/* pending.h - Pending subscription state tracker using splay tree */
#ifndef __PENDING_H__
#define __PENDING_H__

#include <time.h>
#include <ilib/splay.h>

#define PENDING_ID_LEN 16

typedef struct pending_entry {
  splay_node_t node;
  char token[PENDING_ID_LEN + 1];  /* Unique hex string token */
  char *email;                     /* Applicant email address */
  time_t created_at;               /* Unix timestamp for TTL check */
} pending_entry_t;

typedef struct pending_pool {
  splay_t tree;
  char *filepath;
  long ttl_seconds;                /* Default TTL: e.g., 86400 (24h) */
} pending_pool_t;

int pending_pool_init(pending_pool_t *pool, const char *filepath, long ttl_seconds);
void pending_pool_destroy(pending_pool_t *pool);

/*
 * Generates a unique token, attaches the email address, and inserts into tree.
 * Populates out_token with the generated hex identifier string.
 */
int pending_add(pending_pool_t *pool, const char *email, char *out_token, size_t token_buf_len);

/*
 * Looks up a pending token. If found and not expired, returns the associated applicant email.
 * If expired, automatically purges the entry and returns NULL.
 */
char *pending_lookup_email(pending_pool_t *pool, const char *token);

/* Explicitly removes a pending token after successful confirmation */
int pending_remove(pending_pool_t *pool, const char *token);

/* Purges stale pending entries exceeding the TTL */
void pending_purge_expired(pending_pool_t *pool);

int pending_load_file(pending_pool_t *pool);
int pending_save_file(pending_pool_t *pool);

#endif /* __PENDING_H__ */