using FreeSql.DataAnnotations;
using FreeSql.DatabaseModel;
using FreeSql.Internal;
using FreeSql.Internal.Model;
using Newtonsoft.Json.Linq;
using Npgsql.LegacyPostgis;
using NpgsqlTypes;
using System;
using System.Collections;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Data;
using System.Linq;
using System.Net;
using System.Net.NetworkInformation;
using System.Text;
using System.Text.RegularExpressions;

namespace FreeSql.PostgreSQL {

	class PostgreSQLCodeFirst : ICodeFirst {
		IFreeSql _orm;
		protected CommonUtils _commonUtils;
		protected CommonExpression _commonExpression;
		public PostgreSQLCodeFirst(IFreeSql orm, CommonUtils commonUtils, CommonExpression commonExpression) {
			_orm = orm;
			_commonUtils = commonUtils;
			_commonExpression = commonExpression;
		}

		public bool IsAutoSyncStructure { get; set; } = true;
		public bool IsQuoteSqlName { get; set; } = true;
		public bool IsSyncStructureToLower { get; set; } = false;
		public bool IsLazyLoading { get; set; } = false;

		static object _dicCsToDbLock = new object();
		static Dictionary<string, (NpgsqlDbType type, string dbtype, string dbtypeFull, bool? isUnsigned, bool? isnullable, object defaultValue)> _dicCsToDb = new Dictionary<string, (NpgsqlDbType type, string dbtype, string dbtypeFull, bool? isUnsigned, bool? isnullable, object defaultValue)>() {

				{ typeof(sbyte).FullName,  (NpgsqlDbType.Smallint, "int2","int2 NOT NULL", false, false, 0) },{ typeof(sbyte?).FullName,  (NpgsqlDbType.Smallint, "int2", "int2", false, true, null) },
				{ typeof(short).FullName,  (NpgsqlDbType.Smallint, "int2","int2 NOT NULL", false, false, 0) },{ typeof(short?).FullName,  (NpgsqlDbType.Smallint, "int2", "int2", false, true, null) },
				{ typeof(int).FullName,  (NpgsqlDbType.Integer, "int4","int4 NOT NULL", false, false, 0) },{ typeof(int?).FullName,  (NpgsqlDbType.Integer, "int4", "int4", false, true, null) },
				{ typeof(long).FullName,  (NpgsqlDbType.Bigint, "int8","int8 NOT NULL", false, false, 0) },{ typeof(long?).FullName,  (NpgsqlDbType.Bigint, "int8", "int8", false, true, null) },

				{ typeof(byte).FullName,  (NpgsqlDbType.Smallint, "int2","int2 NOT NULL", false, false, 0) },{ typeof(byte?).FullName,  (NpgsqlDbType.Smallint, "int2", "int2", false, true, null) },
				{ typeof(ushort).FullName,  (NpgsqlDbType.Integer, "int4","int4 NOT NULL", false, false, 0) },{ typeof(ushort?).FullName,  (NpgsqlDbType.Integer, "int4", "int4", false, true, null) },
				{ typeof(uint).FullName,  (NpgsqlDbType.Bigint, "int8","int8 NOT NULL", false, false, 0) },{ typeof(uint?).FullName,  (NpgsqlDbType.Bigint, "int8", "int8", false, true, null) },
				{ typeof(ulong).FullName,  (NpgsqlDbType.Numeric, "numeric","numeric(20,0) NOT NULL", false, false, 0) },{ typeof(ulong?).FullName,  (NpgsqlDbType.Numeric, "numeric", "numeric(20,0)", false, true, null) },

				{ typeof(float).FullName,  (NpgsqlDbType.Real, "float4","float4 NOT NULL", false, false, 0) },{ typeof(float?).FullName,  (NpgsqlDbType.Real, "float4", "float4", false, true, null) },
				{ typeof(double).FullName,  (NpgsqlDbType.Double, "float8","float8 NOT NULL", false, false, 0) },{ typeof(double?).FullName,  (NpgsqlDbType.Double, "float8", "float8", false, true, null) },
				{ typeof(decimal).FullName,  (NpgsqlDbType.Numeric, "numeric", "numeric(10,2) NOT NULL", false, false, 0) },{ typeof(decimal?).FullName,  (NpgsqlDbType.Numeric, "numeric", "numeric(10,2)", false, true, null) },

				{ typeof(string).FullName,  (NpgsqlDbType.Varchar, "varchar", "varchar(255)", false, null, "") },

				{ typeof(TimeSpan).FullName,  (NpgsqlDbType.Time, "time","time NOT NULL", false, false, 0) },{ typeof(TimeSpan?).FullName,  (NpgsqlDbType.Time, "time", "time",false, true, null) },
				{ typeof(DateTime).FullName,  (NpgsqlDbType.Timestamp, "timestamp", "timestamp NOT NULL", false, false, new DateTime(1970,1,1)) },{ typeof(DateTime?).FullName,  (NpgsqlDbType.Timestamp, "timestamp", "timestamp", false, true, null) },

				{ typeof(bool).FullName,  (NpgsqlDbType.Boolean, "bool","bool NOT NULL", null, false, false) },{ typeof(bool?).FullName,  (NpgsqlDbType.Boolean, "bool","bool", null, true, null) },
				{ typeof(Byte[]).FullName,  (NpgsqlDbType.Bytea, "bytea", "bytea", false, null, new byte[0]) },
				{ typeof(BitArray).FullName,  (NpgsqlDbType.Varbit, "varbit", "varbit(64)", false, null, new BitArray(new byte[64])) },

				{ typeof(NpgsqlPoint).FullName,  (NpgsqlDbType.Point, "point", "point NOT NULL", false, false, new NpgsqlPoint(0, 0)) },{ typeof(NpgsqlPoint?).FullName,  (NpgsqlDbType.Point, "point", "point", false, true, null) },
				{ typeof(NpgsqlLine).FullName,  (NpgsqlDbType.Line, "line", "line NOT NULL", false, false, new NpgsqlLine(0, 0, 1)) },{ typeof(NpgsqlLine?).FullName,  (NpgsqlDbType.Line, "line", "line", false, true, null) },
				{ typeof(NpgsqlLSeg).FullName,  (NpgsqlDbType.LSeg, "lseg", "lseg NOT NULL", false, false, new NpgsqlLSeg(0, 0, 0, 0)) },{ typeof(NpgsqlLSeg?).FullName,  (NpgsqlDbType.LSeg, "lseg", "lseg", false, true, null) },
				{ typeof(NpgsqlBox).FullName,  (NpgsqlDbType.Box, "box", "box NOT NULL", false, false, new NpgsqlBox(0, 0, 0, 0)) },{ typeof(NpgsqlBox?).FullName,  (NpgsqlDbType.Box, "box", "box", false, true, null) },
				{ typeof(NpgsqlPath).FullName,  (NpgsqlDbType.Path, "path", "path NOT NULL", false, false, new NpgsqlPath(new NpgsqlPoint(0, 0))) },{ typeof(NpgsqlPath?).FullName,  (NpgsqlDbType.Path, "path", "path", false, true, null) },
				{ typeof(NpgsqlPolygon).FullName,  (NpgsqlDbType.Polygon, "polygon", "polygon NOT NULL", false, false, new NpgsqlPolygon(new NpgsqlPoint(0, 0), new NpgsqlPoint(0, 0))) },{ typeof(NpgsqlPolygon?).FullName,  (NpgsqlDbType.Polygon, "polygon", "polygon", false, true, null) },
				{ typeof(NpgsqlCircle).FullName,  (NpgsqlDbType.Circle, "circle", "circle NOT NULL", false, false, new NpgsqlCircle(0, 0, 0)) },{ typeof(NpgsqlCircle?).FullName,  (NpgsqlDbType.Circle, "circle", "circle", false, true, null) },

				{ typeof((IPAddress Address, int Subnet)).FullName,  (NpgsqlDbType.Cidr, "cidr", "cidr NOT NULL", false, false, (IPAddress.Any, 0)) },{ typeof((IPAddress Address, int Subnet)?).FullName,  (NpgsqlDbType.Cidr, "cidr", "cidr", false, true, null) },
				{ typeof(IPAddress).FullName,  (NpgsqlDbType.Inet, "inet", "inet", false, null, IPAddress.Any) },
				{ typeof(PhysicalAddress).FullName,  (NpgsqlDbType.MacAddr, "macaddr", "macaddr", false, null, PhysicalAddress.None) },

				{ typeof(JToken).FullName,  (NpgsqlDbType.Jsonb, "jsonb", "jsonb", false, null, JToken.Parse("{}")) },
				{ typeof(JObject).FullName,  (NpgsqlDbType.Jsonb, "jsonb", "jsonb", false, null, JObject.Parse("{}")) },
				{ typeof(JArray).FullName,  (NpgsqlDbType.Jsonb, "jsonb", "jsonb", false, null, JArray.Parse("[]")) },
				{ typeof(Guid).FullName,  (NpgsqlDbType.Uuid, "uuid", "uuid NOT NULL", false, false, Guid.Empty) },{ typeof(Guid?).FullName,  (NpgsqlDbType.Uuid, "uuid", "uuid", false, true, null) },

				{ typeof(NpgsqlRange<int>).FullName,  (NpgsqlDbType.Range | NpgsqlDbType.Integer, "int4range", "int4range NOT NULL", false, false, NpgsqlRange<int>.Empty) },{ typeof(NpgsqlRange<int>?).FullName,  (NpgsqlDbType.Range | NpgsqlDbType.Integer, "int4range", "int4range", false, true, null) },
				{ typeof(NpgsqlRange<long>).FullName,  (NpgsqlDbType.Range | NpgsqlDbType.Bigint, "int8range", "int8range NOT NULL", false, false, NpgsqlRange<long>.Empty) },{ typeof(NpgsqlRange<long>?).FullName,  (NpgsqlDbType.Range | NpgsqlDbType.Bigint, "int8range", "int8range", false, true, null) },
				{ typeof(NpgsqlRange<decimal>).FullName,  (NpgsqlDbType.Range | NpgsqlDbType.Numeric, "numrange", "numrange NOT NULL", false, false, NpgsqlRange<decimal>.Empty) },{ typeof(NpgsqlRange<decimal>?).FullName,  (NpgsqlDbType.Range | NpgsqlDbType.Numeric, "numrange", "numrange", false, true, null) },
				{ typeof(NpgsqlRange<DateTime>).FullName,  (NpgsqlDbType.Range | NpgsqlDbType.Timestamp, "tsrange", "tsrange NOT NULL", false, false, NpgsqlRange<DateTime>.Empty) },{ typeof(NpgsqlRange<DateTime>?).FullName,  (NpgsqlDbType.Range | NpgsqlDbType.Timestamp, "tsrange", "tsrange", false, true, null) },

				{ typeof(Dictionary<string, string>).FullName,  (NpgsqlDbType.Hstore, "hstore", "hstore", false, null, new Dictionary<string, string>()) },
				{ typeof(PostgisPoint).FullName,  (NpgsqlDbType.Geometry, "geometry", "geometry", false, null, new PostgisPoint(0, 0)) },
				{ typeof(PostgisLineString).FullName,  (NpgsqlDbType.Geometry, "geometry", "geometry", false, null, new PostgisLineString(new []{new Coordinate2D(0, 0),new Coordinate2D(0, 0) })) },
				{ typeof(PostgisPolygon).FullName,  (NpgsqlDbType.Geometry, "geometry", "geometry", false, null, new PostgisPolygon(new []{new []{new Coordinate2D(0, 0),new Coordinate2D(0, 0) }, new []{new Coordinate2D(0, 0),new Coordinate2D(0, 0) } })) },
				{ typeof(PostgisMultiPoint).FullName,  (NpgsqlDbType.Geometry, "geometry", "geometry", false, null, new PostgisMultiPoint(new []{new Coordinate2D(0, 0),new Coordinate2D(0, 0) })) },
				{ typeof(PostgisMultiLineString).FullName,  (NpgsqlDbType.Geometry, "geometry", "geometry", false, null, new PostgisMultiLineString(new[]{new PostgisLineString(new []{new Coordinate2D(0, 0),new Coordinate2D(0, 0) }),new PostgisLineString(new []{new Coordinate2D(0, 0),new Coordinate2D(0, 0) }) })) },
				{ typeof(PostgisMultiPolygon).FullName,  (NpgsqlDbType.Geometry, "geometry", "geometry", false, null, new PostgisMultiPolygon(new[]{new PostgisPolygon(new []{new []{new Coordinate2D(0, 0),new Coordinate2D(0, 0) }, new []{new Coordinate2D(0, 0),new Coordinate2D(0, 0) } }),new PostgisPolygon(new []{new []{new Coordinate2D(0, 0),new Coordinate2D(0, 0) }, new []{new Coordinate2D(0, 0),new Coordinate2D(0, 0) } }) })) },
				{ typeof(PostgisGeometry).FullName,  (NpgsqlDbType.Geometry, "geometry", "geometry", false, null, new PostgisPoint(0, 0)) },
				{ typeof(PostgisGeometryCollection).FullName,  (NpgsqlDbType.Geometry, "geometry", "geometry", false, null, new PostgisGeometryCollection(new[]{new PostgisPoint(0, 0),new PostgisPoint(0, 0) })) },
			};

		public (int type, string dbtype, string dbtypeFull, bool? isnullable, object defaultValue)? GetDbInfo(Type type) {
			var isarray = type.FullName != "System.Byte[]" && type.IsArray;
			var elementType = isarray ? type.GetElementType() : type;
			var info = GetDbInfoNoneArray(elementType);
			if (info == null) return null;
			if (isarray == false) return ((int)info.Value.type, info.Value.dbtype, info.Value.dbtypeFull, info.Value.isnullable, info.Value.defaultValue);
			var dbtypefull = Regex.Replace(info.Value.dbtypeFull, $@"{info.Value.dbtype}(\s*\([^\)]+\))?", "$0[]").Replace(" NOT NULL", "");
			return ((int)(info.Value.type | NpgsqlDbType.Array), $"{info.Value.dbtype}[]", dbtypefull, null, Array.CreateInstance(elementType, 0));
		}
		(NpgsqlDbType type, string dbtype, string dbtypeFull, bool? isnullable, object defaultValue)? GetDbInfoNoneArray(Type type) {
			if (_dicCsToDb.TryGetValue(type.FullName, out var trydc)) return new (NpgsqlDbType, string, string, bool?, object)?((trydc.type, trydc.dbtype, trydc.dbtypeFull, trydc.isnullable, trydc.defaultValue));
			if (type.IsArray) return null;
			var enumType = type.IsEnum ? type : null;
			if (enumType == null && type.IsNullableType() && type.GenericTypeArguments.Length == 1 && type.GenericTypeArguments.First().IsEnum) enumType = type.GenericTypeArguments.First();
			if (enumType != null) {
				var newItem = enumType.GetCustomAttributes(typeof(FlagsAttribute), false).Any() ?
					(NpgsqlDbType.Bigint, "int8", $"int8{(type.IsEnum ? " NOT NULL" : "")}", false, type.IsEnum ? false : true, Enum.GetValues(enumType).GetValue(0)) :
					(NpgsqlDbType.Integer, "int4", $"int4{(type.IsEnum ? " NOT NULL" : "")}", false, type.IsEnum ? false : true, Enum.GetValues(enumType).GetValue(0));
				if (_dicCsToDb.ContainsKey(type.FullName) == false) {
					lock (_dicCsToDbLock) {
						if (_dicCsToDb.ContainsKey(type.FullName) == false)
							_dicCsToDb.Add(type.FullName, newItem);
					}
				}
				return (newItem.Item1, newItem.Item2, newItem.Item3, newItem.Item5, newItem.Item6);
			}
			return null;
		}

		public string GetComparisonDDLStatements<TEntity>() => this.GetComparisonDDLStatements(typeof(TEntity));
		public string GetComparisonDDLStatements(params Type[] entityTypes) {
			var sb = new StringBuilder();
			var seqcols = new List<(ColumnInfo, string[], bool)>(); //序列

			foreach (var entityType in entityTypes) {
				if (sb.Length > 0) sb.Append("\r\n");
				var tb = _commonUtils.GetTableByEntity(entityType);
				var tbname = tb.DbName.Split(new[] { '.' }, 2);
				if (tbname?.Length == 1) tbname = new[] { "public", tbname[0] };

				var tboldname = tb.DbOldName?.Split(new[] { '.' }, 2); //旧表名
				if (tboldname?.Length == 1) tboldname = new[] { "public", tboldname[0] };

				if (string.Compare(tbname[0], "public", true) != 0 && _orm.Ado.ExecuteScalar(CommandType.Text, " select 1 from pg_namespace where nspname={0}".FormatPostgreSQL(tbname[0])) == null) //创建模式
					sb.Append("CREATE SCHEMA IF NOT EXISTS ").Append(tbname[0]).Append(";\r\n");

				var sbalter = new StringBuilder();
				var istmpatler = false; //创建临时表，导入数据，删除旧表，修改
				if (_orm.Ado.ExecuteScalar(CommandType.Text, string.Format(" select 1 from pg_tables a inner join pg_namespace b on b.nspname = a.schemaname where b.nspname || '.' || a.tablename = '{0}.{1}'", tbname)) == null) { //表不存在
					if (tboldname != null) {
						if (_orm.Ado.ExecuteScalar(CommandType.Text, string.Format(" select 1 from pg_tables a inner join pg_namespace b on b.nspname = a.schemaname where b.nspname || '.' || a.tablename = '{0}.{1}'", tboldname)) == null)
							//旧表不存在
							tboldname = null;
					}
					if (tboldname == null) {
						//创建表
						sb.Append("CREATE TABLE IF NOT EXISTS ").Append(_commonUtils.QuoteSqlName($"{tbname[0]}.{tbname[1]}")).Append(" (");
						foreach (var tbcol in tb.Columns.Values) {
							sb.Append(" \r\n  ").Append(_commonUtils.QuoteSqlName(tbcol.Attribute.Name)).Append(" ").Append(tbcol.Attribute.DbType).Append(",");
							if (tbcol.Attribute.IsIdentity == true) seqcols.Add((tbcol, tbname, true));
						}
						if (tb.Primarys.Any() == false)
							sb.Remove(sb.Length - 1, 1);
						else {
							sb.Append(" \r\n  CONSTRAINT ").Append(tbname[0]).Append("_").Append(tbname[1]).Append("_pkey PRIMARY KEY (");
							foreach (var tbcol in tb.Primarys) sb.Append(_commonUtils.QuoteSqlName(tbcol.Attribute.Name)).Append(", ");
							sb.Remove(sb.Length - 2, 2).Append(")");
						}
						sb.Append("\r\n) WITH (OIDS=FALSE);\r\n");
						continue;
					}
					//如果新表，旧表在一个数据库和模式下，直接修改表名
					if (string.Compare(tbname[0], tboldname[0], true) == 0)
						sbalter.Append("ALTER TABLE ").Append(_commonUtils.QuoteSqlName($"{tboldname[0]}.{tboldname[1]}")).Append(" RENAME TO ").Append(_commonUtils.QuoteSqlName($"{tbname[1]}")).Append(";\r\n");
					else {
						//如果新表，旧表不在一起，创建新表，导入数据，删除旧表
						istmpatler = true;
					}
				} else
					tboldname = null; //如果新表已经存在，不走改表名逻辑

				//对比字段，只可以修改类型、增加字段、有限的修改字段名；保证安全不删除字段
				var sql = @"
select
a.attname,
t.typname,
case when a.atttypmod > 0 and a.atttypmod < 32767 then a.atttypmod - 4 else a.attlen end len,
case when t.typelem > 0 and t.typinput::varchar = 'array_in' then t2.typname else t.typname end,
case when a.attnotnull then '0' else '1' end as is_nullable,
e.adsrc,
a.attndims
from pg_class c
inner join pg_attribute a on a.attnum > 0 and a.attrelid = c.oid
inner join pg_type t on t.oid = a.atttypid
left join pg_type t2 on t2.oid = t.typelem
left join pg_description d on d.objoid = a.attrelid and d.objsubid = a.attnum
left join pg_attrdef e on e.adrelid = a.attrelid and e.adnum = a.attnum
inner join pg_namespace ns on ns.oid = c.relnamespace
inner join pg_namespace ns2 on ns2.oid = t.typnamespace
where ns.nspname = {0} and c.relname = {1}".FormatPostgreSQL(tboldname ?? tbname);
				var ds = _orm.Ado.ExecuteArray(CommandType.Text, sql);
				var tbstruct = ds.ToDictionary(a => string.Concat(a[0]), a => {
					var attndims = int.Parse(string.Concat(a[6]));
					var type = string.Concat(a[1]);
					var sqlType = string.Concat(a[3]);
					var max_length = long.Parse(string.Concat(a[2]));
					switch (sqlType.ToLower()) {
						case "bool": case "name": case "bit": case "varbit": case "bpchar": case "varchar": case "bytea": case "text": case "uuid": break;
						default: max_length *= 8; break;
					}
					if (type.StartsWith("_")) {
						type = type.Substring(1);
						if (attndims == 0) attndims++;
					}
					if (sqlType.StartsWith("_")) sqlType = sqlType.Substring(1);
					return new {
						column = string.Concat(a[0]),
						sqlType = string.Concat(sqlType),
						max_length = long.Parse(string.Concat(a[2])),
						is_nullable = string.Concat(a[4]) == "1",
						is_identity = string.Concat(a[5]).StartsWith(@"nextval('") && string.Concat(a[5]).EndsWith(@"'::regclass)"),
						attndims
					};
					}, StringComparer.CurrentCultureIgnoreCase);

				if (istmpatler == false) {
					foreach (var tbcol in tb.Columns.Values) {
						if (tbstruct.TryGetValue(tbcol.Attribute.Name, out var tbstructcol) ||
							string.IsNullOrEmpty(tbcol.Attribute.OldName) == false && tbstruct.TryGetValue(tbcol.Attribute.OldName, out tbstructcol)) {
							if (tbcol.Attribute.DbType.StartsWith(tbstructcol.sqlType, StringComparison.CurrentCultureIgnoreCase) == false ||
								tbcol.Attribute.DbType.Contains("[]") != (tbstructcol.attndims > 0))
								sbalter.Append("ALTER TABLE ").Append(_commonUtils.QuoteSqlName($"{tbname[0]}.{tbname[1]}")).Append(" ALTER COLUMN ").Append(_commonUtils.QuoteSqlName(tbstructcol.column)).Append(" TYPE ").Append(tbcol.Attribute.DbType.Split(' ').First()).Append(";\r\n");
							if (tbcol.Attribute.IsNullable != tbstructcol.is_nullable)
								sbalter.Append("ALTER TABLE ").Append(_commonUtils.QuoteSqlName($"{tbname[0]}.{tbname[1]}")).Append(" ALTER COLUMN ").Append(_commonUtils.QuoteSqlName(tbstructcol.column)).Append(" ").Append(tbcol.Attribute.IsNullable == true ? "DROP" : "SET").Append(" NOT NULL;\r\n");
							if (tbcol.Attribute.IsIdentity != tbstructcol.is_identity)
								seqcols.Add((tbcol, tbname, tbcol.Attribute.IsIdentity == true));
							if (tbstructcol.column == tbcol.Attribute.OldName)
								//修改列名
								sbalter.Append("ALTER TABLE ").Append(_commonUtils.QuoteSqlName($"{tbname[0]}.{tbname[1]}")).Append(" RENAME COLUMN ").Append(_commonUtils.QuoteSqlName(tbcol.Attribute.OldName)).Append(" TO ").Append(_commonUtils.QuoteSqlName(tbcol.Attribute.Name)).Append(";\r\n");
							continue;
						}
						//添加列
						sbalter.Append("ALTER TABLE ").Append(_commonUtils.QuoteSqlName($"{tbname[0]}.{tbname[1]}")).Append(" ADD COLUMN ").Append(_commonUtils.QuoteSqlName(tbcol.Attribute.Name)).Append(" ").Append(tbcol.Attribute.DbType.Split(' ').First()).Append(";\r\n");
						sbalter.Append("UPDATE ").Append(_commonUtils.QuoteSqlName($"{tbname[0]}.{tbname[1]}")).Append(" SET ").Append(_commonUtils.QuoteSqlName(tbcol.Attribute.Name)).Append(_commonUtils.FormatSql(" = {0};\r\n", tbcol.Attribute.DbDefautValue));
						if (tbcol.Attribute.IsNullable == false) sbalter.Append("ALTER TABLE ").Append(_commonUtils.QuoteSqlName($"{tbname[0]}.{tbname[1]}")).Append(" ALTER COLUMN ").Append(_commonUtils.QuoteSqlName(tbcol.Attribute.Name)).Append(" SET NOT NULL;\r\n");
						if (tbcol.Attribute.IsIdentity == true) seqcols.Add((tbcol, tbname, tbcol.Attribute.IsIdentity == true));
					}
				}
				if (istmpatler == false) {
					sb.Append(sbalter);
					continue;
				}
				var oldpk = _orm.Ado.ExecuteScalar(CommandType.Text, @"select pg_constraint.conname as pk_name from pg_constraint
inner join pg_class on pg_constraint.conrelid = pg_class.oid
inner join pg_namespace on pg_namespace.oid = pg_class.relnamespace
where pg_namespace.nspname={0} and pg_class.relname={1} and pg_constraint.contype='p'
".FormatPostgreSQL(tbname))?.ToString();
				if (string.IsNullOrEmpty(oldpk) == false)
					sb.Append("ALTER TABLE ").Append(_commonUtils.QuoteSqlName($"{tbname[0]}.{tbname[1]}")).Append(" DROP CONSTRAINT ").Append(oldpk).Append(";\r\n");

				//创建临时表，数据导进临时表，然后删除原表，将临时表改名为原表名
				var tablename = tboldname == null ? _commonUtils.QuoteSqlName($"{tbname[0]}.{tbname[1]}") : _commonUtils.QuoteSqlName($"{tboldname[0]}.{tboldname[1]}");
				var tmptablename = _commonUtils.QuoteSqlName($"{tbname[0]}.FreeSqlTmp_{tbname[1]}");
				//创建临时表
				sb.Append("CREATE TABLE IF NOT EXISTS ").Append(tmptablename).Append(" (");
				foreach (var tbcol in tb.Columns.Values) {
					sb.Append(" \r\n  ").Append(_commonUtils.QuoteSqlName(tbcol.Attribute.Name)).Append(" ").Append(tbcol.Attribute.DbType).Append(",");
					if (tbcol.Attribute.IsIdentity == true) seqcols.Add((tbcol, tbname, true));
				}
				if (tb.Primarys.Any() == false)
					sb.Remove(sb.Length - 1, 1);
				else {
					sb.Append(" \r\n  CONSTRAINT ").Append(tbname[0]).Append("_").Append(tbname[1]).Append("_pkey PRIMARY KEY (");
					foreach (var tbcol in tb.Primarys) sb.Append(_commonUtils.QuoteSqlName(tbcol.Attribute.Name)).Append(", ");
					sb.Remove(sb.Length - 2, 2).Append(")");
				}
				sb.Append("\r\n) WITH (OIDS=FALSE);\r\n");
				sb.Append("INSERT INTO ").Append(tmptablename).Append(" (");
				foreach (var tbcol in tb.Columns.Values)
					sb.Append(_commonUtils.QuoteSqlName(tbcol.Attribute.Name)).Append(", ");
				sb.Remove(sb.Length - 2, 2).Append(")\r\nSELECT ");
				foreach (var tbcol in tb.Columns.Values) {
					var insertvalue = "NULL";
					if (tbstruct.TryGetValue(tbcol.Attribute.Name, out var tbstructcol) ||
						string.IsNullOrEmpty(tbcol.Attribute.OldName) == false && tbstruct.TryGetValue(tbcol.Attribute.OldName, out tbstructcol)) {
						insertvalue = _commonUtils.QuoteSqlName(tbstructcol.column);
						if (tbcol.Attribute.DbType.StartsWith(tbstructcol.sqlType, StringComparison.CurrentCultureIgnoreCase) == false)
							insertvalue = $"cast({insertvalue} as {tbcol.Attribute.DbType.Split(' ').First()})";
						if (tbcol.Attribute.IsNullable != tbstructcol.is_nullable)
							insertvalue = $"coalesce({insertvalue},{_commonUtils.FormatSql("{0}", tbcol.Attribute.DbDefautValue)})";
					} else if (tbcol.Attribute.IsNullable == false)
						insertvalue = _commonUtils.FormatSql("{0}", tbcol.Attribute.DbDefautValue);
					sb.Append(insertvalue).Append(", ");
				}
				sb.Remove(sb.Length - 2, 2).Append(" FROM ").Append(tablename).Append(";\r\n");
				sb.Append("DROP TABLE ").Append(tablename).Append(";\r\n");
				sb.Append("ALTER TABLE ").Append(tmptablename).Append(" RENAME TO ").Append(_commonUtils.QuoteSqlName(tbname[1])).Append(";\r\n");
			}
			foreach (var seqcol in seqcols) {
				var tbname = seqcol.Item2;
				var seqname = Utils.GetCsName($"{tbname[0]}.{tbname[1]}_{seqcol.Item1.Attribute.Name}_sequence_name");
				var tbname2 = _commonUtils.QuoteSqlName($"{tbname[0]}.{tbname[1]}");
				var colname2 = _commonUtils.QuoteSqlName(seqcol.Item1.Attribute.Name);
				sb.Append("ALTER TABLE ").Append(tbname2).Append(" ALTER COLUMN ").Append(colname2).Append(" SET DEFAULT null;\r\n");
				sb.Append("DROP SEQUENCE IF EXISTS ").Append(seqname).Append(";\r\n");
				if (seqcol.Item3) {
					sb.Append("CREATE SEQUENCE ").Append(seqname).Append(";\r\n");
					sb.Append("ALTER TABLE ").Append(tbname2).Append(" ALTER COLUMN ").Append(colname2).Append(" SET DEFAULT nextval('").Append(seqname).Append("'::regclass);\r\n");
					sb.Append(" SELECT case when max(").Append(colname2).Append(") is null then 0 else setval('").Append(seqname).Append("', max(").Append(colname2).Append(")) end FROM ").Append(tbname2).Append(";\r\n");
				}
			}
			return sb.Length == 0 ? null : sb.ToString();
		}

		static object syncStructureLock = new object();
		ConcurrentDictionary<string, bool> dicSyced = new ConcurrentDictionary<string, bool>();
		public bool SyncStructure<TEntity>() => this.SyncStructure(typeof(TEntity));
		public bool SyncStructure(params Type[] entityTypes) {
			if (entityTypes == null) return true;
			var syncTypes = entityTypes.Where(a => dicSyced.ContainsKey(a.FullName) == false).ToArray();
			if (syncTypes.Any() == false) return true;
			lock (syncStructureLock) {
				var ddl = this.GetComparisonDDLStatements(syncTypes);
				if (string.IsNullOrEmpty(ddl)) {
					foreach (var syncType in syncTypes) dicSyced.TryAdd(syncType.FullName, true);
					return true;
				}
				var affrows = _orm.Ado.ExecuteNonQuery(CommandType.Text, ddl);
				foreach (var syncType in syncTypes) dicSyced.TryAdd(syncType.FullName, true);
				return affrows > 0;
			}
		}
		public ICodeFirst ConfigEntity<T>(Action<TableFluent<T>> entity) => _commonUtils.ConfigEntity(entity);
		public ICodeFirst ConfigEntity(Type type, Action<TableFluent> entity) => _commonUtils.ConfigEntity(type, entity);
	}
}