var _ = require('underscore')._;

var regex = function(dbot) {
    this.last = {};
    this.listener = function(event) {
        var q = event.message.valMatch(/^([\d\w\s]*)?:? ?s\/(.+)\/(.+)?\/([ig]*)?$/, 5);
        if(q) {
            var flags = q[4],
                toMatch = new RegExp(q[2], flags),
                replaceWith = q[3],
                last,
                replacement,
                user;
                
            if(!replaceWith) replaceWith = "";
            
            user = q[1] || event.user;
            last = this.last[event.channel.name][user];
            replacement = last.replace(toMatch, replaceWith);
            replacement = replacement.replace(/^.ACTION/,  user).replace("\x01", '');
            
            if(replacement != last) {
                if(q[1]) {
                    event.reply(event.user + " thinks " + user + " meant: " + replacement);
                } else {
                    event.reply(event.user + " meant: " + replacement);
                }
            }
        } else {
            if(_.has(this.last, event.channel.name)) {
               this.last[event.channel.name][event.user] = event.message; 
            } else {
                this.last[event.channel.name] = { };
                this.last[event.channel.name][event.user] = event.message;
            }
        }
    }.bind(this);
    this.on = [ 'PRIVMSG' ];
};

exports.fetch = function(dbot) {
    return new regex(dbot);
};