#include <fstream>
#include <history.h>

namespace newsbeuter {

history::history() : idx(0) { }

history::~history() { }

void history::add_line(const std::string& line) {
	/*
	 * When a line is added, we need to do so and
	 * reset the index so that the next prev/next
	 * operations start from the beginning again.
	 */
	if (line.length() > 0) {
		lines.insert(lines.begin(), line);
	}
	idx = 0;
}

std::string history::prev() {
	if (idx < lines.size()) {
		return lines[idx++];
	}
	if (lines.size() == 0) {
		return "";
	}
	return lines[idx-1];
}

std::string history::next() {
	if (idx > 0) {
		return lines[--idx];
	}
	return "";
}

void history::load_from_file(const std::string& file) {
	std::fstream f;
	f.open(file.c_str(), std::fstream::in);
	if (f.is_open()) {
		std::string line;
		do {
			std::getline(f, line);
			if (!f.eof() && line.length() > 0) {
				add_line(line);
			}
		} while (!f.eof());
	}
}

void history::save_to_file(const std::string& file, unsigned int limit) {
	std::fstream f;
	f.open(file.c_str(), std::fstream::out | std::fstream::trunc);
	if (f.is_open()) {
		if (limit > lines.size())
			limit = lines.size();
		if (limit > 0) {
			for (unsigned int i=limit-1; i>0; i--) {
				f << lines[i] << std::endl;
			}
			f << lines[0] << std::endl;
		}
	}
}


}
