#include <iostream>
#include <cstdlib>
#include <ctime>

#include <vector>
#include <string>
#include <algorithm>   //for copy, fill, find, greater, random_shuffle, sort

#include "printable.h"
#include "terminal.h"

using namespace std;

void f();
typedef terminal<printable_t> terminal_t;

class closer_to {
	const terminal_t::iterator it;
public:
	closer_to(const terminal_t::iterator& initial_it) throw()
		: it(initial_it) {}

	bool operator()(terminal_t::difference_type d1,
	                terminal_t::difference_type d2) const throw() {

		return dist(it, it + d1)
		     < dist(it, it + d2);
	}
};

int main(int argc, char **argv)
{
	int status = EXIT_FAILURE;
	srand(static_cast<unsigned>(time(0)));

	try {
		f();
		status = EXIT_SUCCESS;
	}

	catch (const exception& e) {
		cerr << argv[0] << ": " << e.what() << "\n";
	}

	catch (...) {
		cerr << argv[0] << ": main caught unexpected exception\n";
	}

	return status;
}

void f()
{
	const terminal_t term('.');
	const terminal_t::difference_type down = term.down();

	const terminal_t::iterator center(term, term.xmax() / 2, term.ymax() / 2);
	terminal_t::iterator it = center;   //copy constructor

	it[1] = it[0] = 'X';

	//Move one step from the center towards the begin, and write a 'Y'.
	const terminal_t::difference_type d = step(center, term.begin());
	it += d;
	*it = 'Y';

	//Move one step from the center away from the begin, and write a 'Z'.
	it = center;
	it -= d;
	*it = 'Z';

	//Move a random step away from the center, and write an 'R'.
	it = center;
	it += term.rand();
	*it = 'R';

	it = term.begin();
	string s = "qwertyuiopasdfghjklzxcvbnm";
	copy(s.begin(), s.end(), it);

	it += down;
	copy(s.begin(), s.end(), it);
	sort(it, it + s.size());

	it += down;
	copy(s.begin(), s.end(), it);
	sort(it, it + s.size(), greater<terminal_t::value_type>());

	it += down;
	copy(s.begin(), s.end(), it);
	random_shuffle(it, it + s.size());

	//Display the characters of the string in order of increasing distance
	//from it0.
	const terminal_t::iterator it0 = it + 3 * term.xmax() / 4;
	s = "abcdefghijklmnopqrstuvwxyz"
	    "ABCDEFGHIJKLMNOPQRSTUVWXYZ";

	vector<terminal_t::difference_type> v;
	for (terminal_t::iterator it1 = term.begin(); it1 != term.end(); ++it1) {
		v.push_back(it1 - it0);
	}

	sort(v.begin(), v.end(), closer_to(it0));

	vector<terminal_t::difference_type>::const_iterator it1 = v.begin();
	for (string::iterator it2 = s.begin(); it2 != s.end(); ++it1, ++it2) {
		it0[*it1] = *it2;
	}

	//Midpoint between begin and center:
	term.begin()[(center - term.begin()) / 2] = 'm';

	it += 2 * down;   //Move two lines down.
	s = "Please type printable characters ending with a q: ";
	it = copy(s.begin(), s.end(), it);

	for (; it != term.end(); ++it) {
		char c;   //uninitialized variable
		while ((c = term.key()) == '\0') {
		}

		if (c == 'q') {
			break;
		}

		*it = c;
	}

	fill(term.begin(), term.end(), term.background());   //Clear the screen.
	s = "Etch-a-sketch: please type hjklq for left, down, up, right, quit.";
	copy(s.begin(), s.end(), term.begin());

	it = find(term.begin(), term.end(), 's');
	if (it != term.end()) {
		*it = 'S';
	}

	const terminal_t::keypad_t k = term.keypad();

	for (it = center;;) {
		*it = 'X';

		char c;   //uninitialized variable
		while ((c = term.key()) == '\0') {
		}

		if (c == 'q') {
			break;
		}

		const terminal_t::keypad_t::const_iterator i = k.find(c);
		//i->first is the char, i->second is its difference_type
		if (i == k.end() || !it.in_range(i->second)) {
			term.beep();
		} else {
			it += i->second;
		}
	}

	term.beep();
	term.wait(1000);
}