using System;
using System.Data.SqlClient;
using System.Linq;
using System.Text;
using System.Collections.Generic;
using System.Configuration;

namespace DataAccessLayer
{
    public static class SqlLogging
    {
        private static readonly string ConnectionString;
        private static readonly object lockObj = new object();

        static SqlLogging()
        {
            ConnectionString = ConfigurationManager.ConnectionStrings["SqlServerStampeC6Connection"]?.ConnectionString;
            if (string.IsNullOrEmpty(ConnectionString))
            {
                throw new ConfigurationErrorsException("SqlServerStampeC6Connection connection string not found in configuration.");
            }
        }

        private static void WriteToLogN(string level, string message, string logger, string callSite, string exception = null)
        {
            try
            {
                using (var conn = new SqlConnection(ConnectionString))
                using (var cmd = conn.CreateCommand())
                {
                    conn.Open();
                    cmd.CommandText = @"INSERT INTO [dbo].LogN ([Logged], [Level], [Message], [Logger], [CallSite], [Exception], [Application]) 
                                      VALUES (GETDATE(), @level, @message, @logger, @callSite, @exception, @application)";
                    
                    cmd.Parameters.AddWithValue("@level", level);
                    cmd.Parameters.AddWithValue("@message", message);
                    cmd.Parameters.AddWithValue("@logger", logger);
                    cmd.Parameters.AddWithValue("@callSite", callSite);
                    cmd.Parameters.AddWithValue("@exception", (object)exception ?? DBNull.Value);
                    cmd.Parameters.AddWithValue("@application", "SqlLogging");

                    cmd.ExecuteNonQuery();
                }
            }
            catch (Exception ex)
            {
                System.Diagnostics.Debug.WriteLine($"Error writing to LogN: {ex.Message}");
            }
        }

        public static void LogStoredProcedure(string spName, Dictionary<string, object> parameters = null, long executionTimeMs = 0)
        {
            try
            {
                var logBuilder = new StringBuilder();
                logBuilder.AppendLine($"STORED PROCEDURE");
                logBuilder.AppendLine($"Name: {spName}");

                if (parameters != null && parameters.Count > 0)
                {
                    logBuilder.AppendLine("Parameters:");
                    foreach (var param in parameters)
                    {
                        var value = param.Value == DBNull.Value ? "NULL" : param.Value?.ToString() ?? "NULL";
                        logBuilder.AppendLine($"\t@{param.Key}: {value}");
                    }
                }

                logBuilder.AppendLine($"Execution Time: {executionTimeMs}ms");

                WriteToLogN(
                    "Info", 
                    logBuilder.ToString(), 
                    "SqlLogging", 
                    $"LogStoredProcedure({spName})"
                );
            }
            catch (Exception ex)
            {
                System.Diagnostics.Debug.WriteLine($"Error logging stored procedure: {ex.Message}");
                WriteToLogN("Error", ex.Message, "SqlLogging", "LogStoredProcedure", ex.ToString());
            }
        }

        public static void LogCommand(SqlCommand command, long executionTimeMs = 0)
        {
            try
            {
                var logBuilder = new StringBuilder();
                logBuilder.AppendLine($"Command Type: {command.CommandType}");
                
                if (command.CommandType == System.Data.CommandType.StoredProcedure)
                {
                    logBuilder.AppendLine($"Stored Procedure Name: {command.CommandText}");
                }
                else
                {
                    logBuilder.AppendLine($"Command Text: {command.CommandText}");
                }

                if (command.Parameters.Count > 0)
                {
                    logBuilder.AppendLine("Parameters:");
                    foreach (SqlParameter param in command.Parameters)
                    {
                        var value = param.Value == DBNull.Value ? "NULL" : param.Value?.ToString() ?? "NULL";
                        logBuilder.AppendLine($"\t{param.ParameterName} ({param.SqlDbType}): {value}");
                    }
                }

                logBuilder.AppendLine($"Execution Time: {executionTimeMs}ms");

                WriteToLogN(
                    "Info", 
                    logBuilder.ToString(), 
                    "SqlLogging", 
                    $"LogCommand({command.CommandType})"
                );
            }
            catch (Exception ex)
            {
                System.Diagnostics.Debug.WriteLine($"Error logging SQL command: {ex.Message}");
                WriteToLogN("Error", ex.Message, "SqlLogging", "LogCommand", ex.ToString());
            }
        }
    }

}