using System;
using System.Collections.Generic;
using System.Text;

namespace MisIngredientesVue.Core.Extensions
{
    public static class DecimalExtensions
    {
        public static string NumberToWords(int number)
        {
            if (number == 0)
                return "CERO";

            if (number < 0)
                return "MENOS " + NumberToWords(Math.Abs(number));

            string words = "";

            if ((number / 1000000) > 0)
            {
                if (number >= 2000000)
                    words += NumberToWords(number / 1000000) + " MILLONES ";
                else
                    words += NumberToWords(number / 1000000) + " MILLÓN ";
                number %= 1000000;
            }

            if ((number / 1000) > 0)
            {
                var thousands = NumberToWords(number / 1000) + " MIL ";
                if (thousands.StartsWith("UN MIL")) thousands = "MIL ";
                words += thousands;
                number %= 1000;
            }

            if ((number / 100) > 0)
            {
                var hundreds = "";
                if (number == 100) hundreds = "CIEN ";
                else if (number > 100 && number < 200) hundreds = "CIENTO ";
                else if (number >= 500 && number < 600) hundreds = "QUINIENTOS ";
                else if (number >= 700 && number < 800) hundreds = "SETECIENTOS ";
                else if (number >= 900 && number < 1000) hundreds = "NOVECIENTOS ";
                else hundreds = NumberToWords(number / 100) + "CIENTOS ";

                words += hundreds;

                number %= 100;
            }

            if (number > 0)
            {
                if (words != "" && !words.EndsWith("CIENTO ") &&
                    !words.EndsWith("IENTOS ") && !words.EndsWith("MIL ") &&
                    !words.EndsWith("MILLÓN ") && !words.EndsWith("MILLONES "))
                    words += "Y ";

                var unitsMap = new[] { "CERO", "UN", "DOS", "TRES", "CUATRO", "CINCO", "SEIS", "SIETE", "OCHO", "NUEVE", "DIEZ", "ONCE", "DOCE", "TRECE", "CATORCE", "QUINCE", "DIECISÉIS", "DIECISIETE", "DIECIOCHO", "DIECINUEVE", "VEINTE", "VEINTIÚN", "VEINTIDÓS", "VEINTITRÉS", "VEINTICUATRO", "VEINTICINCO", "VEINTISÉIS", "VEINTISIETE", "VEINTIOCHO", "VEINTINUEVE" };
                var tensMap = new[] { "CERO", "DIEZ", "VEINTE", "TREINTA", "CUARENTA", "CINCUENTA", "SESENTA", "SETENTA", "OCHENTA", "NOVENTA" };

                if (number < 30)
                    words += unitsMap[number];
                else
                {
                    words += tensMap[number / 10];
                    if ((number % 10) > 0)
                        words += " Y " + unitsMap[number % 10];
                }
            }

            return words;
        }

        public static string CurrencyToWords(this decimal c)
        {
            var cs = "" + c;
            if (!cs.Contains("."))
                return NumberToWords((int)c).Trim() + " 00/100";
            else
            {
                var dec = cs.Split('.')[1];
                if (dec.Length == 1) dec += "0";
                if (dec.Length > 2) dec = dec.Substring(0, 2);
                return NumberToWords(Convert.ToInt32(cs.Split('.')[0])) + " " + dec.PadLeft(2, '0') + "/100";
            }
        }
    }
}