move ecs related code to own folder

src/lib/ecs/system/ScrapSystem.cpp

@@ -0,0 +1,56 @@
+#include "ScrapSystem.h"
+
+#include "DespawnAtComponent.h"
+#include "EntityAdmin.h"
+#include "PositionComponent.h"
+#include "ScrapDataComponent.h"
+
+ScrapSystem::ScrapSystem(EntityAdmin& admin)
+    : m_admin(admin)
+{
+}
+
+entt::entity ScrapSystem::spawn(QVector2D position, int amount, Tick despawnAt)
+{
+    return m_admin.spawnScrap(position, amount, despawnAt);
+}
+
+void ScrapSystem::tickDespawn(Tick currentTick)
+{
+    std::vector<entt::entity> expired;
+    m_admin.forEach<DespawnAtComponent>(
+        [&expired, currentTick](entt::entity e, DespawnAtComponent& d)
+        {
+            if (d.tick <= currentTick)
+            {
+                expired.push_back(e);
+            }
+        });
+
+    for (entt::entity e : expired)
+    {
+        m_admin.destroy(e);
+    }
+}
+
+std::optional<int> ScrapSystem::consume(entt::entity entity)
+{
+    if (!m_admin.isValid(entity) || !m_admin.hasAll<ScrapDataComponent>(entity))
+    {
+        return std::nullopt;
+    }
+    int amount = m_admin.get<ScrapDataComponent>(entity).amount;
+    m_admin.destroy(entity);
+    return amount;
+}
+
+std::vector<ScrapInfo> ScrapSystem::allScrapInfo() const
+{
+    std::vector<ScrapInfo> result;
+    m_admin.forEach<ScrapDataComponent>(
+        [&result, this](entt::entity e, const ScrapDataComponent& /*sd*/)
+        {
+            result.push_back(ScrapInfo{e, m_admin.get<PositionComponent>(e).value});
+        });
+    return result;
+}