// examples/embed.c -- add scripting to a C program with calog, in ~30 lines.
//
// The entire embedding surface is calog.h: create a runtime, register a native C
// function the host provides, create a script context on an engine that exposes it,
// and run a script that calls back into the host. Swap calogJsEngine for
// calogLuaEngine / calogSquirrelEngine to change languages -- nothing else changes.

#include "calog.h"

#include <stdio.h>

// A host-provided native, callable from any embedded engine: hostLog(message).
static int32_t hostLog(CalogValueT *args, int32_t argCount, CalogValueT *result, void *userData) {
    (void)userData;
    calogValueNil(result);
    if (argCount != 1 || args[0].type != calogStringE) {
        return calogFail(result, calogErrArgE, "hostLog expects one string");
    }
    printf("[host] %s\n", args[0].as.s.bytes);
    return calogOkE;
}


int main(void) {
    CalogT        *calog;
    CalogContextT *ctx;
    CalogValueT    result;
    const char    *expose[] = { "hostLog" };
    CalogConfigT   config    = { expose, 1 };

    calog = calogCreate();
    calogRegister(calog, "hostLog", hostLog, NULL, 0);

    calogContextCreate(calog, &calogJsEngine, &config, &ctx);
    calogContextStart(ctx);
    calogContextEval(ctx, "hostLog('hello from JavaScript, ' + (6 * 7))", &result);
    calogValueFree(&result);

    calogContextDestroy(ctx);
    calogDestroy(calog);
    return 0;
}