// testEngineSquirrel.c -- Squirrel on a context thread, driven the host way:
// register natives, open a context, fire-and-forget a script, and calogPump on the
// host thread. Verifies host-thread dispatch, the inline escape hatch, the sec-10
// cross-thread callback, the error handler, and concurrent contexts.

#define _POSIX_C_SOURCE 200809L

#include "calog.h"

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

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

#define PUMP_LIMIT 4000

static CalogT          *calog        = NULL;
static _Atomic int64_t  reportedValue = 0;
static _Atomic uint64_t reportedCtxId = 0xFFFFu;
static _Atomic uint64_t inlineCtxId   = 0xFFFFu;
static _Atomic int32_t  bumpCount     = 0;
static _Atomic bool     scriptDone    = false;
static _Atomic int32_t  errorCount    = 0;
static _Atomic uint64_t errorCtxId    = 0;
static CalogFnT *_Atomic storedCb      = NULL;
static int32_t          testsRun      = 0;
static int32_t          testsFailed   = 0;

static void    checkImpl(bool condition, const char *message, const char *file, int32_t line);
static int32_t nativeAdd(CalogValueT *args, int32_t argCount, CalogValueT *result, void *userData);
static int32_t nativeBump(CalogValueT *args, int32_t argCount, CalogValueT *result, void *userData);
static int32_t nativeDone(CalogValueT *args, int32_t argCount, CalogValueT *result, void *userData);
static int32_t nativeGetAdder(CalogValueT *args, int32_t argCount, CalogValueT *result, void *userData);
static int32_t nativeReport(CalogValueT *args, int32_t argCount, CalogValueT *result, void *userData);
static int32_t nativeReportInline(CalogValueT *args, int32_t argCount, CalogValueT *result, void *userData);
static int32_t nativeSetCb(CalogValueT *args, int32_t argCount, CalogValueT *result, void *userData);
static void    onError(uint64_t contextId, const char *message, void *userData);
static void    pumpUntilDone(void);
static void    testConcurrentContexts(void);
static void    testCrossThreadCallback(void);
static void    testForeignFunction(void);
static void    testHostAndInlineNatives(void);
static void    testScriptError(void);


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 nativeAdd(CalogValueT *args, int32_t argCount, CalogValueT *result, void *userData) {
    (void)userData;
    calogValueNil(result);
    if (argCount != 2 || args[0].type != calogIntE || args[1].type != calogIntE) {
        return calogFail(result, calogErrArgE, "add expects two integers");
    }
    calogValueInt(result, args[0].as.i + args[1].as.i);
    return calogOkE;
}


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


static int32_t nativeDone(CalogValueT *args, int32_t argCount, CalogValueT *result, void *userData) {
    (void)args;
    (void)argCount;
    (void)userData;
    atomic_store(&scriptDone, true);
    calogValueNil(result);
    return calogOkE;
}


static int32_t nativeGetAdder(CalogValueT *args, int32_t argCount, CalogValueT *result, void *userData) {
    CalogFnT *callable;
    int32_t   status;

    (void)args;
    (void)argCount;
    (void)userData;
    calogValueNil(result);
    // A host-owned function value handed to the script; calling it routes back here.
    status = calogFnFromNative(&callable, calog, nativeAdd, NULL);
    if (status != calogOkE) {
        return calogFail(result, status, "getAdder could not allocate");
    }
    calogValueFn(result, callable);
    return calogOkE;
}


static int32_t nativeReport(CalogValueT *args, int32_t argCount, CalogValueT *result, void *userData) {
    (void)userData;
    calogValueNil(result);
    if (argCount != 1 || args[0].type != calogIntE) {
        return calogFail(result, calogErrArgE, "report expects one integer");
    }
    atomic_store(&reportedCtxId, calogCurrentId());
    atomic_store(&reportedValue, args[0].as.i);
    return calogOkE;
}


static int32_t nativeReportInline(CalogValueT *args, int32_t argCount, CalogValueT *result, void *userData) {
    (void)args;
    (void)argCount;
    (void)userData;
    atomic_store(&inlineCtxId, calogCurrentId());
    calogValueNil(result);
    return calogOkE;
}


static int32_t nativeSetCb(CalogValueT *args, int32_t argCount, CalogValueT *result, void *userData) {
    (void)userData;
    calogValueNil(result);
    if (argCount != 1 || args[0].type != calogFnE) {
        return calogFail(result, calogErrArgE, "setCb expects one function");
    }
    calogFnRetain(args[0].as.fn);
    atomic_store(&storedCb, args[0].as.fn);
    return calogOkE;
}


static void onError(uint64_t contextId, const char *message, void *userData) {
    (void)message;
    (void)userData;
    atomic_store(&errorCtxId, contextId);
    atomic_fetch_add(&errorCount, 1);
}


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

    errorsBefore = atomic_load(&errorCount);
    for (i = 0; i < PUMP_LIMIT; i++) {
        calogPump(calog);
        if (atomic_load(&scriptDone) || atomic_load(&errorCount) != errorsBefore) {
            calogPump(calog);
            return;
        }
        nanosleep(&ts, NULL);
    }
}


static void testHostAndInlineNatives(void) {
    CalogContextT *ctx;

    ctx = calogContextOpen(calog, &calogSquirrelEngine);
    CHECK(ctx != NULL, "opened a Squirrel context");

    atomic_store(&scriptDone, false);
    calogContextEval(ctx, "report(42); reportInline(1); done();");
    pumpUntilDone();

    CHECK(atomic_load(&reportedValue) == 42, "host native received the argument");
    CHECK(atomic_load(&reportedCtxId) == 0, "default native ran on the host thread (id 0)");
    CHECK(atomic_load(&inlineCtxId) == calogContextId(ctx), "inline native ran on the script's own thread");

    calogContextClose(ctx);
}


static void testCrossThreadCallback(void) {
    CalogContextT *ctx;
    CalogFnT      *callback;
    CalogValueT    arg;
    CalogValueT    result;
    int32_t        status;

    ctx = calogContextOpen(calog, &calogSquirrelEngine);
    atomic_store(&scriptDone, false);
    atomic_store(&storedCb, NULL);
    calogContextEval(ctx, "setCb(function(x) { return x + 100; }); done();");
    pumpUntilDone();

    callback = atomic_load(&storedCb);
    CHECK(callback != NULL, "a Squirrel closure was captured as a CalogFnT");

    calogValueInt(&arg, 7);
    status = calogFnInvoke(callback, &arg, 1, &result);
    CHECK(status == calogOkE && result.type == calogIntE && result.as.i == 107, "cross-thread callable invoke routed to the owner");
    calogValueFree(&result);
    calogValueFree(&arg);
    calogFnRelease(callback);

    calogContextClose(ctx);
}


static void testForeignFunction(void) {
    CalogContextT *ctx;

    ctx = calogContextOpen(calog, &calogSquirrelEngine);
    atomic_store(&scriptDone, false);
    atomic_store(&reportedValue, 0);
    // The script receives a host-owned function value and calls it.
    calogContextEval(ctx, "report(getAdder()(2, 3))\ndone()");
    pumpUntilDone();

    CHECK(atomic_load(&reportedValue) == 5, "script called a foreign function value pushed in from the host");

    calogContextClose(ctx);
}


static void testScriptError(void) {
    CalogContextT *ctx;
    int32_t        before;

    ctx    = calogContextOpen(calog, &calogSquirrelEngine);
    before = atomic_load(&errorCount);
    atomic_store(&scriptDone, false);
    calogContextEval(ctx, "@@@ not valid squirrel @@@");
    pumpUntilDone();

    CHECK(atomic_load(&errorCount) == before + 1, "a fire-and-forget script error reached the error handler");
    CHECK(atomic_load(&errorCtxId) == calogContextId(ctx), "the error names the failing context");

    calogContextClose(ctx);
}


static void testConcurrentContexts(void) {
    CalogContextT  *ctxs[3];
    struct timespec ts = { 0, 500000 };
    int32_t         i;

    atomic_store(&bumpCount, 0);
    for (i = 0; i < 3; i++) {
        ctxs[i] = calogContextOpen(calog, &calogSquirrelEngine);
        calogContextEval(ctxs[i], "bump(); bump(); bump();");
    }
    for (i = 0; i < PUMP_LIMIT && atomic_load(&bumpCount) < 9; i++) {
        calogPump(calog);
        nanosleep(&ts, NULL);
    }
    CHECK(atomic_load(&bumpCount) == 9, "three concurrent contexts all dispatched to the host thread");
    for (i = 0; i < 3; i++) {
        calogContextClose(ctxs[i]);
    }
}


int main(void) {
    calog = calogCreate();
    if (calog == NULL) {
        printf("calog create failed\n");
        return 1;
    }
    calogSetErrorHandler(calog, onError, NULL);
    calogRegister(calog, "report", nativeReport, NULL);
    calogRegister(calog, "setCb", nativeSetCb, NULL);
    calogRegister(calog, "done", nativeDone, NULL);
    calogRegister(calog, "bump", nativeBump, NULL);
    calogRegister(calog, "getAdder", nativeGetAdder, NULL);
    calogRegisterInline(calog, "reportInline", nativeReportInline, NULL);

    testHostAndInlineNatives();
    testCrossThreadCallback();
    testForeignFunction();
    testScriptError();
    testConcurrentContexts();

    calogDestroy(calog);

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