chaosbot/ChaosBot/Attribute/AssemblyController.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Text;
using ChaosBot.Database;
using NLog;

namespace ChaosBot.Attribute
{
    public static class AssemblyController
    {
        private static ILogger _logger = Program.Logger;
        public static void RegisterAll()
        {
            Assembly dbEntityAssembly = Assembly.GetAssembly(typeof(DBEntity));
            if (dbEntityAssembly != null)
            {
                foreach (Type type in dbEntityAssembly.GetTypes())
                {
                    RegisterDBEntityType(type);
                }
            }
        }

        public static void RegisterDBEntityType(Type type)
        {
            try
            {
                if (type.GetCustomAttributes(typeof(DBEntity), true).Length > 0)
                {
                    // Get a reference to the attribute
                    DBEntity dbEntity = type.GetCustomAttributes(typeof(DBEntity)).Cast<DBEntity>().First();

                    // Generate columns
                    // name, type, constraintName, constraints, 
                    List<Tuple<string, string, string, string>> columnList = new List<Tuple<string, string, string, string>>();

                    // Get the table as an easy variable
                    string table = dbEntity.Table;

                    // Loop through all fields
                    foreach (PropertyInfo prop in type.GetProperties())
                    {
                        string columnName = prop.Name;
                        string columnType = null;
                        if (prop.PropertyType.IsGenericType &&
                            prop.PropertyType.GetGenericTypeDefinition() == typeof(Nullable<>))
                        {
                            Type[] typeArguments = prop.PropertyType.GetGenericArguments();
                            if (typeArguments.Length == 1)
                                columnType = DBEntity.DataTypes.GetValueOrDefault(typeArguments[0]).ToString();
                        }
                        else
                        {
                            columnType = DBEntity.DataTypes.GetValueOrDefault(prop.PropertyType).ToString();
                        }

                        StringBuilder constraintNameBuilder = new StringBuilder($"{table}_{columnName}");
                        List<string> constraintsList = new List<string>();

                        // Go through every attribute
                        foreach (object fieldAttribute in prop.GetCustomAttributes(true))
                        {
                            if (fieldAttribute is DBFieldAttribute dBFieldAttribute)
                            {
                                string constraintSuffix =
                                    DBEntity.ConstrainNames.GetValueOrDefault(dBFieldAttribute.GetType(), null);
                                if (constraintSuffix != null)
                                {
                                    constraintNameBuilder.Append($"_{constraintSuffix}");
                                    constraintsList.Add($"{dBFieldAttribute.GetSQLiteQuery()}");
                                }
                            }
                        }

                        string constraintName = constraintNameBuilder.ToString();
                        if (constraintsList.Count > 0)
                        {
                            constraintsList.Insert(0, "CONSTRAINT");
                            constraintsList.Insert(1, constraintName);
                        }

                        string constraints = String.Join(" ", constraintsList);
                        columnList.Add(
                            new Tuple<string, string, string, string>(columnName, columnType, constraintName, constraints));
                    }

                    // Check table exists
                    bool tableExists =
                        Controller.RawQuery($"SELECT name FROM sqlite_master WHERE type='table' AND name='{table}'")
                            .Rows.Count > 0;

                    if (!tableExists)
                    {
                        string columnDefs = String.Join(", ", columnList.Select(c => $"{c.Item1} {c.Item2} {c.Item4}"));
                        string query = $"CREATE TABLE {table} ({columnDefs})";
                        Controller.RawQuery(query, readOutput: false);
                    }
                    else
                    {
                        foreach (Tuple<string, string, string, string> column in columnList)
                        {
                            try
                            {
                                string query =
                                    $"ALTER TABLE {table} ADD COLUMN {column.Item1} {column.Item2} {column.Item4}";
                                Controller.RawQuery(query, readOutput: false, throwError: true);
                            }
                            catch
                            {
                                // ignored
                            }
                        }
                    }
                }
            }
            catch (Exception ex)
            {
                _logger.Error($"AssemblyController.Register: Exception [{ex}] thrown, <[{ex.Message}]>.");
            }
        }
    }
}