"use strict";
var md5 = require('md5');
// var mysql = require('../connectors/mysql').client();

class DictionaryCatModel {

	/**
	 * Constructor
	 * @param  {object} conn db connection from db pool.
	 * @param  {Object} data values for table fields.
	 *                       At least on of `title` or `id` must be set.
	 */
	constructor(conn, data) {
		this.data = data;
		this.conn = conn;
	}

	field(key, value) {
		if(arguments.length==0) return;
		if(arguments.length==1)
			return this.data[key];
		
		if(value===undefined)
			delete this.data[key];
		else
			this.data[key] = value;
	}

	fields(){

		return this.data;
	}

	save() {
		if(this.data.hasOwnProperty('id')) return this.update();
		else return this.add();
	}

	update() {
		var self = this;
		return new Promise(function(resolve, reject){
			if(!self.data.hasOwnProperty('id') || !self.data.hasOwnProperty('title'))
				return reject('id and title are required.');

			self.conn.query(`SELECT * FROM source_cat WHERE ?`, {id: self.data.id}, function(err, rows, fields){
				if(err) return reject('db error.');
				if(!rows.length) return reject('entry '+self.data.id+' not found.');

				self.conn.query("UPDATE source_cat SET ? where ?", [{title: self.data.title}, {id: self.data.id}], function(err, result){
					if(err) return reject('db error.');
					resolve(self);
				})
			});
		});
	}

	add() {
		var self = this;
		return new Promise(function(resolve, reject){
			if(!self.data.hasOwnProperty('title'))
				return reject('title is required.');

			self.conn.query(`SELECT * FROM source_cat WHERE ?`, {title: self.data.title}, function(err, rows, fields){
				if(err) return reject('db error.');
				if(rows.length) return reject('duplicate entry.');

				self.conn.query(`INSERT INTO source_cat SET ?`, {title: self.data.title}, function(err, result){
					if(err) return reject('db error.');
					self.data.id = result.insertId;
					resolve(self);
				})
			});
		});
	}

	load() {
		var self = this;
		return new Promise(function(resolve, reject){
			if(self.data.hasOwnProperty('id')) {
				self.conn.query(`SELECT * FROM source_cat WHERE ?`, {id: self.data.id}, function(err, rows, fields){
					if (err) return reject(err.message);
					if(rows.length) {
						self.data = rows[0];
						resolve(self);
					}else
						resolve(false);
				});
			}else
			if(self.data.hasOwnProperty('title')) {
				self.conn.query(`SELECT * FROM source_cat WHERE ?`, {title: self.data.title}, function(err, rows, fields){
					if (err) return reject(err.message);
					if(rows.length) {
						self.data = rows[0];
						resolve(self);
					}else
						resolve(false);
				});
			}else {
				reject('At least on of the id and title fields must be provided.');
				return;
			}
		});
	}

	remove() {
		var self = this;
		return new Promise(function(resolve, reject){
			if(!self.data.hasOwnProperty('id')) return reject('id is required.');
			self.conn.query(`DELETE FROM source_cat WHERE ?`, {id: self.data.id}, function(err, rows, fields){
				if(err) return reject(err.message);
				resolve(self);
			});
		});
	}

	unrelateAllDictionaries() {

	}

	static list(conn) {
		return new Promise(function(resolve, reject){
			conn.query(`SELECT * FROM source_cat`, function(err, rows, fields){
				if (err) return reject(err.message);
				resolve(rows);
			});
		});
	}
}

module.exports = DictionaryCatModel;