var chunk_size = 2;

function randomInt(min, max) {
    return Math.floor(Math.random()*(max-min+1)) + min;
}

function analyze(input, chunk_size) {
    var num = input.length;
    var i;
    var j;
    var c;
    var p;
    var cur;
    var len;
    var stats = {};

    for (i = 0; i < num; i++) {
        cur = input[i];
        len = cur.length;
        if (len <= chunk_size)
            continue;
        p = c = "\0";
        
        for (j = 0; j <= len; j++) {
            if (j - chunk_size >= 0)
                p = cur.substr(j-chunk_size, chunk_size);
            else if (j != 0)
                continue;
            c = cur.substr(j, chunk_size);
            if (typeof(stats[p]) == 'undefined')
                stats[p] = {total:0, options: {}};
            if (typeof(stats[p].options[c]) == 'undefined')
                stats[p].options[c] = 0;
            stats[p].total++;
            stats[p].options[c]++;
        }
    }

    return stats;
}

function generate(stats, chunk_size) {
    var c = "\0";
    var ret = "";
    var r;
    var i;
    var options;
    while (typeof(stats[c]) != 'undefined') {
        r = randomInt(1, stats[c].total);
        options = stats[c].options;
        for (i in options) {
            r -= options[i];
            if (r <= 0) {
                if (i != "\n" && i != '') {
                    ret += i;
                    c = ret.substr(-chunk_size, chunk_size);
                }
                else
                    c = "\n";
                break;
            }
        }
    }

    return ret;
}


new Behavior.Class('Wordomatic', {
    context: ".wordomatic",
    events: {
        'submit': {
            'form': 'saveInput'
        },
        'click': {
            '.show-source':'clickShowSource',
            '.hide-source':'clickHideSource',
            '.save':'clickSave',
            '.generate':'clickGenerate'
        }
    },
    initialize: function() {
        this.generate(this.context.down('form'));
        this.context.down('form').onsubmit = null;
        this.defaultTitle = $F(this.context.down('.save-form input'));
        this.context.down('.save-form input').observe('focus', this.focusTitle.bind(this));
        this.context.down('.save-form input').observe('blur', this.blurTitle.bind(this));
    },
    clickShowSource: function(evt) {
        evt.stop();
        this.context.select('div.input,button.save').invoke('show');
        this.context.select('.show-source').invoke('hide');
        this.context.select('.hide-source').invoke('show');
    },
    clickHideSource: function(evt) {
        evt.stop();
        this.context.select('div.input,button.save,div.save-form').invoke('hide');
        this.context.select('.hide-source').invoke('hide');
        this.context.select('.show-source').invoke('show');
    },
    clickSave: function(evt) {
        evt.stop();
        evt.element().up('form').down('.save-form').show();
    },
    focusTitle: function(evt) {
        var el = evt.element();
        if (el.hasClassName('default')) {
            el.removeClassName('default');
            el.value = '';
        }
    },
    blurTitle: function(evt) {
        var el = evt.element();
        if ($F(el).strip() == '') {
            el.value = this.defaultTitle;
            el.addClassName('default');
        }
    },
    saveInput: function(evt) {
        var el = evt.element();
        var input = el.down('textarea.input');
        var title = el.down('input.title');
        if ($F(input).strip() == '') {
            this.error('Please enter some input text before saving.');
            evt.stop();
        }
        else if (title.hasClassName('default') || $F(title).strip() == '') {
            this.error('Please enter a title');
            evt.stop();
        }
    },
    error: function(message) {
        this.context.down('ul.errors').insert({bottom:'<li>'+message+'</li>'});
    },
    clickGenerate: function(evt) {
        evt.stop();
        this.generate(evt.element().up('form'));
    },
    generate: function(form) {
        var input = $F(form.down('textarea.input')).replace(/\W|_/g, ' ').replace(/\s+/g, ' ').split(' ');
        var stats = analyze(input, chunk_size);
        var word = "";
        var i;
        //words shorter than 4 characters tend to suck, so lets try to generate longer words if we can
        for (i = 0; i < 10 && (word.length < 4 || word.length > 15 || input.include(word)); i++)
            word = generate(stats, chunk_size);
        if (word) {
            var result = this.context.down('.results .result');
            if (result.hasClassName('none'))
                result.removeClassName('none');
            else {
                var prev = this.context.down('.results .previous-words ul');
                while (prev.childElements().length >= 5) {
                    prev.childElements()[prev.childElements().length-1].remove();
                }
                prev.insert({top: '<li>'+result.innerHTML+'</li>'});
                prev.up().show();
            }
            result.innerHTML = word.capitalize();
        }
    }
});