///
/// Copyright (c) 2017-2018 Sensus Slovensko a.s.
///
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace Config
{
    public static class Utils
    {
        public static string SignificantDigitsToFmt(double value, int sigDigits)
        {
            if (sigDigits == 6)
            {
                if (value >= 99999.5 || value < -99999.5) return "F0";
                else if (value >= 9999.95 || value < -9999.95) return "F1";
                else if (value >= 999.995 || value < -999.995) return "F2";
                else if (value >= 99.9995 || value < -99.9995) return "F3";
                else if (value >= 9.99995 || value < -9.99995) return "F4";
                else if (value >= 0.999995 || value < -0.999995) return "F5";
                else if (value >= 0.0999995 || value < -0.0999995) return "F6";
                else if (value >= 0.00999995 || value < -0.00999995) return "F7";
                else if (value >= 0.000999995 || value < -0.000999995) return "F8";
                else if (value >= 0.0000999995 || value < -0.0000999995) return "F9";
                else return "F10";
            }
            else if (sigDigits == 5)
            {
                if (value >= 9999.5 || value < -9999.5) return "F0";
                else if (value >= 999.95 || value < -999.95) return "F1";
                else if (value >= 99.995 || value < -99.995) return "F2";
                else if (value >= 9.9995 || value < -9.9995) return "F3";
                else if (value >= 0.99995 || value < -0.99995) return "F4";
                else if (value >= 0.099995 || value < -0.099995) return "F5";
                else if (value >= 0.0099995 || value < -0.0099995) return "F6";
                else if (value >= 0.00099995 || value < -0.00099995) return "F7";
                else if (value >= 0.000099995 || value < -0.000099995) return "F8";
                else return "F9";
            }
            else if (sigDigits == 4)
            {
                if (value >= 999.5 || value < -999.5) return "F0";
                else if (value >= 99.95 || value < -99.95) return "F1";
                else if (value >= 9.995 || value < -9.995) return "F2";
                else if (value >= 0.9995 || value < -0.9995) return "F3";
                else if (value >= 0.09995 || value < -0.09995) return "F4";
                else if (value >= 0.009995 || value < -0.009995) return "F5";
                else if (value >= 0.0009995 || value < -0.0009995) return "F6";
                else if (value >= 0.00009995 || value < -0.00009995) return "F7";
                else return "F8";
            }
            else if (sigDigits == 3)
            {
                if (value >= 99.5 || value < -99.5) return "F0";
                else if (value >= 9.95 || value < -9.95) return "F1";
                else if (value >= 0.995 || value < -0.995) return "F2";
                else if (value >= 0.0995 || value < -0.0995) return "F3";
                else if (value >= 0.00995 || value < -0.00995) return "F4";
                else if (value >= 0.000995 || value < -0.000995) return "F5";
                else if (value >= 0.0000995 || value < -0.0000995) return "F6";
                else return "F7";
            }
            else if (sigDigits == 2)
            {
                if (value >= 9.5 || value < -9.5) return "F0";
                else if (value >= 0.95 || value < -0.95) return "F1";
                else if (value >= 0.095 || value < -0.095) return "F2";
                else if (value >= 0.0095 || value < -0.0095) return "F3";
                else if (value >= 0.00095 || value < -0.00095) return "F4";
                else if (value >= 0.000095 || value < -0.000095) return "F5";
                else return "F6";
            }
            else /// if (sigDigits == 1)
            {
                if (value >= 0.95 || value < -0.95) return "F0";
                else if (value >= 0.095 || value < -0.095) return "F1";
                else if (value >= 0.0095 || value < -0.0095) return "F2";
                else if (value >= 0.00095 || value < -0.00095) return "F3";
                else if (value >= 0.000095 || value < -0.000095) return "F4";
                else return "F5";
            }
        }


        /// <summary>
        /// Extract and return a DB server from a MySQL connection string.
        /// </summary>
        public static string GetDBServer(string connectionString)
        {
            return GetFromConnectionString(connectionString, new string[] { "SERVER=" });
        }

        /// <summary>
        /// Extract and return a DB name from a MySQL connection string.
        /// </summary>
        public static string GetDBName(string connectionString)
        {
            return GetFromConnectionString(connectionString, new string[] { "DATABASE=" });
        }

        /// <summary>
        /// Extract and return a username from a MySQL connection string
        /// </summary>
        public static string GetDBUser(string connectionString)
        {
            return GetFromConnectionString(connectionString, new string[] { "USER=", "UID=" });
        }

        /// <summary>
        /// Extract and return a password from a MySQL connection string
        /// </summary>
        public static string GetDBPassword(string connectionString)
        {
            return GetFromConnectionString(connectionString, new string[] { "PASSWORD=", "PWD=" });
        }

        /// <summary>
        /// Extract and return an element of a MySQL connection string
        /// (a host, a database, a user name or a password).
        /// Return an empty string on any error.
        /// </summary>
        public static string GetFromConnectionString(string connectionString, string[] patterns)
        {
            foreach (var pattern in patterns)
            {
                int startIx = connectionString.IndexOf(pattern);
                if (startIx >= 0)
                {
                    /// pattern found, extract the subsequent element
                    startIx += pattern.Length;
                    int endIx = connectionString.IndexOf(';', startIx);
                    return (endIx > 0) ? connectionString.Substring(startIx, endIx - startIx) : string.Empty;
                }
            }

            /// pattern NOT found
            return string.Empty;
        }
    }
}