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

namespace DO_Lab1_Rect
{
    internal class DualSimplexMethod
    {
        private double[,] array;
        private double[,] oldArray;
        private readonly List<int> basis;
        private double[] assistCof;
        public DualSimplexMethod(string path)
        {
            basis = new List<int>();

            string[] task = File.ReadAllLines(path);
            /*  int variables = task.Length - 1;
              array = new double[task.Length + 1, task.Length + variables]; */
            int variables = task.Length - 1;
            int rows = task[0].Split(' ').Count() - 1;
            array = new double[rows + 1, rows + variables + 1];
            assistCof = new double[array.GetLength(1) - 1];

            //Обраховуємо коефіцієнти функції
            for (int j = 0; j < array.GetLength(1); j++)
            {
                if (j < variables)
                {
                    array[array.GetLength(0) - 1, j] = double.Parse(task[j].Split(' ').Last());
                }
                else
                {
                    array[array.GetLength(0) - 1, j] = 0;
                }
            }

            //обраховуємо коефіцієнти обмежень
            for (int i = 0; i < array.GetLength(0) - 1; i++)
            {
                for (int j = 0; j < array.GetLength(1); j++)
                {
                    if (j == variables + i)
                    {
                        array[i, j] = 1;
                    }
                    else if (j == array.GetLength(1) - 1)
                    {
                        array[i, j] = -double.Parse(task[task.Length - 1].Split(' ')[i]);
                    }
                    else if (j >= variables)
                    {
                        array[i, j] = 0;
                    }
                    else
                    {
                        array[i, j] = -double.Parse(task[j].Split(' ')[i]);
                    }
                }
            }
            PrintCanonicalView();
        }
        private void printCurrentElement(int row, int column)
        {
            if (column < array.GetLength(1) - 2)
            {
                string sym = "";
                if (array[row, column + 1] >= 0) { sym = "+"; }
                else { sym = "-"; }
                if (column != 0)
                {
                    Console.Write($"{Math.Abs(array[row, column])}*Y{column + 1} {sym} ");
                }
                else
                {
                    Console.Write($"{array[row, column]}*Y{column + 1} {sym} ");
                }
            }
            else if (column == array.GetLength(1) - 2)
            {
                Console.Write($"{array[row, column]}*Y{column + 1} = ");
            }
            else
            {
                Console.Write($"{array[row, column]}");
            }
        }
        private void printMainFunc()
        {
            Console.Write($"F* = ");
            string sym = "";
            for (int j = 0; j < array.GetLength(1) - 1; j++)
            {
                if (-array[array.GetLength(0) - 1, j + 1] >= 0)
                {
                    sym = "+";
                }
                else
                {
                    sym = "-";
                }
                if (j == 0)
                {
                    Console.Write($"{-array[array.GetLength(0) - 1, j]}*Y{j + 1} ");
                }
                else
                {
                    Console.Write($"{Math.Abs(array[array.GetLength(0) - 1, j])}*Y{j + 1} ");
                }
                if (j != array.GetLength(1) - 2) Console.Write($"{sym} ");
            }
            Console.Write("-> Max");
        }
        public void PrintCanonicalView()
        {
            printMainFunc();

            for (int j = 0; j < array.GetLength(1); j++)
            {

            }
            Console.WriteLine("\n-----------------------------------");
            for (int i = 0; i < array.GetLength(0) - 1; i++)
            {
                for (int j = 0; j < array.GetLength(1); j++)
                {
                    printCurrentElement(i, j);
                }
                Console.WriteLine();
            }
        }
        private void calcBasis(int mainRow = -1, int mainColumn = -1)
        {
            if (basis.Count == 0)
            {
                for (int i = 0; i < array.GetLength(1); i++)
                {
                    int zeroCount = 0;
                    for (int j = 0; j < array.GetLength(0); j++)
                    {
                        if (array[j, i] == 0)
                        {
                            zeroCount++;
                        }
                    }
                    if (zeroCount == array.GetLength(0) - 1)
                    {
                        basis.Add(i + 1);
                    }
                }
            }
            else
            {
                //int toInsertIndex = basis.IndexOf(mainRow);
                int toInsertIndex = mainRow;
                basis.RemoveAt(toInsertIndex);
                basis.Insert(toInsertIndex, mainColumn + 1);
            }
        }
        private void printFinalTable()
        {
            Console.Write("Basis   ");
            for (int i = 0; i < array.GetLength(1) - 1; i++)
            {
                Console.Write($"x{i + 1,-4}");
            }
            Console.WriteLine("Bi   ");

            for (int i = 0; i < array.GetLength(0); i++)
            {
                if (i < basis.Count)
                {
                    Console.Write($"X{basis[i],-7}");
                }
                else
                {
                    Console.Write("{0,-8}", "Q");
                }
                for (int j = 0; j < array.GetLength(1); j++)
                {
                    Console.Write($"{array[i, j],-7}");
                }
                Console.WriteLine();
            }

            double[] answer = new double[array.GetLength(1) - 1];
            for (int j = 0; j < answer.Length; j++)
            {
                if (basis.Contains(j + 1))
                {
                    int index = basis.IndexOf(j + 1);
                    answer[j] = array[index, array.GetLength(1) - 1];
                }
                else
                {
                    answer[j] = 0;
                }
            }
            Console.WriteLine("Answer:");
            for (int i = 0; i < answer.Length; i++)
            {
                Console.Write($"Y{i + 1} = {answer[i]}    ");
            }
        }
        private void printTable()
        {
            Console.Write("Basis   ");
            for (int i = 0; i < array.GetLength(1) - 1; i++)
            {
                Console.Write($"x{i + 1,-4}");
            }
            Console.WriteLine("Bi   ");

            for (int i = 0; i < array.GetLength(0); i++)
            {
                if (i < basis.Count)
                {
                    Console.Write($"X{basis[i],-7}");
                }
                else
                {
                    Console.Write("{0,-8}", "Q");
                }
                for (int j = 0; j < array.GetLength(1); j++)
                {
                    Console.Write($"{array[i, j],-7}");
                }
                Console.WriteLine();
            }
            Console.Write("{0, -8}", "rel");
            for (int i = 0; i < assistCof.Length; i++)
            {
                if (!double.IsNaN(assistCof[i]))
                {
                    Console.Write($"{assistCof[i],-4} ");
                }
                else
                {
                    Console.Write("{0, -5}", "-");
                }
            }
            Console.WriteLine();
        }
        public void Solve()
        {
            bool isSolved = true;
            for (int i = 0; i < array.GetLength(0) - 1; i++)
            {
                if (array[i, array.GetLength(1) - 1] < 0)
                {
                    isSolved = false;
                    break;
                }
            }

            //Знайдемо базисні елемент
            calcBasis();
            int iter = 0;
            while (!isSolved)
            {

                double max = -1;
                int mainRow = -1;

                for (int i = 0; i < array.GetLength(0) - 1; i++)
                {
                    double tst = array[i, array.GetLength(1) - 1];
                    if (array[i, array.GetLength(1) - 1] < 0 && Math.Abs(array[i, array.GetLength(1) - 1]) > max)
                    {
                        max = Math.Abs(array[i, array.GetLength(1) - 1]);
                        mainRow = i;
                    }
                }

                //Обрахуємо допоміжні коефіцієнти
                for (int j = 0; j < assistCof.Length; j++)
                {
                    if (array[mainRow, j] >= 0)
                    {
                        assistCof[j] = double.NaN;
                    }
                    else
                    {
                        assistCof[j] = -array[array.GetLength(0) - 1, j] / array[mainRow, j];
                    }
                }

                double min = -1;
                int mainColumn = -1;

                for (int i = 0; i < assistCof.Length; i++)
                {
                    if (!double.IsNaN(assistCof[i]))
                    {
                        if (Math.Abs(min + 1) < 1e-5)
                        {
                            min = assistCof[i];
                            mainColumn = i;
                        }
                        else if (assistCof[i] < min)
                        {
                            min = assistCof[i];
                            mainColumn = i;
                        }
                    }
                }
                Console.WriteLine("\n******************");
                Console.WriteLine($"Table {iter + 1} -- Main row {mainRow + 1} -- Main column {mainColumn + 1} -- Main element {array[mainRow, mainColumn]}");
                Console.WriteLine("******************");
                printTable();
                calcBasis(mainRow, mainColumn);

                oldArray = (double[,])array.Clone();
                double mainElement = array[mainRow, mainColumn];
                for (int i = 0; i < array.GetLength(0); i++)
                {
                    for (int j = 0; j < array.GetLength(1); j++)
                    {
                        if (i == mainRow)
                        {
                            array[i, j] = oldArray[i, j] / mainElement;
                        }
                        else
                        {
                            if (j == mainColumn)
                            {
                                array[i, j] = 0;
                            }
                            else
                            {
                                //array[i, j] = oldArray[i, j] * mainElement - oldArray[mainRow, j] * oldArray[i, mainColumn];
                                array[i, j] = oldArray[i, j] - (oldArray[i, mainColumn] * oldArray[mainRow, j]) / mainElement;
                            }
                        }
                    }
                }
                //перевіряємо на вирішеність
                isSolved = true;
                for (int i = 0; i < array.GetLength(0) - 1; i++)
                {
                    double tst = array[i, array.GetLength(1) - 1];
                    if (array[i, array.GetLength(1) - 1] < 0)
                    {
                        isSolved = false;
                        break;
                    }
                }
                iter++;
                if (isSolved)
                {
                    calcBasis(mainRow, mainColumn);
                }
            }
            Console.WriteLine("******************");
            Console.WriteLine($"Table {iter + 1}");
            Console.WriteLine("******************");
            printFinalTable();
        }
    }
}