// SPDX-License-Identifier: Apache-2.0
// SPDX-FileCopyrightText: 2022 The Ebitengine Authors

package purego

import (
	"syscall"
	_ "unsafe" // only for go:linkname

	"golang.org/x/sys/windows"
)

var syscall15XABI0 uintptr

type syscall15Args struct {
	fn, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12, a13, a14, a15 uintptr
	f1, f2, f3, f4, f5, f6, f7, f8                                       uintptr
	r1, r2, err                                                          uintptr
}

func syscall_syscall15X(fn, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12, a13, a14, a15 uintptr) (r1, r2, err uintptr) {
	r1, r2, errno := syscall.Syscall15(fn, 15, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12, a13, a14, a15)
	return r1, r2, uintptr(errno)
}

// NewCallback converts a Go function to a function pointer conforming to the stdcall calling convention.
// This is useful when interoperating with Windows code requiring callbacks. The argument is expected to be a
// function with one uintptr-sized result. The function must not have arguments with size larger than the
// size of uintptr. Only a limited number of callbacks may be created in a single Go process, and any memory
// allocated for these callbacks is never released. Between NewCallback and NewCallbackCDecl, at least 1024
// callbacks can always be created. Although this function is similiar to the darwin version it may act
// differently.
func NewCallback(fn interface{}) uintptr {
	return syscall.NewCallback(fn)
}

//go:linkname openLibrary openLibrary
func openLibrary(name string) (uintptr, error) {
	handle, err := windows.LoadLibrary(name)
	return uintptr(handle), err
}

func loadSymbol(handle uintptr, name string) (uintptr, error) {
	return windows.GetProcAddress(windows.Handle(handle), name)
}