//go:build windows

package main

import (
	"encoding/base64"
	"errors"
	"fmt"
	"syscall"
	"unicode/utf16"
	"unsafe"
)

const (
	mbOK              = 0x00000000
	mbIconError       = 0x10
	mbIconInformation = 0x40
	mbTaskModal       = 0x00002000
	mbSetForeground   = 0x00010000
	mbTopMost         = 0x00040000
)

var (
	user32          = syscall.NewLazyDLL("user32.dll")
	procMessageBoxW = user32.NewProc("MessageBoxW")
	callMessageBoxW = func(hwnd, text, caption, flags uintptr) (uintptr, error) {
		ret, _, err := procMessageBoxW.Call(hwnd, text, caption, flags)
		return ret, err
	}
)

func platformStartupChannels(runner commandRunner) []promptChannel {
	return []promptChannel{
		{
			name: "windows-toast",
			available: func() error {
				_, err := findPowerShell(runner)
				return err
			},
			run: func(req promptRequest) error {
				name, err := findPowerShell(runner)
				if err != nil {
					return err
				}
				return runner.Run(promptCommandTimeout, []string{
					"NEX_TOAST_TITLE=" + req.title,
					"NEX_TOAST_BODY=" + req.message,
				}, name, "-NoProfile", "-NonInteractive", "-ExecutionPolicy", "Bypass", "-EncodedCommand", encodePowerShellCommand(windowsToastScript()))
			},
		},
		{
			name: "windows-messagebox",
			available: func() error {
				return messageBoxAvailable()
			},
			run: func(req promptRequest) error {
				return messageBox(req.title, req.message, messageBoxStartupFlags())
			},
		},
	}
}

func findPowerShell(runner commandRunner) (string, error) {
	for _, name := range []string{"powershell.exe", "powershell"} {
		if _, err := runner.LookPath(name); err == nil {
			return name, nil
		}
	}
	return "", fmt.Errorf("PowerShell 不可用")
}

func windowsToastScript() string {
	return `$ErrorActionPreference = 'Stop'
Add-Type -AssemblyName System.Runtime.WindowsRuntime
$template = [Windows.UI.Notifications.ToastTemplateType]::ToastText02
$xml = [Windows.UI.Notifications.ToastNotificationManager]::GetTemplateContent($template)
$texts = $xml.GetElementsByTagName('text')
$texts.Item(0).AppendChild($xml.CreateTextNode($env:NEX_TOAST_TITLE)) | Out-Null
$texts.Item(1).AppendChild($xml.CreateTextNode($env:NEX_TOAST_BODY)) | Out-Null
$toast = [Windows.UI.Notifications.ToastNotification]::new($xml)
[Windows.UI.Notifications.ToastNotificationManager]::CreateToastNotifier('Nex').Show($toast)`
}

func encodePowerShellCommand(script string) string {
	encoded := utf16.Encode([]rune(script))
	buf := make([]byte, 0, len(encoded)*2)
	for _, value := range encoded {
		buf = append(buf, byte(value), byte(value>>8))
	}
	return base64.StdEncoding.EncodeToString(buf)
}

func messageBoxAvailable() error {
	if _, err := syscall.UTF16PtrFromString("Nex"); err != nil {
		return err
	}
	if _, err := syscall.UTF16PtrFromString("test"); err != nil {
		return err
	}
	return procMessageBoxW.Find()
}

func messageBoxStartupFlags() uint {
	return mbOK | mbIconError | mbTaskModal | mbSetForeground | mbTopMost
}

func messageBox(title, message string, flags uint) error {
	titlePtr, err := syscall.UTF16PtrFromString(title)
	if err != nil {
		return err
	}

	messagePtr, err := syscall.UTF16PtrFromString(message)
	if err != nil {
		return err
	}

	ret, callErr := callMessageBoxW(
		0,
		uintptr(unsafe.Pointer(messagePtr)),
		uintptr(unsafe.Pointer(titlePtr)),
		uintptr(flags),
	)
	if ret != 0 {
		return nil
	}

	if callErr != nil && !errors.Is(callErr, syscall.Errno(0)) {
		return callErr
	}

	return fmt.Errorf("MessageBoxW 调用失败")
}