// testTask.c -- exercises the calog task library: a parent Lua script spawns child script
// contexts, feeds them code, queries the task count and its own id, loads a script file, and
// closes tasks. Children report values back through a host native so the parent's management
// of them can be observed.

#define _POSIX_C_SOURCE 200809L

#include "calog.h"
#include "calogTask.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
#define TAG_COUNT  16

static CalogT         *calog       = NULL;
static _Atomic int64_t results[TAG_COUNT];
static _Atomic bool    scriptDone   = false;
static _Atomic int32_t errorCount   = 0;
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 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    pumpUntilDone(void);
static void    pumpUntilScriptDone(void);
static void    resetTags(void);
static void    testTaskCrossEngine(void);
static void    testTaskError(void);
static void    testTaskLoad(void);
static void    testTaskMutualClose(void);
static void    testTaskSelfClose(void);
static void    testTaskSpawn(void);
static void    writeFile(const char *path, const char *text);


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_store(&scriptDone, true);
    calogValueNil(result);
    return calogOkE;
}


// Accept int or real so the same observer works from every engine (e.g. JS numbers marshal
// as reals).
static int64_t asInt(const CalogValueT *value) {
    if (value->type == calogIntE) {
        return value->as.i;
    }
    return (int64_t)value->as.r;
}


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 >= TAG_COUNT) {
        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 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);
    }
}


// Waits for the parent script's done() regardless of child errors (used by tests that
// deliberately trigger a refused operation in a child but expect the parent to finish).
static void pumpUntilScriptDone(void) {
    struct timespec ts = { 0, 500000 };
    int             i;

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


static void resetTags(void) {
    int32_t i;

    atomic_store(&scriptDone, false);
    for (i = 0; i < TAG_COUNT; i++) {
        atomic_store(&results[i], -1);
    }
}


static void testTaskCrossEngine(void) {
    CalogContextT *ctx;

    ctx = calogContextOpen(calog, &calogLuaEngine);
    resetTags();
    // A Lua script launches a JavaScript task -- the whole point of naming the engine.
    calogContextEval(ctx,
        "local j = taskSpawn('js', 'report(8, 55)')\n"
        "taskClose(j)\n"
        "done()");
    pumpUntilDone();

    CHECK(atomic_load(&results[8]) == 55, "a Lua script spawned and ran a JavaScript task");

    calogContextClose(ctx);
}


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

    ctx    = calogContextOpen(calog, &calogLuaEngine);
    before = atomic_load(&errorCount);
    resetTags();
    // Spawning an unknown engine must raise a clean script-level error.
    calogContextEval(ctx, "taskSpawn('nosuchengine', 'return 1')\n done()");
    pumpUntilDone();

    CHECK(atomic_load(&errorCount) == before + 1, "taskSpawn of an unknown engine raised a script error");

    calogContextClose(ctx);
}


static void testTaskLoad(void) {
    CalogContextT *ctx;

    writeFile("clTask.lua", "report(6, 77)\n");
    ctx = calogContextOpen(calog, &calogLuaEngine);
    resetTags();
    // taskLoad launches the script FILE by base name; it reports 77, then we close it.
    calogContextEval(ctx,
        "local f = taskLoad('clTask')\n"
        "taskClose(f)\n"
        "done()");
    pumpUntilDone();

    CHECK(atomic_load(&results[6]) == 77, "taskLoad launched a script file that ran");

    calogContextClose(ctx);
    remove("clTask.lua");
}


static void testTaskMutualClose(void) {
    CalogContextT *ctx;

    ctx = calogContextOpen(calog, &calogLuaEngine);
    resetTags();
    // Two children each told to close the OTHER's handle. Both are refused (the parent owns
    // both), so there is no mutual pthread_join deadlock -- reaching the end proves it.
    calogContextEval(ctx,
        "local a = taskSpawn('lua', '')\n"
        "local b = taskSpawn('lua', '')\n"
        "taskEval(a, 'taskClose(' .. b .. ')')\n"
        "taskEval(b, 'taskClose(' .. a .. ')')\n"
        "taskClose(a)\n"
        "taskClose(b)\n"
        "report(1, 1)\n"
        "done()");
    pumpUntilScriptDone();

    CHECK(atomic_load(&results[1]) == 1, "mutual cross-close is refused, not a deadlock");

    calogContextClose(ctx);
}


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

    ctx    = calogContextOpen(calog, &calogLuaEngine);
    before = atomic_load(&errorCount);
    resetTags();
    // A child is told to close its OWN handle. That must be refused (only the owner closes),
    // NOT a self-join that frees the running context -- reaching the end proves no crash.
    calogContextEval(ctx,
        "local t = taskSpawn('lua', '')\n"
        "taskEval(t, 'taskClose(' .. t .. ')')\n"
        "taskClose(t)\n"
        "report(1, 1)\n"
        "done()");
    pumpUntilScriptDone();

    CHECK(atomic_load(&results[1]) == 1, "a task closing its own handle is refused, not a self-join crash");
    CHECK(atomic_load(&errorCount) > before, "the self-close attempt raised a clean error");

    calogContextClose(ctx);
}


static void testTaskSpawn(void) {
    CalogContextT *ctx;

    ctx = calogContextOpen(calog, &calogLuaEngine);
    resetTags();
    // Spawn a child (reports 42), read the live task count + own id, feed the child more code
    // (reports 99), close it, then read the count again.
    calogContextEval(ctx,
        "local t = taskSpawn('lua', 'report(1, 42)')\n"
        "report(2, taskCount())\n"
        "report(3, taskSelf())\n"
        "taskEval(t, 'report(4, 99)')\n"
        "taskClose(t)\n"
        "report(5, taskCount())\n"
        "done()");
    pumpUntilDone();

    CHECK(atomic_load(&results[1]) == 42, "a spawned child task ran its code");
    CHECK(atomic_load(&results[2]) == 1, "taskCount saw the one open task");
    CHECK(atomic_load(&results[3]) > 0, "taskSelf returned the caller's own non-zero context id");
    CHECK(atomic_load(&results[4]) == 99, "taskEval fed more code into the running task");
    CHECK(atomic_load(&results[5]) == 0, "taskCount saw the task gone after taskClose");

    calogContextClose(ctx);
}


static void writeFile(const char *path, const char *text) {
    FILE *file;

    file = fopen(path, "wb");
    if (file == NULL) {
        return;
    }
    fwrite(text, 1, strlen(text), file);
    fclose(file);
}


int main(void) {
    calog = calogCreate();
    if (calog == NULL) {
        printf("calog create failed\n");
        return 1;
    }
    calogSetErrorHandler(calog, onError, NULL);
    calogRegisterEngine(calog, &calogLuaEngine);   // so taskLoad can find *.lua
    // Inline observers: they run on the reporting task's own thread and complete within its
    // eval, so they are not aborted when a task is closed mid-report (unlike a host native,
    // whose cross-thread call taskClose's cooperative shutdown can interrupt).
    calogRegisterInline(calog, "report", nativeReport, NULL);
    calogRegisterInline(calog, "done", nativeDone, NULL);
    if (calogTaskRegister(calog) != calogOkE) {
        printf("calogTaskRegister failed\n");
        return 1;
    }

    testTaskSpawn();
    testTaskLoad();
    testTaskCrossEngine();
    testTaskSelfClose();
    testTaskMutualClose();
    testTaskError();

    calogDestroy(calog);
    calogTaskShutdown();

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