// testTimer.c -- exercises the timer library from Lua: a one-shot fires once after a delay, a
// cancelled one-shot never fires, and a repeating timer fires several times before cancelling
// itself. Each callback runs on its owning context and reports back through host natives, which
// the main thread services by pumping.

#define _POSIX_C_SOURCE 200809L

#include "calog.h"
#include "calogTimer.h"

#include <stdatomic.h>
#include <stdio.h>
#include <time.h>

#define CHECK(cond, msg) checkImpl((cond), (msg), __FILE__, __LINE__)

#define PUMP_LIMIT   4000
#define RESULT_SLOTS 12

static CalogT         *calog      = NULL;
static _Atomic int64_t results[RESULT_SLOTS];
static _Atomic int32_t doneCount   = 0;
static _Atomic int32_t errorCount   = 0;
static int32_t         testsRun     = 0;
static int32_t         testsFailed  = 0;

static int64_t asInt(const CalogValueT *value);
static void    checkImpl(bool condition, const char *message, const char *file, int32_t line);
static int32_t nativeDone(CalogValueT *args, int32_t argCount, CalogValueT *result, void *userData);
static int32_t nativeReport(CalogValueT *args, int32_t argCount, CalogValueT *result, void *userData);
static void    onError(uint64_t contextId, const char *message, void *userData);
static void    pumpSettle(void);
static void    pumpUntilDone(int32_t target);


static int64_t asInt(const CalogValueT *value) {
    if (value->type == calogIntE) {
        return value->as.i;
    }
    return (int64_t)value->as.r;
}


static void checkImpl(bool condition, const char *message, const char *file, int32_t line) {
    testsRun++;
    if (!condition) {
        testsFailed++;
        printf("FAIL %s:%d  %s\n", file, line, message);
    }
}


static int32_t nativeDone(CalogValueT *args, int32_t argCount, CalogValueT *result, void *userData) {
    (void)args;
    (void)argCount;
    (void)userData;
    atomic_fetch_add(&doneCount, 1);
    calogValueNil(result);
    return calogOkE;
}


static int32_t nativeReport(CalogValueT *args, int32_t argCount, CalogValueT *result, void *userData) {
    int64_t tag;

    (void)userData;
    calogValueNil(result);
    if (argCount != 2 || (args[0].type != calogIntE && args[0].type != calogRealE) || (args[1].type != calogIntE && args[1].type != calogRealE)) {
        return calogFail(result, calogErrArgE, "report expects (tag, value)");
    }
    tag = asInt(&args[0]);
    if (tag < 0 || tag >= RESULT_SLOTS) {
        return calogFail(result, calogErrArgE, "report: tag out of range");
    }
    atomic_store(&results[tag], asInt(&args[1]));
    return calogOkE;
}


static void onError(uint64_t contextId, const char *message, void *userData) {
    (void)contextId;
    (void)userData;
    fprintf(stderr, "  [script error] %s\n", (message != NULL) ? message : "(null)");
    atomic_fetch_add(&errorCount, 1);
}


static void pumpSettle(void) {
    struct timespec ts = { 0, 500000 };
    int             i;

    // Keep pumping for ~60ms so a broken cancel or a stray extra fire has time to show up.
    for (i = 0; i < 120; i++) {
        calogPump(calog);
        nanosleep(&ts, NULL);
    }
}


static void pumpUntilDone(int32_t target) {
    struct timespec ts = { 0, 500000 };
    int             i;

    for (i = 0; i < PUMP_LIMIT; i++) {
        calogPump(calog);
        if (atomic_load(&doneCount) >= target) {
            calogPump(calog);
            return;
        }
        nanosleep(&ts, NULL);
    }
}


int main(void) {
    CalogContextT *ctxAfter;
    CalogContextT *ctxCancel;
    CalogContextT *ctxEvery;
    int32_t        i;

    calog = calogCreate();
    if (calog == NULL) {
        printf("calog create failed\n");
        return 1;
    }
    calogSetErrorHandler(calog, onError, NULL);
    calogRegister(calog, "report", nativeReport, NULL);
    calogRegister(calog, "done", nativeDone, NULL);
    if (calogTimerRegister(calog) != calogOkE) {
        printf("calogTimerRegister failed\n");
        return 1;
    }
    for (i = 0; i < RESULT_SLOTS; i++) {
        atomic_store(&results[i], -1);
    }

    // A one-shot fires its callback once, ~10ms from now, on its owning context.
    ctxAfter = calogContextOpen(calog, &calogLuaEngine);
    calogContextEval(ctxAfter,
        "timerAfter(10, function() report(1, 42); done() end)");

    // A one-shot cancelled immediately must NEVER fire (slot 3 stays -1). Slot 4 confirms the
    // script itself ran to completion.
    ctxCancel = calogContextOpen(calog, &calogLuaEngine);
    calogContextEval(ctxCancel,
        "local h = timerAfter(20, function() report(3, 999) end)\n"
        "timerCancel(h)\n"
        "report(4, 1)\n"
        "local okr = pcall(function() timerAfter(1/0, function() end) end)\n"
        "report(5, okr and 0 or 1)\n"                                    // 1, a non-finite delay is rejected, not UB
        "done()");

    // A repeating timer fires every ~5ms; after the third fire it cancels itself and reports the
    // final count. Slot 2 must settle at exactly 3.
    ctxEvery = calogContextOpen(calog, &calogLuaEngine);
    calogContextEval(ctxEvery,
        "local count = 0\n"
        "local id\n"
        "id = timerEvery(5, function()\n"
        "  count = count + 1\n"
        "  report(2, count)\n"
        "  if count >= 3 then timerCancel(id); done() end\n"
        "end)");

    pumpUntilDone(3);
    pumpSettle();

    CHECK(atomic_load(&results[1]) == 42, "timerAfter fires its callback once after the delay");
    CHECK(atomic_load(&results[4]) == 1, "a script that cancels a pending one-shot still runs to completion");
    CHECK(atomic_load(&results[3]) == -1, "timerCancel of a one-shot before it fires prevents the callback");
    CHECK(atomic_load(&results[2]) == 3, "timerEvery fires repeatedly and timerCancel stops it after 3 fires");
    CHECK(atomic_load(&results[5]) == 1, "a non-finite / out-of-range delay is rejected");
    CHECK(atomic_load(&doneCount) >= 3, "all three timer scripts completed");
    CHECK(atomic_load(&errorCount) == 0, "no uncaught errors");

    // Release pending callbacks + stop the thread while the contexts are still alive.
    calogTimerShutdown();

    calogContextClose(ctxAfter);
    calogContextClose(ctxCancel);
    calogContextClose(ctxEvery);
    calogDestroy(calog);

    printf("\n%d checks, %d failed\n", testsRun, testsFailed);
    fflush(stdout);
    if (testsFailed != 0) {
        return 1;
    }
    return 0;
}