#include <stdbool.h>
#include <stdint.h>
#include <stddef.h>
#include "spinlock/spinlock.h"
#include "errors.h"
#include "hal/hal.h"
#include "hshtb.h"
#include "kprintf.h"
#include "vfs/vfs.h"
#include "dlmalloc/malloc.h"
#include "util/util.h"

int32_t kvfs_read(struct VfsMountPoint *vmp, const char *key, uint8_t *const buffer, size_t n, size_t off) {
  KvfsNode *node = NULL;

  spinlock_acquire(&vmp->spinlock);
  HSHTB_GET(&vmp->fs.kvfs, nodes, (char *)key, key_, node);
  spinlock_release(&vmp->spinlock);

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

  spinlock_acquire(&node->spinlock);
  hal_memcpy(buffer + off, node->buffer, MIN(n, KVFS_BUFFER_SIZE - off));
  spinlock_release(&node->spinlock);
  return E_OK;
}

int32_t kvfs_write(struct VfsMountPoint *vmp, const char *key, const uint8_t *const buffer, size_t n, size_t off) {
  KvfsNode *node = NULL;

  spinlock_acquire(&vmp->spinlock);
  HSHTB_GET(&vmp->fs.kvfs, nodes, (char *)key, key_, node);
  if (node == NULL) {
    HSHTB_ALLOC(&vmp->fs.kvfs, nodes, (char *)key, key_, node);
    if (node == NULL) {
      spinlock_release(&vmp->spinlock);
      return E_NOMEMORY;
    }
  }
  spinlock_release(&vmp->spinlock);

  spinlock_acquire(&node->spinlock);
  if (node->buffer == NULL) {
    node->buffer = dlmalloc(KVFS_BUFFER_SIZE);
    if (node->buffer == NULL) {
      spinlock_release(&node->spinlock);
      return E_NOMEMORY;
    }
  }

  hal_memcpy(node->buffer + off, buffer, MIN(n, KVFS_BUFFER_SIZE - off));
  spinlock_release(&node->spinlock);
  return E_OK;
}

int32_t kvfs_remove(struct VfsMountPoint *vmp, const char *key) {
  KvfsNode *node = NULL;

  spinlock_acquire(&vmp->spinlock);
  HSHTB_GET(&vmp->fs.kvfs, nodes, (char *)key, key_, node);
  spinlock_release(&vmp->spinlock);

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

  spinlock_acquire(&node->spinlock);
  if (node->buffer != NULL) {
    dlfree(node->buffer);
  }
  hal_memset(node, 0, sizeof(*node));
  spinlock_release(&node->spinlock);
  return E_OK;
}

int32_t kvfs_cleanup(struct VfsMountPoint *vmp) {
  for (size_t i = 0; i < KVFS_NODES_MAX; i++) {
    KvfsNode *node = &vmp->fs.kvfs.nodes[i];
    spinlock_acquire(&node->spinlock);
    if (node->buffer != NULL) {
      dlfree(node->buffer);
    }
    spinlock_release(&node->spinlock);
  }
  return E_OK;
}

bool kvfs_check(void) {
  int32_t ret;

  char *hello = "WAWAWAWA!!!";
  ret = vfs_write("tmpvars", "hello", hello, hal_strlen(hello)+1, 0);
  if (ret != E_OK) return false;

  char buf[20];
  ret = vfs_read("tmpvars", "hello", buf, sizeof(buf), 0);
  if (ret != E_OK) return false;

  vfs_remove("tmpvars", "hello");
  if (ret != E_OK) return false;
  
  ret = vfs_read("tmpvars", "hello", buf, sizeof(buf), 0);
  if (ret != E_NOENTRY) return false;

  return true;
}