//

 //  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;

 }