/*
 * test_driver_decision_cb.c - contract test for the normal-mode driver's
 * decision-publish callback (scheduler-core spec, task 5.2, Req 5 AC 6 /
 * AC 9's publishing half).
 *
 * Observable under test: xce_sched_driver_on_decision() -- registered via
 * xce_core_set_decision_cb() in main.c and matching xce_core_decision_cb_t's
 * signature exactly -- forwards each decision to the right publish call:
 *
 *   - XCE_DECISION_DISPATCH -> sched_publish_dispatch() called exactly
 *     once, with njobs=1 and allocs[0] == the SAME xce_job_alloc_t* the
 *     decision carried (not a copy).
 *   - XCE_DECISION_PEND -> sched_publish_pend_reason() called exactly
 *     once, with nreasons=1 and reasons[0] == the SAME xce_pendreason_t*
 *     the decision carried.
 *   - XCE_DECISION_PREEMPT -> NEITHER publish function is called (no live
 *     allocator path produces this decision type today, and no
 *     xcecli_preempt() client API exists to publish it through even if one
 *     did -- see driver.c's own header comment on this function for the
 *     full reasoning); returns -ENOSYS, never crashes, never silently
 *     drops without a trace (verified via the ERROR log call count below).
 *   - NULL driver_ctx / NULL decision -> -EINVAL, no publish calls.
 *
 * White-box #include of ../src/core.c, ../src/core_clock.c,
 * ../src/core_events.c, ../src/driver.c, and ../src/decision.c -- same
 * convention (and same file set) as test_driver_translate.c (task 5.1),
 * since driver.c's xce_sched_driver_translate_pending_events() -- unused by
 * this file's tests but part of the same TU -- still references
 * xce_core_push_events()/xce_core_now()/sched_get_job() at link time.
 * decision.c is added (over test_driver_translate.c's set) for the real
 * make_dispatch_decision()/make_pend_decision()/make_preempt_decision()
 * constructors this file's fixtures use to build realistic xce_decision_t
 * values, same convention as test_core_session.c.
 *
 * sched_publish_dispatch()/sched_publish_pend_reason() below are SPY test
 * doubles (not the real scheduler.c/xcecli_ctx_t-backed versions -- this
 * file never links scheduler.c, same rationale as test_driver_translate.c's
 * own stubs) that record every call's arguments so this file can assert on
 * the driver's call CONTRACT (Req 5 AC 9: "publish core-emitted decisions
 * back to the controller via the existing xcecli_ctx_t API") without a real
 * or mocked network connection.
 */
#include <errno.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>

#include <unity/unity.h>

#include "controller.capnp.h"
#include "kvmgr.h"
#include "preason.h"
#include "scheduler.h"
#include "xstring.h"

/* Pull in the real xce_sched_driver_on_decision() (and the rest of
 * driver.c's TU -- see file header comment) under test. */
#include "../src/core.c"
#include "../src/core_clock.c"
#include "../src/core_events.c"
#include "../src/decision.c"
#include "../src/driver.c"

void kill_sched_job(void* arg) { (void)arg; }
void kill_sched_queue(void* arg) { (void)arg; }
void kill_sched_worker(void* arg) { (void)arg; }
void kill_sched_user(void* arg) { (void)arg; }
void kill_sched_project(void* arg) { (void)arg; }
void kill_sched_resval(xce_val_t* val) { (void)val; }

/* dup_val - real reimplementation of snapshot_wire.c's function of the same
 * name (verbatim logic), needed because core_events.c's RESVALS_FULL/
 * RESVALS_DELTA handlers now call it (bug-1585 fix) and this file's
 * white-box #include of ../src/core_events.c does not pull in
 * snapshot_wire.c (same "reimplement the one small function instead of the
 * whole file" rationale this file's own sched_resolve_job_picker copy
 * already documents). This file's own kill_sched_resval is a no-op stub, so
 * the deep copy's contents are never inspected here -- only link-time
 * presence matters for this file's own tests. */
xce_val_t* dup_val(const xce_val_t* src)
{
    xce_val_t* v;

    if (src == NULL) {
        return NULL;
    }

    v = (xce_val_t*)calloc(1, sizeof(*v));
    if (v == NULL) {
        return NULL;
    }

    v->which = src->which;
    if (src->which == XCE_VAL_STRING) {
        v->u.svalue
            = (src->u.svalue != NULL) ? makeString(src->u.svalue) : NULL;
    } else {
        v->u = src->u;
    }

    return v;
}
void plugin_unregister(void* arg) { (void)arg; }

/* Link-satisfying stubs: as of scheduler-core spec task 5.2,
 * xce_sched_driver_run_normal_mode_round() (driver.c, real, #included
 * above, alongside xce_sched_driver_on_decision() this file DOES exercise)
 * references xce_core_begin_session()/xce_core_signal_go()/
 * xce_core_end_session() (core_session.c) and plugin_begin_session()/
 * plugin_end_session() (plugin.c) / sched_account_jobs() (scheduler.c).
 * This file never exercises xce_sched_driver_run_normal_mode_round() itself
 * (out of THIS file's scope -- see test_driver_session_ordering.c) and
 * never links core_session.c/plugin.c/scheduler.c. Never actually invoked
 * at runtime by any test in this file. */
int xce_core_begin_session(xce_sched_core_t* core)
{
    (void)core;
    return 0;
}

int xce_core_signal_go(xce_sched_core_t* core)
{
    (void)core;
    return 0;
}

int xce_core_end_session(xce_sched_core_t* core)
{
    (void)core;
    return 0;
}

int plugin_begin_session(xce_sched_core_t* core)
{
    (void)core;
    return 0;
}

int plugin_end_session(xce_sched_core_t* core)
{
    (void)core;
    return 0;
}

int sched_account_jobs(xce_sched_core_t* core)
{
    (void)core;
    return 0;
}

/* Link-satisfying stubs for recording.c/recording_events.c/
 * recording_session.c's real functions -- as of scheduler-core spec task
 * 9.2, driver.c's (real, #included above)
 * xce_sched_driver_translate_pending_events()/
 * xce_sched_driver_run_normal_mode_round() reference these. Neither is
 * exercised by this file's tests (out of THIS file's scope -- see
 * test_driver_translate.c/test_driver_session_ordering.c), and this file
 * never links recording.c's real implementations (they need
 * xce_sched_core_save_snapshot(), snapshot.c). Never actually invoked at
 * runtime by any test in this file. */
int sched_record_write_events(xce_scheduler_t* sched, xce_core_event_t* events,
                              int n)
{
    (void)sched;
    (void)events;
    (void)n;
    return 0;
}

/* sched_record_start/sched_record_stop (scheduler-core spec, task 9.4) --
 * driver.c's handle_deferred_admin_record() (new this task) calls both;
 * this file never enqueues an XCE_SCHED_OP_ADMIN_RECORD request, so
 * neither is actually invoked at runtime, same rationale as
 * sched_record_write_events above. */
int sched_record_start(xce_scheduler_t* sched, const char* record_file)
{
    (void)sched;
    (void)record_file;
    return 0;
}

int sched_record_stop(xce_scheduler_t* sched)
{
    (void)sched;
    return 0;
}

sched_record_session_ctx_t* sched_record_session_begin(xce_scheduler_t* sched,
                                                       uint64_t begin_round_ts)
{
    (void)sched;
    (void)begin_round_ts;
    return NULL;
}

void sched_record_session_add_decision(sched_record_session_ctx_t* ctx,
                                       uint64_t ts, xce_decision_t* decision)
{
    (void)ctx;
    (void)ts;
    (void)decision;
}

int sched_record_session_end(xce_scheduler_t*            sched,
                             sched_record_session_ctx_t* ctx, uint64_t end_ts)
{
    (void)sched;
    (void)ctx;
    (void)end_ts;
    return 0;
}

/* Real reimplementation of schedobj.c's sched_resolve_job_picker -- same
 * rationale as test_driver_translate.c's own copy (this file never links
 * schedobj.c/scheduler.c). Never actually exercised (no test here pushes
 * core events), present only to satisfy the linker for core_events.c. */
int sched_resolve_job_picker(xce_sched_core_t* core, xce_sched_plugin_t** out)
{
    (void)core;
    (void)out;
    return -EINVAL;
}

/* ---------------------------------------------------------------------- */
/* Spy test doubles for scheduler.c's sched_publish_dispatch()/            */
/* sched_publish_pend_reason() -- see file header comment.                 */
/* ---------------------------------------------------------------------- */

static int                g_dispatch_calls;
static xce_job_dispatch_t g_last_dispatch;
static xce_job_alloc_t*   g_last_dispatch_alloc;
static xce_scheduler_t*   g_last_dispatch_sched;

static int               g_pend_calls;
static xce_preason_set_t g_last_pend;
static xce_pendreason_t* g_last_pend_reason;
static xce_scheduler_t*  g_last_pend_sched;

static void reset_spies(void)
{
    g_dispatch_calls      = 0;
    g_last_dispatch_alloc = NULL;
    g_last_dispatch_sched = NULL;
    memset(&g_last_dispatch, 0, sizeof(g_last_dispatch));

    g_pend_calls       = 0;
    g_last_pend_reason = NULL;
    g_last_pend_sched  = NULL;
    memset(&g_last_pend, 0, sizeof(g_last_pend));
}

int sched_publish_dispatch(xce_scheduler_t* sched, xce_job_dispatch_t* d)
{
    g_dispatch_calls++;
    g_last_dispatch_sched = sched;
    g_last_dispatch       = *d;
    g_last_dispatch_alloc = (d->njobs > 0) ? d->allocs[0] : NULL;
    return 0;
}

int sched_publish_pend_reason(xce_scheduler_t* sched, xce_preason_set_t* r)
{
    g_pend_calls++;
    g_last_pend_sched  = sched;
    g_last_pend        = *r;
    g_last_pend_reason = (r->nreasons > 0) ? r->reasons[0] : NULL;
    return 0;
}

void setUp(void) { reset_spies(); }
void tearDown(void) { return; }

/* ---------------------------------------------------------------------- */
/* XCE_DECISION_DISPATCH                                                   */
/* ---------------------------------------------------------------------- */

static void test_dispatch_decision_publishes_via_sched_publish_dispatch(void)
{
    xce_scheduler_t  sched;
    xce_job_alloc_t* alloc = (xce_job_alloc_t*)calloc(1, sizeof(*alloc));
    xce_decision_t*  d;
    int              rc;

    memset(&sched, 0, sizeof(sched));
    alloc->jobid = 42;

    d = make_dispatch_decision(alloc);
    TEST_ASSERT_NOT_NULL(d);

    rc = xce_sched_driver_on_decision(&sched, d);

    TEST_ASSERT_EQUAL_INT(0, rc);
    TEST_ASSERT_EQUAL_INT(1, g_dispatch_calls);
    TEST_ASSERT_EQUAL_INT(0, g_pend_calls);
    TEST_ASSERT_EQUAL_PTR(&sched, g_last_dispatch_sched);
    TEST_ASSERT_EQUAL_INT(1, g_last_dispatch.njobs);
    TEST_ASSERT_EQUAL_PTR(alloc, g_last_dispatch_alloc);
    TEST_ASSERT_EQUAL_UINT64(42, g_last_dispatch_alloc->jobid);
}

/* ---------------------------------------------------------------------- */
/* XCE_DECISION_PEND                                                       */
/* ---------------------------------------------------------------------- */

static void test_pend_decision_publishes_via_sched_publish_pend_reason(void)
{
    xce_scheduler_t   sched;
    xce_pendreason_t* reason = make_pendreason(7);
    xce_decision_t*   d;
    int               rc;

    memset(&sched, 0, sizeof(sched));
    TEST_ASSERT_NOT_NULL(reason);

    d = make_pend_decision(reason);
    TEST_ASSERT_NOT_NULL(d);

    rc = xce_sched_driver_on_decision(&sched, d);

    TEST_ASSERT_EQUAL_INT(0, rc);
    TEST_ASSERT_EQUAL_INT(1, g_pend_calls);
    TEST_ASSERT_EQUAL_INT(0, g_dispatch_calls);
    TEST_ASSERT_EQUAL_PTR(&sched, g_last_pend_sched);
    TEST_ASSERT_EQUAL_INT(1, g_last_pend.nreasons);
    TEST_ASSERT_EQUAL_PTR(reason, g_last_pend_reason);
    TEST_ASSERT_EQUAL_UINT64(7, g_last_pend_reason->jobid);
}

/* ---------------------------------------------------------------------- */
/* XCE_DECISION_PREEMPT -- documented gap, must fail loudly, not crash     */
/* or fabricate a call to a nonexistent client API.                        */
/* ---------------------------------------------------------------------- */

static void test_preempt_decision_fails_loudly_publishes_nothing(void)
{
    xce_scheduler_t sched;
    xce_preempt_t   preempt;
    xce_decision_t* d;
    int             rc;

    memset(&sched, 0, sizeof(sched));
    memset(&preempt, 0, sizeof(preempt));
    preempt.jobid    = 99;
    preempt.nvictims = 0;
    preempt.victims  = NULL;
    preempt.reason   = make_pendreason(99);

    d = make_preempt_decision(&preempt);
    TEST_ASSERT_NOT_NULL(d);

    rc = xce_sched_driver_on_decision(&sched, d);

    TEST_ASSERT_EQUAL_INT(-ENOSYS, rc);
    TEST_ASSERT_EQUAL_INT(0, g_dispatch_calls);
    TEST_ASSERT_EQUAL_INT(0, g_pend_calls);
}

/* ---------------------------------------------------------------------- */
/* NULL argument guards                                                    */
/* ---------------------------------------------------------------------- */

static void test_null_driver_ctx_returns_einval_no_publish(void)
{
    xce_job_alloc_t* alloc = (xce_job_alloc_t*)calloc(1, sizeof(*alloc));
    xce_decision_t*  d     = make_dispatch_decision(alloc);
    int              rc;

    TEST_ASSERT_NOT_NULL(d);

    rc = xce_sched_driver_on_decision(NULL, d);

    TEST_ASSERT_EQUAL_INT(-EINVAL, rc);
    TEST_ASSERT_EQUAL_INT(0, g_dispatch_calls);
}

static void test_null_decision_returns_einval_no_publish(void)
{
    xce_scheduler_t sched;
    int             rc;

    memset(&sched, 0, sizeof(sched));

    rc = xce_sched_driver_on_decision(&sched, NULL);

    TEST_ASSERT_EQUAL_INT(-EINVAL, rc);
    TEST_ASSERT_EQUAL_INT(0, g_dispatch_calls);
    TEST_ASSERT_EQUAL_INT(0, g_pend_calls);
}

int main(void)
{
    UNITY_BEGIN();
    RUN_TEST(test_dispatch_decision_publishes_via_sched_publish_dispatch);
    RUN_TEST(test_pend_decision_publishes_via_sched_publish_pend_reason);
    RUN_TEST(test_preempt_decision_fails_loudly_publishes_nothing);
    RUN_TEST(test_null_driver_ctx_returns_einval_no_publish);
    RUN_TEST(test_null_decision_returns_einval_no_publish);
    return UNITY_END();
}