using System;
using System.Data;
using System.Data.SQLite;
using System.Diagnostics;
using System.Collections;


using BCG;
using System.Linq;
using System.Data.Entity;
using System.Collections.Generic;
using System.Data.SQLite;


namespace bts.SilverPine {

   public static class SQLiteHelper {
      public static string location = "C:\\Users\\m_tah\\development\\data\\";
      public static string db_name = "stream_data.db";

      public static DataTable execute_select_query(string connection_string, string query) {
         // Create a new DataTable to store the results
         DataTable dataTable = new DataTable();

         // Create and open a SQLite connection using the provided connection string
         using (SQLiteConnection connection = new SQLiteConnection(connection_string)) {
            try {
               connection.Open();

               // Create a SQLite command with the provided query
               using (SQLiteCommand command = new SQLiteCommand(query, connection)) {
                  // Use SQLiteDataAdapter to fill the DataTable
                  using (SQLiteDataAdapter adapter = new SQLiteDataAdapter(command)) {
                     adapter.Fill(dataTable);
                  }
               }
            } catch (Exception ex) {
               Console.WriteLine("An error occurred: " + ex.Message);
            }
         }
         // Return the populated DataTable
         return dataTable;
      }

      public static List<Dictionary<string, object>> ExecuteBulkRead(string connectionString, string query) {
         var result = new List<Dictionary<string, object>>();

         using (var connection = new SQLiteConnection(connectionString)) {
            connection.Open();

            // Begin a transaction to optimize read speed
            using (var transaction = connection.BeginTransaction())
            using (var command = new SQLiteCommand(query, connection, transaction))
            using (var reader = command.ExecuteReader()) {
               while (reader.Read()) {
                  var row = new Dictionary<string, object>();

                  for (int i = 0; i < reader.FieldCount; i++) {
                     string columnName = reader.GetName(i);
                     object columnValue = reader.IsDBNull(i) ? null : reader.GetValue(i);
                     row[columnName] = columnValue;
                  }

                  result.Add(row);
               }

               // Commit the transaction
               transaction.Commit();
            }
         }

         return result;
      }

      public static List<Dictionary<string, object>> get_table(string connectionString, string query) {
         var result = new List<Dictionary<string, object>>();

         using (var connection = new SQLiteConnection(connectionString)) {
            try {
               connection.Open();

               using (var command = new SQLiteCommand(query, connection))
               using (var reader = command.ExecuteReader()) {
                  while (reader.Read()) {
                     var row = new Dictionary<string, object>();

                     for (int i = 0; i < reader.FieldCount; i++) {
                        string columnName = reader.GetName(i);
                        object columnValue = reader.IsDBNull(i) ? null : reader.GetValue(i);
                        row[columnName] = columnValue;
                     }

                     result.Add(row);
                  }
               }
            } catch (Exception ex) {
               Console.WriteLine("An error occurred: " + ex.Message);
            }
         }
         return result;
      }

      public static IEnumerable<Dictionary<string, object>> get_table_2(string connectionString, string query) {
         using (var connection = new SQLiteConnection(connectionString)) {
            connection.Open();
            using (var command = new SQLiteCommand(query, connection))
            using (var reader = command.ExecuteReader()) {
               while (reader.Read()) {
                  var row = new Dictionary<string, object>();
                  for (int i = 0; i < reader.FieldCount; i++) {
                     string columnName = reader.GetName(i);
                     object columnValue = reader.IsDBNull(i) ? null : reader.GetValue(i);
                     row[columnName] = columnValue;
                  }
                  yield return row;
               }
            }
         }
      }
   }
}