feat: basic line graph component and cpu graph module

include/modules/cpu_graph.hpp

@@ -0,0 +1,32 @@
+#pragma once
+
+#include <fmt/format.h>
+
+#include <cstdint>
+#include <fstream>
+#include <numeric>
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "AGraph.hpp"
+#include "util/sleeper_thread.hpp"
+
+namespace waybar::modules {
+
+class CpuGraph : public AGraph {
+ public:
+  CpuGraph(const std::string&, const Json::Value&);
+  virtual ~CpuGraph() = default;
+  auto update() -> void override;
+
+ private:
+  static constexpr const char *MODERATE_CLASS = "cpu-moderate";
+  static constexpr const char *HIGH_CLASS = "cpu-high";
+  static constexpr const char *INTENSIVE_CLASS = "cpu-intensive";
+
+  std::vector<std::tuple<size_t, size_t>> prev_times_;
+  util::SleeperThread thread_;
+};
+
+}  // namespace waybar::modules