KWMessagePattern.m

//
// Licensed under the terms in License.txt
//
// Copyright 2010 Allen Ding. All rights reserved.
//

#import "KWMessagePattern.h"
#import "KWFormatter.h"
#import "KWNull.h"
#import "KWObjCUtilities.h"
#import "KWValue.h"
#import "NSInvocation+KiwiAdditions.h"
#import "NSMethodSignature+KiwiAdditions.h"
#import "KWHCMatcher.h"

@implementation KWMessagePattern

#pragma mark -
#pragma mark Initializing

- (id)initWithSelector:(SEL)aSelector {
    return [self initWithSelector:aSelector argumentFilters:nil];
}

- (id)initWithSelector:(SEL)aSelector argumentFilters:(NSArray *)anArray {
    if ((self = [super init])) {
        selector = aSelector;

        if ([anArray count] > 0)
            argumentFilters = [anArray copy];
    }

    return self;
}

- (id)initWithSelector:(SEL)aSelector firstArgumentFilter:(id)firstArgumentFilter argumentList:(va_list)argumentList {
    NSUInteger count = KWSelectorParameterCount(aSelector);
    NSMutableArray *array = [NSMutableArray arrayWithCapacity:count];
    [array addObject:(firstArgumentFilter != nil) ? firstArgumentFilter : [KWNull null]];

    for (NSUInteger i = 1; i < count; ++i)
    {
        id object = va_arg(argumentList, id);
        [array addObject:(object != nil) ? object : [KWNull null]];
    }

    va_end(argumentList);
    return [self initWithSelector:aSelector argumentFilters:array];
}

+ (id)messagePatternWithSelector:(SEL)aSelector {
    return [self messagePatternWithSelector:aSelector argumentFilters:nil];
}

+ (id)messagePatternWithSelector:(SEL)aSelector argumentFilters:(NSArray *)anArray {
    return [[[self alloc] initWithSelector:aSelector argumentFilters:anArray] autorelease];
}

+ (id)messagePatternWithSelector:(SEL)aSelector firstArgumentFilter:(id)firstArgumentFilter argumentList:(va_list)argumentList {
    return [[[self alloc] initWithSelector:aSelector firstArgumentFilter:firstArgumentFilter argumentList:argumentList] autorelease];
}

+ (id)messagePatternFromInvocation:(NSInvocation *)anInvocation {
    NSMethodSignature *signature = [anInvocation methodSignature];
    NSUInteger numberOfMessageArguments = [signature numberOfMessageArguments];
    NSMutableArray *argumentFilters = nil;

    if (numberOfMessageArguments > 0) {
        argumentFilters = [[NSMutableArray alloc] initWithCapacity:numberOfMessageArguments];

        for (NSUInteger i = 0; i < numberOfMessageArguments; ++i) {
            const char *type = [signature messageArgumentTypeAtIndex:i];
            id object = nil;

            if (KWObjCTypeIsObject(type)) {
                [anInvocation getMessageArgument:&object atIndex:i];
            } else {
                NSData *data = [anInvocation messageArgumentDataAtIndex:i];
                object = [KWValue valueWithBytes:[data bytes] objCType:type];
            }

            [argumentFilters addObject:(object != nil) ? object : [KWNull null]];
        }
    }

    return [self messagePatternWithSelector:[anInvocation selector] argumentFilters:[argumentFilters autorelease]];
}

- (void)dealloc {
    [argumentFilters release];
    [super dealloc];
}

#pragma mark -
#pragma mark Copying

- (id)copyWithZone:(NSZone *)zone {
    return [self retain];
}

#pragma mark -
#pragma mark Properties

@synthesize selector;
@synthesize argumentFilters;

#pragma mark -
#pragma mark Matching Invocations

- (BOOL)argumentFiltersMatchInvocationArguments:(NSInvocation *)anInvocation {
    if (self.argumentFilters == nil)
        return YES;

    NSMethodSignature *signature = [anInvocation methodSignature];
    NSUInteger numberOfArgumentFilters = [self.argumentFilters count];
    NSUInteger numberOfMessageArguments = [signature numberOfMessageArguments];

    for (NSUInteger i = 0; i < numberOfMessageArguments && i < numberOfArgumentFilters; ++i) {
        const char *objCType = [signature messageArgumentTypeAtIndex:i];
        id object = nil;

        // Extract message argument into object (wrapping values if neccesary)
        if (KWObjCTypeIsObject(objCType)) {
            [anInvocation getMessageArgument:&object atIndex:i];
        } else {
            NSData *data = [anInvocation messageArgumentDataAtIndex:i];
            object = [KWValue valueWithBytes:[data bytes] objCType:objCType];
        }

        // Match argument filter to object
        id argumentFilter = [self.argumentFilters objectAtIndex:i];

        if (KWObjCTypeIsObject(objCType)) {
            if ([argumentFilter isEqual:[KWNull null]]) {
                if (object != nil)
                    return NO;
            } else if ([argumentFilter respondsToSelector:@selector(matches:)]) {
              return [(id<HCMatcher>)argumentFilter matches:object];
            } else if (![argumentFilter isEqual:object]) {
                return NO;
            }
        } else {
            if ([argumentFilter isEqual:[KWNull null]]) {
                if (!KWObjCTypeIsPointerLike(objCType))
                    [NSException raise:@"KWMessagePatternException" format:@"nil was specified as an argument filter, but argument is not a pointer"];

                void *p = nil;
                [anInvocation getMessageArgument:&p atIndex:i];

                if (p != nil)
                    return NO;
            } else if (![argumentFilter isEqual:object]) {
                return NO;
            }
        }
    }

    return YES;
}

- (BOOL)matchesInvocation:(NSInvocation *)anInvocation {
    return self.selector == [anInvocation selector] && [self argumentFiltersMatchInvocationArguments:anInvocation];
}

#pragma mark -
#pragma mark Comparing Message Patterns

- (NSUInteger)hash {
    return [NSStringFromSelector(self.selector) hash];
}

- (BOOL)isEqual:(id)object {
    if (![object isKindOfClass:[KWMessagePattern class]])
        return NO;

    return [self isEqualToMessagePattern:object];
}

- (BOOL)isEqualToMessagePattern:(KWMessagePattern *)aMessagePattern {
    if (self.selector != aMessagePattern.selector)
        return NO;

    if (self.argumentFilters == nil && aMessagePattern.argumentFilters == nil)
        return YES;

    return [self.argumentFilters isEqualToArray:aMessagePattern.argumentFilters];
}

#pragma mark -
#pragma mark Retrieving String Representations

- (NSString *)selectorString {
    return NSStringFromSelector(self.selector);
}

- (NSString *)selectorAndArgumentFiltersString {
    NSMutableString *description = [[[NSMutableString alloc] init] autorelease];
    NSArray *components = [NSStringFromSelector(self.selector) componentsSeparatedByString:@":"];
    NSUInteger count = [components count] - 1;

    for (NSUInteger i = 0; i < count; ++i) {
        NSString *selectorComponent = [components objectAtIndex:i];
        NSString *argumentFilterString = [KWFormatter formatObject:[self.argumentFilters objectAtIndex:i]];
        [description appendFormat:@"%@:%@ ", selectorComponent, argumentFilterString];
    }

    return description;
}

- (NSString *)stringValue {
    if (self.argumentFilters == nil)
        return [self selectorString];
    else
        return [self selectorAndArgumentFiltersString];
}

#pragma mark -
#pragma mark Debugging

- (NSString *)description {
    return [NSString stringWithFormat:@"selector: %@\nargumentFilters: %@",
                                      NSStringFromSelector(self.selector),
                                      self.argumentFilters];
}

@end