#include <stdint.h>
#include <stddef.h>
#include <stdbool.h>
#include "hal/hal.h"
#include "syscall.h"
#include "vfs.h"
#include "errors.h"
#include "sysdefs/dev.h"
#include "sysdefs/vfs.h"
#include "vfs/vfs.h"
#include "spinlock/spinlock.h"
#include "dev/dev.h"
#include "proc/proc.h"
#include "storedev/storedev.h"
#include "util/util.h"
#include "hshtb.h"
#include "std/string.h"

int32_t SYSCALL4(sys_vfsmount, mountpoint1, fstypestr1, devid1, format1) {
  int32_t ret = E_OK;
  char *mountpoint = (char *)mountpoint1;
  char *fstypestr = (char *)fstypestr1;
  Dev_t *dev = (Dev_t *)devid1;
  bool format = (bool)format1;

  if (mountpoint == NULL) { ret = E_INVALIDARGUMENT; goto done; }
  if (fstypestr == NULL) { ret = E_INVALIDARGUMENT; goto done; }
  if (dev == NULL) { ret = E_INVALIDARGUMENT; goto done; }

  if (*dev >= PROC_DEVHANDLES_MAX) { ret = E_INVALIDARGUMENT; goto done; }

  int32_t fstype;

  if (strcmp(fstypestr, "LittleFS") == 0) {
    fstype = VFS_LITTLEFS;
  } else {
    ret = E_INVALIDARGUMENT;
    goto done;
  }

  spinlock_acquire(&PROCS.spinlock);
  Proc *proc = NULL;
  LL_FINDPROP(PROCS.procs, proc, pid, _caller_pid);
  spinlock_release(&PROCS.spinlock);

  Dev *dp = proc->devs[*dev];
  if (dp == NULL) { ret = E_NOENTRY; goto done; }

  StoreDev *sd = (StoreDev *)dp->extra;
  if (sd != NULL && sd->_magic != STOREDEV_MAGIC) { ret = E_NOENTRY; goto done; }

  ret = vfs_mount(mountpoint, fstype, sd, format);

done:
  return ret;
}

int32_t SYSCALL1(sys_vfsunmount, mountpoint1) {
  int32_t ret = E_OK;
  char *mountpoint = (char *)mountpoint1;
  
  if (mountpoint == NULL) { ret = E_INVALIDARGUMENT; goto done; }

  ret = vfs_unmount(mountpoint);

done:
  return ret;
}

int32_t SYSCALL1(sys_vfsavailmounts, availmounts1) {
  VfsAvailMounts *availmounts = (VfsAvailMounts *)availmounts1;
  if (availmounts == NULL) {
    return E_INVALIDARGUMENT;
  }

  spinlock_acquire(&VFS_TABLE.spinlock);
  for (size_t i = 0; i < VFS_MOUNTPOINTS_MAX; i++) {
    VfsMountPoint *vmp = &VFS_TABLE.mountpoints[i];
    if (vmp->_hshtbstate == HSHTB_TAKEN) {
      memcpy(availmounts->labels[i], vmp->label, VFS_MOUNTPOINT_LABEL_MAX);
      availmounts->fieldavail[i] = 1;
    }
  }
  spinlock_release(&VFS_TABLE.spinlock);

  return E_OK;
}

int32_t SYSCALL2(sys_vfsmountstat, statbuf1, label1) {
  VfsMountStat *statbuf = (VfsMountStat *)statbuf1;
  if (statbuf == NULL) {
    return E_INVALIDARGUMENT;
  }

  char *label = (char *)label1;
  if (label == NULL) {
    return E_INVALIDARGUMENT;
  }

  VfsMountPoint *vmp = NULL;
  spinlock_acquire(&VFS_TABLE.spinlock);
  HSHTB_GET(VFS_TABLE.mountpoints, label, label, vmp);
  spinlock_release(&VFS_TABLE.spinlock);

  if (vmp == NULL) {
    return E_NOENTRY;
  }

  memcpy(statbuf->label, vmp->label, sizeof(statbuf->label));
  statbuf->fstype = vmp->fstype;
  
  StoreDev *vmpsd = vmp->backingsd;
  spinlock_acquire(&DEVTABLE.spinlock);
  for (size_t i = 0; i < LEN(DEVTABLE.devs); i++) {
    Dev *dev = &DEVTABLE.devs[i];
    if (dev->extra != NULL && ((StoreDev *)dev->extra)->_magic == STOREDEV_MAGIC && vmpsd == dev->extra) {
      memcpy(statbuf->devname, dev->ident, sizeof(statbuf->devname));
      break;
    }
  }
  spinlock_release(&DEVTABLE.spinlock);

  return E_OK;
}