/* Book.cpp
 *
 * Kubo Ryosuke
 */

#include "Book.hpp"
#include "../core/position/Position.hpp"
#include "../core/record/SfenParser.hpp"
#include "../common/string/StringUtil.hpp"
#include "../bookbin.hpp"
#include <fstream>
#include <sstream>
#include <cstring>

namespace {
	
	const char* const BookBin = "book.bin";
	
} // namespace

namespace sunfish {
	
	void Book::insert(const Position& position, Move move, int count) {
		std::string sfen = position.toStringSFEN();
		auto ite = map_.find(sfen);
		if (ite == map_.end()) {
			map_[sfen].push_back({ move, static_cast<uint16_t>(count) });
			return;
		}
		
		auto& bookMoves = ite->second;
		
		for (auto& bookMove : bookMoves) {
			if (bookMove.move == move) {
				bookMove.count += static_cast<uint16_t>(count);
				return;
			}
		}
		
		bookMoves.push_back({ move, static_cast<uint16_t>(count) });
	}
	
	void Book::sort() {
		for (auto& pair : map_) {
			std::sort(pair.second.begin(), pair.second.end(), [](BookMove lhs, BookMove rhs) {
				return lhs.count >= rhs.count;
			});
		}
	}
	
	const BookMoves* Book::get(const Position& position) const {
		std::string sfen = position.toStringSFEN();
		auto ite = map_.find(sfen);
		return ite != map_.end() ? &ite->second : nullptr;
	}
	
	bool Book::load() {
		std::string buffer;
		Position pos;
		
		for (int i = 0; i < sizeof(book) / sizeof(book[0]); i++) {
			buffer = book[i];
			
			if (strncmp(buffer.c_str(), "sfen ", 5) == 0) {
				bool ok = SfenParser::parsePosition(buffer.c_str() + 5, pos);
				if (!ok) {
					return false;
				}
			} else {
				auto columns = StringUtil::split(buffer, ' ');
				
				Move move;
				bool ok = SfenParser::parseMove(columns[0], move);
				if (!ok) {
					return false;
				}
				
				int count = std::stoi(columns[1]);
				
				insert(pos, move, count);
				
			}
		}
		
		return true;
	}
	
	bool Book::save() const {
		std::ofstream file(BookBin);
		if (!file) {
			LOG(error) << "could not open a file: " << BookBin;
			return false;
		}
		
		bool ok = save(file);
		
		file.close();
		
		return ok;
	}
	
	bool Book::save(std::ostream& os) const {
		for (const auto& pair : map_) {
			auto& sfen = pair.first;
			auto& bookMoves = pair.second;
			
			os << "sfen " << sfen << '\n';
			for (auto& bookMove : bookMoves) {
				os << bookMove.move.toStringSFEN() << ' ' << bookMove.count << '\n';
			}
		}
		
		return true;
	}
	
} // namespace sunfish