require([
         'dojo/_base/json',
         'dojo/_base/lang',
         'dojo/_base/xhr',
         'dojo/parser',
         'dojo/query',
         'dijit/registry',
         'dojo/domReady!'
],function(json,lang,xhr,parser,query,registry){
    var logNode;
    var usernameInput, passwordInput, resetInput, configButton;
    var defaultUsername = "", defaultPassword = "";
    var dbUrl = "../data/";

    parser.parse()
    .then(function(){
        query("#log").forEach(function(n){logNode = n;});
        usernameInput = registry.byId('username');
        passwordInput = registry.byId('password');
        resetInput = registry.byId('reset');
        configButton = registry.byId('configure');

        usernameInput.set('value',defaultUsername);
        passwordInput.set('value',defaultPassword);
        configButton.on('click',configure);

        log("Give CouchDB admin username & password and click 'Configure' to start.\nIf the database already exists, rft_admin password will suffice.",true);
    });

    function configure(){
        var docs;

        log("Configuring CouchDB for RFT:",true);

        var username = usernameInput.get('value');
        var password = passwordInput.get('value');
        var reset = resetInput.get('value');

        log("Downloading most recent configuration.");
        xhr('GET',{
            url: 'docs.json',
            handleAs: 'json',
            sync: true
        },true)
        .then(function(result){
            docs = result;
        });

        function req(method,url,body) {
            var args = {
                url: dbUrl+url,
                contentType: 'application/json',
                handleAs: 'json',
                sync: true
            };
            if ( !body || lang.isObject(body) ) {
                body = json.toJson(body || {});
            }
            args.rawBody = body;
            if ( username ) {
                args.user = username;
                args.password = password;
            }
            return xhr(method,args,true);
        }

        log("Checking CouchDB version");
        req('GET','/')
        .then(function(res){
            if (res.version !== "1.2.0" ) {
                log("Found "+res.version+", only tested with CouchDB 1.2.0")
            } else {
                log("CouchDB 1.2.0 found")
            }
        });

        var exists = false;
        log("Checking database 'rft'");
        req('GET','/rft')
        .then(function(db){
            log("Database 'rft' found.")
            exists = true;
        });
        if ( exists && reset ) {
            req('DELETE','/rft');
            exists = false;
        }
        if ( !exists ) {
            log("Creating database 'rft'")
            req('PUT','/rft')
        };

        function processDoc(docUrl,doc){
            var configAction = doc.__configAction;
            delete doc.__configAction;
            switch (configAction) {
                case "ignore":
                    log(docUrl+" ignored.");
                    return false;
                case "update":
                    log(docUrl+" updating.");
                    return req('GET',docUrl)
                    .then(function(oldDoc){
                        lang.mixin(oldDoc,doc);
                        return req('PUT',docUrl,oldDoc);
                    },function(){
                        return req('PUT',docUrl,doc);
                    });
                case "replace":
                default:
                    log(docUrl+" replacing.");
                    return req('GET',docUrl)
                    .then(function(oldDoc){
                        doc['_rev'] = oldDoc['_rev'];
                        return req('PUT',docUrl,doc);
                    },function(){
                        return req('PUT',docUrl,doc);
                    });
            }
        }

        for (var docUrl in docs) {
            processDoc(docUrl,docs[docUrl]);
        }

        log("Done!");
    }

    function log(text,overwrite) {
        if ( overwrite ) logNode.innerHTML = text
        else logNode.innerHTML = logNode.innerHTML + '\n' + text;
    }

});