#include "syscall/handler.h"

#include "../arch/core.h"
#include "../arch/core_interrupt.h"
#include "../arch/gdt.h"
#include "../arch/idt.h"
#include "../debug/kernelpanic.h"
#include "../debug/output.h"
#include "../interrupt/guard.h"
#include "../syscall/skeleton.h"
#include "../syscall/stub.h"
#include "types.h"

/*! \brief Interrupt based system call entry function
 *
 * Low-level function written in assembly (located in `syscall/handler.asm`),
 * calls \ref syscall_handler
 */
extern "C" [[gnu::interrupt]] void syscall_entry(InterruptContext *context);

namespace Syscall {
/*! \brief High level system call handler
 * called by both low level handler in `syscall/handler.asm`.
 *
 * Processes the request by delegating it to the appropriate function identified
 * by the system call number -- allowing up to five parameters for the system
 * call.
 *
 * \param p1 first parameter
 * \param p2 second parameter
 * \param p3 third parameter
 * \param p4 fourth parameter
 * \param p5 fifth parameter
 * \param sysnum identifier for the system call
 * \param user pointer to the interrupt \ref context (for example to determine
 * instruction pointer)
 * \return system call return value
 */
extern "C" size_t syscall_handler(size_t sysnum, size_t p1, size_t p2,
								  size_t p3, size_t p4, size_t p5,
								  InterruptContext *user) {
    switch ((Syscall::ID)sysnum) {
        case Syscall::ID::TEST:
            return Syscall::Skeleton::test(Guard::enter().vault(), p1, p2, p3, p4, p5);
        case Syscall::ID::WRITE:
            return Syscall::Skeleton::write(Guard::enter().vault(), p1, (char*)p2, p3, (int)p4, (int)p5);
        case Syscall::ID::READ:
            return Syscall::Skeleton::read(Guard::enter().vault(), 0, (void*) p2, p3);
        case Syscall::ID::SLEEP:
            Syscall::Skeleton::sleep(Guard::enter().vault(), p1);
            return 0;
        case Syscall::ID::SEM_INIT:
            Syscall::Skeleton::sem_init(Guard::enter().vault(), p1, p2);
            break;
        case Syscall::ID::SEM_DESTROY:
            Syscall::Skeleton::sem_destroy(Guard::enter().vault(), p1);
            break;
         case Syscall::ID::SEM_WAIT:
            Syscall::Skeleton::sem_wait(Guard::enter().vault(), p1);
            break;
         case Syscall::ID::SEM_SIGNAL:
            Syscall::Skeleton::sem_signal(Guard::enter().vault(), p1);
            break;
         case Syscall::ID::SYS_GETPID:
            return Syscall::Skeleton::getpid(Guard::enter().vault());
         case Syscall::ID::SYS_EXIT:
            Syscall::Skeleton::exit(Guard::enter().vault());
            return 0;
     }

	return static_cast<size_t>(-1);
}

void init() {
	// Set interrupt based syscall handler
	IDT::set(Core::Interrupt::Vector::SYSCALL, IDT::InterruptDescriptor::Returning(syscall_entry, 0, IDT::DPL_USER));
	IDT::load();
}

}  // namespace Syscall