//

//  Game-Persistence.m

//  GeekGameBoard

//

//  Created by Jens Alfke on 3/16/08.

//  Copyright 2008 __MyCompanyName__. All rights reserved.

//

#import "Game-Persistence.h"

static NSDictionary* parseURLFields( NSURL* url );

@implementation Game (Persistence)

static NSMutableDictionary *sPersistentGames;

- (id) initWithCoder: (NSCoder*)decoder

{

    self = [self init];

    if( self ) {

        _players = [[decoder decodeObjectForKey: @"players"] mutableCopy];

        _states  = [[decoder decodeObjectForKey: @"states"] mutableCopy];

        _moves   = [[decoder decodeObjectForKey: @"moves"] mutableCopy];

        self.currentTurn = self.maxTurn;

    }

    return self;

}

- (void) encodeWithCoder: (NSCoder*)coder

{

    [coder encodeObject: _players forKey: @"players"];

    [coder encodeObject: _states  forKey: @"states"];

    [coder encodeObject: _moves   forKey: @"moves"];

}

- (NSURL*) asURL

{

    return [NSURL URLWithString: 

            [NSString stringWithFormat: @"game:type=%@&id=%@&turn=%u&move=%@",

             [[self class] identifier], _uniqueID, self.currentTurn,_moves.lastObject]];

}

+ (Game*) gameWithURL: (NSURL*)url

{

    if( 0 != [@"game" caseInsensitiveCompare: url.scheme] )

        return nil;

    NSDictionary *fields = parseURLFields(url);

    NSString *type = [fields objectForKey: @"type"];

    NSString *uuid = [fields objectForKey: @"id"];

    int turn = [[fields objectForKey: @"turn"] intValue];

    if( !type || !uuid || turn<=0 )

        return nil;

    Game *game = [sPersistentGames objectForKey: uuid];

    if( game ) {

        if( ![type isEqualToString: [[game class] identifier]] )

            return nil;

    } else if( turn == 1 ) {

        Class gameClass = NSClassFromString( [type stringByAppendingString: @"Game"] );

        if( ! gameClass || ! [gameClass isSubclassOfClass: [Game class]] )

            return nil;

        game = [[gameClass alloc] initWithUniqueID: uuid];

        [game setNumberOfPlayers: 2];

        if( ! sPersistentGames )

            sPersistentGames = [[NSMutableDictionary alloc] init];

        [sPersistentGames setObject: game forKey: uuid];

        [game release];

    }

    return game;

}

- (BOOL) addMoveFromURL: (NSURL*)url

{

    NSDictionary *fields = parseURLFields(url);

    NSString *uuid = [fields objectForKey: @"id"];

    NSString *move = [fields objectForKey: @"move"];

    int turn = [[fields objectForKey: @"turn"] intValue];

    return [uuid isEqualToString: self.uniqueID]

        && turn==self.currentTurn

        && move.length > 0

        && [self applyMoveString: move];

}

@end

static NSDictionary* parseURLFields( NSURL* url )

{

    // Parse the URL into key-value pairs:

    NSMutableDictionary *fields = [NSMutableDictionary dictionary];

    for( NSString *field in [url.resourceSpecifier componentsSeparatedByString: @"&"] ) {

        NSRange e = [field rangeOfString: @"="];

        NSString *key, *value;

        if( e.length>0 ) {

            key = [field substringToIndex: e.location];

            value = [field substringFromIndex: NSMaxRange(e)];

        } else {

            key= field;

            value = @"";

        }

        [fields setObject: value forKey: key];

    }

    return fields;

}