just some more thoughts

src2/component.cpp

@@ -0,0 +1,65 @@
+#include "component.h"
+
+#include <array>
+#include <string_view>
+
+constexpr std::array<std::string_view, Component::done + 1> stringStates {
+    "initial",
+    "reading",
+    "ready",
+    "building",
+    "done"
+};
+
+Component::Component(
+    const std::filesystem::path& path,
+    const std::shared_ptr<Collection>& collection,
+    const std::shared_ptr<TaskManager>& taskManager,
+    const std::shared_ptr<Logger>& logger
+):
+    Loggable(logger),
+    collection(collection),
+    taskManager(taskManager),
+    location(path)
+{}
+
+void Component::read() {
+    if (state != initial)
+        throw WrongState(state, "read");
+
+    try {
+        collection->addSource(location);
+    } catch (const Collection::DuplicateSource e) {
+        state = error;
+        throw e;
+    }
+    state = reading;
+    taskManager->queue(std::bind(&Component::performRead, this));
+}
+
+void Component::build(const std::filesystem::path& destination, const std::string& target) {
+    if (state != ready)
+        throw WrongState(state, "build");
+
+    state = building;
+    taskManager->queue(std::bind(&Component::performBuild, this, destination, target));
+}
+
+void Component::performRead() {
+}
+
+void Component::performBuild(std::filesystem::path destination, std::string target) {
+}
+
+Component::State Component::getState() const {
+    return state;
+}
+
+Component::Type Component::getType() const {
+    return type;
+}
+
+Component::WrongState::WrongState(State state, const std::string& action):
+    std::runtime_error("An attempt to perform action \"" + action
+                        + "\" on a wrong state \"" + stringStates[state].data() + '\"')
+{}