RestySqlite/DatabaseRepository.cs

using Microsoft.AspNetCore.Http.HttpResults;
using Microsoft.AspNetCore.Mvc;

namespace RestySqlite
{
    public class DatabaseRepository(DatabaseWrapper db)
    {
        private readonly DatabaseWrapper _db = db;

        public async Task<Dictionary<string, List<string>>?> ListTables()
        {
            return await Task.Run(() => {
                try
                {
                    return _db.MapColumns();
                }
                catch (Exception e)
                {
                    Console.WriteLine(e);
                    return null;
                }
                
            });
            
        }

        public async Task<Dictionary<string, List<string>>?> ListColumns(string table)
        {
            return await Task.Run(() => {
                try
                {
                    var scheme = _db.MapColumns();
                    var filtered = from tbl in scheme.Keys where tbl == table select scheme[tbl];
                    
                    var result = new Dictionary<string, List<string>>();
                    foreach (var column in filtered.Single())
                    {
                        result.Add(column, _db.MapColumn(column, table) ?? throw new NullReferenceException("Column value is null!"));
                    }

                    return result;
                }
                catch (Exception e)
                {
                    Console.WriteLine(e);
                    return null;
                }
            });
            
            
        }

        public async Task<List<string>?> ListColumnValues(string table, string column)
        {
            return await Task.Run(() => {
                var values = _db.MapColumn(column, table);
                return values;
            });
            
        }

        public async Task<Dictionary<string, string>?> FetchValue(string table, int id)
        {
            return await Task.Run(() => {
                try
                {
                    var reader = _db.GetReader($"SELECT * FROM {table} WHERE id = {id}") ?? throw new NullReferenceException("Reader is null!");
                    /* var sqlCommand = "SELECT * FROM $table WHERE id = $id";
                    var reader = _db.GetReader(sqlCommand, 
                        new Parameter("$table", table),
                        new Parameter("$id", id)
                    ); */
                    var result = new Dictionary<string, string>();
                    using (reader)
                    {
                        while (reader.Read())
                        {
                            foreach (var column in _db.MapColumns()[table])
                            {
                                if (column == null) throw new NullReferenceException("Column value is null!");
                                if (!result.ContainsKey(column))
                                {;
                                    result.Add(column, reader[column].ToString() ?? throw new NullReferenceException("Readed value is null!"));
                                    continue;
                                } 
                                result[column] = reader[column].ToString() ?? throw new NullReferenceException("Readed value is null!");
                                
                            }
                        }
                    }
                    return result;
                }
                catch (Exception e)
                {
                    Console.WriteLine(e);
                    return null;
                }
            });
        }

        public async Task<string> ProcessCommand(string sqlCommand)
        {
            return await Task.Run(() => {
                try
                {
                    _db.ExecuteCommand(sqlCommand);
                    return "succses";
                }
                catch (Exception e)
                {
                    return e.Message;
                }
                
            });
        }
    }
}