MigrationManager.cs - main - Frexto/frexto-orm

MigrationManager.cs
71 строка2 KB
Maksim Fomin
orm
07 окт 2025, 10:58
07 окт 2025, 10:58f4c0f72
using System.Reflection;
using System.Text;

namespace FrextoORM;

public class MigrationManager
{
    private static string GetDataType(PropertyInfo prop)
    {
        if (prop.Name == "Id") return "SERIAL";
        var type = prop.PropertyType;
        if (type == typeof(int))
        {
            if (prop.GetCustomAttribute<OneToOneAttribute>() != null) return "INT UNIQUE";
            return "INT";
        }
        if (type == typeof(string))
        {
            var typeName = "VARCHAR";
            var maxLength = prop.GetCustomAttribute<MaxLengthAttribute>()?.MaxLength;
            if (maxLength != null) typeName += $"({maxLength.ToString()})";
            
            return typeName;
        }
        if (type == typeof(bool)) return "BIT";
        throw new Exception("Unsupported migration type");
    }
    
    public string GenerateCreateTableSql<T>()
    {
        var type = typeof(T);
        var tableName = type.Name.ToLower();
        var properties = type.GetProperties();
        
        var script = new StringBuilder();
        script.AppendLine($"create table {tableName} (");

        foreach (var prop in properties)
        {
            script.AppendLine($"{prop.Name.ToLower()} {GetDataType(prop)},");
            var fk = prop.GetCustomAttribute<ForeignKeyAttribute>();
            if (fk is OneToOneAttribute || fk is OneToManyAttribute)
            {
                script.AppendLine($"FOREIGN KEY ({prop.Name.ToLower()}) REFERENCES {fk.Name.ToLower()}(id),");
            }
        }

        script.Append("PRIMARY KEY (id));");

        return script.ToString();
    }

    public string GetMigrationSql()
    {
        var ass = Assembly.GetExecutingAssembly();
        var modelTypes = ass.GetTypes().Where(t => t.IsSubclassOf(typeof(FrextoModel)));

        var script = new StringBuilder();
        
        foreach (var modelType in modelTypes)
        {
            var sql = typeof(MigrationManager)
                .GetMethod("GenerateCreateTableSql")!
                .MakeGenericMethod(modelType)
                .Invoke(this, null) as string;
            script.AppendLine(sql);
        }

        return script.ToString();
    }
}