#include <stdlib.h>

#include "lsm/store_internal.h"

lsm_error lsm_read_handle_init(lsm_read_handle **out) {
  lsm_read_handle *handle = calloc(1, sizeof(lsm_read_handle));

  if (handle == NULL) {
    return lsm_error_failed_alloc;
  }

  *out = handle;

  return lsm_error_ok;
}

bool lsm_read_attr_present(lsm_read_handle *handle, uint8_t type) {
  return lsm_entry_attr_present(handle->wrapper->entry, type);
}

lsm_error lsm_read_attr_get(const lsm_str **out, const lsm_read_handle *handle,
                            uint8_t type) {
  return lsm_entry_attr_get(out, handle->wrapper->entry, type);
}

lsm_error lsm_read_attr_get_uint64_t(uint64_t *out,
                                     const lsm_read_handle *handle,
                                     uint8_t type) {
  return lsm_entry_attr_get_uint64_t(out, handle->wrapper->entry, type);
}

lsm_error lsm_read_attr_get_uint8_t(uint8_t *out, const lsm_read_handle *handle,
                                    uint8_t type) {
  return lsm_entry_attr_get_uint8_t(out, handle->wrapper->entry, type);
}

uint64_t lsm_read_data_len(const lsm_read_handle *handle) {
  return handle->wrapper->entry->data_len;
}

lsm_error lsm_read_data_read(uint64_t *out, char *buf, lsm_read_handle *handle,
                             uint64_t len) {
  const lsm_entry *entry = handle->wrapper->entry;

  if (entry->data_len == 0) {
    *out = 0;

    return lsm_error_ok;
  }

  // Entries don't open their file unless needed
  if (handle->data.f == NULL) {
    LSM_RES(lsm_entry_data_open(&handle->data.f, handle->store,
                                handle->wrapper->entry, "rb"));
  }

  uint64_t read;

  read = fread(buf, sizeof(char), len, handle->data.f);

  if ((read == 0) && (ferror(handle->data.f) != 0)) {
    return lsm_error_failed_io;
  }

  handle->data.pos += read;
  *out = read;

  return lsm_error_ok;
}

void lsm_read_close(lsm_read_handle *handle) {
  if (handle->data.f != NULL) {
    fclose(handle->data.f);
    handle->data.f = NULL;
  }

  pthread_rwlock_unlock(&handle->wrapper->lock);
  free(handle);
}