(NULL != types);
    }
    
    return [NSMethodSignature signatureWithObjCTypes:types];
}

- (void)forwardInvocation:(NSInvocation *)anInvocation
{
    anInvocation.target = self.target;
    anInvocation.selector = self.selector;
    
    // 勿删，调试观察类名和方法名
    __unused const char *className = [NSStringFromClass([self.target class]) UTF8String];
    __unused const char *selectorName = [NSStringFromSelector(self.selector) UTF8String];
    
    [[OCMethodTrace sharedInstance] omt_forwardInvocation:anInvocation];
}

- (NSString *)description
{
    return [NSString stringWithFormat:@"<%@: %p target: %p selector: %@>",
            NSStringFromClass([self class]), self, self.target, NSStringFromSelector(self.selector)];
}

@end

////////////////////////////////////////////////////////////////////////////////
#pragma mark - NSObject (OCMethodTrace)

@implementation NSObject (OCMethodTrace)

+ (void)load
{
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        swizzle_class_method([self class], @selector(forwardingTargetForSelector:), @selector(omt_forwardingTargetForSelector:));
        swizzle_instance_method([self class], @selector(forwardingTargetForSelector:), @selector(omt_forwardingTargetForSelector:));
    });
}

+ (id)omt_forwardingTargetForSelector:(SEL)aSelector
{
    if ([NSStringFromSelector(aSelector) hasPrefix:OMTMessageTempPrefix] && ![self isKindOfClass:[OMTMessageStub class]]) {
        return [[OMTMessageStub alloc] initWithTarget:self selector:aSelector];
    }
    return [self omt_forwardingTargetForSelector:aSelector];
}

- (id)omt_forwardingTargetForSelector:(SEL)aSelector
{
    if ([NSStringFromSelector(aSelector) hasPrefix:OMTMessageTempPrefix] && ![self isKindOfClass:[OMTMessageStub class]]) {
        return [[OMTMessageStub alloc] initWithTarget:self selector:aSelector];
    }
    return [self omt_forwardingTargetForSelector:aSelector];
}

@end

////////////////////////////////////////////////////////////////////////////////
#pragma mark - NSInvocation (OCMethodTrace)

@implementation NSInvocation (OCMethodTrace)

- (Class)omt_originClass
{
    NSString *finalSelectorName = [NSStringFromSelector(self.selector) stringByReplacingOccurrencesOfString:OMTMessageFinalPrefix withString:@""];
    NSUInteger location = [finalSelectorName rangeOfString:@"->"].location;
    NSString *originClassName = [finalSelectorName substringWithRange:NSMakeRange(0, location)];
    return NSClassFromString(originClassName);
}

- (SEL)omt_originSelector
{
    NSString *finalSelectorName = [NSStringFromSelector(self.selector) stringByReplacingOccurrencesOfString:OMTMessageFinalPrefix withString:@""];
    NSUInteger location = [finalSelectorName rangeOfString:@"->"].location;
    NSString *originSelectorName = [finalSelectorName substringWithRange:NSMakeRange(location + 2, finalSelectorName.length - location - 2)];
    return NSSelectorFromString(originSelectorName);
}

- (id)omt_getReturnValue
{
    const char *returnType = self.methodSignature.methodReturnType;
    id ret = nil;
    
    // 跳过类型限定符
    if (omt_isTypeQualifier(returnType[0])) {
        returnType++;
    }
    
    // 基本类型
    #define GET_RETURN_VALUE(_type) \
        if (0 == strcmp(returnType, @encode(_type))) { \
            _type ret_temp; \
            [self getReturnValue:&ret_temp]; \
            ret = @(ret_temp); \
        }
    
    // 结构体类型
    #define GET_STRUCT_RETURN_VALUE(_type) \
        if (is##_type(returnType)) { \
            _type ret_temp; \
            [self getReturnValue:&ret_temp]; \
            ret = NSStringFrom##_type(ret_temp); \
        }
    
    if (omt_isStructType(returnType)) {
        GET_STRUCT_RETURN_VALUE(CGRect)
        else GET_STRUCT_RETURN_VALUE(CGPoint)
        else GET_STRUCT_RETURN_VALUE(CGSize)
        else GET_STRUCT_RETURN_VALUE(CGVector)
        else GET_STRUCT_RETURN_VALUE(UIOffset)
        else GET_STRUCT_RETURN_VALUE(UIEdgeInsets)
        else GET_STRUCT_RETURN_VALUE(CGAffineTransform)
    }
    else if (omt_isUnionType(returnType)) {
        // do nothing
    }
    else GET_RETURN_VALUE(char)
    else GET_RETURN_VALUE(int)
    else GET_RETURN_VALUE(short)
    else GET_RETURN_VALUE(long)
    else GET_RETURN_VALUE(long long)
    else GET_RETURN_VALUE(unsigned char)
    else GET_RETURN_VALUE(unsigned int)
    else GET_RETURN_VALUE(unsigned short)
    else GET_RETURN_VALUE(unsigned long)
    else GET_RETURN_VALUE(unsigned long long)
    else GET_RETURN_VALUE(float)
    else GET_RETURN_VALUE(double)
    else GET_RETURN_VALUE(BOOL)
    else if (strcmp(returnType, @encode(void)) == 0) {
        ret = @"void";
    }
    else if (0 == strcmp(returnType, @encode(char *))) {
        char *ret_temp;
        [self getReturnValue:&ret_temp];
        ret = [NSString stringWithUTF8String:ret_temp ? ret_temp : "NULL"];
    }
    else if (0 == strcmp(returnType, @encode(id))) {
        __unsafe_unretained id ret_temp;
        [self getReturnValue:&ret_temp];
        ret = [[OCMethodTrace sharedInstance] descriptionWithTarget:ret_temp class:[self omt_originClass] selector:[self omt_originSelector] targetPosition:OMTTargetPositionAfterReturnValue];
    }
    else if (0 == strcmp(returnType, @encode(Class))) {
        Class ret_temp;
        [self getReturnValue:&ret_temp];
        ret = NSStringFromClass(ret_temp);
    }
    else if (0 == strcmp(returnType, @encode(SEL))) {
        SEL ret_temp;
        [self getReturnValue:&ret_temp];
        ret = NSStringFromSelector(ret_temp);
    }
    else if (0 == strcmp(returnType, "@?")) { // block
        // 则模仿lldb bt堆栈打印形式，直接打印地址
        void *ret_temp;
        [self getReturnValue:&ret_temp];
        ret = [NSString stringWithFormat:@"%p", ret_temp];
    }
    else if (returnType[0] == _C_PTR) {
        void *ret_temp;
        [self getReturnValue:&ret_temp];
        if (0 == strcmp(returnType, @encode(CFStringRef))) {
            ret = [NSString stringWithString:ret_temp ? (__bridge NSString *)ret_temp : @"NULL"]; // 深拷贝
        }
        if (nil == ret) {
            // 模仿lldb bt堆栈打印形式，直接打印地址
            ret = [NSString stringWithFormat:@"%p", ret_temp];
        }
    }
    
    if (nil == ret) {
        NSUInteger valueSize = 0;
        NSGetSizeAndAlignment(returnType, &valueSize, NULL);
        unsigned char valueBytes[valueSize];
        [self getReturnValue:valueBytes];
        ret = [NSValue valueWithBytes:valueBytes objCType:returnType];
    }
    
    return ret;
}

- (NSArray *)omt_getArguments
{
    NSMethodSignature *methodSignature = [self methodSignature];
    NSMutableArray *argList = (methodSignature.numberOfArguments > 2 ? [NSMutableArray array] : nil);
    for (NSUInteger i = 2; i < methodSignature.numberOfArguments; i++) {
        const char *argumentType = [methodSignature getArgumentTypeAtIndex:i];
        id arg = nil;
        
        // 跳过类型限定符
        if (omt_isTypeQualifier(argumentType[0])) {
            argumentType++;
        }
        
        // 基本类型
        #define GET_ARGUMENT(_type) \
            if (0 == strcmp(argumentType, @encode(_type))) { \
                _type arg_temp; \
                [self getArgument:&arg_temp atIndex:i]; \
                arg = @(arg_temp); \
            }

        // 结构体类型
        #define GET_STRUCT_ARGUMENT(_type) \
            if (is##_type(argumentType)) { \
                _type arg_temp; \
                [self getArgument:&arg_temp atIndex:i]; \
                arg = NSStringFrom##_type(arg_temp); \
            }

        
        if (omt_isStructType(argumentType)) {
            GET_STRUCT_ARGUMENT(CGRect)
            else GET_STRUCT_ARGUMENT(CGPoint)
            else GET_STRUCT_ARGUMENT(CGSize)
            else GET_STRUCT_ARGUMENT(CGVector)
            else GET_STRUCT_ARGUMENT(UIOffset)
            else GET_STRUCT_ARGUMENT(UIEdgeInsets)
            else GET_STRUCT_ARGUMENT(CGAffineTransform)
        }
        else if (omt_isUnionType(argumentType)) {
            // do nothing
        }
        else GET_ARGUMENT(char)
        else GET_ARGUMENT(int)
        else GET_ARGUMENT(short)
        else GET_ARGUMENT(long)
        else GET_ARGUMENT(long long)
        else GET_ARGUMENT(unsigned char)
        else GET_ARGUMENT(unsigned int)
        else GET_ARGUMENT(unsigned short)
        else GET_ARGUMENT(unsigned long)
        else GET_ARGUMENT(unsigned long long)
        else GET_ARGUMENT(float)
        else GET_ARGUMENT(double)
        else GET_ARGUMENT(BOOL)
        else if (0 == strcmp(argumentType, @encode(char *))) {
            char *arg_temp;
            [self getArgument:&arg_temp atIndex:i];
            arg = [NSString stringWithUTF8String:arg_temp ? arg_temp : "NULL"];
        }
        else if (0 == strcmp(argumentType, @encode(id))) {
            __unsafe_unretained id arg_temp;
            [self getArgument:&arg_temp atIndex:i];
            arg = [[OCMethodTrace sharedInstance] descriptionWithTarget:arg_temp class:[arg_temp class] selector:[self omt_originSelector] targetPosition:OMTTargetPositionBeforeArgument];
        }
        else if (0 == strcmp(argumentType, @encode(Class))) {
            Class arg_temp;
            [self getArgument:&arg_temp atIndex:i];
            arg = NSStringFromClass(arg_temp);
        }
        else if (0 == strcmp(argumentType, @encode(SEL))) {
            SEL arg_temp;
            [self getArgument:&arg_temp atIndex:i];
            arg = NSStringFromSelector(arg_temp);
        }
        else if (0 == strcmp(argumentType, "@?")) { // block
            // 则模仿lldb bt堆栈打印形式，直接打印地址
            void *arg_temp;
            [self getArgument:&arg_temp atIndex:i];
            arg = [NSString stringWithFormat:@"%p", arg_temp];
        }
        else if (argumentType[0] == _C_PTR) {
            void *arg_temp;
            [self getArgument:&arg_temp atIndex:i];
            if (0 == strcmp(argumentType, @encode(CFStringRef))) {
                arg = [NSString stringWithString:arg_temp ? (__bridge NSString *)arg_temp : @"NULL"]; // 深拷贝
            }
            if (nil == arg) {
                // 则模仿lldb bt堆栈打印形式，直接打印地址
                arg = [NSString stringWithFormat:@"%p", arg_temp];
            }
        }
        
        if (nil == arg) {
            NSUInteger valueSize = 0;
            NSGetSizeAndAlignment(argumentType, &valueSize, NULL);
            unsigned char valueBytes[valueSize];
            [self getArgument:valueBytes atIndex:i];
            arg = [NSValue valueWithBytes:valueBytes objCType:argumentType];
        }

        [argList addObject:arg];
    }
    return argList;
}

@end
