/* This class represents a TV which has the ability to generate a picture-in-picture (pip).  The class will remember its current channel and volume,
 *   have a max number of channels, a max volume of 100, and if pip capable, then whether pip is on or off and if on, the channel and the location
 *   of the picture in picture (location is a number from 0-3 to represent UL, UR, LR, LL).  The instance data startChannel and lastVolume are used
 *   to indicate what channel and volume the TV is set to upon being turned on and on is used to indicate whether the tv is on or off. */

public class TV
{
					// maxChannels - maximum channel, assumed to be 99 if not specified
					// channel - current channel, set to 1 initially but if startChannel is establisehd, then the startChannel is used every time the tv is turned on
					// volume - set to 0 initially, is set to lastVolume every time the tv is turned on thereafter
					// channel2 - the pip channel if on
					// location - the quadrant of the screen that the pip is displayed if on
					// pipCapable - can the TV do pip?
					// pipOn - whether pip is on or off (if pipCapable)
					// on - whether the tv is on or off, all TVs start with the tv off
	
	private int maxChannels, channel, volume, startChannel, channel2, location, lastVolume;
	private boolean pipCapable, pipOn, on;
	
	// 3 constructors, a no-arg, a 1-arg where we are given the maximum number of channels, and a 2-arg where we are given the max channels and pipCapable, everything
	// else is set to "manufacturer values" (channel 1, volume 0, startChannel 1, pipOn and on are false)
	public TV() {
		maxChannels = 99; channel = 1; volume = 0; startChannel = 1; channel2 = -1; location = -1; lastVolume = 0; pipCapable = false; pipOn = false; on = false;
	}
	
	public TV(int m) {
		maxChannels = m; channel = 1; volume = 0; startChannel = 1; channel2 = -1; location = -1; lastVolume = 0; pipCapable = false; pipOn = false; on = false;
	}

	public TV(int m, boolean p) {
		maxChannels = m; channel = 1; volume = 0; startChannel = 1; channel2 = -1; location = -1; lastVolume = 0; pipCapable = p; pipOn = false; on = false;
	}	
		
	// mutator to change the channel as long as the new channel is within bounds
	public void setChannel(int c)
	{
		if(c<=maxChannels&&c>0) channel = c;
	}
	
	// program the TV to have a new start channel rather than the default of 1
	public void setStartChannel(int c)
	{
		if(c>0&&c<=maxChannels) startChannel = c;
	}
	
	// mutator to change the volume as long as the new volume is within bounds
	public void setVolume(int v)
	{
		if(v>=0&&v<=100) volume = v;
	}
	
	// increase the channel by 1, if you reach maxChannels, rotate around back to channel 1
	public void incChannel() 
	{
		if(channel<maxChannels) channel++;
		else channel = 1;
	}

	// decrease the channel by 1, if you reach 0, rotate around back to maxChannels
	public void decChannel() 
	{
		if(channel>1) channel--;
		else channel=maxChannels;
	}
	
	// increase the volume by 1, max at 100
	public void incVolume()
	{
		if(volume<100) volume++;
	}

	// decrease the volume by 1, min at 0
	public void decVolume()
	{
		if(volume>0) volume--;
	}	
	
	// if pipCapable, turn on pip establishing the channel as the same as the larger screen's channel, and its location in the UL (0)
	public void turnOnPip() {
		if(pipCapable&&!pipOn)
		{
			pipOn = true;
			channel2 = channel;
			location = 0;
		}
	}
	
	// turn pip off (note that we don't bother to check for pipCapable, not really needed)
	public void turnOffPip() {
		pipOn = false;
	}
	
	// if pip is on, rotate the location by 1, wrapping back to UL upon a full rotation
	public void moveLocation() {
		if(pipOn) location++;
		if(location>3) location = 0;
	}
	
	// change the pip channel as long as pip is on and the new channel is in bounds
	public void changePipChannel(int c)
	{
		if(pipOn&&c<=maxChannels&&c>0) channel2 = c;
	}
	
	// turn the TV on or off
	public void onOff()
	{
		if(on) 							// if on, TV turned off, reset channels, save last volume so that the next time we turn on the TV, it starts at the new volume
		{
			on = false;
			channel = channel2 = 1;
			lastVolume = volume;
			volume = 1;
			pipOn = false;
		}
		else {							// turn TV on, set channel to startChannel and set volume to the last volume before it was turned off, keep pip off
			on = true;
			channel = startChannel;
			volume = lastVolume;
			pipOn = false;
		}
	}
	
	public String toString()				// If the TV is on, output info about what the TV is doing now including if pip is on, if off, output "OFF"
	{
		if(!on) return "OFF";
		else {
			String temp = "Current channel: " + channel + "\nCurrent volume: " + volume;
			if(pipOn)
			{
				temp += "\nPicture in Picture on\n   Channel: " + channel2 + " at location " + (location+1);
			}
			return temp;
		}
	}
}