(function() {
"use strict";

var PredatorSystem = function() {
    this.initialize();
}
var p = PredatorSystem.prototype = new creatine.System();

    p.initialize = function() {

    }

    p.process = function(wolfs, fdelta) {
        for (var i=0; i<wolfs.length; i++) {
            var wolf = wolfs[i];
            var predator = wolf.getComponent('Predator');

            // console.log('wolf!');
            if (predator.state == PREDATOR_STATE_FLEEING)
                this._fleeing(wolf);
            else if (predator.state == PREDATOR_STATE_FOLLOWTARGET)
                this._followTarget(wolf, fdelta);
            else if (predator.state == PREDATOR_STATE_WAITING)
                this._seekTarget(wolf);
        }
    }

    p._followTarget = function(wolf, fdelta) {
        var predator = wolf.getComponent('Predator');
        var target = predator.target;

        if (target.getComponent('Flock').dead) {
            predator.target = null;
            predator.state = PREDATOR_STATE_WAITING;
        }

        var dx = (target.display.x - wolf.display.x);
        var dy = (target.display.y - wolf.display.y);
        var norm = norm2d(dx, dy);

        dx = dx/norm;
        dy = dy/norm;

        wolf.display.rotation =  Math.atan2(dy, dx)*(180/Math.PI);
        wolf.display.x += dx*WOLF_SPEED*fdelta;
        wolf.display.y += dy*WOLF_SPEED*fdelta;
    }
    p._seekTarget = function(wolf) {
        var boids = registry.sheepEntities;
        for (var i=0; i<boids.length; i++) {
            var b = boids[i];
            var d = dist(b.display.x, b.display.y, wolf.display.x, wolf.display.y);

            if (d < WOLF_PERCEPTION_AREA) {
                var predator = wolf.getComponent('Predator');
                predator.target = b;
                predator.state = PREDATOR_STATE_FOLLOWTARGET;
            }
        }
    }
    p._fleeing = function(predator) {

    }

window.PredatorSystem = PredatorSystem;

})();