/*
 * Copyright 2010 www.Zhaizj.Framework.com
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

using System;
using System.Collections;
using System.Collections.Generic;
using System.Reflection;

using Zhaizj.Framework.Data;
using Zhaizj.Framework.DI;
using Zhaizj.Framework.Reflection;
using System.Web;
using System.IO;
using System.Web.Hosting;

namespace Zhaizj.Framework.ORM {

    /// <summary>
    /// 实体类和数据表关联映射的信息
    /// </summary>
    [Serializable]
    public class MappingClass {

        private static readonly ILog logger = LogManager.GetLogger( typeof( MappingClass ) );

        private IDictionary _assemblyList = new Hashtable();
        private IDictionary _classList = new Hashtable();
        private IDictionary _typeList = new Hashtable();
        private IDictionary _factoryList;

        private List<IInterceptor> _interceptorList = new List<IInterceptor>();
        private List<String> _tableList = new List<String>();

        /// <summary>
        /// ORM需要加载的所有程序集
        /// </summary>
        public IDictionary AssemblyList {
            get { return _assemblyList; }
            set { _assemblyList = value; }
        }

        /// <summary>
        /// 所有需要持久化的实体的 EntityInfo(每个EntityInfo包括类型、映射的表名等信息)
        /// </summary>
        public IDictionary ClassList {
            get { return _classList; }
            set { _classList = value; }
        }

        /// <summary>
        /// 所有需要持久化的实体的类型(type)
        /// </summary>
        public IDictionary TypeList {
            get { return _typeList; }
            set { _typeList = value; }
        }

        /// <summary>
        /// 所有需要持久化的实体的创建工厂
        /// </summary>
        public IDictionary FactoryList {
            get { return _factoryList; }
            set { _factoryList = value; }
        }

        /// <summary>
        /// 所有拦截器
        /// </summary>
        public List<IInterceptor> InterceptorList {
            get { return _interceptorList; }
            set { _interceptorList = value; }
        }

        /// <summary>
        /// 所有表名
        /// </summary>
        public List<String> TableList {
            get { return _tableList; }
            set { _tableList = value; }
        }

        private MappingClass() {
        }

        private static volatile MappingClass _instance;
        private static Object _syncRoot = new object();
        public static MappingClass Instance {
            get {
                if (_instance == null) {
                    lock (_syncRoot) {
                        if (_instance == null) _instance = loadInstance();
                    }
                }
                return _instance;
            }
        }

        public static void Clear() {
            _instance = null;
        }


        private static MappingClass loadInstance() {

            logger.Info( "begin MappingClass ..." );

            MappingClass result;
            if (strUtil.HasText( DbConfig.Instance.MetaDLL )) {
                result = loadByCacheDLL();
            }
            else {
                result = loadByReflection();
            }

            logger.Info( "end MappingClass ..." );

            return result;
        }


        private static MappingClass loadByCacheDLL() {

            String dllPath = DbConfig.Instance.GetMetaDllAbsPath();

            MappingClass map = null;
            try {

                map = EasyDB.LoadFromFile( dllPath ) as MappingClass;
            }
            catch (Exception exception) {
                logger.Error( "[MappingClass.loadInstance=>db.LoadFromFile( DbConfig.Instance.MetaDLL=" + DbConfig.Instance.MetaDLL + ")]:" + exception.Message );
            }

            if (map == null) {
                map = loadByReflection();
                EasyDB.SaveToFile( map, dllPath );
            }
            else
                logger.Info( "load meta from cache" );

            checkMultiDB( map );

            return map;
        }

        public static MappingClass loadByReflection() {

            logger.Info( "loadByReflection" );

            IList asmList = DbConfig.Instance.AssemblyList;

            MappingClass map = new MappingClass();
            for (int i = 0; i < asmList.Count; i++) {
                Assembly assembly = ObjectContext.LoadAssembly( asmList[i].ToString() );
                map.AssemblyList[asmList[i].ToString()] = assembly;
                Type[] typeArray = ObjectContext.FindTypes( asmList[i].ToString() );
                foreach (Type type in typeArray) {
                    ResolveOneType( map, type );
                }
                logger.Info( "loaded assembly: " + assembly.FullName );
            }

            logger.Info( "FinishPropertyInfo" );
            FinishPropertyInfo( map.ClassList );


            logger.Info( "cacheInterceptor" );
            cacheInterceptor( map );

            logger.Info( "AccessorUtil.Init" );

            MetaList list = new MetaList( map.AssemblyList, map.ClassList );
            map.FactoryList = AccessorUtil.Init( list );

            checkMultiDB( map );

            return map;
        }

        //------------------------------------------------------------------------------


        private static void ResolveOneType( MappingClass map, Type t ) {
            map.TypeList.Add( t.FullName, t );
            //if (!t.IsAbstract && ( t.IsSubclassOf( typeof( ObjectBase ) ) || t is IEntity )) {
            //    map.ClassList[t.FullName] = EntityInfo.GetByType( t );
            //    logger.Info( "Loading Type : " + t.FullName );
            //}
            // 1029
            logger.Info( "Loading Type : " + t.FullName );

            if (rft.IsInterface( t, typeof( IEntity ) ) && !OrmHelper.IsEntityBase( t )) {
                map.ClassList.Add( t.FullName, EntityInfo.GetByType( t ) );
            }

        }


        private static IDictionary FinishPropertyInfo( IDictionary mapClassList ) {
            foreach (DictionaryEntry entry in mapClassList) {

                EntityInfo info = entry.Value as EntityInfo;

                foreach (EntityPropertyInfo ep in info.SavedPropertyList) {

                    //if (mapClassList.Contains( ep.Type.FullName )) {
                    //    ep.EntityInfo = mapClassList[ep.Type.FullName] as EntityInfo;
                    //}

                    if (mapClassList.Contains( ep.Type.FullName ) && ep.SaveToDB) {
                        ep.EntityInfo = mapClassList[ep.Type.FullName] as EntityInfo;
                        ep.IsEntity = true;
                        info.EntityPropertyList.Add( ep );
                    }

                    ep.ColumnName = getColumnName( ep.Property, mapClassList );
                    //if (!(!ep.SaveToDB || ep.IsList)) {
                    //    info.ColumnList = info.ColumnList + ep.ColumnName + ",";
                    //}

                    if (isSavedProperty( ep )) info.ColumnList = info.ColumnList + ep.ColumnName + ",";
                }

                foreach (EntityPropertyInfo ep in info.PropertyListAll) {
                    info.AddPropertyToHashtable( ep );
                }

                info.ColumnList = info.ColumnList.Trim().TrimEnd( new char[] { ',' } );
                //if (!((info.Type.BaseType == typeof( ObjectBase )) || info.Type.BaseType.IsAbstract)) {
                //    EntityInfo info4 = mapClassList[info.Type.BaseType.FullName] as EntityInfo;
                //    info4.ChildEntityList.Add( info );
                //}

                // 找到父对象，然后给父对象的ChildEntityList加上当前对象
                if (updateParentInfo( info )) {
                    EntityInfo parentEi = mapClassList[info.Type.BaseType.FullName] as EntityInfo;
                    parentEi.ChildEntityList.Add( info );
                }


            }
            return mapClassList;
        }

        //1029
        private static Boolean updateParentInfo( EntityInfo info ) {
            if (info.Type.BaseType == typeof( Object )) return false;
            if (OrmHelper.IsEntityBase( info.Type.BaseType )) return false;

            if (info.Type.BaseType.IsAbstract) return false;
            return true;
        }

        //1029
        private static Boolean isSavedProperty( EntityPropertyInfo ep ) {
            if (ep.SaveToDB) return true;
            return false;
        }

        private static void cacheInterceptor( MappingClass map ) {

            List<object> interceptor = DbConfig.Instance.Interceptor;
            for (int i = 0; i < interceptor.Count; i++) {
                Dictionary<String, object> info = interceptor[i] as Dictionary<String, object>;
                String asmName = info["AssemblyName"].ToString();
                String typeName = info["TypeFullName"].ToString();
                IInterceptor obj = rft.GetInstance( asmName, typeName ) as IInterceptor;
                if (obj == null) {
                    throw new Exception( "load ORM interceptor error( Assembly:" + asmName + ", Type:" + typeName + ")" );
                }

                map.InterceptorList.Add( obj );
            }

        }

        private static void checkMultiDB( MappingClass map ) {

            if (DbConfig.Instance.IsCheckDatabase == false) {
                logger.Info( "skip check database" );
                return;
            }


            if (map.TableList == null) map.TableList = new List<String>();

            if (DbConfig.Instance.ConnectionStringTable == null || DbConfig.Instance.ConnectionStringTable.Count == 0) {
                createDB( map );
                return;
            }

            logger.Info( "begin check database..." );

            foreach (KeyValuePair<String, ConnectionString> kv in DbConfig.Instance.GetConnectionStringMap()) {

                String connectionString = kv.Value.StringContent;
                if (strUtil.IsNullOrEmpty( connectionString ))
                    throw new NotImplementedException( lang.get( "exConnectionString" ) + ":" + kv.Key );

                DatabaseType dbtype = kv.Value.DbType;

                IDatabaseChecker databaseChecker = DataFactory.GetDatabaseChecker( dbtype );
                databaseChecker.ConnectionString = connectionString;
                databaseChecker.DatabaseType = dbtype;

                logger.Info( "CheckDatabase" );
                databaseChecker.CheckDatabase();

                logger.Info( "CheckTable" );
                databaseChecker.CheckTable( map, kv.Key );

                logger.Info( "GetTables" );
                map.TableList.AddRange( databaseChecker.GetTables() );

            }

            logger.Info( "end check database..." );


        }

        private static void createDB( MappingClass map ) {

            logger.Info( "begin create database ..." );

            DatabaseType dbtype = DatabaseType.Access;

            IDatabaseChecker databaseChecker = DataFactory.GetDatabaseChecker( dbtype );
            databaseChecker.DatabaseType = dbtype;

            logger.Info( "CheckDatabase" );
            databaseChecker.CheckDatabase();

            logger.Info( "CheckTable" );
            databaseChecker.CheckTable( map, DbConfig.DefaultDbName );

            logger.Info( "GetTables" );
            map.TableList = databaseChecker.GetTables();
        }


        private static String getColumnName( PropertyInfo property, IDictionary mapClassList ) {
            ColumnAttribute attribute = ReflectionUtil.GetAttribute( property, typeof( ColumnAttribute ) ) as ColumnAttribute;
            if ((attribute != null) && strUtil.HasText( attribute.Name )) {
                return attribute.Name;
            }
            if (mapClassList.Contains( property.PropertyType.FullName )) {
                return (property.Name + "Id");
            }
            if (property.PropertyType.IsInterface) {
                return String.Format( "{0}Id", property.PropertyType.Name.TrimStart( new char[] { 'I' } ) );
            }
            if (property.PropertyType.Name == "IList") {
                throw new Exception( "property data type can not be IList" );
            }
            return property.Name;
        }

        //-------------------------------------------------------------------------------------------------------


        internal Boolean ContainsTable( String tableName ) {
            for (int i = 0; i < TableList.Count; i++) {
                if (strUtil.EqualsIgnoreCase( TableList[i], tableName )) {
                    return true;
                }
            }
            return false;
        }

    }
}