1 files changed, 157 insertions, 0 deletions
diff --git a/VNLib.Plugins.Extensions.Loading.Sql/SqlDbConnectionLoader.cs b/VNLib.Plugins.Extensions.Loading.Sql/SqlDbConnectionLoader.cs
new file mode 100644
index 0000000..f0898a0
--- /dev/null
+++ b/VNLib.Plugins.Extensions.Loading.Sql/SqlDbConnectionLoader.cs
@@ -0,0 +1,157 @@
+using System;
+using System.Text.Json;
+using System.Data.Common;
+using System.Runtime.CompilerServices;
+
+using MySqlConnector;
+
+using Microsoft.Data.Sqlite;
+using Microsoft.Data.SqlClient;
+using Microsoft.EntityFrameworkCore;
+
+using VNLib.Utils.Logging;
+using VNLib.Utils.Extensions;
+using VNLib.Plugins.Extensions.Loading.Configuration;
+
+namespace VNLib.Plugins.Extensions.Loading.Sql
+{
+    /// <summary>
+    /// Provides common basic SQL loading extensions for plugins
+    /// </summary>
+    public static class SqlDbConnectionLoader
+    {
+        public const string SQL_CONFIG_KEY = "sql";
+        public const string DB_PASSWORD_KEY = "db_password";
+
+        private static readonly ConditionalWeakTable<PluginBase, Func<DbConnection>> LazyDbFuncTable = new();
+        private static readonly ConditionalWeakTable<PluginBase, DbContextOptions> LazyCtxTable = new();
+     
+
+        /// <summary>
+        /// Gets (or loads) the ambient sql connection factory for the current plugin
+        /// </summary>
+        /// <param name="plugin"></param>
+        /// <returns>The ambient <see cref="DbConnection"/> factory</returns>
+        /// <exception cref="KeyNotFoundException"></exception>
+        /// <exception cref="ObjectDisposedException"></exception>
+        public static Func<DbConnection> GetConnectionFactory(this PluginBase plugin)
+        {
+            plugin.ThrowIfUnloaded();
+            //Get or load
+            return LazyDbFuncTable.GetValue(plugin, FactoryLoader);
+        }
+
+        private static Func<DbConnection> FactoryLoader(PluginBase plugin)
+        {
+            IReadOnlyDictionary<string, JsonElement>? sqlConf = plugin.TryGetConfig(SQL_CONFIG_KEY);
+            
+            if(sqlConf == null)
+            {
+                throw new KeyNotFoundException($"{SQL_CONFIG_KEY} configuration missing in configuration");
+            }
+            
+            //Get the db-type
+            string? type = sqlConf.GetPropString("db_type");
+            string? password = plugin.TryGetSecretAsync(DB_PASSWORD_KEY).Result;
+
+            if ("sqlite".Equals(type, StringComparison.OrdinalIgnoreCase))
+            {
+                //Use connection builder
+                DbConnectionStringBuilder sqlBuilder = new SqliteConnectionStringBuilder()
+                {
+                    DataSource = sqlConf["source"].GetString(),
+                };
+                string connectionString = sqlBuilder.ToString();
+                DbConnection DbFactory() => new SqliteConnection(connectionString);
+                return DbFactory;
+            }
+            else if("mysql".Equals(type, StringComparison.OrdinalIgnoreCase))
+            {
+                DbConnectionStringBuilder sqlBuilder = new MySqlConnectionStringBuilder()
+                {
+                    Server = sqlConf["hostname"].GetString(),
+                    Database = sqlConf["database"].GetString(),
+                    UserID = sqlConf["username"].GetString(),
+                    Password = password,
+                    Pooling = true,
+                    LoadBalance = MySqlLoadBalance.LeastConnections,
+                    MinimumPoolSize = sqlConf["min_pool_size"].GetUInt32()
+                };
+                
+                string connectionString = sqlBuilder.ToString();
+                DbConnection DbFactory() => new MySqlConnection(connectionString);
+                return DbFactory;
+            }
+            //Default to mssql
+            else
+            {
+                //Use connection builder
+                DbConnectionStringBuilder sqlBuilder = new SqlConnectionStringBuilder()
+                {
+                    DataSource = sqlConf["hostname"].GetString(),
+                    UserID = sqlConf["username"].GetString(),
+                    Password = password,
+                    InitialCatalog = sqlConf["catalog"].GetString(),
+                    IntegratedSecurity = sqlConf["ms_security"].GetBoolean(),
+                    Pooling = true,
+                    MinPoolSize = sqlConf["min_pool_size"].GetInt32(),
+                    Replication = true
+                };
+                string connectionString = sqlBuilder.ToString();
+                DbConnection DbFactory() => new SqlConnection(connectionString);
+                return DbFactory;
+            }           
+        }
+
+        /// <summary>
+        /// Gets (or loads) the ambient <see cref="DbContextOptions"/> configured from 
+        /// the ambient sql factory
+        /// </summary>
+        /// <param name="plugin"></param>
+        /// <returns>The ambient <see cref="DbContextOptions"/> for the current plugin</returns>
+        /// <exception cref="KeyNotFoundException"></exception>
+        /// <exception cref="ObjectDisposedException"></exception>
+        /// <remarks>If plugin is in debug mode, writes log data to the default log</remarks>
+        public static DbContextOptions GetContextOptions(this PluginBase plugin)
+        {
+            plugin.ThrowIfUnloaded();
+            return LazyCtxTable.GetValue(plugin, GetDbOptionsLoader);
+        }
+
+        private static DbContextOptions GetDbOptionsLoader(PluginBase plugin)
+        {
+            //Get a db connection object
+            DbConnection connection = plugin.GetConnectionFactory().Invoke();
+            DbContextOptionsBuilder builder = new();
+            
+            //Determine connection type
+            if(connection is SqlConnection sql)
+            {
+                //Use sql server from connection
+                builder.UseSqlServer(sql.ConnectionString);
+            }
+            else if(connection is SqliteConnection slc)
+            {
+                builder.UseSqlite(slc.ConnectionString);
+            }
+            else if(connection is MySqlConnection msconn)
+            {
+                //Detect version
+                ServerVersion version = ServerVersion.AutoDetect(msconn);
+
+                builder.UseMySql(msconn.ConnectionString, version);
+            }
+            
+            //Enable logging
+            if(plugin.IsDebug())
+            {
+                builder.LogTo(plugin.Log.Debug);
+            }
+            
+            //Get context and freez it before returning
+            DbContextOptions options = builder.Options;
+            options.Freeze();
+            return options;
+        }
+    }
+}