#ifndef PLAND_SYSCALL_H
#define PLAND_SYSCALL_H

#include <stdint.h>
#include <stdbool.h>

typedef uint32_t _file_handle_t;
typedef uint32_t _task_handle_t;
typedef uint32_t _drive_number_t;
typedef enum {
  _KEY_BACKSPACE = '\b',
  _KEY_RETURN    = '\n',
  //etc.

  _KEY_LSHIFT = 0x00000100,
  _KEY_RSHIFT = 0x00000200,
  _KEY_CAPS   = 0x00000400,
  _KEY_INSERT = 0x00000800,
  _KEY_NUM    = 0x00001000,
  _KEY_SCROLL = 0x00002000,
  _KEY_LALT   = 0x00004000,
  _KEY_RALT   = 0x00008000,
  _KEY_LCTRL  = 0x00010000,
  _KEY_RCTRL  = 0x00020000,
  _KEY_LMETA  = 0x00040000,
  _KEY_RMETA  = 0x00080000,

  _KEY_SHIFT  = 0x00000300,
  _KEY_SCAPS  = 0x00000700,
  _KEY_ALT    = 0x0000c000,
  _KEY_CTRL   = 0x00030000,
  _KEY_META   = 0x000c0000,
} _key_code_t;

enum _scn {
  _SCN_OPEN_FILE,
  _SCN_CLOSE_FILE,
  _SCN_FILE_READ,
  _SCN_FILE_SIZE,
  _SCN_START_TASK,
  _SCN_LOG_STRING,
  _SCN_GET_KEY,
  _SCN_ALLOCATE_RAM
};

static inline uint32_t _sc0(enum _scn eax) {
  volatile uint32_t out;
  asm (
    "int $0x30"
  : "=a" (out) : "a" (eax) : "ecx", "edx");
  return out;
}

static inline uint32_t _sc1(enum _scn eax, uint32_t ebx) {
  volatile uint32_t out;
  asm (
    "int $0x30"
  : "=a" (out) : "a" (eax), "b" (ebx) : "ecx", "edx");
  return out;
}

static inline uint32_t _sc2(enum _scn eax, uint32_t ebx, uint32_t ecx) {
  volatile uint32_t out;
  asm (
    "int $0x30"
  : "=a" (out) : "a" (eax), "b" (ebx), "c" (ecx) : "edx");
  return out;
}

static inline uint32_t _sc3(enum _scn eax, uint32_t ebx, uint32_t ecx, uint32_t edx) {
  volatile uint32_t out;
  asm (
    "int $0x30"
  : "=a" (out) : "a" (eax), "b" (ebx), "c" (ecx), "d" (edx));
  return out;
}

static inline uint32_t _sc4(enum _scn eax, uint32_t ebx, uint32_t ecx, uint32_t edx, uint32_t esi) {
  volatile uint32_t out;
  asm (
    "int $0x30"
  : "=a" (out) : "a" (eax), "b" (ebx), "c" (ecx), "d" (edx), "S" (esi));
  return out;
}

static inline uint32_t _sc5(enum _scn eax, uint32_t ebx, uint32_t ecx, uint32_t edx, uint32_t esi, uint32_t edi) {
  volatile uint32_t out;
  asm (
    "int $0x30"
  : "=a" (out) : "a" (eax), "b" (ebx), "c" (ecx), "d" (edx), "S" (esi), "D" (edi));
  return out;
}

static inline void _yield_task() {
  asm (
    "int $0x39"
  );
}

__attribute__ ((noreturn))
static inline void _exit_task() {
  asm (
    "int $0x38"
  );
  __builtin_unreachable();
}

static inline _file_handle_t _open_file(_drive_number_t drive_number, const char *path) {
  return _sc2(_SCN_OPEN_FILE, drive_number, (uint32_t)path);
}

static inline void _close_file(_file_handle_t handle) {
  _sc1(_SCN_CLOSE_FILE, handle);
}

static inline uint32_t _file_read(_file_handle_t handle, uint32_t file_offset, uint32_t count, void *buffer) {
  return _sc4(_SCN_FILE_READ, handle, file_offset, count, (uint32_t)buffer);
}

static inline uint32_t _file_size(_file_handle_t handle) {
  return _sc1(_SCN_FILE_SIZE, handle);
}

static inline bool _start_task(_drive_number_t drive_number, const char *path) {
  return (bool)_sc2(_SCN_START_TASK, drive_number, (uint32_t)path);
}

static inline void _log_string(const char *sz) {
  _sc1(_SCN_LOG_STRING, (uint32_t)sz);
}

static inline _key_code_t _get_key() {
  return _sc0(_SCN_GET_KEY);
}

static inline void *_allocate_ram(uint32_t pages) {
  return (void *)_sc1(_SCN_ALLOCATE_RAM, pages);
}

#endif