var state = require('st8');

//a target component to apply properties (usually a class instance)
var target = {
    a: 1,
    b: 2
};

//apply stateful behaviour to the target
state(target, {
    a: {
        //called once on init
        init: function(value){
            //value === 1
            return value;
        },
        //called any time `a` has changed
        changed: function(v){
            assert.equal(v, 2);
        }
    },

    b: {
        //for any value of `b` (`_` wildcard) — use a setter for `a`
        _: {
            a: {
                set: function(v){
                    assert.equal(v,1)
                    return 2;
                }
            }
        }
    }
});

assert.equal(target.a, 2);

state(target, {
    //define plain property
    myProperty: 1,

    //define method
    myMethod: function(){},

    //define stateful property
    mySpecialProperty: {
        /**
         * Property hooks
         */

        //called once on init
        init: function(initValue){
            //go to state 1
            return 1;
        },

        //getter - called on each get
        get: function(value){
            return value * 5
        },

        //setter - called on each set
        set: function(value, oldValue){
            if (value < 20) return oldValue;

            //returned value is used as a new value
            return value / 5;
        },

        //called on each change
        changed: function(value, oldValue){
            this.updateSomething();
        },


        /**
         * State values
         * Each key corresponds to the value of the property
         */

        //applied when mySpecialProperty === 1
        1: {
            //called on entering state
            before: function(){},

            //called on leaving state
            after: function(){},

            //redefine base things
            myMethod: function(){},
            myProperty: 2
        },

        //state 3 & 4 shortcut - go to the state 1
        '3,4': 1,

        //any other state wildcard
        _: function(){
            //go back to 1
            return 1;
        }
    },


    /**
     * Events
     * Declared along with properties.
     * Enot is used for events: https://github.com/dfcreative/enot
     */

    //accessing `this.*` properties for binding events
    '@parentNode click, @div mouseenter': function(){},

    //only elements with `.item` or `.other-item` classes trigger this callback
    ':root click:delegate(.item, .other-item)': function(){},

    //only right mouse button triggers this callback
    'click:pass(right_mouse)': function(){},

    //only keys from the subset triggers this callback
    'keypress:pass(12,13,14,15)': function(){},

    //callback is triggered once
    'someEvent:one': function(){},

    //combined modifier
    'keypress:pass(escape, enter):one': function(){},

    //call after 200 ms
    'switch:defer(200)': function(){},

    //call no more than 1 per 20ms
    'update:throttle(20)': function(){},

    //redirect to other events
    'a': '@firstChild click, document specialEvent'
});