//
//  DAO.m
//
// Copyright (c) 2008-2009, Route-Me Contributors
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// * Redistributions of source code must retain the above copyright notice, this
//   list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright notice,
//   this list of conditions and the following disclaimer in the documentation
//   and/or other materials provided with the distribution.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.

#import "RMTileCacheDAO.h"
#import "FMDatabase.h"
#import "RMTileCache.h"
#import "RMTileImage.h"


@implementation RMTileCacheDAO

-(void)configureDBForFirstUse
{
	[db executeUpdate:@"CREATE TABLE IF NOT EXISTS ZCACHE (ztileHash INTEGER PRIMARY KEY, zlastUsed DOUBLE, zdata BLOB)"];
    [db executeUpdate:@"CREATE INDEX IF NOT EXISTS zlastUsedIndex ON ZCACHE(zLastUsed)"];
    // adding more than once does not seem to break anything
    [db executeUpdate:@"ALTER TABLE ZCACHE ADD COLUMN zInserted DOUBLE"];
    [db executeUpdate:@"CREATE INDEX IF NOT EXISTS zInsertedIndex ON ZCACHE(zInserted)"];
}

-(id) initWithDatabase: (NSString*)path
{
	if (![super init])
		return nil;

	RMLog(@"Opening database at %@", path);
	
	db = [[FMDatabase alloc] initWithPath:path];
	if (![db open])
	{
		RMLog(@"Could not connect to database - %@", [db lastErrorMessage]);
		return nil;
	}
	
	[db setCrashOnErrors:TRUE];
        [db setShouldCacheStatements:TRUE];
	
	[self configureDBForFirstUse];
	
	return self;
}

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


-(NSUInteger) count
{
	FMResultSet *results = [db executeQuery:@"SELECT COUNT(ztileHash) FROM ZCACHE"];
	
	NSUInteger count = 0;
	
	if ([results next])
		count = [results intForColumnIndex:0];
	else
	{
		RMLog(@"Unable to count columns");
	}
	
	[results close];
	
	return count;
}

-(NSData*) dataForTile: (uint64_t) tileHash
{
	FMResultSet *results = [db executeQuery:@"SELECT zdata FROM ZCACHE WHERE ztilehash = ?", [NSNumber numberWithUnsignedLongLong:tileHash]];
	
	if ([db hadError])
	{
		RMLog(@"DB error while fetching tile data: %@", [db lastErrorMessage]);
		return nil;
	}
	
	NSData *data = nil;
	
	if ([results next])
	{
		data = [results dataForColumnIndex:0];
	}
	
	[results close];
	
	return data;
}

-(void) purgeTiles: (NSUInteger) count;
{
	RMLog(@"purging %u old tiles from db cache", count);
	
	// does not work: "DELETE FROM ZCACHE ORDER BY zlastUsed LIMIT"

	BOOL result = [db executeUpdate: @"DELETE FROM ZCACHE WHERE ztileHash IN (SELECT ztileHash FROM ZCACHE ORDER BY zlastUsed LIMIT ? )", 
				   [NSNumber numberWithUnsignedInt: count]];
	if (result == NO) {
		RMLog(@"Error purging cache");
	}
	
}

-(void) purgeTilesFromBefore: (NSDate*) date;
{
    NSUInteger count = 0;
    FMResultSet *results = [db executeQuery:@"SELECT COUNT(ztileHash) FROM ZCACHE WHERE zInserted < ?", date];
	if ([results next]) {
        count = [results intForColumnIndex:0];
        RMLog(@"Will purge %i tile(s) from before %@", count, date);
    }
	[results close];
    
    if (count == 0) {
        return;
    }
    
	BOOL result = [db executeUpdate: @"DELETE FROM ZCACHE WHERE zInserted < ?", 
				   date];
	if (result == NO) {
		RMLog(@"Error purging cache");
	}
}

-(void) removeAllCachedImages 
{
	BOOL result = [db executeUpdate: @"DELETE FROM ZCACHE"];
	if (result == NO) {
		RMLog(@"Error purging all cache");
	}	
}

-(void) touchTile: (uint64_t) tileHash withDate: (NSDate*) date
{
	BOOL result = [db executeUpdate: @"UPDATE ZCACHE SET zlastUsed = ? WHERE ztileHash = ? ", 
				   date, [NSNumber numberWithUnsignedInt: tileHash]];
	
	if (result == NO) {
		RMLog(@"Error touching tile");
	}
}

-(void) addData: (NSData*) data LastUsed: (NSDate*)date ForTile: (uint64_t) tileHash
{
	// Fixme
//	RMLog(@"addData\t%d", tileHash);
	BOOL result = [db executeUpdate:@"INSERT OR REPLACE INTO ZCACHE (ztileHash, zlastUsed, zInserted, zdata) VALUES (?, ?, ?, ?)", 
		[NSNumber numberWithUnsignedLongLong:tileHash], date, [NSDate date], data];
	if (result == NO)
	{
		RMLog(@"Error occured adding data");
	}
}

-(void)didReceiveMemoryWarning
{
	[db clearCachedStatements];
}

@end