// Copyright 2018 The Walk Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

// +build windows

package walk

import (
	"io/ioutil"
	"os"
	"path/filepath"
	"strings"
	"syscall"

	"github.com/lxn/win"
)

/*
This function creates a manifest file for this application and activates it
before creating the GUI controls. This way, the common controls version 6 is
used automatically and the users of this library does not need to mess with
manifest files themselves.
*/
func init() {
	appName := filepath.Base(os.Args[0])
	appName = strings.TrimSuffix(appName, filepath.Ext(appName))
	manifest := `<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<assembly xmlns="urn:schemas-microsoft-com:asm.v1" manifestVersion="1.0" xmlns:asmv3="urn:schemas-microsoft-com:asm.v3">
    <assemblyIdentity version="1.0.0.0" processorArchitecture="*" name="` + appName + `" type="win32"/>
    <dependency>
        <dependentAssembly>
            <assemblyIdentity type="win32" name="Microsoft.Windows.Common-Controls" version="6.0.0.0" processorArchitecture="*" publicKeyToken="6595b64144ccf1df" language="*"/>
        </dependentAssembly>
    </dependency>
    <asmv3:application>
        <asmv3:windowsSettings xmlns="http://schemas.microsoft.com/SMI/2005/WindowsSettings">
            <dpiAware>true</dpiAware>
        </asmv3:windowsSettings>
    </asmv3:application>
</assembly>`
	// create a temporary manifest file, load it, then delete it
	f, err := ioutil.TempFile("", "manifest_")
	if err != nil {
		return
	}
	manifestPath := f.Name()
	defer os.Remove(manifestPath)
	f.WriteString(manifest)
	f.Close()
	ctx := win.CreateActCtx(&win.ACTCTX{
		Source: syscall.StringToUTF16Ptr(manifestPath),
	})
	win.ActivateActCtx(ctx)
}