how to implement a reverse countdown and then call a method - iphone

Question

I am developing a 2d game in which on my game screen I have to implement a reverse timer from 30 sec till 0 sec and if a player does not move his character he will win otherwise he will lose and the game will be over.
This is my init method:
-(id)init
{
if(self==[super init])
{
self.isTouchEnabled=YES;
self.isAccelerometerEnabled=YES;
CGSize size=[[CCDirector sharedDirector] winSize];
screenwidth=size.width;
screenheight=size.height;
west_pic=[CCSprite spriteWithFile:#"west_pic.png"];
west_pic.anchorPoint=ccp(1, 1);
west_pic.scaleX=1.4;
west_pic.position=ccp(size.width, size.height);
[self addChild:west_pic];
label1=[CCLabelTTF labelWithString:#"Level One" fontName:#"Arial" fontSize:20];
label1.position=ccp(size.width/3.8,size.height/1.2);
[self addChild:label1];
label2=[CCLabelTTF labelWithString:#"Lives :" fontName:#"ArcadeClassic" fontSize:18];
label2.position=ccp(size.width/1.5,size.height/8.2);
[self addChild:label2];
player=[CCSprite spriteWithFile:#"player.png"];
player.position=ccp(size.width/1.7, size.height/2);
player.scale=0.2;
player.tag=2;
player.anchorPoint=ccp(1, 0);
[self addChild:player];
[self schedule:#selector(updateplayer:) interval:1.0f/60.0f];
}
return self;
}

Answer 1

for example, you can have an instance with number of seconds, that player must not to move character, then you must have ssome event methods to know when the character begins and stops movement, create updatable label(if you want to show the rest of the time to player) and schedule timer, which will decrease number of seconds. smth like this
- (void) onEnter
{
[super onEnter];
// if player character not move on start
[self schedule:#selector(reduceRestTime) interval:1.f];
}
- (void) onExit
{
[self unscheduleAllSelectors];
[super onExit];
}
- (void) onCharacterStop
{
m_restTime = // your time left. in your case, 30 sec
// if you have time label
[self updateRestTimeLabel];
[self schedule:#selector(reduceRestTime) interval:1.f];
}
- (void) onCharacterBeginMovement
{
[self unscheduleSelector:#selector(reduceRestTime)];
}
- (void) reduceRestTime
{
m_restTime--;
// if you have time label
[self updateRestTimeLabel];
if( m_timeLeft == 0 )
{
[self unscheduleSelector:#selector(reduceRestTime)];
// your win code
}
}
- (void) updateRestTimeLabel
{
[m_timeLabel setString:[NSString stringWithFormat:#"Time left: %d", m_timeLeft]];
}