#include <iostream>
#include <cstdlib>
#include "referee.h"
#include "params.h"

// Timeout in milliseconds for the feature negotiation at the start of the
// protocol. If the referee hasn't sent anything after this timeout, we assume
// the referee isn't capable of sending feature lines and will be treated as
// such for the duration of the competition.
#define FEATURE_TIMEOUT 200


Referee::Referee(const string_view execname, const vector<string> &players)
		: proc(execname), refereeExecname(execname) {

	proc.run();

	if (referee_verbose) {
		cout << "REF(" << proc.getPid() << ") starting for:";
		for (const string &p : players) cout << " " << p;
		cout << endl;
	}

	queryFeatures();

	proc.writeLine(to_string(players.size()));
	for (const string &p : players) {
		proc.writeLine(p);
	}

	readWriteLines();
}

Referee::~Referee() {
	if (referee_verbose) {
		cout << "REF(" << proc.getPid() << ") stopping" << endl;
	}
	proc.wait();
	proc.terminate();
}

bool Referee::moveValid(int player, const string_view line) {
	string s = to_string(player) + " ";
	s.append(line);

	if (referee_verbose) {
		cout << "REF(" << proc.getPid() << ") write <" << s << ">" << endl;
	}

	proc.writeLine(s);

	optional<string> response = proc.readLine();
	if (response) {
		if (referee_verbose) {
			cout << "REF(" << proc.getPid() << ") read <" << *response << ">" << endl;
		}

		bool result;
		if (*response == "valid end") {
			isEnd = true;
			result = true;
		} else if (*response == "valid") {
			result = true;
		} else if (*response == "invalid") {
			result = false;
		} else {
			cout << "REF(" << proc.getPid() << ") Invalid validity judgement '" << *response << "'!" << endl;
			exit(1);
		}

		readWriteLines();

		if (isEnd) readScores();

		return result;
	} else {
		cout << "REF(" << proc.getPid() << ") EOF!" << endl;
		return false;
	}
}

vector<pair<int, string>> Referee::playerWriteLines() {
	return writeLinesList;
}

bool Referee::gameEnded() {
	return isEnd;
}

void Referee::queryFeatures() {
	bool first = true;

	while (true) {
		optional<string> line;
		if (first) {
			line = proc.readLineTimeout(FEATURE_TIMEOUT);
			if (!line) {
				cout << "Referee '" << refereeExecname << "' seems to follow the old protocol!" << endl;
				return;
			}

			first = false;
		} else {
			line = proc.readLine();
		}

		if (!line) {
			cout << "REF(" << proc.getPid() << ") EOF!" << endl;
			exit(1);
		}

		if (referee_verbose) {
			cout << "REF(" << proc.getPid() << ") read <" << *line << ">" << endl;
		}

		if (*line == "feature_end") {
			return;
		} else if (line->substr(0, 8) == "feature ") {
			string featname = line->substr(8);
			if (featname == "write_lines") features.writeLines = true;
			else if (featname == "no_last_move") features.noLastMove = true;
			else {
				cerr << "REF(" << proc.getPid() << ") Referee requested unsupported feature '" << featname << "'" << endl;
				exit(1);
			}
		} else {
			cerr << "REF(" << proc.getPid() << ") Referee protocol violation in feature negotiation" << endl;
			exit(1);
		}
	}
}

void Referee::readWriteLines() {
	writeLinesList.clear();

	if (!features.writeLines) return;

	while (true) {
		optional<string> line = proc.readLine();
		if (!line) {
			cout << "REF(" << proc.getPid() << ") EOF!" << endl;
			break;
		}

		if (referee_verbose) {
			cout << "REF(" << proc.getPid() << ") read <" << *line << ">" << endl;
		}

		if (line == "write_end") break;

		size_t idx = line->find(' ');
		if (idx == string::npos) {
			cerr << "REF(" << proc.getPid() << ") Referee feature_write_lines protocol violation!" << endl;
			exit(1);
		}

		int player = stoi(line->substr(0, idx));
		writeLinesList.emplace_back(player, line->substr(idx + 1));
	}
}

void Referee::readScores() {
	optional<string> line = proc.readLine();
	if (!line) {
		cerr << "Referee stopped before providing scores" << endl;
		exit(1);
	}

	size_t cursor = 0;
	while (cursor < line->size()) {
		size_t idx = line->find(' ', cursor);
		if (idx == string::npos) idx = line->size();
		scores.push_back(stoi(line->substr(cursor, idx - cursor)));
		cursor = idx + 1;
	}
}

optional<vector<int>> Referee::getScores() {
	if (isEnd) return scores;
	else return nullopt;
}

void Referee::terminate() {
	proc.terminate();
}

const Features& Referee::getFeatures() const {
	return features;
}