#pragma once

#include <AK/Assertions.h>
#include <AK/Types.h>
#include <AK/Function.h>
#include <AK/IntrusiveList.h>

class Process;
class Thread;
class WaitQueue;
struct RegisterDump;
struct SchedulerData;

extern Thread* current;
extern Thread* g_last_fpu_thread;
extern Thread* g_finalizer;
extern Thread* g_colonel;
extern WaitQueue* g_finalizer_wait_queue;
extern u64 g_uptime;
extern SchedulerData* g_scheduler_data;

class Scheduler {
public:
    static void initialize();
    static void timer_tick(RegisterDump&);
    static bool pick_next();
    static void pick_next_and_switch_now();
    static void switch_now();
    static bool yield();
    static bool donate_to(Thread*, const char* reason);
    static bool context_switch(Thread&);
    static void prepare_to_modify_tss(Thread&);
    static Process* colonel();
    static bool is_active();
    static void beep();
    static void idle_loop();
    static void stop_idling();

    template<typename Callback>
    static inline IterationDecision for_each_runnable(Callback);

    template<typename Callback>
    static inline IterationDecision for_each_nonrunnable(Callback);

    static void init_thread(Thread& thread);
    static void update_state_for_thread(Thread& thread);

private:
    static void prepare_for_iret_to_new_process();
};