/*
    This file is part of ethereum.js.

    ethereum.js is free software: you can redistribute it and/or modify
    it under the terms of the GNU Lesser General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    ethereum.js is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public License
    along with ethereum.js.  If not, see <http://www.gnu.org/licenses/>.
*/
/**
 * @file property.js
 * @author Fabian Vogelsteller <fabian@frozeman.de>
 * @author Marek Kotewicz <marek@ethdev.com>
 * @date 2015
 */

var RequestManager = require('./requestmanager');
var utils = require('../utils/utils');

var Property = function (options) {
    this.name = options.name;
    this.getter = options.getter;
    this.setter = options.setter;
    this.outputFormatter = options.outputFormatter;
    this.inputFormatter = options.inputFormatter;
};

/**
 * Should be called to format input args of method
 * 
 * @method formatInput
 * @param {Array}
 * @return {Array}
 */
Property.prototype.formatInput = function (arg) {
    return this.inputFormatter ? this.inputFormatter(arg) : arg;
};

/**
 * Should be called to format output(result) of method
 *
 * @method formatOutput
 * @param {Object}
 * @return {Object}
 */
Property.prototype.formatOutput = function (result) {
    return this.outputFormatter && result !== null ? this.outputFormatter(result) : result;
};

/**
 * Should be used to extract callback from array of arguments. Modifies input param
 *
 * @method extractCallback
 * @param {Array} arguments
 * @return {Function|Null} callback, if exists
 */
Property.prototype.extractCallback = function (args) {
    if (utils.isFunction(args[args.length - 1])) {
        return args.pop(); // modify the args array!
    }
};

/**
 * Should attach function to method
 * 
 * @method attachToObject
 * @param {Object}
 * @param {Function}
 */
Property.prototype.attachToObject = function (obj) {
    var proto = {
        get: this.get.bind(this),
    };

    var names = this.name.split('.');
    var name = names[0];
    if (names.length > 1) {
        obj[names[0]] = obj[names[0]] || {};
        obj = obj[names[0]];
        name = names[1];
    }
    
    Object.defineProperty(obj, name, proto);

    var toAsyncName = function (prefix, name) {
        return prefix + name.charAt(0).toUpperCase() + name.slice(1);
    };

    var func = this.getAsync.bind(this);
    func.request = this.request.bind(this);

    obj[toAsyncName('get', name)] = func;
};

/**
 * Should be used to get value of the property
 *
 * @method get
 * @return {Object} value of the property
 */
Property.prototype.get = function () {
    return this.formatOutput(RequestManager.getInstance().send({
        method: this.getter
    }));
};

/**
 * Should be used to asynchrounously get value of property
 *
 * @method getAsync
 * @param {Function}
 */
Property.prototype.getAsync = function (callback) {
    var self = this;
    RequestManager.getInstance().sendAsync({
        method: this.getter
    }, function (err, result) {
        if (err) {
            return callback(err);
        }
        callback(err, self.formatOutput(result));
    });
};

/**
 * Should be called to create pure JSONRPC request which can be used in batch request
 *
 * @method request
 * @param {...} params
 * @return {Object} jsonrpc request
 */
Property.prototype.request = function () {
    var payload = {
        method: this.getter,
        params: [],
        callback: this.extractCallback(Array.prototype.slice.call(arguments))
    };
    payload.format = this.formatOutput.bind(this);
    return payload;
};

module.exports = Property;