using System;
using System.Collections;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace CoolCalculator
{
    class MathValue
    {
        private ArrayList args = new ArrayList();
        public MathValue(string input)
        {
            Console.WriteLine("Parsing " + input);
            int paranthesisLevel = 0;
            int paranthesisStart = -1;
            int numberStart = -1;
            int functionNameStart = -1;
            for(int i = 0; i < input.Length; i++)
            {
                char currChar = input[i];
                if(currChar == '(')
                {
                    if(paranthesisLevel==0)
                    {
                        paranthesisStart = i;
                        if (numberStart != -1)
                        {
                            args.Add(Double.Parse(input.Substring(numberStart, i - numberStart)));
                            numberStart = -1;
                        }
                        else if(functionNameStart != -1)
                        {
                            args.Add(input.Substring(functionNameStart, i - functionNameStart));
                            functionNameStart = -1;
                        }
                    }
                    paranthesisLevel++;
                }
                else if(currChar == ')')
                {
                    paranthesisLevel--;
                    if(paranthesisLevel==0)
                    {
                        args.Add(new MathValue(input.Substring(paranthesisStart+1, i-paranthesisStart-1)));
                        paranthesisStart = 0;
                    }
                }
                else if(paranthesisLevel!=0)
                {
                    //do nothing, we let other math values do that parsing...
                }
                else if(isAllowedOperator(currChar))
                {
                    if(numberStart!=-1)
                    {
                        args.Add(Double.Parse(input.Substring(numberStart, i - numberStart)));
                        numberStart = -1;
                    }
                    args.Add(currChar);
                }
                else if(isNumeric(currChar) || currChar == Convert.ToChar(CultureInfo.CurrentCulture.NumberFormat.NumberDecimalSeparator))
                {
                    if(functionNameStart != -1)
                    {
                        throw new Exception("Fuck you no loose numbers next to a function you wanker");
                    }
                    if(numberStart==-1)
                    {
                        numberStart = i;
                    }
                }
                else
                {
                    //function call
                    if(functionNameStart == -1)
                    {
                        functionNameStart = i;
                    }
                }
            }
            if(numberStart != -1)
            {
                //Parse remaining numbers
                args.Add(Double.Parse(input.Substring(numberStart, input.Length - numberStart)));
            }
            Console.WriteLine("Done parsing!");
        }
        private bool isAllowedOperator(char a)
        {
            return a == '*' || a == '/' || a == '+' || a == '-';
        }
        private bool isNumeric(char a)
        {
            return a == '1' || a == '2' || a == '3' || a == '4' || a == '5' || a == '6' || a == '7' || a == '8' || a == '9' || a == '0';
        }
        private double doFunction(string funcName, double arg)
        {
            switch(funcName)
            {
                case "sqrt":
                    return Math.Sqrt(arg);
            }
            throw new Exception("Unknown function");
            return -1;
        }
        public double solve()
        {
            //First iteration, handle * and /
            for (int i = 0; i < args.Count; i++)
            {
                if (args[i].GetType() == typeof(char) && ((char)args[i] == '/' || (char)args[i] == '*'))
                {
                    double leftSideVal = 0.0;
                    double rightSideVal = 0.0;
                    //Get left and right side
                    if (args[i - 1].GetType() == typeof(double))
                    {
                        leftSideVal = (double)args[i - 1];
                    }
                    else if(args[i-1].GetType() == typeof(MathValue))
                    {
                        leftSideVal = ((MathValue)args[i - 1]).solve();
                    }
                    //Left side can't have a function string, that would be weird

                    if (args[i + 1].GetType() == typeof(double))
                    {
                        rightSideVal = (double)args[i + 1];
                    }
                    else if (args[i + 1].GetType() == typeof(MathValue))
                    {
                        rightSideVal = ((MathValue)args[i + 1]).solve();
                    }
                    else
                    {
                        //Right side can have a function string
                        rightSideVal = doFunction((string)args[i + 1], ((MathValue)args[i + 1]).solve());
                    }
                    //Calculate and set value
                    if((char)args[i] == '/')
                    {
                        args[i - 1] = leftSideVal / rightSideVal;
                    }
                    else if((char)args[i] == '*')
                    {
                        args[i - 1] = leftSideVal * rightSideVal;
                    }
                    //Remove stuff we have calculated
                    args.RemoveAt(i);
                    args.RemoveAt(i);
                    //Jump back a bit
                    i -= 2;
                }
            }
            //We have divided and multiplied everything, sum it up
            double sum = 0;
            char opcode = '+';
            for (int i = 0; i < args.Count; i++)
            {
                if(args[i].GetType() == typeof(double))
                {
                    if(opcode == '+')
                    {
                        sum += (double)args[i];
                    }
                    else if(opcode == '-')
                    {
                        sum -= (double)args[i];
                    }
                    else
                    {
                        throw new Exception("Illegal opcode");
                    }
                    opcode = ' '; //Swallow the opcode
                }
                else if(args[i].GetType() == typeof(MathValue))
                {
                    if (opcode == '+')
                    {
                        sum += ((MathValue)args[i]).solve();
                    }
                    else if (opcode == '-')
                    {
                        sum -= ((MathValue)args[i]).solve();
                    }
                    else
                    {
                        throw new Exception("Illegal opcode");
                    }
                    opcode = ' '; //Swallow the opcode
                }
                else if(args[i].GetType() == typeof(string))
                {
                    if (opcode == '+')
                    {
                        sum += doFunction((string)args[i], ((MathValue)args[i + 1]).solve());
                        i++;
                    }
                    else if (opcode == '-')
                    {
                        sum -= doFunction((string)args[i], ((MathValue)args[i + 1]).solve());
                        i++;
                    }
                    else
                    {
                        throw new Exception("Illegal opcode");
                    }
                    opcode = ' '; //Swallow the opcode
                }
                else
                {
                    opcode = (char)args[i];
                }
            }
            return sum;
        }
    }
}