/*
 * Copyright (c) 2009, Wayne Meissner
 *
 * Copyright (c) 2008-2013, Ruby FFI project contributors
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the Ruby FFI project nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef _MSC_VER
#include <sys/param.h>
#endif
#include <sys/types.h>
#include <stdio.h>
#include <stdint.h>
#include <stdbool.h>
#include <errno.h>
#include <ruby.h>

#include <ffi.h>
#include "rbffi.h"
#include "compat.h"

#include "Type.h"
#include "StructByValue.h"
#include "Struct.h"

#define FFI_ALIGN(v, a)  (((((size_t) (v))-1) | ((a)-1))+1)

static VALUE sbv_allocate(VALUE);
static VALUE sbv_initialize(VALUE, VALUE);
static void sbv_mark(StructByValue *);
static void sbv_free(StructByValue *);

VALUE rbffi_StructByValueClass = Qnil;

static VALUE
sbv_allocate(VALUE klass)
{
    StructByValue* sbv;

    VALUE obj = Data_Make_Struct(klass, StructByValue, sbv_mark, sbv_free, sbv);

    sbv->rbStructClass = Qnil;
    sbv->rbStructLayout = Qnil;
    sbv->base.nativeType = NATIVE_STRUCT;

    sbv->base.ffiType = xcalloc(1, sizeof(*sbv->base.ffiType));
    sbv->base.ffiType->size = 0;
    sbv->base.ffiType->alignment = 1;
    sbv->base.ffiType->type = FFI_TYPE_STRUCT;

    return obj;
}

static VALUE
sbv_initialize(VALUE self, VALUE rbStructClass)
{
    StructByValue* sbv = NULL;
    StructLayout* layout = NULL;
    VALUE rbLayout = Qnil;

    rbLayout = rb_ivar_get(rbStructClass, rb_intern("@layout"));
    if (!rb_obj_is_instance_of(rbLayout, rbffi_StructLayoutClass)) {
        rb_raise(rb_eTypeError, "wrong type in @layout ivar (expected FFI::StructLayout)");
    }

    Data_Get_Struct(rbLayout, StructLayout, layout);
    Data_Get_Struct(self, StructByValue, sbv);
    sbv->rbStructClass = rbStructClass;
    sbv->rbStructLayout = rbLayout;

    /* We can just use everything from the ffi_type directly */
    *sbv->base.ffiType = *layout->base.ffiType;
    
    return self;
}

static void
sbv_mark(StructByValue *sbv)
{
    rb_gc_mark(sbv->rbStructClass);
    rb_gc_mark(sbv->rbStructLayout);
}

static void
sbv_free(StructByValue *sbv)
{
    xfree(sbv->base.ffiType);
    xfree(sbv);
}


static VALUE
sbv_layout(VALUE self)
{
    StructByValue* sbv;

    Data_Get_Struct(self, StructByValue, sbv);
    return sbv->rbStructLayout;
}

static VALUE
sbv_struct_class(VALUE self)
{
    StructByValue* sbv;

    Data_Get_Struct(self, StructByValue, sbv);

    return sbv->rbStructClass;
}

void
rbffi_StructByValue_Init(VALUE moduleFFI)
{
    rbffi_StructByValueClass = rb_define_class_under(moduleFFI, "StructByValue", rbffi_TypeClass);
    rb_global_variable(&rbffi_StructByValueClass);
    rb_define_const(rbffi_TypeClass, "Struct", rbffi_StructByValueClass);

    rb_define_alloc_func(rbffi_StructByValueClass, sbv_allocate);
    rb_define_method(rbffi_StructByValueClass, "initialize", sbv_initialize, 1);
    rb_define_method(rbffi_StructByValueClass, "layout", sbv_layout, 0);
    rb_define_method(rbffi_StructByValueClass, "struct_class", sbv_struct_class, 0);
}