//
//  PersistentDictionary.m
//
//  Created by Michael Heyeck on 9/8/10.
//

#import "PersistentDictionary.h"


@interface PersistentDictionary ()

- (NSArray*)fetchForKey:(NSString*)key;
- (void)deleteForKey:(NSString*)key;
- (void)insertValue:(NSString*)value forKey:(NSString*)key;

@end


@implementation PersistentDictionary

- (id)init
{
	return [self initWithEntityName:nil inContext:nil];
}


- (id)initWithEntityName:(NSString*)name inContext:(NSManagedObjectContext*)managedObjectContext
{
	if (self = [super init])
	{
		NSEntityDescription* e = nil;
		@try
		{
			e = [NSEntityDescription entityForName:name inManagedObjectContext:managedObjectContext];
		}
		@catch (NSException* ne) {}
		if (!e)
		{
			[self release];
			return nil;
		}
		
		moc = [managedObjectContext retain];
		entity = [e retain];
	}
	return self;
}


- (BOOL)hasValueForKey:(NSString*)key
{
	NSArray* a = [self fetchForKey:key];
	if (![a count])
	{
		// Error/nonexistent pair
		return NO;
	}
	else
	{
		// Found a non-empty array of results associated with the key
		return YES;
	}
}


- (BOOL)boolForKey:(NSString*)key
{
	NSArray* a = [self fetchForKey:key];
	if (![a count])
	{
		// On an error/nonexistent pair, default to NO
		return NO;
	}
	
	// In principle, there could be several pairs (this would be a bug); grab the first one arbitrarily
	// Note that on non-integer (i.e., buggy) values, this also defaults to 0 (NO)
	return [[[a objectAtIndex:0] valueForKey:@"value"] integerValue] == YES;
}


- (float)floatForKey:(NSString*)key
{
	NSArray* a = [self fetchForKey:key];
	if (![a count])
	{
		// On an error/nonexistent pair, default to 0.0
		return 0.0;
	}
	
	// In principle, there could be several pairs (this would be a bug); grab the first one arbitrarily
	// Note that on non-float (i.e., buggy) values, this also defaults to 0.0
	return [[[a objectAtIndex:0] valueForKey:@"value"] floatValue];
}


- (double)doubleForKey:(NSString*)key
{
	NSArray* a = [self fetchForKey:key];
	if (![a count])
	{
		// On an error/nonexistent pair, default to 0.0
		return 0.0;
	}
	
	// In principle, there could be several pairs (this would be a bug); grab the first one arbitrarily
	// Note that on non-double (i.e., buggy) values, this also defaults to 0.0
	return [[[a objectAtIndex:0] valueForKey:@"value"] doubleValue];
}


- (NSInteger)integerForKey:(NSString*)key
{
	NSArray* a = [self fetchForKey:key];
	if (![a count])
	{
		// On an error/nonexistent pair, default to 0
		return 0;
	}
	
	// In principle, there could be several pairs (this would be a bug); grab the first one arbitrarily
	// Note that on non-integer (i.e., buggy) values, this also defaults to 0
	return [[[a objectAtIndex:0] valueForKey:@"value"] integerValue];
}


- (NSString*)stringForKey:(NSString*)key
{
	NSArray* a = [self fetchForKey:key];
	if (![a count])
	{
		// On an error/nonexistent pair, default to an empty string
		return @"";
	}
	
	// In principle, there could be several pairs (this would be a bug); grab the first one arbitrarily
	NSString* r = [[a objectAtIndex:0] valueForKey:@"value"];
	return r?r:@"";
}


- (void)setBool:(BOOL)value forKey:(NSString*)key
{
	[self deleteForKey:key];
	[self insertValue:[NSString stringWithFormat:@"%d",value] forKey:key];
}


- (void)setFloat:(float)value forKey:(NSString*)key
{
	[self deleteForKey:key];
	[self insertValue:[NSString stringWithFormat:@"%f",value] forKey:key];
}


- (void)setDouble:(double)value forKey:(NSString*)key
{
	[self deleteForKey:key];
	[self insertValue:[NSString stringWithFormat:@"%f",value] forKey:key];
}


- (void)setInteger:(NSInteger)value forKey:(NSString*)key
{
	[self deleteForKey:key];
	[self insertValue:[NSString stringWithFormat:@"%d",value] forKey:key];
}


- (void)setString:(NSString*)value forKey:(NSString*)key
{
	[self deleteForKey:key];
	[self insertValue:value?value:@"" forKey:key];
}


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

#pragma mark Extension methods

- (NSArray*)fetchForKey:(NSString*)key
{
	// Create a request (for edited Event)
	NSFetchRequest* request = [[[NSFetchRequest alloc] init] autorelease];
	request.entity = entity;
	
	// Add a predicate to the request
	request.predicate = [NSPredicate predicateWithFormat:@"key == %@",key];
	
	// Do a simple fetch (ignore errors)
	NSError* err;
	return [moc executeFetchRequest:request error:&err];
}


- (void)deleteForKey:(NSString*)key
{
	// Perform the delete(s)
	for (NSManagedObject* o in [self fetchForKey:key])
	{
		[moc deleteObject:o];
	}

	// Commit the change(s)
	NSError* err;
	if (![moc save:&err])
	{
		// Handle the error.
		NSLog(@"Unresolved error %@, %@", err, [err userInfo]);
	}
}


- (void)insertValue:(NSString*)value forKey:(NSString*)key
{
	// Can't associate values with nil keys
	if (!key) return;
	
	// Create the object
	NSManagedObject* o = [[[NSManagedObject alloc] initWithEntity:entity insertIntoManagedObjectContext:moc] autorelease];

	// Store the KV pair
	[o setValue:key forKey:@"key"];
	[o setValue:value forKey:@"value"];
	
	// Commit the changes
	NSError* err;
	if (![moc save:&err])
	{
		// Handle the error.
		NSLog(@"Unresolved error %@, %@", err, [err userInfo]);
	}
}

@end