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

function CouchDB(url, db) {
    this.serverURL = normalizeURL(url);
    this.db = db;
    if (this.db) {
        this.url = "" + this.serverURL + "/" + this.db;
    } else {
        this.url = "" + this.serverURL;
    }
}

CouchDB.prototype.get = function(id, opts) {
    var url = "" + this.url + "/" + id;
    return couchRequest('GET', url, null, opts);
};

CouchDB.prototype.post = function(doc, opts) {
    var url = "" + this.url + "/";
    return couchRequest('POST', url, doc, opts);
};

CouchDB.prototype.put = function(id, doc, opts) {
    var url = "" + this.url + "/" + id;
    return couchRequest('PUT', url, doc, opts);
};

CouchDB.prototype["delete"] = function(id, opts) {
    var url = "" + this.url + "/" + id;
    return couchRequest('DELETE', url, null, opts);
};

CouchDB.prototype.uuids = function(opts) {
    var url = "" + this.serverURL + "/_uuids";
    return couchRequest('GET', url, null, opts);
};

function normalizeURL(url) {
    return url.replace(/\/$/, '');
}

function couchRequest (method, url, body, opts, retries) {
    body = body || {};
    retries = _.isNumber(retries) ? retries : 3;
    var options = {
        method: method,
        headers: {},
        body: stringifyFunctions(body),
        json: true,
        timeout: 5000
    };
    if (opts) {
        if (opts.query) { options.qs = createQueryObj(opts.query); }
        if (opts.headers) { _.extend(options.headers, opts.headers); }
    }
    return request(url, options)
    .handle(function(status,body){
        if ( _.isUndefined(body) ) {
            if ( retries > 0) {
                return couchRequest(method,url,body,opts,retries-1);
            } else {
                return new HTTPResult(-1,new Error("No response after several retries."));
            }
        } else {
            return body;
        }
    });
}

function createQueryObj (obj) {
    var newObj = {};
    _.each(obj, function(val, key) {
        newObj[key] = JSON.stringify(val);
    });
    return newObj;
}

function stringifyFunctions (value) {
    if (value === null) {
        return null;
    } else if (_.isArray(value)) {
        return value;
    } else if (_.isFunction(value)) {
        return value.toString();
    } else if (_.isObject(value)) {
        value = _.clone(value);
        _.each(value, function(propValue, propName) {
            value[propName] = stringifyFunctions(propValue);
        });
        return value;
    } else {
        return value;
    }
}

module.exports = CouchDB;