//
//  RKObjectPropertyInspector.m
//  RestKit
//
//  Created by Blake Watters on 3/4/10.
//  Copyright 2010 Two Toasters. All rights reserved.
//

#import <objc/message.h>
#import "RKObjectPropertyInspector.h"
#import "Logging.h"

static RKObjectPropertyInspector* sharedInspector = nil;

@implementation RKObjectPropertyInspector

+ (RKObjectPropertyInspector*)sharedInspector {
    if (sharedInspector == nil) {
        sharedInspector = [RKObjectPropertyInspector new];
    }
    
    return sharedInspector;
}

- (id)init {
	if ((self = [super init])) {
		_cachedPropertyNamesAndTypes = [[NSMutableDictionary alloc] init];
	}
	
	return self;
}

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

- (NSString*)propertyTypeFromAttributeString:(NSString*)attributeString {
	NSString *type = [NSString string];
	NSScanner *typeScanner = [NSScanner scannerWithString:attributeString];
	[typeScanner scanUpToCharactersFromSet:[NSCharacterSet characterSetWithCharactersInString:@"@"] intoString:NULL];
	
	// we are not dealing with an object
	if([typeScanner isAtEnd]) {
		return @"NULL";
	}
	[typeScanner scanCharactersFromSet:[NSCharacterSet characterSetWithCharactersInString:@"\"@"] intoString:NULL];
	// this gets the actual object type
	[typeScanner scanUpToCharactersFromSet:[NSCharacterSet characterSetWithCharactersInString:@"\""] intoString:&type];
	return type;
}

- (NSDictionary *)propertyNamesAndTypesForClass:(Class)class {
	NSMutableDictionary* propertyNames = [_cachedPropertyNamesAndTypes objectForKey:class];
	if (propertyNames) {
		return propertyNames;
	}
	propertyNames = [NSMutableDictionary dictionary];
	
	//include superclass properties
	Class currentClass = class;
	while (currentClass != nil) {
		// Get the raw list of properties
		unsigned int outCount;
		objc_property_t *propList = class_copyPropertyList(currentClass, &outCount);
		
		// Collect the property names
		int i;
		NSString *propName;
		for (i = 0; i < outCount; i++) {
			// property_getAttributes() returns everything we need to implement this...
			// See: http://developer.apple.com/mac/library/DOCUMENTATION/Cocoa/Conceptual/ObjCRuntimeGuide/Articles/ocrtPropertyIntrospection.html#//apple_ref/doc/uid/TP40008048-CH101-SW5
			objc_property_t* prop = propList + i;
			NSString* attributeString = [NSString stringWithCString:property_getAttributes(*prop) encoding:NSUTF8StringEncoding];			
			propName = [NSString stringWithCString:property_getName(*prop) encoding:NSUTF8StringEncoding];
			
			if (![propName isEqualToString:@"_mapkit_hasPanoramaID"]) {
				const char* className = [[self propertyTypeFromAttributeString:attributeString] cStringUsingEncoding:NSUTF8StringEncoding];
				Class class = objc_getClass(className);
				if (class) {
					[propertyNames setObject:class forKey:propName];
				}
			}
		}
		
		free(propList);
		currentClass = [currentClass superclass];
	}
	
	[_cachedPropertyNamesAndTypes setObject:propertyNames forKey:class];
    RKLOG_MAPPING(RKLogLevelDebug, @"Cached property names and types for Class '%@': %@", NSStringFromClass(class), propertyNames);
	return propertyNames;
}

- (Class)typeForProperty:(NSString*)propertyName ofClass:(Class)objectClass {
    NSDictionary* dictionary = [self propertyNamesAndTypesForClass:objectClass];
    return [dictionary objectForKey:propertyName];
}

@end