/*
Welcome to the tutorial!!!

This file is full of helpful comments to walk you through acheiving your mission.

Below is your AI function.  At the bottom of thie file there is more detail on
exactly what that means.
*/

Game.IntroPlayerAI = function(units, waypoints) {

  //First lets define some variables

   var i;  //iterator for loops
   var ourShip;  //the ship we are controlling
   var nextDestination;  //where our ship is moving to next
   var moveInstruction;  //the instruction that tells our ship to move there
   var target;           //the target for our ship to attack when it is ready
   var attackInstruction; //the instruction telling it to attack

  // Next lets write a few helper functions...

  /* This function finds our ship.
     We only have 1 ship so its pretty simple.
     The units array contains all ships so we just loop through that array and
     find the first ship that isn't an enemy ship. */
  function getOurShip(units) {
    //loop through the array of units
    for ( i = 0; i < units.length; i++) {
      //check if its an enemy ship
      if (units[i].isEnemy === false) {
        return units[i];  //if its not return it
      }
    }
  };

  //This function finds an enemy ship using the exact same approach
  function getNextEnemy(units) {
    //loop through the array of units
    for (i = 0; i < units.length; i++) {
      //check if it is an enemy ship
      if(units[i].isEnemy) {
        return units[i];  //if it is return it.
      }
    }
    return 'none'; // if we don't find an enemy return none;
  };

  //This function loops through the waypoints and finds the first waypoint
  //that we have not reached
  function getNextWayPoint(waypoints) {
    //go through the way points
    for(var i = 0; i < waypoints.length; i++) {
      //if we find one we haven't reached, return it
      if(!waypoints[i].reached) {
        return waypoints[i];
      }
    }
    return 'none'; // if we don't find a waypoint return none;
  };

  //That's most of the hard work :)  Now we just have to use our helper
  //functions

	// Now that we've taken care of the way points lets add some code
  // to deal with our enemies...  The idea is exactly the same.
  // but you'll have to do some of the work yourself :)

  //Step 1: add code to use your getNextEnemy helper function to get
  //        the next enemy (hint nextEnemy = getNextEnemy(units);)
  var nextEnemy = getNextEnemy(units);


  //Step 2:  if the next enemy is not equal to 'none' create an
  //         attack instruction to attack it and issue the command.
  //         example code for those two lines is commented out below.
  if (nextEnemy != 'none') {
    attackInstruction = new AttackInstruction(nextEnemy);
    return [new Command(ourShip, [attackInstruction])];
  }

 /*   Code to create an AttackInstruction to attack the nextEnemy and to
      send that instruction as a Command to our ship.

      attackInstruction = new AttackInstruction(nextEnemy);
      return [new Command(ourShip, [attackInstruction])];
 */

  ourShip = getOurShip(units);  //get our ship
  nextDestination = getNextWayPoint(waypoints);  //get the next waypoint


  //Okay if we have a destination lets go there...
  if(nextDestination !== 'none') {

    //To go to the waypoint we want a move instruction.
    moveInstruction = new MoveInstruction(nextDestination);

    //A command takes a list of instructions and assigns
    //them to a particular ship.  To make our ship fly to the first way point
    //We need to issue it a command with our move instruction and return it
    //like so.  Just uncomment the line below and then click begin battle
    //and watch your ship go.

    return [new Command(ourShip, [moveInstruction])];
  }


};

/*

DETAILS ON HOW YOUR AI FUNCTION WORKS:

Each tick the game will call your AI function with a list of the units that are alive in the game and a list of waypoints.  Your job is to take that data and return an array of Commands that tell your ship(s) what to do.  If you do not return a command for a specific ship it will continue executing whatever instructions it received previously until they are all completed at which point it will just wait for additional commands.
*/