// Script that puts a window on-screen where the player can toggle who he controls
// It works by sending SetControllable messages to turn the different characters on and off.
// It also changes who the CameraScrolling scripts looks at.

// An internal reference to the attached CameraScrolling script
private var cameraScrolling : CameraScrolling;

// Who is the player controlling
private var selected = 0;

// List of objects to control
var targets : Transform[];

// What to display on the buttons in the window
var targetButtonNames : String[];


// On start up, we send the SetControllable () message to turn the different players on and off.
function Awake () {

	// Get the reference to our CameraScrolling script attached to this camera;
	cameraScrolling = GetComponent (CameraScrolling);
	
	// Set the scrolling camera's target to be our character at the start.
	cameraScrolling.SetTarget (targets[0], true);
	
	// tell all targets (except the first one) to switch off.
	for (var i=0; i < targets.Length; i++) 
		targets[i].gameObject.SendMessage ("SetControllable", (i == 0), SendMessageOptions.DontRequireReceiver);
}

private var windowRect = Rect (20, 20, 250, 50);
// Make the onscreen GUI to let the player switch control between Lerpz and the spaceship.
function OnGUI () {
	// Make a popup window
	windowRect = GUILayout.Window (0, windowRect, DoControlsWindow, "Controls");
	
	// The window can be dragged around by the users - make sure that it doesn't go offscreen.
	windowRect.x = Mathf.Clamp (windowRect.x, 0.0, Screen.width - windowRect.width);
	windowRect.y = Mathf.Clamp (windowRect.y, 0.0, Screen.height - windowRect.height);
}

// Make the contents of the window
function DoControlsWindow (windowID : int) {
	// Make the window be draggable in the top 20 pixels.
	GUI.DragWindow (Rect (0,0, System.Decimal.MaxValue, 20));
	
	GUILayout.Label ("Select a character...");

	// Let the player select the character
	selected = GUILayout.Toolbar (selected, targetButtonNames);

	// If the user has selected a new character, we'll send new SetControllable messages to turn on the other character. 
	// Then we'll change who the CameraScrolling script is tracking.
	if (GUI.changed && targets[selected] != cameraScrolling.GetTarget ()) {
		targets[selected].gameObject.SendMessage ("SetControllable", true, SendMessageOptions.DontRequireReceiver);
		cameraScrolling.GetTarget ().gameObject.SendMessage ("SetControllable", false, SendMessageOptions.DontRequireReceiver);
		cameraScrolling.SetTarget (targets[selected]);
	}
	
	// Show a different instruction label depending on what was selected above.
	switch (selected) {
		case 0:
			GUILayout.Label ("Instructions:\nUse the left and right arrow keys to move and space bar to jump.  To run, hold down the control key.");
		break;
		case 1:
			GUILayout.Label ("Instructions:\nUse the left and right arrow keys to rotate and the up arrow to thrust.");
		break;
	}
}

// Ensure there is a CameraScrolling script attached to the same GameObject, as this script
// relies on it.
@script RequireComponent (CameraScrolling)