using BaseCalculator;
using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace Calculator
{
    internal class Analaizer
    {
        private static int erposition = 0;

        public static string expression = "";

        public static ArrayList opz = null;

        public static bool CheckCurrency()
        {
            bool result = true;
            int num = 0;
            for (int i = 0; i < expression.Length; i++)
            {
                if (expression[i] == '(')
                {
                    num++;
                }
                else if (expression[i] == ')')
                {
                    num--;
                }

                if (num < 0)
                {
                    result = false;
                    erposition = i;
                    return result;
                }
            }

            if (num != 0)
            {
                result = false;
            }

            return result;
        }

        public static string Format()
        {
            string text = "";
            string text2 = "";
            if (expression.Length <= 65536)
            {
                for (int i = 0; i < expression.Length; i++)
                {
                    switch (expression[i])
                    {
                        case '0':
                            text = ((!(text2 == "число") && !(text2 == "")) ? (text + " " + expression[i]) : (text + expression[i]));
                            text2 = "число";
                            break;
                        case '1':
                            text = ((!(text2 == "число") && !(text2 == "")) ? (text + " " + expression[i]) : (text + expression[i]));
                            text2 = "число";
                            break;
                        case '2':
                            text = ((!(text2 == "число") && !(text2 == "")) ? (text + " " + expression[i]) : (text + expression[i]));
                            text2 = "число";
                            break;
                        case '3':
                            text = ((!(text2 == "число") && !(text2 == "")) ? (text + " " + expression[i]) : (text + expression[i]));
                            text2 = "число";
                            break;
                        case '4':
                            text = ((!(text2 == "число") && !(text2 == "")) ? (text + " " + expression[i]) : (text + expression[i]));
                            text2 = "число";
                            break;
                        case '5':
                            text = ((!(text2 == "число") && !(text2 == "")) ? (text + " " + expression[i]) : (text + expression[i]));
                            text2 = "число";
                            break;
                        case '6':
                            text = ((!(text2 == "число") && !(text2 == "")) ? (text + " " + expression[i]) : (text + expression[i]));
                            text2 = "число";
                            break;
                        case '7':
                            text = ((!(text2 == "число") && !(text2 == "")) ? (text + " " + expression[i]) : (text + expression[i]));
                            text2 = "число";
                            break;
                        case '8':
                            text = ((!(text2 == "число") && !(text2 == "")) ? (text + " " + expression[i]) : (text + expression[i]));
                            text2 = "число";
                            break;
                        case '9':
                            text = ((!(text2 == "число") && !(text2 == "")) ? (text + " " + expression[i]) : (text + expression[i]));
                            text2 = "число";
                            break;
                        case '+':
                            if (text2 != "")
                            {
                                if (!(text2 != "оператор"))
                                {
                                    MessageBox.Show("Два подряд оператора на " + i + " символе.");
                                    return "&Error 04 at " + i;
                                }

                                text = text + " " + expression[i];
                            }
                            else
                            {
                                text += expression[i];
                            }

                            text2 = "оператор";
                            break;
                        case '-':
                            if (text2 != "")
                            {
                                if (!(text2 != "оператор"))
                                {
                                    MessageBox.Show("Два подряд оператора на " + i + " символе.");
                                    return "&Error 04 at " + i;
                                }

                                text = text + " " + expression[i];
                            }
                            else
                            {
                                text += expression[i];
                            }

                            text2 = "оператор";
                            break;
                        case '*':
                            if (text2 != "")
                            {
                                if (!(text2 != "оператор"))
                                {
                                    MessageBox.Show("Два подряд оператора на " + i + " символе.");
                                    return "&Error 04 at " + i;
                                }

                                text = text + " " + expression[i];
                            }
                            else
                            {
                                text += expression[i];
                            }

                            text2 = "оператор";
                            break;
                        case '/':
                            if (text2 != "")
                            {
                                if (!(text2 != "оператор"))
                                {
                                    MessageBox.Show("Два подряд оператора на " + i + " символе.");
                                    return "&Error 04 at " + i;
                                }

                                text = text + " " + expression[i];
                            }
                            else
                            {
                                text += expression[i];
                            }

                            text2 = "оператор";
                            break;
                        case '(':
                            text = ((!(text2 != "")) ? (text + expression[i]) : (text + " " + expression[i]));
                            text2 = "скобка";
                            break;
                        case ')':
                            text = ((!(text2 != "")) ? (text + expression[i]) : (text + " " + expression[i]));
                            text2 = "скобка";
                            break;
                        case 'm':
                            if (i + 1 < expression.Length && expression[i + 1] == 'o' && expression[i + 2] == 'd')
                            {
                                if (text2 != "")
                                {
                                    if (!(text2 != "оператор"))
                                    {
                                        MessageBox.Show("Два подряд оператора на " + i + " символе.");
                                        return "&Error 04 at " + i;
                                    }

                                    string text3 = text;
                                    text = text3 + " " + expression[i] + expression[i + 1] + expression[i + 2];
                                }
                                else
                                {
                                    text = text + expression[i] + expression[i + 1] + expression[i + 2];
                                }

                                text2 = "оператор";
                                i += 2;
                            }
                            else
                            {
                                text = ((!(text2 != "")) ? (text + expression[i]) : (text + " " + expression[i]));
                                text2 = "унарный оператор";
                            }

                            break;
                        case 'p':
                            text = ((!(text2 != "")) ? (text + expression[i]) : (text + " " + expression[i]));
                            text2 = "унарный оператор";
                            break;
                        default:
                            MessageBox.Show("Неизвестный оператор на " + i + " символе.");
                            return "&Error 02 at " + i;
                        case ' ':
                            break;
                    }
                }

                if (text2 != "оператор" && text2 != "унарный оператор")
                {
                    return text + " ";
                }

                MessageBox.Show("Незаконченное выражение. ");
                return "&Error 05";
            }

            MessageBox.Show("Слишком длинное выражение. Максмальная длина - 65536 символов.");
            return "&Error 07";
        }

        public static ArrayList CreateStack()
        {
            ArrayList arrayList = new ArrayList(30);
            Stack stack = new Stack(15);
            string text = expression;
            while (text != "")
            {
                string text2 = text.Substring(0, text.IndexOf(" "));
                text = text.Substring(text.IndexOf(" ") + 1);
                switch (text2)
                {
                    case "(":
                        stack.Push(text2);
                        break;
                    case "m":
                        while (stack.Count != 0 && (stack.Peek().ToString() == "m" || stack.Peek().ToString() == "p"))
                        {
                            if (arrayList.Capacity > arrayList.Count)
                            {
                                arrayList.Add(stack.Pop());
                                continue;
                            }

                            return null;
                        }

                        stack.Push(text2);
                        break;
                    case "p":
                        while (stack.Count != 0 && (stack.Peek().ToString() == "m" || stack.Peek().ToString() == "p"))
                        {
                            if (arrayList.Capacity > arrayList.Count)
                            {
                                arrayList.Add(stack.Pop());
                                continue;
                            }

                            return null;
                        }

                        stack.Push(text2);
                        break;
                    case "*":
                        while (stack.Count != 0 && (stack.Peek().ToString() == "*" || stack.Peek().ToString() == "/" || stack.Peek().ToString() == "mod" || stack.Peek().ToString() == "m" || stack.Peek().ToString() == "p"))
                        {
                            if (arrayList.Capacity > arrayList.Count)
                            {
                                arrayList.Add(stack.Pop());
                                continue;
                            }

                            return null;
                        }

                        stack.Push(text2);
                        break;
                    case "/":
                        while (stack.Count != 0 && (stack.Peek().ToString() == "*" || stack.Peek().ToString() == "/" || stack.Peek().ToString() == "mod" || stack.Peek().ToString() == "m" || stack.Peek().ToString() == "p"))
                        {
                            if (arrayList.Capacity > arrayList.Count)
                            {
                                arrayList.Add(stack.Pop());
                                continue;
                            }

                            return null;
                        }

                        stack.Push(text2);
                        break;
                    case "mod":
                        while (stack.Count != 0 && (stack.Peek().ToString() == "*" || stack.Peek().ToString() == "/" || stack.Peek().ToString() == "mod" || stack.Peek().ToString() == "m" || stack.Peek().ToString() == "p"))
                        {
                            if (arrayList.Capacity > arrayList.Count)
                            {
                                arrayList.Add(stack.Pop());
                                continue;
                            }

                            return null;
                        }

                        stack.Push(text2);
                        break;
                    case "+":
                        while (stack.Count != 0 && (stack.Peek().ToString() == "*" || stack.Peek().ToString() == "/" || stack.Peek().ToString() == "mod" || stack.Peek().ToString() == "+" || stack.Peek().ToString() == "-" || stack.Peek().ToString() == "m" || stack.Peek().ToString() == "p"))
                        {
                            if (arrayList.Capacity > arrayList.Count)
                            {
                                arrayList.Add(stack.Pop());
                                continue;
                            }

                            return null;
                        }

                        stack.Push(text2);
                        break;
                    case "-":
                        while (stack.Count != 0 && (stack.Peek().ToString() == "*" || stack.Peek().ToString() == "/" || stack.Peek().ToString() == "mod" || stack.Peek().ToString() == "+" || stack.Peek().ToString() == "-" || stack.Peek().ToString() == "m" || stack.Peek().ToString() == "p"))
                        {
                            if (arrayList.Capacity > arrayList.Count)
                            {
                                arrayList.Add(stack.Pop());
                                continue;
                            }

                            return null;
                        }

                        stack.Push(text2);
                        break;
                    case ")":
                        while (stack.Peek().ToString() != "(")
                        {
                            if (arrayList.Capacity > arrayList.Count)
                            {
                                arrayList.Add(stack.Pop());
                                continue;
                            }

                            return null;
                        }

                        stack.Pop();
                        break;
                    default:
                        if (arrayList.Capacity > arrayList.Count)
                        {
                            arrayList.Add(text2);
                            break;
                        }

                        return null;
                }
            }

            while (stack.Count != 0)
            {
                arrayList.Add(stack.Pop());
            }

            return arrayList;
        }

        public static string RunEstimate()
        {
            bool flag = false;
            while (!flag)
            {
                int i = 0;
                bool flag2 = false;
                for (; i < opz.Count; i++)
                {
                    if (flag2)
                    {
                        break;
                    }

                    flag2 = true;
                    try
                    {
                        switch (opz[i].ToString())
                        {
                            case "+":
                                opz[i - 2] = CalcClass.Add(Convert.ToInt64(opz[i - 2]), Convert.ToInt64(opz[i - 1]));
                                opz.RemoveAt(i - 1);
                                opz.RemoveAt(i - 1);
                                break;
                            case "-":
                                opz[i - 2] = CalcClass.Sub(Convert.ToInt64(opz[i - 2]), Convert.ToInt64(opz[i - 1]));
                                opz.RemoveAt(i - 1);
                                opz.RemoveAt(i - 1);
                                break;
                            case "*":
                                opz[i - 2] = CalcClass.Mult(Convert.ToInt64(opz[i - 2]), Convert.ToInt64(opz[i - 1]));
                                opz.RemoveAt(i - 1);
                                opz.RemoveAt(i - 1);
                                break;
                            case "/":
                                opz[i - 2] = CalcClass.Div(Convert.ToInt64(opz[i - 2]), Convert.ToInt64(opz[i - 1]));
                                opz.RemoveAt(i - 1);
                                opz.RemoveAt(i - 1);
                                break;
                            case "mod":
                                opz[i - 2] = CalcClass.Mod(Convert.ToInt64(opz[i - 2]), Convert.ToInt64(opz[i - 1]));
                                opz.RemoveAt(i - 1);
                                opz.RemoveAt(i - 1);
                                break;
                            case "m":
                                opz[i - 1] = CalcClass.IABS(Convert.ToInt64(opz[i - 1]));
                                opz.RemoveAt(i);
                                break;
                            case "p":
                                opz[i - 1] = CalcClass.ABS(Convert.ToInt64(opz[i - 1]));
                                opz.RemoveAt(i);
                                break;
                            default:
                                flag2 = false;
                                break;
                        }
                    }
                    catch (DivideByZeroException)
                    {
                        MessageBox.Show("Ошибка деления на 0");
                        return "Error 09";
                    }
                    catch (OverflowException)
                    {
                        MessageBox.Show("Слишком малое или слишком большое значение числа для int\n Числа должны быть в пределах от -2147483648 до 2147483647");
                        return "Error 06";
                    }
                }

                if (!flag2 && i == opz.Count)
                {
                    flag = true;
                }

                string lastError = CalcClass.lastError;
                if (lastError != "")
                {
                    return lastError;
                }
            }

            if (opz.Count != 1)
            {
                MessageBox.Show("Неверная синтаксическая конструкция входного выражения!");
                return "Error 03";
            }

            return opz[0].ToString();
        }

        public static string Estimate()
        {
            if (CheckCurrency())
            {
                string text = Format();
                if (text[0] == '&')
                {
                    return text.Substring(1);
                }

                expression = text;
                opz = CreateStack();
                if (opz != null)
                {
                    return RunEstimate();
                }

                MessageBox.Show("Суммарное количество чисел и операторов превышает 30!");
                return "Error 08";
            }

            MessageBox.Show("Неправильная скобочная структура, ошибка на " + erposition + " символе !");
            return "Error 01 at " + erposition;
        }
    }
}