From 726a147becd9cfac381eca455b0ff6986581d4e1 Mon Sep 17 00:00:00 2001
From: Aki <please@ignore.pl>
Date: Tue, 13 Dec 2022 00:11:42 +0100
Subject: Random target selection is now really random

---
 sim/src/BaseBattle.cpp  |  2 +-
 sim/src/TeamManager.cpp | 18 ++++++++++++------
 sim/src/TeamManager.h   |  2 +-
 3 files changed, 14 insertions(+), 8 deletions(-)

(limited to 'sim')

diff --git a/sim/src/BaseBattle.cpp b/sim/src/BaseBattle.cpp
index 945ef89..b85c0eb 100644
--- a/sim/src/BaseBattle.cpp
+++ b/sim/src/BaseBattle.cpp
@@ -64,7 +64,7 @@ BaseBattle::pick_random_targets()
 	auto view = _registry.view<Team, AIState>();
 	for (auto&& [entity, team, ai] : view.each()) {
 		if (!_registry.valid(ai.target))
-			ai.target = manager.random((team.id + 1) % 2);  // FIXME
+			ai.target = manager.random(team.id);
 	}
 }
 
diff --git a/sim/src/TeamManager.cpp b/sim/src/TeamManager.cpp
index 2dc3196..b792297 100644
--- a/sim/src/TeamManager.cpp
+++ b/sim/src/TeamManager.cpp
@@ -1,9 +1,9 @@
 #include "TeamManager.h"
 
 #include <algorithm>
+#include <numeric>
 #include <random>
 #include <utility>
-#include <vector>
 
 #include <entt/entity/registry.hpp>
 
@@ -38,13 +38,19 @@ TeamManager::get(int team) const
 
 
 entt::entity
-TeamManager::random(int team)
+TeamManager::random(const int exclude)
 {
-	auto& members = teams.at(team);
-	if (members.size() == 0)
+	std::vector<int> open;
+	open.resize(teams.size());
+	std::iota(open.begin(), open.end(), 0);
+	auto is_closed = [&](const int team){ return team == exclude || teams.at(team).empty(); };
+	open.erase(std::remove_if(open.begin(), open.end(), is_closed), open.end());
+	if (open.empty())
 		return entt::null;
-	std::uniform_int_distribution<Team::size_type> uniform{0, members.size() - 1};
-	return members.at(uniform(generator));
+	std::uniform_int_distribution<Team::size_type> team{0, open.size() - 1};
+	const auto& members = teams.at(open.at(team(generator)));
+	std::uniform_int_distribution<Team::size_type> member{0, members.size() - 1};
+	return members.at(member(generator));
 }
 
 
diff --git a/sim/src/TeamManager.h b/sim/src/TeamManager.h
index abc6d23..050af94 100644
--- a/sim/src/TeamManager.h
+++ b/sim/src/TeamManager.h
@@ -19,7 +19,7 @@ public:
 	TeamManager();
 	void add(int team, entt::entity entity);
 	Team get(int team) const;
-	entt::entity random(int team);
+	entt::entity random(int exclude);
 	void clear(entt::registry& registry);
 private:
 	std::vector<Team> teams;
-- 
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