//go:build windows

package main

// Is the WebView2 runtime actually installed?
//
// It is the one dependency OpsLog cannot ship inside its own executable, and
// its absence is invisible: the process starts, Wails fails to create the
// browser environment, and on some machines that failure arrives as a silent
// exit rather than as an error we can print. So the version is read straight
// from where the runtime registers itself, and written to the startup log
// BEFORE the window is attempted — a log that says "WebView2: not found"
// answers the whole question in one line.

import (
	"fmt"

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

// webview2Client is the runtime's own update-client GUID, the key it registers
// its version under. Documented by Microsoft for exactly this check.
const webview2Client = `Software\Microsoft\EdgeUpdate\Clients\{F3017226-FE2A-4295-8BDF-00C3A9A7E4C5}`

// webView2Version returns the installed runtime version, or "" if there is none.
//
// Both hives: a per-machine install writes to HKLM (and to the WOW6432 view of
// it on 64-bit Windows, which is where it usually lands), a per-user install to
// HKCU. Missing all three is the answer that matters.
func webView2Version() string {
	type place struct {
		key    registry.Key
		access uint32
	}
	for _, p := range []place{
		{registry.CURRENT_USER, registry.QUERY_VALUE},
		{registry.LOCAL_MACHINE, registry.QUERY_VALUE},
		{registry.LOCAL_MACHINE, registry.QUERY_VALUE | registry.WOW64_32KEY},
	} {
		k, err := registry.OpenKey(p.key, webview2Client, p.access)
		if err != nil {
			continue
		}
		v, _, err := k.GetStringValue("pv")
		k.Close()
		if err == nil && v != "" && v != "0.0.0.0" {
			return v
		}
	}
	return ""
}

// windowsVersion reads the build from the registry, for the startup log.
//
// Not curiosity: "WebView2 will not install either" is a statement about the
// machine, not about OpsLog, and the build number is the first thing anyone
// diagnosing that will ask for.
func windowsVersion() string {
	k, err := registry.OpenKey(registry.LOCAL_MACHINE,
		`SOFTWARE\Microsoft\Windows NT\CurrentVersion`, registry.QUERY_VALUE)
	if err != nil {
		return "unknown"
	}
	defer k.Close()
	name, _, _ := k.GetStringValue("ProductName")
	build, _, _ := k.GetStringValue("CurrentBuild")
	ubr, _, _ := k.GetIntegerValue("UBR")
	display, _, _ := k.GetStringValue("DisplayVersion")
	return fmt.Sprintf("%s %s build %s.%d", name, display, build, ubr)
}