var Q = require('q')
  , _ = require('underscore')
  , validator = require('../util/validator')
  , CouchDB = require('../util/couch').CouchDB
  ;

var schema = require('./couchdb-schema');

module.exports = function(couchServerURL,dbName) {
    var server = new CouchDB(couchServerURL,dbName);
    var designRe = /^_design\//;

    var codes = {};
    function codeUnique(code) {
        if ( code in codes ) {
            return false;
        } else {
            codes[code] = true;
            return true;
        }
    }

    return server.get('/_all_docs')
    .then(function(allDocs){
        return _.chain(allDocs.rows)
        .filter(function(doc){
            return doc.id.match(designRe) === null;
        })
        .reduce(function(memo, doc){
            return memo.then(function(result){
                return server.get(doc.id)
                .then(function(doc){
                    var valid = validator(doc,schema);
                    if ( doc.type === "Question" && !codeUnique(doc.code) ) {
                        valid.valid = false;
                        valid.error = "Question code "+doc.code+" is not unique.";
                    }
                    result[doc._id] = valid;
                    return result;
                });
            });
        }, Q.resolve({}))
        .value();
    }).all();
};