using FreeSql.Internal;
using FreeSql.Internal.Model;
using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;
using System.Text;

namespace FreeSql.Oracle
{
    class OracleExpression : CommonExpression
    {

        public OracleExpression(CommonUtils common) : base(common) { }

        public override string ExpressionLambdaToSqlOther(Expression exp, ExpTSC tsc)
        {
            Func<Expression, string> getExp = exparg => ExpressionLambdaToSql(exparg, tsc);
            switch (exp.NodeType)
            {
                case ExpressionType.Convert:
                    var operandExp = (exp as UnaryExpression)?.Operand;
                    var gentype = exp.Type.NullableTypeOrThis();
                    if (gentype != operandExp.Type.NullableTypeOrThis())
                    {
                        switch (exp.Type.NullableTypeOrThis().ToString())
                        {
                            //case "System.Boolean": return $"({getExp(operandExp)} not in ('0','false'))";
                            case "System.Byte": return $"cast({getExp(operandExp)} as number)";
                            case "System.Char": return $"substr(to_char({getExp(operandExp)}), 1, 1)";
                            case "System.DateTime": return $"to_timestamp({getExp(operandExp)},'YYYY-MM-DD HH24:MI:SS.FF6')";
                            case "System.Decimal": return $"cast({getExp(operandExp)} as number)";
                            case "System.Double": return $"cast({getExp(operandExp)} as number)";
                            case "System.Int16":
                            case "System.Int32":
                            case "System.Int64":
                            case "System.SByte": return $"cast({getExp(operandExp)} as number)";
                            case "System.Single": return $"cast({getExp(operandExp)} as number)";
                            case "System.String": return $"to_char({getExp(operandExp)})";
                            case "System.UInt16":
                            case "System.UInt32":
                            case "System.UInt64": return $"cast({getExp(operandExp)} as number)";
                            case "System.Guid": return $"substr(to_char({getExp(operandExp)}), 1, 36)";
                        }
                    }
                    break;
                case ExpressionType.Call:
                    var callExp = exp as MethodCallExpression;

                    switch (callExp.Method.Name)
                    {
                        case "Parse":
                        case "TryParse":
                            switch (callExp.Method.DeclaringType.NullableTypeOrThis().ToString())
                            {
                                //case "System.Boolean": return $"({getExp(callExp.Arguments[0])} not in ('0','false'))";
                                case "System.Byte": return $"cast({getExp(callExp.Arguments[0])} as number)";
                                case "System.Char": return $"substr(to_char({getExp(callExp.Arguments[0])}), 1, 1)";
                                case "System.DateTime": return $"to_timestamp({getExp(callExp.Arguments[0])},'YYYY-MM-DD HH24:MI:SS.FF6')";
                                case "System.Decimal": return $"cast({getExp(callExp.Arguments[0])} as number)";
                                case "System.Double": return $"cast({getExp(callExp.Arguments[0])} as number)";
                                case "System.Int16":
                                case "System.Int32":
                                case "System.Int64":
                                case "System.SByte": return $"cast({getExp(callExp.Arguments[0])} as number)";
                                case "System.Single": return $"cast({getExp(callExp.Arguments[0])} as number)";
                                case "System.UInt16":
                                case "System.UInt32":
                                case "System.UInt64": return $"cast({getExp(callExp.Arguments[0])} as number)";
                                case "System.Guid": return $"substr(to_char({getExp(callExp.Arguments[0])}), 1, 36)";
                            }
                            break;
                        case "NewGuid":
                            break;
                        case "Next":
                            if (callExp.Object?.Type == typeof(Random)) return "cast(dbms_random.value*1000000000 as smallint)";
                            break;
                        case "NextDouble":
                            if (callExp.Object?.Type == typeof(Random)) return "dbms_random.value";
                            break;
                        case "Random":
                            if (callExp.Method.DeclaringType.IsNumberType()) return "dbms_random.value";
                            break;
                        case "ToString":
                            if (callExp.Object != null) return $"to_char({getExp(callExp.Object)})";
                            break;
                    }

                    var objExp = callExp.Object;
                    var objType = objExp?.Type;
                    if (objType?.FullName == "System.Byte[]") return null;

                    var argIndex = 0;
                    if (objType == null && callExp.Method.DeclaringType == typeof(Enumerable))
                    {
                        objExp = callExp.Arguments.FirstOrDefault();
                        objType = objExp?.Type;
                        argIndex++;
                    }
                    if (objType == null) objType = callExp.Method.DeclaringType;
                    if (objType != null || objType.IsArray || typeof(IList).IsAssignableFrom(callExp.Method.DeclaringType))
                    {
                        var left = objExp == null ? null : getExp(objExp);
                        switch (callExp.Method.Name)
                        {
                            case "Contains":
                                //判断 in
                                return $"({getExp(callExp.Arguments[argIndex])}) in {left}";
                        }
                    }
                    break;
                case ExpressionType.NewArrayInit:
                    var arrExp = exp as NewArrayExpression;
                    var arrSb = new StringBuilder();
                    arrSb.Append("(");
                    for (var a = 0; a < arrExp.Expressions.Count; a++)
                    {
                        if (a > 0) arrSb.Append(",");
                        arrSb.Append(getExp(arrExp.Expressions[a]));
                    }
                    if (arrSb.Length == 1) arrSb.Append("NULL");
                    return arrSb.Append(")").ToString();
                case ExpressionType.ListInit:
                    var listExp = exp as ListInitExpression;
                    var listSb = new StringBuilder();
                    listSb.Append("(");
                    for (var a = 0; a < listExp.Initializers.Count; a++)
                    {
                        if (listExp.Initializers[a].Arguments.Any() == false) continue;
                        if (a > 0) listSb.Append(",");
                        listSb.Append(getExp(listExp.Initializers[a].Arguments.FirstOrDefault()));
                    }
                    if (listSb.Length == 1) listSb.Append("NULL");
                    return listSb.Append(")").ToString();
                case ExpressionType.New:
                    var newExp = exp as NewExpression;
                    if (typeof(IList).IsAssignableFrom(newExp.Type))
                    {
                        if (newExp.Arguments.Count == 0) return "(NULL)";
                        if (typeof(IEnumerable).IsAssignableFrom(newExp.Arguments[0].Type) == false) return "(NULL)";
                        return getExp(newExp.Arguments[0]);
                    }
                    return null;
            }
            return null;
        }

        public override string ExpressionLambdaToSqlMemberAccessString(MemberExpression exp, ExpTSC tsc)
        {
            if (exp.Expression == null)
            {
                switch (exp.Member.Name)
                {
                    case "Empty": return "''";
                }
                return null;
            }
            var left = ExpressionLambdaToSql(exp.Expression, tsc);
            switch (exp.Member.Name)
            {
                case "Length": return $"length({left})";
            }
            return null;
        }
        public override string ExpressionLambdaToSqlMemberAccessDateTime(MemberExpression exp, ExpTSC tsc)
        {
            if (exp.Expression == null)
            {
                switch (exp.Member.Name)
                {
                    case "Now": return "systimestamp";
                    case "UtcNow": return "sys_extract_utc(systimestamp)";
                    case "Today": return "trunc(systimestamp)";
                    case "MinValue": return "to_timestamp('0001-01-01 00:00:00','YYYY-MM-DD HH24:MI:SS.FF6')";
                    case "MaxValue": return "to_timestamp('9999-12-31 23:59:59','YYYY-MM-DD HH24:MI:SS.FF6')";
                }
                return null;
            }
            var left = ExpressionLambdaToSql(exp.Expression, tsc);
            switch (exp.Member.Name)
            {
                case "Date": return $"trunc({left})";
                case "TimeOfDay": return $"({left}-trunc({left}))";
                case "DayOfWeek": return $"case when to_char({left})='7' then 0 else cast(to_char({left}) as number) end";
                case "Day": return $"cast(to_char({left},'DD') as number)";
                case "DayOfYear": return $"cast(to_char({left},'DDD') as number)";
                case "Month": return $"cast(to_char({left},'MM') as number)";
                case "Year": return $"cast(to_char({left},'YYYY') as number)";
                case "Hour": return $"cast(to_char({left},'HH24') as number)";
                case "Minute": return $"cast(to_char({left},'MI') as number)";
                case "Second": return $"cast(to_char({left},'SS') as number)";
                case "Millisecond": return $"cast(to_char({left},'FF3') as number)";
                case "Ticks": return $"cast(to_char({left},'FF7') as number)";
            }
            return null;
        }
        public override string ExpressionLambdaToSqlMemberAccessTimeSpan(MemberExpression exp, ExpTSC tsc)
        {
            if (exp.Expression == null)
            {
                switch (exp.Member.Name)
                {
                    case "Zero": return "numtodsinterval(0,'second')";
                    case "MinValue": return "numtodsinterval(-233720368.5477580,'second')";
                    case "MaxValue": return "numtodsinterval(233720368.5477580,'second')";
                }
                return null;
            }
            var left = ExpressionLambdaToSql(exp.Expression, tsc);
            switch (exp.Member.Name)
            {
                case "Days": return $"extract(day from {left})";
                case "Hours": return $"extract(hour from {left})";
                case "Milliseconds": return $"cast(substr(extract(second from {left})-floor(extract(second from {left})),2,3) as number)";
                case "Minutes": return $"extract(minute from {left})";
                case "Seconds": return $"floor(extract(second from {left}))";
                case "Ticks": return $"(extract(day from {left})*86400+extract(hour from {left})*3600+extract(minute from {left})*60+extract(second from {left}))*10000000";
                case "TotalDays": return $"extract(day from {left})";
                case "TotalHours": return $"(extract(day from {left})*24+extract(hour from {left}))";
                case "TotalMilliseconds": return $"(extract(day from {left})*86400+extract(hour from {left})*3600+extract(minute from {left})*60+extract(second from {left}))*1000";
                case "TotalMinutes": return $"(extract(day from {left})*1440+extract(hour from {left})*60+extract(minute from {left}))";
                case "TotalSeconds": return $"(extract(day from {left})*86400+extract(hour from {left})*3600+extract(minute from {left})*60+extract(second from {left}))";
            }
            return null;
        }

        public override string ExpressionLambdaToSqlCallString(MethodCallExpression exp, ExpTSC tsc)
        {
            Func<Expression, string> getExp = exparg => ExpressionLambdaToSql(exparg, tsc);
            if (exp.Object == null)
            {
                switch (exp.Method.Name)
                {
                    case "IsNullOrEmpty":
                        var arg1 = getExp(exp.Arguments[0]);
                        return $"({arg1} is null or {arg1} = '')";
                    case "IsNullOrWhiteSpace":
                        var arg2 = getExp(exp.Arguments[0]);
                        return $"({arg2} is null or {arg2} = '' or ltrim({arg2}) = '')";
                    case "Concat":
                        return _common.StringConcat(exp.Arguments.Select(a => getExp(a)).ToArray(), null);
                }
            }
            else
            {
                var left = getExp(exp.Object);
                switch (exp.Method.Name)
                {
                    case "StartsWith":
                    case "EndsWith":
                    case "Contains":
                        var args0Value = getExp(exp.Arguments[0]);
                        if (args0Value == "NULL") return $"({left}) IS NULL";
                        if (exp.Method.Name == "StartsWith") return $"({left}) LIKE {(args0Value.EndsWith("'") ? args0Value.Insert(args0Value.Length - 1, "%") : $"(to_char({args0Value})||'%')")}";
                        if (exp.Method.Name == "EndsWith") return $"({left}) LIKE {(args0Value.StartsWith("'") ? args0Value.Insert(1, "%") : $"('%'||to_char({args0Value}))")}";
                        if (args0Value.StartsWith("'") && args0Value.EndsWith("'")) return $"({left}) LIKE {args0Value.Insert(1, "%").Insert(args0Value.Length, "%")}";
                        return $"({left}) LIKE ('%'||to_char({args0Value})||'%')";
                    case "ToLower": return $"lower({left})";
                    case "ToUpper": return $"upper({left})";
                    case "Substring":
                        var substrArgs1 = getExp(exp.Arguments[0]);
                        if (long.TryParse(substrArgs1, out var testtrylng1)) substrArgs1 = (testtrylng1 + 1).ToString();
                        else substrArgs1 += "+1";
                        if (exp.Arguments.Count == 1) return $"substr({left}, {substrArgs1})";
                        return $"substr({left}, {substrArgs1}, {getExp(exp.Arguments[1])})";
                    case "IndexOf":
                        var indexOfFindStr = getExp(exp.Arguments[0]);
                        if (exp.Arguments.Count > 1 && exp.Arguments[1].Type.FullName == "System.Int32")
                        {
                            var locateArgs1 = getExp(exp.Arguments[1]);
                            if (long.TryParse(locateArgs1, out var testtrylng2)) locateArgs1 = (testtrylng2 + 1).ToString();
                            else locateArgs1 += "+1";
                            return $"(instr({left}, {indexOfFindStr}, {locateArgs1}, 1)-1)";
                        }
                        return $"(instr({left}, {indexOfFindStr}, 1, 1))-1";
                    case "PadLeft":
                        if (exp.Arguments.Count == 1) return $"lpad({left}, {getExp(exp.Arguments[0])}, ' ')";
                        return $"lpad({left}, {getExp(exp.Arguments[0])}, {getExp(exp.Arguments[1])})";
                    case "PadRight":
                        if (exp.Arguments.Count == 1) return $"rpad({left}, {getExp(exp.Arguments[0])}, ' ')";
                        return $"rpad({left}, {getExp(exp.Arguments[0])}, {getExp(exp.Arguments[1])})";
                    case "Trim":
                    case "TrimStart":
                    case "TrimEnd":
                        if (exp.Arguments.Count == 0)
                        {
                            if (exp.Method.Name == "Trim") return $"trim({left})";
                            if (exp.Method.Name == "TrimStart") return $"ltrim({left})";
                            if (exp.Method.Name == "TrimEnd") return $"rtrim({left})";
                        }
                        foreach (var argsTrim02 in exp.Arguments)
                        {
                            var argsTrim01s = new[] { argsTrim02 };
                            if (argsTrim02.NodeType == ExpressionType.NewArrayInit)
                            {
                                var arritem = argsTrim02 as NewArrayExpression;
                                argsTrim01s = arritem.Expressions.ToArray();
                            }
                            foreach (var argsTrim01 in argsTrim01s)
                            {
                                if (exp.Method.Name == "Trim") left = $"trim(both {getExp(argsTrim01)} from {left})";
                                if (exp.Method.Name == "TrimStart") left = $"ltrim({left},{getExp(argsTrim01)})";
                                if (exp.Method.Name == "TrimEnd") left = $"rtrim({left},{getExp(argsTrim01)})";
                            }
                        }
                        return left;
                    case "Replace": return $"replace({left}, {getExp(exp.Arguments[0])}, {getExp(exp.Arguments[1])})";
                    case "CompareTo": return $"case when {left} = {getExp(exp.Arguments[0])} then 0 when {left} > {getExp(exp.Arguments[0])} then 1 else -1 end";
                    case "Equals": return $"({left} = {getExp(exp.Arguments[0])})";
                }
            }
            return null;
        }
        public override string ExpressionLambdaToSqlCallMath(MethodCallExpression exp, ExpTSC tsc)
        {
            Func<Expression, string> getExp = exparg => ExpressionLambdaToSql(exparg, tsc);
            switch (exp.Method.Name)
            {
                case "Abs": return $"abs({getExp(exp.Arguments[0])})";
                case "Sign": return $"sign({getExp(exp.Arguments[0])})";
                case "Floor": return $"floor({getExp(exp.Arguments[0])})";
                case "Ceiling": return $"ceil({getExp(exp.Arguments[0])})";
                case "Round":
                    if (exp.Arguments.Count > 1 && exp.Arguments[1].Type.FullName == "System.Int32") return $"round({getExp(exp.Arguments[0])}, {getExp(exp.Arguments[1])})";
                    return $"round({getExp(exp.Arguments[0])})";
                case "Exp": return $"exp({getExp(exp.Arguments[0])})";
                case "Log":
                    if (exp.Arguments.Count > 1) return $"log({getExp(exp.Arguments[1])},{getExp(exp.Arguments[0])})";
                    return $"log(2.7182818284590451,{getExp(exp.Arguments[0])})";
                case "Log10": return $"log(10,{getExp(exp.Arguments[0])})";
                case "Pow": return $"power({getExp(exp.Arguments[0])}, {getExp(exp.Arguments[1])})";
                case "Sqrt": return $"sqrt({getExp(exp.Arguments[0])})";
                case "Cos": return $"cos({getExp(exp.Arguments[0])})";
                case "Sin": return $"sin({getExp(exp.Arguments[0])})";
                case "Tan": return $"tan({getExp(exp.Arguments[0])})";
                case "Acos": return $"acos({getExp(exp.Arguments[0])})";
                case "Asin": return $"asin({getExp(exp.Arguments[0])})";
                case "Atan": return $"atan({getExp(exp.Arguments[0])})";
                //case "Atan2": return $"atan2({getExp(exp.Arguments[0])}, {getExp(exp.Arguments[1])})";
                case "Truncate": return $"trunc({getExp(exp.Arguments[0])}, 0)";
            }
            return null;
        }
        public override string ExpressionLambdaToSqlCallDateTime(MethodCallExpression exp, ExpTSC tsc)
        {
            Func<Expression, string> getExp = exparg => ExpressionLambdaToSql(exparg, tsc);
            if (exp.Object == null)
            {
                switch (exp.Method.Name)
                {
                    case "Compare": return $"extract(day from ({getExp(exp.Arguments[0])}-({getExp(exp.Arguments[1])})))";
                    case "DaysInMonth": return $"cast(to_char(last_day(({getExp(exp.Arguments[0])})||'-'||({getExp(exp.Arguments[1])})||'-01'),'DD') as number)";
                    case "Equals": return $"({getExp(exp.Arguments[0])} = {getExp(exp.Arguments[1])})";

                    case "IsLeapYear":
                        var isLeapYearArgs1 = getExp(exp.Arguments[0]);
                        return $"(mod({isLeapYearArgs1},4)=0 AND mod({isLeapYearArgs1},100)<>0 OR mod({isLeapYearArgs1},400)=0)";

                    case "Parse": return $"to_timestamp({getExp(exp.Arguments[0])},'YYYY-MM-DD HH24:MI:SS.FF6')";
                    case "ParseExact":
                    case "TryParse":
                    case "TryParseExact": return $"to_timestamp({getExp(exp.Arguments[0])},'YYYY-MM-DD HH24:MI:SS.FF6')";
                }
            }
            else
            {
                var left = getExp(exp.Object);
                var args1 = exp.Arguments.Count == 0 ? null : getExp(exp.Arguments[0]);
                switch (exp.Method.Name)
                {
                    case "Add": return $"({left}+{args1})";
                    case "AddDays": return $"({left}+{args1})";
                    case "AddHours": return $"({left}+({args1})/24)";
                    case "AddMilliseconds": return $"({left}+({args1})/86400000)";
                    case "AddMinutes": return $"({left}+({args1})/1440)";
                    case "AddMonths": return $"add_months({left},{args1})";
                    case "AddSeconds": return $"({left}+({args1})/86400)";
                    case "AddTicks": return $"({left}+({args1})/864000000000)";
                    case "AddYears": return $"add_months({left},({args1})*12)";
                    case "Subtract":
                        switch ((exp.Arguments[0].Type.IsNullableType() ? exp.Arguments[0].Type.GenericTypeArguments.FirstOrDefault() : exp.Arguments[0].Type).FullName)
                        {
                            case "System.DateTime": return $"numtodsinterval(({left}+0)-({args1}+0),'day')";
                            case "System.TimeSpan": return $"({left}-{args1})";
                        }
                        break;
                    case "Equals": return $"({left} = {getExp(exp.Arguments[0])})";
                    case "CompareTo": return $"extract(day from ({left}-({getExp(exp.Arguments[0])})))";
                    case "ToString": return $"to_char({left},'YYYY-MM-DD HH24:MI:SS.FF6')";
                }
            }
            return null;
        }
        public override string ExpressionLambdaToSqlCallTimeSpan(MethodCallExpression exp, ExpTSC tsc)
        {
            Func<Expression, string> getExp = exparg => ExpressionLambdaToSql(exparg, tsc);
            if (exp.Object == null)
            {
                switch (exp.Method.Name)
                {
                    case "Compare": return $"extract(day from ({getExp(exp.Arguments[0])}-({getExp(exp.Arguments[1])})))";
                    case "Equals": return $"({getExp(exp.Arguments[0])} = {getExp(exp.Arguments[1])})";
                    case "FromDays": return $"numtodsinterval(({getExp(exp.Arguments[0])})*{(long)60 * 60 * 24},'second')";
                    case "FromHours": return $"numtodsinterval(({getExp(exp.Arguments[0])})*{(long)60 * 60},'second')";
                    case "FromMilliseconds": return $"numtodsinterval(({getExp(exp.Arguments[0])})/1000,'second')";
                    case "FromMinutes": return $"numtodsinterval(({getExp(exp.Arguments[0])})*60,'second')";
                    case "FromSeconds": return $"numtodsinterval(({getExp(exp.Arguments[0])}),'second')";
                    case "FromTicks": return $"numtodsinterval(({getExp(exp.Arguments[0])})/10000000,'second')";
                    case "Parse": return $"cast({getExp(exp.Arguments[0])} as interval day(9) to second(7))";
                    case "ParseExact":
                    case "TryParse":
                    case "TryParseExact": return $"cast({getExp(exp.Arguments[0])} as interval day(9) to second(7))";
                }
            }
            else
            {
                var left = getExp(exp.Object);
                var args1 = exp.Arguments.Count == 0 ? null : getExp(exp.Arguments[0]);
                switch (exp.Method.Name)
                {
                    case "Add": return $"({left}+{args1})";
                    case "Subtract": return $"({left}-({args1}))";
                    case "Equals": return $"({left} = {getExp(exp.Arguments[0])})";
                    case "CompareTo": return $"extract(day from ({left}-({getExp(exp.Arguments[0])})))";
                    case "ToString": return $"to_char({left})";
                }
            }
            return null;
        }
        public override string ExpressionLambdaToSqlCallConvert(MethodCallExpression exp, ExpTSC tsc)
        {
            Func<Expression, string> getExp = exparg => ExpressionLambdaToSql(exparg, tsc);
            if (exp.Object == null)
            {
                switch (exp.Method.Name)
                {
                    //case "ToBoolean": return $"({getExp(exp.Arguments[0])} not in ('0','false'))";
                    case "ToByte": return $"cast({getExp(exp.Arguments[0])} as number)";
                    case "ToChar": return $"substr(to_char({getExp(exp.Arguments[0])}), 1, 1)";
                    case "ToDateTime": return $"to_timestamp({getExp(exp.Arguments[0])},'YYYY-MM-DD HH24:MI:SS.FF6')";
                    case "ToDecimal": return $"cast({getExp(exp.Arguments[0])} as number)";
                    case "ToDouble": return $"cast({getExp(exp.Arguments[0])} as number)";
                    case "ToInt16":
                    case "ToInt32":
                    case "ToInt64":
                    case "ToSByte": return $"cast({getExp(exp.Arguments[0])} as number)";
                    case "ToSingle": return $"cast({getExp(exp.Arguments[0])} as number)";
                    case "ToString": return $"to_char({getExp(exp.Arguments[0])})";
                    case "ToUInt16":
                    case "ToUInt32":
                    case "ToUInt64": return $"cast({getExp(exp.Arguments[0])} as number)";
                }
            }
            return null;
        }
    }
}