1 files changed, 88 insertions, 39 deletions

diff --git a/referee.cpp b/referee.cpp
index 15f49c3..ffcbd14 100644
--- a/referee.cpp
+++ b/referee.cpp
@@ -3,9 +3,15 @@
 #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) {
+		: proc(execname), refereeExecname(execname) {
 
 	proc.run();
 
@@ -14,11 +20,15 @@ Referee::Referee(const string_view execname, const vector<string> &players)
 		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() {
@@ -39,49 +49,32 @@ bool Referee::moveValid(int player, const string_view line) {
 
 	proc.writeLine(s);
 
-	optional<string> response = readLine();
+	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;
-			readScores();
 			result = true;
 		} else if (*response == "valid") {
 			result = true;
-		} else {
+		} else if (*response == "invalid") {
 			result = false;
+		} else {
+			cout << "REF(" << proc.getPid() << ") Invalid validity judgement '" << *response << "'!" << endl;
+			exit(1);
 		}
 
-		if (featureWriteLines) {
-			writeLinesList.clear();
-
-			while (true) {
-				optional<string> line = readLine();
-				if (!line) {
-					if (referee_verbose) {
-						cout << "REF(" << proc.getPid() << ") EOF!" << endl;
-					}
-					return false;
-				}
-
-				if (line == "write_end") break;
+		readWriteLines();
 
-				size_t idx = line->find(' ');
-				if (idx == string::npos) {
-					cerr << "Referee feature_write_lines protocol violation!" << endl;
-					exit(1);
-				}
-
-				int player = stoi(line->substr(0, idx));
-				writeLinesList.emplace_back(player, line->substr(idx + 1));
-			}
-		}
+		if (isEnd) readScores();
 
 		return result;
 	} else {
-		if (referee_verbose) {
-			cout << "REF(" << proc.getPid() << ") EOF!" << endl;
-		}
+		cout << "REF(" << proc.getPid() << ") EOF!" << endl;
 		return false;
 	}
 }
@@ -94,28 +87,80 @@ bool Referee::gameEnded() {
 	return isEnd;
 }
 
-optional<string> Referee::readLine() {
+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) return line;
+		if (!line) {
+			cout << "REF(" << proc.getPid() << ") EOF!" << endl;
+			break;
+		}
 
 		if (referee_verbose) {
 			cout << "REF(" << proc.getPid() << ") read <" << *line << ">" << endl;
 		}
 
-		if (line->substr(0, 8) != "feature ") return line;
+		if (line == "write_end") break;
 
-		string featname = line->substr(8);
-		if (featname == "write_lines") featureWriteLines = true;
-		else {
-			cerr << "Referee requested unsupported feature '" << featname << "'" << endl;
+		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 = readLine();
+	optional<string> line = proc.readLine();
 	if (!line) {
 		cerr << "Referee stopped before providing scores" << endl;
 		exit(1);
@@ -138,3 +183,7 @@ optional<vector<int>> Referee::getScores() {
 void Referee::terminate() {
 	proc.terminate();
 }
+
+const Features& Referee::getFeatures() const {
+	return features;
+}