using System;
using System.Collections;
using System.Text.RegularExpressions;
using IwbZero.ExprFunctions;
using IwbZero.IwbBase;
using IwbZero.ToolCommon.StringModel;

namespace IwbZero.Expr
{
    public class EvalExpr

    {
        // Fields
        private static IdCollection _functions;
        private static IdCollection _operators;

        private static Regex _RegexDate = new Regex("[0-9]{1,2}/[0-9]{1,2}/[0-9]{2,4}( [0-9]{1,2}:[0-9]{1,2}:[0-9]{1,2}[ ]*(AM|PM)?)?", RegexOptions.IgnoreCase);
        private static Regex _RegexDateAdd = new Regex("[0-9]+(d|m|y)", RegexOptions.IgnoreCase);
        private static Regex _RegexDecimal = new Regex(@"-?[0-9]*\.[0-9]*", RegexOptions.IgnoreCase);
        private static Regex _RegexInt = new Regex("-?[0-9]+", RegexOptions.IgnoreCase);
        private static Regex _RegexVariable = new Regex("[_@a-zA-Z][_@a-zA-Z0-9.$]*", RegexOptions.IgnoreCase);

        // Methods

        public static string Evaluate(ExprObject exprObj)
        {
            string str = "";
            if (exprObj.ChildCount == 0)
            {
                return exprObj.Expr;
            }
            EvaluateAllChildren(exprObj);
            ExprObject expr = null;
            for (int i = 0; i < exprObj.ChildCount; i++)
            {
                ExprObject child = exprObj.GetChild(i);
                if (child.IsOperator)
                {
                    var @operator = child.GetOperator();
                    ExprObject expr3 = exprObj.GetChild(i + 1);
                    if (expr3 != null)
                    {
                        expr = @operator.Calculate(expr, expr3);
                        i++;
                    }
                }
                else if (expr == null)
                {
                    expr = child;
                }
            }

            if (expr != null) str = expr.Expr;
            return str;
        }

        public static string Evaluate(string exprStr)
        {
            string str = exprStr;
            try
            {
                ExprObject exprObj = new ExprObject(exprStr, ExprElements.Expression);
                if (Parse(exprObj, true))
                {
                    str = Evaluate(exprObj);
                }
            }
            catch (Exception)
            {
                // ignored
            }

            return str;
        }

        public static string Evaluate(string exprStr, Hashtable variableValueDic)
        {
            var exprStr2 = TransVariable(exprStr, variableValueDic);
            var str = Evaluate(exprStr2);
            return str;
        }

        #region Methods
        public static ExprElements GetElementType(string expression)
        {
            ExprElements variable = ExprElements.Value;
            expression = expression.Trim();
            Match match = _RegexVariable.Match(expression);
            if (((match.Index == 0)) && (match.Length == expression.Length))
            {
                variable = ExprElements.Variable;
            }
            return variable;
        }

        public static ExprTypes GetExprTypes(string expression)
        {
            ExprTypes date = ExprTypes.String;
            expression = expression.Trim();
            if ((expression.UAndT() == "TRUE") || (expression.UAndT() == "FALSE"))
            {
                return ExprTypes.Bool;
            }
            Match match = _RegexVariable.Match(expression);
            if (((match.Index == 0)) && (match.Length == expression.Length))
            {
                return ExprTypes.Variable;
            }
            match = _RegexDecimal.Match(expression);
            if (((match.Index == 0)) && (match.Length == expression.Length))
            {
                return ExprTypes.Decimal;
            }
            match = _RegexInt.Match(expression);
            if (((match.Index == 0)) && (match.Length == expression.Length))
            {
                return ExprTypes.Integer;
            }
            match = _RegexDateAdd.Match(expression);
            if (((match.Index == 0)) && (match.Length == expression.Length))
            {
                return ExprTypes.DateAdd;
            }
            match = _RegexDate.Match(expression);
            if (((match.Index == 0)) && (match.Length == expression.Length))
            {
                date = ExprTypes.Date;
            }
            return date;
        }

        public static ExprTypes GetExprTypes(ExprObject exprObj)
        {
            ExprTypes @bool = ExprTypes.String;
            if (exprObj.ElementType != ExprElements.String)
            {
                string str = exprObj.Expr.Trim();
                if ((str.UAndT() == "TRUE") || (str.UAndT() == "FALSE"))
                {
                    @bool = ExprTypes.Bool;
                    str = "";
                }
                if (str == "")
                {
                    return @bool;
                }
                Match match = _RegexDecimal.Match(str);
                if (((match.Index == 0)) && (match.Length == str.Length))
                {
                    return ExprTypes.Decimal;
                }
                match = _RegexInt.Match(str);
                if (((match.Index == 0)) && (match.Length == str.Length))
                {
                    return ExprTypes.Integer;
                }
                match = _RegexDateAdd.Match(str);
                if (((match.Index == 0)) && (match.Length == str.Length))
                {
                    return ExprTypes.DateAdd;
                }
                match = _RegexDate.Match(str);
                if (((match.Index == 0)) && (match.Length == str.Length))
                {
                    @bool = ExprTypes.Date;
                }
            }
            return @bool;
        }

        public static DateTime GetLastDayOfMonth(DateTime datetime)
        {
            int year = datetime.Year;
            int month = datetime.Month + 1;
            if (month > 12)
            {
                year++;
                month = 1;
            }
            int day = 1;
            return (new DateTime(year, month, day) - new TimeSpan(1, 0, 0, 0));
        }

        public static DateTime AddDays(DateTime datetime, string toAdd)
        {
            DateTime time = datetime;
            toAdd = toAdd.UAndT();
            int days = toAdd.ValI();
            if (toAdd.IndexOf("D", StringComparison.Ordinal) >= 0)
            {
                return (time + new TimeSpan(days, 0, 0, 0));
            }
            int year;
            int month = datetime.Month;
            int day = datetime.Day;
            if (toAdd.IndexOf("M", StringComparison.Ordinal) >= 0)
            {
                int num5 = ((datetime.Year * 12) + datetime.Month) + days;
                year = num5 / 12;
                month = num5 - (year * 12);
            }
            else
            {
                year = datetime.Year + days;
            }
            DateTime lastDayOfMonth = GetLastDayOfMonth(new DateTime(year, month, 1));
            if (lastDayOfMonth.Day < day)
            {
                day = lastDayOfMonth.Day;
            }
            return new DateTime(year, month, day, datetime.Hour, datetime.Minute, datetime.Second, datetime.Millisecond);
        }

        public static string TransVariable(string exprStr, Hashtable variableValueDic)
        {
            string str = exprStr;
            var variables = GetVariablesInString(exprStr);
            if (variables != null)
            {
                foreach (string v in variables)
                {
                    var value = GetVariableValue(v, variableValueDic);
                    if (value != null)
                    {
                        str = str.Replace(v, value);
                    }
                }
            }
            return str;
        }

        public static string TransGlobalVariable(string exprStr, Hashtable variableValueDic)
        {
            string str = exprStr;
            var variables = GetVariablesInString(exprStr);
            if (variables != null)
            {
                foreach (string v in variables)
                {
                    var value = GetVariableValue(v, variableValueDic);
                    str = str.Replace(v, value);
                }
            }
            return str;
        }

        private static void EvaluateAllChildren(ExprObject exprObj)
        {
            if (exprObj != null)
            {
                for (int i = 0; i < exprObj.ChildCount; i++)
                {
                    ExprObject child = exprObj.GetChild(i);
                    EvaluateAllChildren(child);
                    if (child != null)
                    {
                        string str = null;
                        switch (child.ElementType)
                        {
                            case ExprElements.Function:
                                str = EvaluateFunction(child);
                                break;

                            case ExprElements.Variable:
                                //str = TransSessionVariables(child.Expr);
                                break;

                            case ExprElements.Expression:
                                str = Evaluate(child);
                                break;
                        }
                        if (str != null)
                        {
                            child.Expr = str;
                            child.ElementType = ExprElements.Value;
                        }
                    }
                }
            }
        }

        public static string EvaluateFunction(ExprObject exprObj)
        {
            string str = "";
            string functionId = exprObj.Expr.UAndT();

            if (_functions == null)
            {
                _functions = new IdCollection();
            }
            IwbFunction function = (IwbFunction)_functions[functionId];
            if (function == null)
            {
                function = IwbFunction.LoadById(functionId);
                if (function != null)
                {
                    _functions.Add(function);
                }
            }
            if (function != null)
            {
                str = function.InvokeFunction(exprObj);
            }
            return str;
        }
        private static bool IsStartingParent(char pcChar)
        {
            return (pcChar == '(');
        }

        private static bool IsStartingQuote(char pcChar)
        {
            if (pcChar != '"')
            {
                return (pcChar == '\'');
            }
            return true;
        }

        private static int GetStaticString(string pcString, char pcQuote)
        {
            int length = pcString.Length;
            for (int i = 0; i < length; i++)
            {
                char ch = pcString[i];
                if (ch == pcQuote)
                {
                    return i;
                }
                if ((ch == '\\') && (i < (length - 1)))
                {
                    switch (pcString[i + 1])
                    {
                        case '"':
                        case '\'':
                            i++;
                            break;
                    }
                }
            }
            return -1;
        }

        private static int GetClosingParenthesis(string pcString)
        {
            int num = -1;
            int length = pcString.Length;
            int num3 = 0;
            for (int i = 0; i < length; i++)
            {
                char pcQuote = pcString[i];
                if (((pcQuote == '"') || (pcQuote == '\'')) && (i < (length - 1)))
                {
                    int staticString = GetStaticString(pcString.Substring(i + 1), pcQuote);
                    if (staticString >= 0)
                    {
                        i += staticString + 1;
                    }
                }
                if (pcQuote == '(')
                {
                    num3++;
                }
                else if (pcQuote == ')')
                {
                    if (num3 == 0)
                    {
                        num = i;
                    }
                    else
                    {
                        num3--;
                    }
                }
            }
            return num;
        }
        #endregion

        #region 变量赋值

        public static ArrayList GetVariablesInString(string pcString)
        {
            var arr1 = GetStringVariables(pcString) ?? new ArrayList();
            var arr2 = GetStringVariables(pcString, IwbVariableType.Global) ?? new ArrayList();
            arr1.AddRange(arr2);
            return arr1;
        }
        public static ArrayList GetStringVariables(string pcString, string variableHeader = IwbVariableType.Local)
        {
            int index;
            ArrayList poArrayList = new ArrayList();
            for (int i = pcString.IndexOf(variableHeader, StringComparison.Ordinal); i >= 0; i = pcString.IndexOf(variableHeader, index, StringComparison.Ordinal))
            {
                string pcName = variableHeader;
                for (index = i + variableHeader.Length; index < pcString.Length; index++)
                {
                    char ch = pcString[index];
                    if ((((ch < 'a') || (ch > 'z')) && ((ch < 'A') || (ch > 'Z'))) && (((ch < '0') || (ch > '9')) && (ch != '_')))
                    {
                        break;
                    }
                    pcName = pcName + ch;
                }
                poArrayList.InsertIdentifier(pcName);
            }
            return poArrayList;
        }

        public static string GetVariableValue(string pcVariable, Hashtable variableValueDic)
        {
            var key = pcVariable.UAndT();
            foreach (DictionaryEntry dic in variableValueDic)
            {
                if (dic.Key.UAndT() == key)
                {
                    return ((IwbRtVariable)dic.Value).GetStringValue();
                }
            }

            return null;
        }

        #endregion 变量赋值

        #region 表达式转换为ExprObject

        public static bool Parse(ExprObject exprObj, bool plThrowException)
        {
            bool flag = true;
            try
            {
                Parse(exprObj);
            }
            catch (Exception)
            {
                if (plThrowException)
                {
                    throw;
                }
                flag = false;
            }
            return flag;
        }

        private static void Parse(ExprObject exprObj, string pcExpression = null)
        {
            pcExpression = (pcExpression ?? exprObj.Expr)?.Trim() ?? "";
            switch (GetExprTypes(pcExpression))
            {
                case ExprTypes.Integer:
                case ExprTypes.Decimal:
                case ExprTypes.Date:
                case ExprTypes.Bool:
                    exprObj.AddChild(new ExprObject(pcExpression, ExprElements.Value));
                    return;

                case ExprTypes.Variable:
                    exprObj.AddChild(new ExprObject(pcExpression, ExprElements.Variable));
                    return;
            }
            ExprObject exprObject = null;
            string str = "";
            while (pcExpression != "")
            {
                var poNode = GetNextElement(ref pcExpression);
                if (poNode != null)
                {
                    if (((poNode.ElementType != ExprElements.String) && (poNode.Expr == "-")) && ((exprObject == null) || exprObject.IsOperator))
                    {
                        str = "-";
                    }
                    else
                    {
                        poNode.Expr = str + poNode.Expr;
                        exprObj.AddChild(poNode);
                        str = "";
                    }
                    exprObject = poNode;
                }
            }
            CollapseSyntaxTree(exprObj);
        }

        private static ExprObject GetNextElement(ref string pcString)
        {
            ExprObject exprObj = null;
            string pcExpr = "";
            bool flag = false;
            int length = pcString.Length;
            for (int i = 0; i < length; i++)
            {
                char pcChar = pcString[i];
                string str2 = "";
                if (i < (length - 1))
                {
                    str2 = pcString.Substring(i + 1);
                }

                int closingParenthesis;
                if (IsStartingParent(pcChar))
                {
                    closingParenthesis = GetClosingParenthesis(str2);
                    if (closingParenthesis < 0)
                    {
                        throw new Exception("No ending parenthesis.");
                    }
                    if (pcExpr != "")
                    {
                        string pcExpression = pcString.Substring(i + 1, closingParenthesis);
                        exprObj = new ExprObject(pcExpr, ExprElements.Function);
                        if (pcExpression != "")
                        {
                            Parse(exprObj, pcExpression);
                            CollapseFunctionCall(exprObj);
                        }
                    }
                    else
                    {
                        exprObj = new ExprObject(pcString.Substring(i + 1, closingParenthesis), ExprElements.Expression);
                        Parse(exprObj, exprObj.Expr);
                    }
                    i = (i + closingParenthesis) + 2;
                    flag = true;
                }
                else if (IsStartingQuote(pcChar))
                {
                    if (pcExpr != "")
                    {
                        throw new Exception("Operand required.");
                    }
                    closingParenthesis = GetStaticString(str2, pcChar);
                    if (closingParenthesis < 0)
                    {
                        throw new Exception("No ending quote.");
                    }
                    exprObj = new ExprObject(pcString.Substring(i + 1, closingParenthesis), ExprElements.String);
                    i = (i + closingParenthesis) + 2;
                    flag = true;
                }
                else
                {
                    ExprOperator @operator = GetOperator(pcString.Substring(i));
                    bool flag2 = true;
                    if (i == (length - 1))
                    {
                        pcString = "";
                    }
                    if (((@operator != null) && (pcExpr != "")) && (GetExprTypes(pcExpr) == ExprTypes.String))
                    {
                        @operator = null;
                    }
                    if (@operator != null)
                    {
                        if (pcExpr == "")
                        {
                            exprObj = new ExprObject(@operator.Id, ExprElements.Operator);
                            i += @operator.Symbol.Length;
                        }
                        flag = true;
                        flag2 = false;
                    }
                    else if ((pcExpr == "") && (pcChar == ' '))
                    {
                        flag2 = false;
                    }
                    if (flag2)
                    {
                        pcExpr = pcExpr + pcChar.ToString();
                    }
                    if ((pcExpr != "") && ((@operator != null) || (i == (length - 1))))
                    {
                        ExprElements elementType = GetElementType(pcExpr);
                        exprObj = new ExprObject(pcExpr, elementType);
                        flag = true;
                    }
                }
                if (flag)
                {
                    if (i < pcString.Length)
                    {
                        pcString = pcString.Substring(i);
                        return exprObj;
                    }
                    pcString = "";
                    return exprObj;
                }
            }
            return null;
        }

        private static ExprOperator GetOperator(string pcString)
        {
            foreach (ExprOperator operator2 in Operators)
            {
                if (operator2.IsSymbolMatched(pcString))
                {
                    return operator2;
                }
            }
            return null;
        }

        /// <summary>
        /// 构建表达式树
        /// </summary>
        /// <param name="poExprObject"></param>
        private static void CollapseSyntaxTree(ExprObject poExprObject)
        {
            int level = -1;
            int piStart = -1;
            int piLevel = 100;
            for (int i = 0; i < poExprObject.ChildCount; i++)
            {
                ExprOperator @operator = poExprObject.GetChild(i).GetOperator();
                if (i == (poExprObject.ChildCount - 1))
                {
                    @operator = new ExprOperator("", "", piLevel, 0);
                    i++;
                }
                if (@operator != null)
                {
                    if (piLevel > @operator.Level)
                    {
                        piLevel = @operator.Level;
                    }
                    if (@operator.Level > level)
                    {
                        piStart = i - @operator.LeftOperands;
                    }
                    else if (@operator.Level < level)
                    {
                        CollapseSyntaxTree(poExprObject, piStart, i - 1);
                        CollapseSyntaxTree(poExprObject);
                    }
                    level = @operator.Level;
                }
            }
        }

        /// <summary>
        /// 构建表达式树
        /// </summary>
        /// <param name="poExprObject"></param>
        /// <param name="piStart"></param>
        /// <param name="piEnd"></param>
        private static void CollapseSyntaxTree(ExprObject poExprObject, int piStart, int piEnd)
        {
            if (piEnd > piStart)
            {
                ExprObject poNode = new ExprObject("", ExprElements.Expression);
                for (int i = piStart; i <= piEnd; i++)
                {
                    ExprObject child = poExprObject.GetChild(piStart);
                    poExprObject.RemoveChildAt(piStart);
                    poNode.AddChild(child);
                    poNode.Expr = poNode.Expr + " " + child.Expr;
                }
                poExprObject.InsertChildAt(poNode, piStart);
            }
        }

        private static void CollapseFunctionCall(ExprObject poExprObject)
        {
            if (poExprObject.ChildCount > 1)
            {
                bool flag = false;
                foreach (ExprObject expr in poExprObject.ChildNodes)
                {
                    if (expr.IsOperator && (expr.Expr.Trim() == ","))
                    {
                        flag = true;
                        break;
                    }
                }
                if (!flag)
                {
                    ExprObject poNode = new ExprObject(poExprObject.Expr, ExprElements.Expression);
                    foreach (ExprObject expr3 in poExprObject.ChildNodes)
                    {
                        poNode.AddChild(expr3);
                    }
                    poExprObject.ChildNodes.Clear();
                    poExprObject.AddChild(poNode);
                }
            }
        }

        public static IdCollection Operators =>
            _operators ?? (_operators = new IdCollection
            {
                new ExprOperator("+", "+", 4, 1),
                new ExprOperator("-", "-", 4, 1),
                new ExprOperator(",", ",", 0, 0),
                new ExprOperator("and", " and ", 1, 1),
                new ExprOperator("&&", " && ", 1, 1),
                new ExprOperator("or", " or ", 1, 1),
                new ExprOperator("||", " || ", 1, 1),
                new ExprOperator("not", "not ", 2, 0),
                new ExprOperator("!", "! ", 2, 0),
                new ExprOperator("!=", "!=", 3, 1),
                new ExprOperator("=", "=", 3, 1),
                new ExprOperator(">=", ">=", 3, 1),
                new ExprOperator(">", ">", 3, 1),
                new ExprOperator("<=", "<=", 3, 1),
                new ExprOperator("<", "<", 3, 1),
                new ExprOperator("like", " like ", 3, 1),
                new ExprOperator("*", "*", 5, 1),
                new ExprOperator("/", "/", 5, 1),
                new ExprOperator("%", "%", 5, 1)
            });

        #endregion 表达式转换为ExprObject
    }
}