var HTTPResult = require('../util/http-result')
  , _ = require('underscore')
  , CouchDB = require('../util/couch')
  , util = require('util')
  ;

module.exports = function(couchServerURL, dbName, designDocs) {
    var server = new CouchDB(couchServerURL);

    if ( !designDocs ) { throw new Error("Forgot to pass design docs to checkCouch."); }

    console.log("Configuring CouchDB for QED");
    console.log("Checking CouchDB version");
    return server.get('')
    .then(function(info){
        if (info.version !== "1.4.0" ) {
            console.log("Found "+info.version+", only tested with CouchDB 1.2.0");
        } else {
            console.log("CouchDB 1.4.0 found");
        }
    }).then(function(res){
        console.log("Checking database '"+dbName+"'");
        return server.get(dbName)
        .then(function(db){
            console.log("Database found.");
        },function(err){
            console.log("Creating database.");
            return server.put(dbName);
        });
    }).then(function(){
        console.log("Putting documents in database.");
        return _.reduce(designDocs, function(memo, doc, docUrl) {
            return memo.then(function(){
                var configAction = doc.__configAction || "replace";
                delete doc.__configAction;
                docUrl = dbName+'/'+docUrl;
                switch (configAction) {
                case "ignore":
                    console.log(docUrl+" ignored.");
                    return null;
                case "update":
                    console.log(docUrl+" updating.");
                    return server.get(docUrl)
                    .then(function(oldDoc){
                        _.extend(oldDoc,doc);
                        return server.put(docUrl,oldDoc);
                    },function(){
                        return server.put(docUrl,doc);
                    });
                case "replace":
                    console.log(docUrl+" replacing.");
                    return server.get(docUrl)
                    .then(function(oldDoc){
                        _.extend(doc,_.pick(oldDoc,'_id','_rev'));
                        return server.put(docUrl,doc);
                    },function(){
                        return server.put(docUrl,doc);
                    });
                default:
                    console.warn("Unknown action",configAction);
                    return null;
                }
            });
        }, new HTTPResult(200));
    });
};