/*!
 * @file segment.h
 *
 * @brief Common functionality shared by external and datastore segment support.
 */
#ifndef LIBNEWRELIC_SEGMENT_H
#define LIBNEWRELIC_SEGMENT_H

#include <stdbool.h>
#include "nr_segment_datastore.h"
#include "nr_segment_external.h"
#include "nr_txn.h"

typedef struct _newrelic_segment_t {
  nr_segment_t* segment;
  nrtxn_t* transaction;

  /*! The lock inherited from the transaction. */
  nrthread_mutex_t* txn_lock;

  /* Type fields. Which union is valid depends on segment->type, which is the
   * source of truth for what type of segment this is. */
  union {
    struct {
      /* The datastore API offers that the user supplies segment
       * metadata at a segment's start. The user-facing functions,
       * newrelic_start_datastore_segment() and newrelic_start_external_segment(),
       * perform a few checks on this metadata and then save it here. This metadata
       * is used to record metrics on a call to newrelic_end_segment() */
      char* collection;
      char* operation;
      nr_datastore_instance_t instance;
      nr_datastore_t type;
      char* string;
      char* sql;
    } datastore;
    struct {
      char* uri;
      char* library;
      char* procedure;
    } external;
  } type;
} newrelic_segment_t;

/*!
 * @brief Create a new segment.
 *
 * This function ensures that segments are created correctly, particularly
 * around exclusive time calculations.
 *
 * @param [in] txn The transaction to create the segment on.
 * @return A segment, or NULL if an error occurred.
 *
 * @warning As this is an internal function, a NULL check is _not_ performed on
 *          txn! Additionally, the transaction must be locked before calling
 *          this function.
 */
extern newrelic_segment_t* newrelic_segment_create(nrtxn_t* txn);

extern void newrelic_segment_destroy(newrelic_segment_t** segment_ptr);

/*!
 * @brief Validate segment parameter.
 *
 * This function ensures that any given parameter does not include a slash. As
 * segment parameter values are generally used in metric names, slashes will
 * break the APM UI.
 *
 * @param [in] in   The parameter value.
 * @param [in] name The parameter name (used in any error message).
 *
 * @return True if the parameter value is valid, false otherwise. A message at
 * level LOG_ERROR will be logged if validation fails.
 */
bool newrelic_validate_segment_param(const char* in, const char* name);

#endif /* LIBNEWRELIC_SEGMENT_H */