AtomicGameEngine/Source/AtomicJS/Javascript/JSAPI.cpp

// Copyright (c) 2014-2015, THUNDERBEAST GAMES LLC All rights reserved
// Please see LICENSE.md in repository root for license information
// https://github.com/AtomicGameEngine/AtomicGameEngine

#include <Atomic/Core/Context.h>
#include <Atomic/Resource/ResourceCache.h>

#include "JSAPI.h"
#include "JSVM.h"

/*

  // script can new an instance
  // script can get an engine ptr back (which may be to a previously script new'd instance)
  // script should always get the same JS Object back which means a lookup table (strong ref)
  // we can look directly at the tval (exposed from duktape internals) to see if the reference count is 1

  // script owned
  // new'd script side, script holds a RefCounted reference

  // native owned

  // native script classes not derived from refcounted
  // if not inherited from RefCounted can script access?
  // if so, script side will always need to delete?

*/

namespace Atomic
{

void js_class_get_prototype(duk_context* ctx, const char* package, const char *classname)
{
    duk_get_global_string(ctx, package);
    duk_get_prop_string(ctx, -1, classname);
    duk_get_prop_string(ctx, -1, "prototype");
    duk_remove(ctx, -2); // remove class object
    duk_remove(ctx, -2); // remove Atomic object
}

void js_class_get_constructor(duk_context* ctx, const char* package, const char *classname)
{
    duk_get_global_string(ctx, package);
    duk_get_prop_string(ctx, -1, classname);
    duk_remove(ctx, -2); // remove package
}

void js_constructor_basecall(duk_context* ctx, const char* package, const char* baseclass)
{
    int top = duk_get_top(ctx);
    duk_get_global_string(ctx, package);
    duk_get_prop_string(ctx, -1, baseclass);
    assert(duk_is_function(ctx, -1));
    duk_push_this(ctx);
    duk_call_method(ctx, 0);
    duk_pop_n(ctx, 2);
    assert (top == duk_get_top(ctx));
}

void js_class_declare_internal(JSVM* vm, void* uniqueClassID, const char* package, const char* classname, duk_c_function constructor)
{
    duk_context* ctx = vm->GetJSContext();

    // uniqueClassID must be non-null
    assert(uniqueClassID);

    // stash a lookup from the uniqueID to the package and class name

    duk_push_heap_stash(ctx);
    duk_push_pointer(ctx, uniqueClassID);

    duk_push_object(ctx);
    duk_push_string(ctx, package);
    duk_put_prop_index(ctx, -2, 0);
    duk_push_string(ctx, classname);
    duk_put_prop_index(ctx, -2, 1);

    // store class object into uniqueClassID key
    duk_put_prop(ctx, -3);

    // pop heap stash
    duk_pop(ctx);

    // store the constructor
    duk_get_global_string(ctx, package);
    duk_push_c_function(ctx, constructor, DUK_VARARGS);
    duk_put_prop_string(ctx, -2, classname);
    duk_pop(ctx);
}

void js_class_push_propertyobject(JSVM* vm, const char* package, const char* classname)
{
    duk_context* ctx = vm->GetJSContext();
    String pname;
    pname.AppendWithFormat("__%s__Properties", classname);

    duk_get_global_string(ctx, package);
    duk_push_object(ctx);
    duk_dup(ctx, -1);
    duk_put_prop_string(ctx, -3, pname.CString());
    duk_remove(ctx, -2); // remove Atomic object
}

void js_setup_prototype(JSVM* vm, const char* package, const char* classname, const char* basePackage, const char* basename, bool hasProperties)
{
    duk_context* ctx = vm->GetJSContext();

    String pname;
    pname.AppendWithFormat("__%s__Properties", classname);

    int top = duk_get_top(ctx);

    duk_get_global_string(ctx,package);
    duk_get_prop_string(ctx, -1, classname);
    assert(duk_is_c_function(ctx, -1));

    if (!strlen(basename))
    {
        // prototype
        duk_push_object(ctx);
        duk_dup(ctx, -2); // AObject constructor function
        duk_put_prop_string(ctx, -2, "constructor");
        duk_put_prop_string(ctx, -2, "prototype");

        duk_pop_n(ctx, 2);

        assert (top == duk_get_top(ctx));

        return;

    }

    // prototype
    duk_get_global_string(ctx, "Object");
    duk_get_prop_string(ctx, -1, "create");

    assert(duk_is_function(ctx, -1));

    duk_remove(ctx, -2); // remove Object

    duk_get_global_string(ctx, basePackage);
    duk_get_prop_string(ctx, -1, basename);
    assert(duk_is_function(ctx, -1));
    duk_get_prop_string(ctx, -1, "prototype");

    assert(duk_is_object(ctx, -1));

    duk_remove(ctx, -2); // remove basename

    int numargs = 1;
    if (hasProperties)
    {
        duk_get_global_string(ctx, package);
        duk_get_prop_string(ctx, -1, pname.CString());
        assert(duk_is_object(ctx, -1));
        duk_remove(ctx, -2);
        duk_remove(ctx, -3); // remove package
        numargs++;
    }
    else
        duk_remove(ctx, -2); // remove package

    duk_call(ctx, numargs);

    assert(duk_is_object(ctx, -1));

    duk_dup(ctx, -2);
    duk_put_prop_string(ctx, -2, "constructor");

    //duk_dup(ctx, -1);
    duk_put_prop_string(ctx, -2, "prototype");

    // pop the classname object
    duk_pop(ctx);

    // pop the Atomic Object
    duk_pop(ctx);

    assert (top == duk_get_top(ctx));
}

void js_object_to_variantmap(duk_context* ctx, int objIdx, VariantMap &v)
{
    v.Clear();

    duk_enum(ctx, objIdx, DUK_ENUM_OWN_PROPERTIES_ONLY);

    while (duk_next(ctx, -1 /*enum_index*/, 1 /*get_value*/)) {

        /* [ ... enum key ] */

        const char* key = duk_to_string(ctx, -2);

        if (duk_is_number(ctx, -1)) {

            v[key] = (float) duk_to_number(ctx, -1);

        } else if (duk_is_boolean(ctx, -1)) {

            v[key] = duk_to_boolean(ctx, -1) ? true : false;

        }
        else if (duk_is_string(ctx, -1)) {

            v[key] = duk_to_string(ctx, -1);

        } else if (duk_get_heapptr(ctx, -1)) {

            v[key] = js_to_class_instance<Object>(ctx, -1, 0);

        }

        duk_pop_2(ctx);  /* pop_key & value*/
    }

    duk_pop(ctx);  /* pop enum object */

}

void js_to_variant(duk_context* ctx, int variantIdx, Variant &v)
{
    v.Clear();

    // convert to abs index
    if (variantIdx < 0)
        variantIdx = duk_get_top(ctx) + variantIdx;

    if (duk_is_boolean(ctx, variantIdx))
    {
        v = duk_to_boolean(ctx, variantIdx) ? true : false;
        return;
    }

    if (duk_is_string(ctx, variantIdx))
    {
        v = duk_to_string(ctx, variantIdx);
        return;
    }

    if (duk_is_number(ctx, variantIdx))
    {
        v = (float) duk_to_number(ctx, variantIdx);
        return;
    }

    if (duk_is_pointer(ctx, variantIdx))
    {
        v = (RefCounted*) duk_get_pointer(ctx, variantIdx);
        return;
    }

    if (duk_is_object(ctx, variantIdx))
    {
        RefCounted* o = js_to_class_instance<RefCounted>(ctx, variantIdx, 0);
        if (o)
            v = o;
        return;
    }

    if (duk_is_array(ctx, variantIdx))
    {
        if (duk_get_length(ctx, variantIdx) == 2)
        {
            Vector2 v2;
            duk_get_prop_index(ctx, variantIdx, 0);
            v2.x_ = duk_to_number(ctx, -1);
            duk_get_prop_index(ctx, variantIdx, 1);
            v2.y_ = duk_to_number(ctx, -1);
            duk_pop_n(ctx, 2);
            v = v2;
            return;
        }
        else if (duk_get_length(ctx, variantIdx) == 3)
        {
            Vector3 v3;
            duk_get_prop_index(ctx, variantIdx, 0);
            v3.x_ = duk_to_number(ctx, -1);
            duk_get_prop_index(ctx, variantIdx, 1);
            v3.y_ = duk_to_number(ctx, -1);
            duk_get_prop_index(ctx, variantIdx, 2);
            v3.z_ = duk_to_number(ctx, -1);
            duk_pop_n(ctx, 3);
            v = v3;
            return;
        }
        else if (duk_get_length(ctx, variantIdx) == 4)
        {
            Vector4 v4;
            duk_get_prop_index(ctx, variantIdx, 0);
            v4.x_ = duk_to_number(ctx, -1);
            duk_get_prop_index(ctx, variantIdx, 1);
            v4.y_ = duk_to_number(ctx, -1);
            duk_get_prop_index(ctx, variantIdx, 2);
            v4.z_ = duk_to_number(ctx, -1);
            duk_get_prop_index(ctx, variantIdx, 3);
            v4.w_ = duk_to_number(ctx, -1);
            duk_pop_n(ctx, 4);
            v = v4;
            return;
        }


        return;
    }

}


// variant map Proxy getter, so we can convert access to string based
// member lookup, to string hash on the fly

static int variantmap_property_get(duk_context* ctx)
{
    // targ, key, recv

    if (duk_is_string(ctx, 1))
    {
        StringHash key = duk_to_string(ctx, 1);
        duk_get_prop_index(ctx, 0, (unsigned) key.Value());
        return 1;
    }

    duk_push_undefined(ctx);
    return 1;

}

// removes all keys from the variant map proxy target, REGARDLESS of key given for delete
// see (lengthy) note in JSEventDispatcher::EndSendEvent
static int variantmap_property_deleteproperty(duk_context* ctx)
{
    // deleteProperty: function (targ, key)

    duk_enum(ctx, 0, DUK_ENUM_OWN_PROPERTIES_ONLY);

    while (duk_next(ctx, -1, 0)) {        
        duk_del_prop(ctx, 0);
    }

    duk_push_boolean(ctx, 1);
    return 1;

}


void js_push_variantmap(duk_context* ctx, const VariantMap &vmap)
{

    // setup proxy so we can map string
    duk_get_global_string(ctx, "Proxy");

    duk_push_object(ctx);

    VariantMap::ConstIterator itr = vmap.Begin();

    while (itr != vmap.End()) {

        js_push_variant(ctx, itr->second_);


        if (duk_is_undefined(ctx, -1)) {

            duk_pop(ctx);
        }
        else
        {
            duk_put_prop_index(ctx, -2, (unsigned) itr->first_.Value());
        }

        itr++;

    }

    // setup property handler
    duk_push_object(ctx);
    duk_push_c_function(ctx, variantmap_property_get, 3);
    duk_put_prop_string(ctx, -2, "get");
    duk_push_c_function(ctx, variantmap_property_deleteproperty, 2);
    duk_put_prop_string(ctx, -2, "deleteProperty");

    duk_new(ctx, 2);


}

void js_push_variant(duk_context *ctx, const Variant& v)
{
    VariantType type = v.GetType();
    RefCounted* ref;
    Vector2 vector2 = Vector2::ZERO;
    Vector3 vector3 = Vector3::ZERO;
    Vector4 vector4 = Vector4::ZERO;
    Color color = Color::BLACK;
    Resource* resource = NULL;
    ResourceCache* cache = NULL;
    ResourceRef resourceRef;

    switch (type)
    {
    case VAR_NONE:
        duk_push_undefined(ctx);
        break;

    case VAR_VOIDPTR:
        duk_push_null(ctx);
        break;
    case VAR_PTR:

        ref = v.GetPtr();

        // if we're null or don't have any refs, return null
        if (!ref || !ref->Refs())
        {
            duk_push_null(ctx);
            break;
        }

        // check that class is supported
        duk_push_heap_stash(ctx);
        duk_push_pointer(ctx, (void*) ref->GetClassID());
        duk_get_prop(ctx, -2);

        if (!duk_is_object(ctx, -1))
        {
            duk_pop_2(ctx);
            duk_push_undefined(ctx);
        }
        else
        {
            duk_pop_2(ctx);
            js_push_class_object_instance(ctx, ref);
        }

        break;

    case VAR_RESOURCEREF:
        resourceRef = v.GetResourceRef();
        cache = JSVM::GetJSVM(ctx)->GetContext()->GetSubsystem<ResourceCache>();
        resource = cache->GetResource(resourceRef.type_, resourceRef.name_);
        js_push_class_object_instance(ctx, resource);
        break;

    case VAR_BOOL:
        duk_push_boolean(ctx, v.GetBool() ? 1 : 0);
        break;
    case VAR_INT:
        duk_push_number(ctx, v.GetInt());
        break;
    case VAR_FLOAT:
        duk_push_number(ctx, v.GetFloat());
        break;
    case VAR_STRING:
        duk_push_string(ctx, v.GetString().CString());
        break;
    case VAR_VECTOR2:
        vector2 = v.GetVector2();
        duk_push_array(ctx);
        duk_push_number(ctx, vector2.x_);
        duk_put_prop_index(ctx, -2, 0);
        duk_push_number(ctx, vector2.y_);
        duk_put_prop_index(ctx, -2, 1);
        break;
    case VAR_VECTOR3:
        vector3 = v.GetVector3();
        duk_push_array(ctx);
        duk_push_number(ctx, vector3.x_);
        duk_put_prop_index(ctx, -2, 0);
        duk_push_number(ctx, vector3.y_);
        duk_put_prop_index(ctx, -2, 1);
        duk_push_number(ctx, vector3.z_);
        duk_put_prop_index(ctx, -2, 2);
        break;
    case VAR_QUATERNION:
        vector3 = v.GetQuaternion().EulerAngles();
        duk_push_array(ctx);
        duk_push_number(ctx, vector3.x_);
        duk_put_prop_index(ctx, -2, 0);
        duk_push_number(ctx, vector3.y_);
        duk_put_prop_index(ctx, -2, 1);
        duk_push_number(ctx, vector3.z_);
        duk_put_prop_index(ctx, -2, 2);
        break;
    case VAR_COLOR:
        color = v.GetColor();
        duk_push_array(ctx);
        duk_push_number(ctx, color.r_);
        duk_put_prop_index(ctx, -2, 0);
        duk_push_number(ctx, color.g_);
        duk_put_prop_index(ctx, -2, 1);
        duk_push_number(ctx, color.b_);
        duk_put_prop_index(ctx, -2, 2);
        duk_push_number(ctx, color.a_);
        duk_put_prop_index(ctx, -2, 3);
        break;
    case VAR_VECTOR4:
        vector4 = v.GetVector4();
        duk_push_array(ctx);
        duk_push_number(ctx, vector4.x_);
        duk_put_prop_index(ctx, -2, 0);
        duk_push_number(ctx, vector4.y_);
        duk_put_prop_index(ctx, -2, 1);
        duk_push_number(ctx, vector4.z_);
        duk_put_prop_index(ctx, -2, 2);
        duk_push_number(ctx, vector4.w_);
        duk_put_prop_index(ctx, -2, 3);
        break;

    default:
        duk_push_undefined(ctx);
        break;
    }


}


}