#include <ncurses.h>
#include <curses.h>
#include <string>
#include <vector>
#include <fstream>

#include "treap.hpp"

using std::string;
using std::vector;

#define adds(s) addstr(s.c_str())
enum mode_type { insert, normal };


// Global variables
treap file;
int row = 0, col = 0;

// Accessing the file
string get_line(int r) { return file.find(r)->text; }
char get(int r, int s) { return get_line(r)[s]; }
void set(int r, int s, char ch) { file.find(r)->text[s] = ch; }
void add_line(int r, string text = "") { file.insert(r, text); }
void remove_line(int r) { file.remove(r); }
void insert_char(int r, int s, char ch) { file.find(r)->text.insert(s, string{ch}); }
void remove_char(int r, int s) { file.find(r)->text.erase(s); }

// For normal mode not to write to terminal
void step_back() {
	move(row, col);
	char ch = col < get_line(row).size() ? get(row, col) : ' ';
	addch(ch);
	move(row, col);
}


// Load file to buffer
bool load(string filename) {
	std::ifstream infile(filename);
	if(!infile.good())
		return 1;

	string line;
	while (std::getline(infile, line))
		file.insert(file.size(), line);
	return 0;
}

// Save file from buffer
bool save(string filename) {
	std::ofstream outfile(filename);
	if(!outfile.good())
		return 1;
	for(int i = 0; i < file.size(); ++i)
		outfile << get_line(i) << std::endl;
	return 0;
}

// Print file content
void print_file() {
	clear();
	for(int i = 0; i < file.size(); i++) {
		move(i, 0);
		adds(get_line(i));
	}
	move(row, col);
}
// Print line
void print_line(int r) {
	move(r, 0);
	clrtoeol();
	move(r, 0);
	adds(get_line(r));
	move(row, col);
}

// TODO mazání v souboru

// TODO skoky a přesuny
// TODO kopirování
// TODO hledání a nahrazování
// TODO undo

// Jump to end of line
void jump_line_end() {
	int line_size = get_line(row).size();
	if(col > line_size) {
		col = line_size;
		move(row, col);
	}
}

// Cursor movement
void move_cursor(char ch) {
	switch(ch) {
		case 'h':
			if(col > 0)
				move(row, --col);
			break;

		case 'j':
			if(row < file.size()-1) {
				move(++row, col);
				jump_line_end();
			}
			break;

		case 'k':
			if(row > 0) {
				move(--row, col);
				jump_line_end();
			}
			break;

		case 'l':
			if(col < get_line(row).size())
				move(row, ++col);
			break;
	}
}

int main(int argc, char* argv[]) {
	
	// Init
	initscr();
	refresh();

	// Check valid filename and load
	if(argc <= 1)
		return 1;
	string filename = argv[1];
	if(load(filename))
		return 1;

	print_file();

	mode_type mode = normal;

	// Main loop
	bool run = true;
	while(run) {
		char ch = getch();
		switch(mode) {
			case normal:
				step_back();
				switch(ch) {
					case 'h': case 'j': case 'k': case 'l':
						move_cursor(ch);
						break;
					case 'd':
						remove_line(row);
						print_file();
						break;
					case 'x':
						remove_char(row, col);
						print_line(row);
						break;
					case 'o':
						add_line(row);
						print_file();
						break;
					case 'q':
						run = false;
						break;
					case 'w':
						save(filename);
						break;
					case 'i':
						mode = insert;
						break;
				}
				break;
			case insert:
				insert_char(row, col++, ch);
				print_line(row);
				break;
		}
		refresh();
	}

	if(argc > 1 && save(argv[1]))
		return 1;

	// End
	endwin();
	return 0;
}