/*
 * client_failover.h — public StatusClassifier surface for the libxce-failover
 * spec.
 *
 * Task 2.1 (StatusClassifier): pure mapping from a reply status / transport rc
 * to a failover action. No I/O, no globals — see design.md
 * "Components and Interfaces → StatusClassifier".
 */
#ifndef XCE_CLIENT_FAILOVER_H
#define XCE_CLIENT_FAILOVER_H

#include <stdbool.h>

/* Failover action a round-trip outcome maps to. Order mirrors the harness'
 * fo_expected_action_t (failover_harness.h) and design.md. */
typedef enum {
    XCE_FO_SUCCESS,       /* status == 0, or idempotent-replay success
                             (DUP on a re-sent write)                        */
    XCE_FO_RETRY_NOW,     /* E_XCE_REDIRECT / E_XCE_STANDBY / transport error
                             — rotate, no backoff                            */
    XCE_FO_RETRY_BACKOFF, /* E_XCE_NOMASTER / E_XCE_NOT_READY — rotate after
                             jittered backoff                                */
    XCE_FO_TERMINAL       /* AUTH/PERM/INVALID/NOENT and other non-retriable
                             — surface to caller                             */
} xce_fo_action_t;

/*
 * Map a reply status / transport rc to a failover action.
 *
 *   status  : the controller reply status or negative -errno transport rc, as
 *             the failover loop observes it. Controller codes (E_XCE_*) are
 *             accepted in either sign.
 *   is_write: true for mutating ops (e.g. job submit); false for reads.
 *   attempt : 0 for the first send; >0 for a re-send after failover.
 *
 * Invariant (2.5): E_XCE_REDIRECT/STANDBY/NOMASTER/NOT_READY never map to
 * XCE_FO_SUCCESS.
 *
 * Idempotent-replay rule (5.2): E_XCE_DUP_JOB / EEXIST on a re-sent write
 * (is_write && attempt > 0) → XCE_FO_SUCCESS; otherwise → XCE_FO_TERMINAL.
 *
 * Unknown / unrecognized statuses are treated conservatively as
 * XCE_FO_TERMINAL (surfaced, not retried).
 *
 * Pure function: no I/O, no globals.
 */
xce_fo_action_t xce_failover_classify(int status, bool is_write, int attempt);

#endif /* XCE_CLIENT_FAILOVER_H */