/*
 * Copyright (c) 2009, Wayne Meissner
 * All rights reserved.
 *
 * This file is part of ruby-ffi.
 *
 * This code is free software: you can redistribute it and/or modify it under
 * the terms of the GNU Lesser General Public License version 3 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
 * version 3 for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * version 3 along with this work.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <sys/param.h>
#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 "AbstractMemory.h"
#include "Types.h"
#include "Type.h"
#include "StructByValue.h"
#include "Function.h"

static VALUE fntype_allocate(VALUE klass);
static VALUE fntype_initialize(int argc, VALUE* argv, VALUE self);
static void fntype_mark(FunctionType*);
static void fntype_free(FunctionType *);

VALUE rbffi_FunctionTypeClass = Qnil;

static VALUE
fntype_allocate(VALUE klass)
{
    FunctionType* fnInfo;
    VALUE obj = Data_Make_Struct(klass, FunctionType, fntype_mark, fntype_free, fnInfo);

    fnInfo->type.ffiType = &ffi_type_pointer;
    fnInfo->type.nativeType = NATIVE_FUNCTION;
    fnInfo->rbReturnType = Qnil;
    fnInfo->rbParameterTypes = Qnil;
    fnInfo->rbEnums = Qnil;
    fnInfo->invoke = rbffi_CallFunction;
    fnInfo->closurePool = NULL;

    return obj;
}

static void
fntype_mark(FunctionType* fnInfo)
{
    rb_gc_mark(fnInfo->rbReturnType);
    rb_gc_mark(fnInfo->rbParameterTypes);
    rb_gc_mark(fnInfo->rbEnums);
    if (fnInfo->callbackCount > 0 && fnInfo->callbackParameters != NULL) {
        rb_gc_mark_locations(&fnInfo->callbackParameters[0], &fnInfo->callbackParameters[fnInfo->callbackCount]);
    }
}

static void
fntype_free(FunctionType* fnInfo)
{
    xfree(fnInfo->parameterTypes);
    xfree(fnInfo->ffiParameterTypes);
    xfree(fnInfo->nativeParameterTypes);
    xfree(fnInfo->callbackParameters);
    if (fnInfo->closurePool != NULL) {
        rbffi_ClosurePool_Free(fnInfo->closurePool);
    }
    xfree(fnInfo);
}

static VALUE
fntype_initialize(int argc, VALUE* argv, VALUE self)
{
    FunctionType *fnInfo;
    ffi_status status;
    VALUE rbReturnType = Qnil, rbParamTypes = Qnil, rbOptions = Qnil;
    VALUE rbEnums = Qnil, rbConvention = Qnil, rbBlocking = Qnil;
#if defined(_WIN32) || defined(__WIN32__)
    VALUE rbConventionStr;
#endif
    int i, nargs;

    nargs = rb_scan_args(argc, argv, "21", &rbReturnType, &rbParamTypes, &rbOptions);
    if (nargs >= 3 && rbOptions != Qnil) {
        rbConvention = rb_hash_aref(rbOptions, ID2SYM(rb_intern("convention")));
        rbEnums = rb_hash_aref(rbOptions, ID2SYM(rb_intern("enums")));
        rbBlocking = rb_hash_aref(rbOptions, ID2SYM(rb_intern("blocking")));
    }

    Check_Type(rbParamTypes, T_ARRAY);

    Data_Get_Struct(self, FunctionType, fnInfo);
    fnInfo->parameterCount = (int) RARRAY_LEN(rbParamTypes);
    fnInfo->parameterTypes = xcalloc(fnInfo->parameterCount, sizeof(*fnInfo->parameterTypes));
    fnInfo->ffiParameterTypes = xcalloc(fnInfo->parameterCount, sizeof(ffi_type *));
    fnInfo->nativeParameterTypes = xcalloc(fnInfo->parameterCount, sizeof(*fnInfo->nativeParameterTypes));
    fnInfo->rbParameterTypes = rb_ary_new2(fnInfo->parameterCount);
    fnInfo->rbEnums = rbEnums;
    fnInfo->blocking = RTEST(rbBlocking);
    fnInfo->hasStruct = false;

    for (i = 0; i < fnInfo->parameterCount; ++i) {
        VALUE entry = rb_ary_entry(rbParamTypes, i);
        VALUE type = rbffi_Type_Lookup(entry);

        if (!RTEST(type)) {
            VALUE typeName = rb_funcall2(entry, rb_intern("inspect"), 0, NULL);
            rb_raise(rb_eTypeError, "Invalid parameter type (%s)", RSTRING_PTR(typeName));
        }

        if (rb_obj_is_kind_of(type, rbffi_FunctionTypeClass)) {
            REALLOC_N(fnInfo->callbackParameters, VALUE, fnInfo->callbackCount + 1);
            fnInfo->callbackParameters[fnInfo->callbackCount++] = type;
        }

        if (rb_obj_is_kind_of(type, rbffi_StructByValueClass)) {
            fnInfo->hasStruct = true;
        }

        rb_ary_push(fnInfo->rbParameterTypes, type);
        Data_Get_Struct(type, Type, fnInfo->parameterTypes[i]);
        fnInfo->ffiParameterTypes[i] = fnInfo->parameterTypes[i]->ffiType;
        fnInfo->nativeParameterTypes[i] = fnInfo->parameterTypes[i]->nativeType;
    }

    fnInfo->rbReturnType = rbffi_Type_Lookup(rbReturnType);
    if (!RTEST(fnInfo->rbReturnType)) {
        VALUE typeName = rb_funcall2(rbReturnType, rb_intern("inspect"), 0, NULL);
        rb_raise(rb_eTypeError, "Invalid return type (%s)", RSTRING_PTR(typeName));
    }
    
    if (rb_obj_is_kind_of(fnInfo->rbReturnType, rbffi_StructByValueClass)) {
        fnInfo->hasStruct = true;
    }

    Data_Get_Struct(fnInfo->rbReturnType, Type, fnInfo->returnType);
    fnInfo->ffiReturnType = fnInfo->returnType->ffiType;


#if defined(_WIN32) || defined(__WIN32__)
    rbConventionStr = (rbConvention != Qnil) ? rb_funcall2(rbConvention, rb_intern("to_s"), 0, NULL) : Qnil;
    fnInfo->abi = (rbConventionStr != Qnil && strcmp(StringValueCStr(rbConventionStr), "stdcall") == 0)
            ? FFI_STDCALL : FFI_DEFAULT_ABI;
#else
    fnInfo->abi = FFI_DEFAULT_ABI;
#endif

    status = ffi_prep_cif(&fnInfo->ffi_cif, fnInfo->abi, fnInfo->parameterCount,
            fnInfo->ffiReturnType, fnInfo->ffiParameterTypes);
    switch (status) {
        case FFI_BAD_ABI:
            rb_raise(rb_eArgError, "Invalid ABI specified");
        case FFI_BAD_TYPEDEF:
            rb_raise(rb_eArgError, "Invalid argument type specified");
        case FFI_OK:
            break;
        default:
            rb_raise(rb_eArgError, "Unknown FFI error");
    }

    fnInfo->invoke = rbffi_GetInvoker(fnInfo);

    return self;
}

static VALUE
fntype_result_type(VALUE self)
{
    FunctionType* ft;

    Data_Get_Struct(self, FunctionType, ft);

    return ft->rbReturnType;
}

static VALUE
fntype_param_types(VALUE self)
{
    FunctionType* ft;

    Data_Get_Struct(self, FunctionType, ft);

    return rb_ary_dup(ft->rbParameterTypes);
}

void
rbffi_FunctionInfo_Init(VALUE moduleFFI)
{
    /*
     * Document-class: FFI::FunctionType < FFI::Type
     */
    rbffi_FunctionTypeClass = rb_define_class_under(moduleFFI, "FunctionType", rbffi_TypeClass);
    rb_global_variable(&rbffi_FunctionTypeClass);
    /*
     * Document-const: FFI::CallbackInfo = FFI::FunctionType
     */
    rb_define_const(moduleFFI, "CallbackInfo", rbffi_FunctionTypeClass);
    /*
     * Document-const: FFI::FunctionInfo = FFI::FunctionType
     */
    rb_define_const(moduleFFI, "FunctionInfo", rbffi_FunctionTypeClass);
    /*
     * Document-const: FFI::Type::Function = FFI::FunctionType
     */
    rb_define_const(rbffi_TypeClass, "Function", rbffi_FunctionTypeClass);

    rb_define_alloc_func(rbffi_FunctionTypeClass, fntype_allocate);
    rb_define_method(rbffi_FunctionTypeClass, "initialize", fntype_initialize, -1);
    rb_define_method(rbffi_FunctionTypeClass, "result_type", fntype_result_type, 0);
    rb_define_method(rbffi_FunctionTypeClass, "param_types", fntype_param_types, 0);

}