using System;
using System.Collections.Generic;
using Microsoft.Data.SqlClient;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace bnhtrade.Core.Data.Database.Log
{
    public class DateTimeLog : Connection
    {
        public DateTimeLog()
        {
        }

        /// <summary>
        /// Gets the Date and Time by a unique string.
        /// </summary>
        /// <param name="logDateTimeId">Unique string</param>
        /// <returns>UTC DateTime</returns>
        public DateTime GetDateTimeUtc(string logDateTimeId)
        {
            using (SqlConnection conn = new SqlConnection(SqlConnectionString))
            {
                conn.Open();

                using (SqlCommand cmd = new SqlCommand(@"
                    SELECT
                        DateTimeUtc
                    FROM
                        tblLogDateTime
                    WHERE
                        LogDateTimeID = @logDateTimeID
                    ", conn))
                {
                    cmd.Parameters.AddWithValue("@logDateTimeID", logDateTimeId);

                    object obj = cmd.ExecuteScalar();

                    if (obj == null || obj == DBNull.Value)
                    {
                        throw new Exception("Id not found.");
                    }
                    else
                    {
                        DateTime returnDt = (DateTime)obj;
                        return DateTime.SpecifyKind(returnDt, DateTimeKind.Utc);
                    }
                }
            }
        }

        public void SetDateTimeUtc(string logDateTimeID, DateTime utcDateTime)
        {
            if (utcDateTime.Kind != DateTimeKind.Utc)
            {
                throw new Exception("Datetime kind is not set to UTC");
            }

            using (SqlConnection conn = new SqlConnection(SqlConnectionString))
            {
                conn.Open();

                using (SqlCommand cmd = new SqlCommand(@"
                    UPDATE tblLogDateTime
                    SET 
                        DateTimeUtc = @utcDateTime
                        ,RecordModified = @recordModified
                    WHERE 
                        LogDateTimeID = @logDateTimeID
                    ", conn))
                {
                    cmd.Parameters.AddWithValue("@utcDateTime", utcDateTime.ToUniversalTime());
                    cmd.Parameters.AddWithValue("@recordModified", DateTime.UtcNow.ToUniversalTime());
                    cmd.Parameters.AddWithValue("@logDateTimeID", logDateTimeID);

                    int count = cmd.ExecuteNonQuery();

                    if (count == 0)
                    {
                        throw new Exception("Error, failed to update record.");
                    }
                }
            }
        }

        public void NewDateTimeUtc(string LogDateTimeId, DateTime utcDateTime, string comments = null)
        {
            if (string.IsNullOrWhiteSpace(LogDateTimeId))
            { throw new Exception("Invalid LogDateTimeID"); }

            if (utcDateTime.Kind != DateTimeKind.Utc)
            {
                throw new Exception("Datetime kind is not set to UTC");
            }

            using (SqlConnection conn = new SqlConnection(SqlConnectionString))
            {
                conn.Open();

                using (SqlCommand cmd = new SqlCommand(@"
                    INSERT INTO tblLogDateTime (
                        LogDateTimeID
                        ,DateTimeUtc
                        ,Comments
                        ,RecordModified
                        ,RecordCreated
                        )
                    VALUES (
                        @logDateTimeId
                        ,@utcDateTime
                        ,@comments
                        ,@recordModified
                        ,@recordCreated
                        )
                    ", conn))
                {
                    var nowTime = DateTime.UtcNow;
                    cmd.Parameters.AddWithValue("@logDateTimeId", LogDateTimeId);
                    cmd.Parameters.AddWithValue("@utcDateTime", utcDateTime.ToUniversalTime());
                    if (string.IsNullOrWhiteSpace(comments)) { cmd.Parameters.AddWithValue("@comments", DBNull.Value); }
                    else { cmd.Parameters.AddWithValue("@comments", comments); }
                    cmd.Parameters.AddWithValue("@recordModified", nowTime.ToUniversalTime());
                    cmd.Parameters.AddWithValue("@recordCreated", nowTime.ToUniversalTime());

                    int count = cmd.ExecuteNonQuery();

                    if (count == 0)
                    {
                        throw new Exception("Error updating, no records where effected.");
                    }
                }
            }
        }
    }
}