// TODO(dev): use 'halfdelay()' to parse input for pi menu choice 'secret.'

// NOTE(dev): Gonna need this:
// mvwprintw(win, y, x, string);   /* Move to (y, x) relative to window   */
//                                 /* co-ordinates and then print         */

#include <ncurses.h>

#include "Problem.h"

#include <vector>
#include <chrono>

#define PROMPT " > "

std::vector<Problem*> GenerateProblems(bool addition, bool subtraction,
                                       bool multiplication, bool division);
char MainMenu();

int main(int argc, char *argv[])
{
	initscr();
	noecho(); // don't show user input
	cbreak(); // handle user input immediately (i.e. don't wait for the user to press enter)
	keypad(stdscr, true); // enable the numpad, F1-F12 keys, arrow keys, etc.

	while(true)
	{
		// game boolean flags:
		bool addition = false;
		bool subtraction = false;
		bool multiplication = false;
		bool division = false;

		// Main Menu:
		char menu_action = MainMenu();
		if(menu_action == 'q')
			break;
		else if(menu_action == '1')
			addition = true;
		else if(menu_action == '2')
			subtraction = true;
		else if(menu_action == '3')
			addition = subtraction = true;
		else if(menu_action == '4')
			multiplication = true;
		else if(menu_action == '5')
			division = true;
		else if(menu_action == '6')
			multiplication = division = true;
		else
			continue; // restart loop

		clear();
		wrefresh(stdscr);

		std::vector<Problem*> problems = GenerateProblems(addition, subtraction,
		                                                  multiplication, division);
		std::vector<Problem*>::iterator selected = problems.begin();

		INPUT_STYLE input_style = INPUT_STYLE::INPUT_APPEND;
		for(auto *problem : problems)
			if(problem)
				problem->Draw(problem == *selected, input_style);

		// Keep track of time:
		auto start_time = std::chrono::steady_clock::now();

		unsigned int input = 'q';
		while(selected != problems.end() && *selected)
		{
			Problem *current_problem = *selected;
			current_problem->Draw(true, input_style); // refresh with new input
			input = getch();
			if(input == 'q') // early exit
				break;
			switch(input)
			{
			case KEY_LEFT:
				input_style = INPUT_STYLE::INPUT_PREPEND;
				break;
			case KEY_RIGHT:
				input_style = INPUT_STYLE::INPUT_APPEND;
				break;
			case KEY_BACKSPACE:
				current_problem->ClearInput();
				break;
			case '0':
			case '1':
			case '2':
			case '3':
			case '4':
			case '5':
			case '6':
			case '7':
			case '8':
			case '9':
				current_problem->Input(input_style, input);
				break;
			};

			// NOTE(dev): If the answer is zero and they hit backspace to clear input, it treated it
			//             as if they had entered zero themselves.
			if(input != KEY_BACKSPACE && current_problem->Correct())
				++selected;
			current_problem->Draw(current_problem == *selected, input_style); // refresh with new input
		}

		if(input != 'q') // if you didn't quit
		{
			// Keep track of time:
			auto end_time = std::chrono::steady_clock::now();
			auto elapsed_time = std::chrono::duration_cast<std::chrono::seconds>(end_time - start_time);
			int middle_h = COLS / 2;
			int middle_v = LINES / 2;
			clear();
			mvprintw(middle_v - 3, middle_h - 5,
			         "You did it!");
			mvprintw(middle_v - 1, middle_h - 14,
			         "Questions Answered: %7d\n",
			         problems.size());
			mvprintw(middle_v - 0, middle_h - 8,
			         "Time Elapsed: %02dm %02ds\n",
			         elapsed_time / 60, elapsed_time % 60);
			mvprintw(middle_v + 1, middle_h - 13,
			         "Time Per Question: %02dm %02ds\n",
			         (elapsed_time / problems.size() / 60),
			         (elapsed_time / problems.size() % 60));
			mvprintw(middle_v + 3, middle_h - 8,
			         "Press Q to quit.");
			box(stdscr, '*', '*');
			wrefresh(stdscr);

			while(!(getch() == 'q'))
				;
		}

		for(auto *problem : problems)
			if(problem)
				delete problem;
	}

	endwin();
	return 0;
}

char MainMenu()
{
	int middle_h = COLS / 2;
	int middle_v = LINES / 2;

	clear();
	mvprintw(middle_v - 6, middle_h - 20, "\n");
	mvprintw(middle_v - 5, middle_h - 20, " Welcome to Math Practice.\n");
	mvprintw(middle_v - 4, middle_h - 20, " Please choose from the following menu:\n");
	mvprintw(middle_v - 3, middle_h - 20, "  1.  Addition\n");
	mvprintw(middle_v - 2, middle_h - 20, "  2.  Subtraction\n");
	mvprintw(middle_v - 1, middle_h - 20, "  3.  Both / Mixed\n");
	mvprintw(middle_v - 0, middle_h - 20, "  4.  Multiplication\n");
	mvprintw(middle_v + 1, middle_h - 20, "  5.  Division\n");
	mvprintw(middle_v + 2, middle_h - 20, "  6.  Both / Mixed\n");
	mvprintw(middle_v + 3, middle_h - 20, "  q.  Quit\n");
	mvprintw(middle_v + 4, middle_h - 20, "\n");
	mvprintw(middle_v + 5, middle_h - 20, PROMPT);
	refresh();

	return getch();
}

std::vector<Problem*> GenerateProblems(bool addition, bool subtraction,
                                       bool multiplication, bool division)
{
	std::vector<Problem*> rtn;
	for(auto y = 1;  y < LINES - 10; y += 9)
	{
		for(auto x = 2; x < COLS - 16; x += 15)
		{
			Problem *test = nullptr;
			if(addition || subtraction)
			{
				if(addition != subtraction)
				{
					if(addition)
						test = new Problem(EASY_ADDITION, 3, x, y);
					if(subtraction)
						test = new Problem(EASY_SUBTRACTION, 3, x, y);
				}
				else
				{
					if(rand() % 2)
						test = new Problem(HARD_ADDITION, 5, x, y);
					else
						test = new Problem(HARD_SUBTRACTION, 5, x, y);
				}
				rtn.push_back(test);
			}

			if(multiplication || division)
			{
				if(multiplication && !division)
					test = new Problem(EASY_MULTIPLICATION, 2, x, y);
				else if(division && !multiplication)
					test = new Problem(EASY_DIVISION, 2, x, y);
				else
				{
					// TODO(dev): Add hard problems
					if(rand() % 2)
						test = new Problem(HARD_MULTIPLICATION, 3, x, y);
					else
						test = new Problem(HARD_DIVISION, 3, x, y);
				}
				rtn.push_back(test);
			}
		}
	}
	return rtn;
}