# ==============================================================================
# Script Name: 8x8_Work_Updater.ps1
# Description: Downloads 8x8 with a progress bar, detects the active interactive 
#              desktop user, presents the unclosable HTA countdown prompt, 
#              installs silently, relaunches 8x8 Work, and logs everything to
#              C:\IntuneLogs\8x8Updater_log.txt.
# ==============================================================================

# Ensure script is running elevated
if (-not ([Security.Principal.WindowsPrincipal][Security.Principal.WindowsIdentity]::GetCurrent()).IsInRole([Security.Principal.WindowsBuiltInRole]::Administrator)) {
    Write-Error "This script must be executed with Administrator privileges."
    exit 1
}

Add-Type -AssemblyName System.Net.Http

# Configure logging directory and log file
$logDir  = "C:\IntuneLogs"
$logFile = Join-Path $logDir "8x8Updater_log.txt"

if (-not (Test-Path $logDir)) {
    New-Item -Path $logDir -ItemType Directory -Force | Out-Null
}

function Write-Log {
    param (
        [string]$Message,
        [ConsoleColor]$Color = [ConsoleColor]::Gray
    )
    $timestamp = (Get-Date).ToString("yyyy-MM-dd HH:mm:ss")
    $logLine   = "[$timestamp] $Message"
    
    # Output to Console
    Write-Host $Message -ForegroundColor $Color
    
    # Append to Log File
    Add-Content -Path $logFile -Value $logLine -Force
}

$workDir       = "C:\ProgramData\JCT600_8x8Update"
$flagFile      = Join-Path $workDir "8x8_Update_Proceed.flag"
$htaPromptPath = Join-Path $workDir "Show-8x8Prompt.hta"
$installerPath = Join-Path $workDir "8x8_Work_Installer.msi"

if (-not (Test-Path $workDir)) {
    New-Item -Path $workDir -ItemType Directory -Force | Out-Null
}

$acl = Get-Acl $workDir
$rule = New-Object System.Security.AccessControl.FileSystemAccessRule("BUILTIN\Users", "FullControl", "ContainerInherit,ObjectInherit", "None", "Allow")
$acl.AddAccessRule($rule)
Set-Acl $workDir $acl

if (Test-Path $flagFile) { Remove-Item $flagFile -Force }

Write-Log "========== Starting 8x8 Work Update Script ==========" -Color Cyan

try {
    # --------------------------------------------------------------------------
    # Step 1: Download 8x8 Setup Installer with Console Progress Bar
    # --------------------------------------------------------------------------
    $installerUrl = "https://work-desktop-assets.8x8.com/prod-publish/ga/work-64-msi-v8.36.2-3.msi"
    Write-Log "[1/4] Downloading 8x8 Work installer from $installerUrl..." -Color Cyan

    try {
        $httpClient = New-Object System.Net.Http.HttpClient
        $response = $httpClient.GetAsync($installerUrl, [System.Net.Http.HttpCompletionOption]::ResponseHeadersRead).Result
        if (-not $response.IsSuccessStatusCode) { throw "HTTP Error $($response.StatusCode)" }

        $totalBytes = $response.Content.Headers.ContentLength
        $inputStream = $response.Content.ReadAsStreamAsync().Result
        $outputStream = [System.IO.File]::Create($installerPath)
        $buffer = New-Object byte[] 8192
        $totalBytesRead = 0; $bytesRead = 0

        while (($bytesRead = $inputStream.Read($buffer, 0, $buffer.Length)) -gt 0) {
            $outputStream.Write($buffer, 0, $bytesRead)
            $totalBytesRead += $bytesRead

            if ($totalBytes -gt 0) {
                $percent = [math]::Round(($totalBytesRead / $totalBytes) * 100)
                $downloadedMB = [math]::Round($totalBytesRead / 1MB, 2)
                $totalMB = [math]::Round($totalBytes / 1MB, 2)
                $barLength = 30
                $filledLength = [math]::Round(($percent / 100) * $barLength)
                $bar = ("#" * $filledLength) + ("-" * ($barLength - $filledLength))

                Write-Host "`rDownloading: [$bar] $percent% ($downloadedMB MB / $totalMB MB)" -NoNewline -ForegroundColor Yellow
            }
        }
        $outputStream.Close(); $inputStream.Close(); $httpClient.Dispose()
        Write-Host "" # Newline after progress bar
        Write-Log "Download complete: $installerPath ($([math]::Round($totalBytesRead / 1MB, 2)) MB)" -Color Green
    } catch {
        Write-Log "Failed to download installer. Error: $_" -Color Red
        exit 1
    }

    # --------------------------------------------------------------------------
    # Step 2: Generate Sleep-Safe Wall-Clock HTA Countdown Dialog
    # --------------------------------------------------------------------------
    Write-Log "[2/4] Generating sleep-safe unclosable dialog..." -Color Cyan

    $htaContent = @"
<!DOCTYPE html>
<html>
<head>
    <title>JCT600 IT Support - 8x8 Work Update</title>
    <HTA:APPLICATION 
        ID="o8x8Update"
        APPLICATIONNAME="JCT600 8x8 Work Update"
        BORDER="dialog"
        BORDERSTYLE="normal"
        CAPTION="yes"
        CONTEXTMENU="no"
        ICON=""
        INNERBORDER="no"
        MAXIMIZEBUTTON="no"
        MINIMIZEBUTTON="no"
        NAVIGABLE="no"
        SCROLL="no"
        SCROLLFLAT="no"
        SELECTION="no"
        SHOWINTASKBAR="yes"
        SINGLEINSTANCE="yes"
        SYSMENU="no"
        WINDOWSTATE="normal"
    />
    <style>
        body {
            background-color: #F0F2F5;
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            margin: 0;
            padding: 20px;
            text-align: center;
            user-select: none;
        }
        .header {
            color: #002B49;
            font-size: 17px;
            font-weight: bold;
            margin-bottom: 8px;
        }
        .message {
            color: #333333;
            font-size: 13px;
            line-height: 1.4;
            margin-bottom: 15px;
        }
        .timer {
            color: #C00000;
            font-size: 32px;
            font-weight: bold;
            margin-bottom: 18px;
            letter-spacing: 2px;
        }
        .btn-update {
            background-color: #002B49;
            color: #FFFFFF;
            font-size: 14px;
            font-weight: bold;
            padding: 10px 32px;
            border: none;
            border-radius: 4px;
            cursor: pointer;
        }
        .btn-update:hover {
            background-color: #004B7D;
        }
    </style>
    <script language="javascript">
        var targetTime = new Date().getTime() + (3600 * 1000);

        function initWindow() {
            window.resizeTo(480, 270);
            window.moveTo((screen.width - 480) / 2, (screen.height - 270) / 2);
            tick();
            setInterval(tick, 1000);
        }

        function tick() {
            var now = new Date().getTime();
            var remainingMilliseconds = targetTime - now;
            var totalSeconds = Math.floor(remainingMilliseconds / 1000);

            if (totalSeconds > 0) {
                var mins = Math.floor(totalSeconds / 60);
                var secs = totalSeconds % 60;
                var formattedMins = mins < 10 ? "0" + mins : mins;
                var formattedSecs = secs < 10 ? "0" + secs : secs;
                document.getElementById("timerDisplay").innerText = formattedMins + ":" + formattedSecs;
            } else {
                proceedUpdate();
            }
        }

        function proceedUpdate() {
            try {
                var fso = new ActiveXObject("Scripting.FileSystemObject");
                var file = fso.CreateTextFile("$($flagFile.Replace('\', '\\'))", true);
                file.WriteLine("proceed");
                file.Close();
            } catch(e) {}
            window.close();
        }
    </script>
</head>
<body onload="initWindow()">
    <div class="header">JCT600 - IT SUPPORT</div>
    <div class="message">
        An automatic update for 8x8 Work has been scheduled.<br>
        Please save active work or click <b>Update Now</b> to begin.
    </div>
    <div class="timer" id="timerDisplay">60:00</div>
    <button class="btn-update" onclick="proceedUpdate()">Update Now</button>
</body>
</html>
"@

    [System.IO.File]::WriteAllText($htaPromptPath, $htaContent, [System.Text.Encoding]::ASCII)

    # --------------------------------------------------------------------------
    # Step 3: Detect Active Desktop User & Launch HTA Prompt
    # --------------------------------------------------------------------------
    Write-Log "[3/4] Detecting active console user and launching dialog..." -Color Cyan

    $explorerProc = Get-Process -Name explorer -ErrorAction SilentlyContinue | Select-Object -First 1

    if (-not $explorerProc) {
        Write-Log "No active interactive desktop detected. Proceeding directly to update." -Color Yellow
    } else {
        $ownerInfo  = Get-CimInstance -ClassName Win32_Process -Filter "ProcessId = $($explorerProc.Id)" | Invoke-CimMethod -MethodName GetOwner
        $activeUser = "$($ownerInfo.Domain)\$($ownerInfo.User)"
        Write-Log "Active Desktop User: $activeUser (Session ID: $($explorerProc.SessionId))" -Color Green

        $taskName = "JCT600_8x8_UpdatePrompt"

        $action = New-ScheduledTaskAction -Execute "mshta.exe" -Argument "`"$htaPromptPath`""
        $trigger = New-ScheduledTaskTrigger -At (Get-Date).AddSeconds(2) -Once
        $principal = New-ScheduledTaskPrincipal -UserId $activeUser -LogonType Interactive -RunLevel Limited
        $settings = New-ScheduledTaskSettingsSet -AllowStartIfOnBatteries -DontStopIfGoingOnBatteries -ExecutionTimeLimit (New-TimeSpan -Hours 2)

        Register-ScheduledTask -TaskName $taskName -Action $action -Trigger $trigger -Principal $principal -Settings $settings -Force | Out-Null
        Start-ScheduledTask -TaskName $taskName | Out-Null

        Write-Log "Dialog prompt active. Waiting for user action or 1-hour expiration..." -Color Yellow
        while (-not (Test-Path $flagFile)) {
            Start-Sleep -Seconds 2
        }

        Write-Log "User action/timeout received. Proceeding with installation." -Color Green
        Unregister-ScheduledTask -TaskName $taskName -Confirm:$false -ErrorAction SilentlyContinue
    }

    # --------------------------------------------------------------------------
    # Step 4: Close 8x8 Processes & Install Silently
    # --------------------------------------------------------------------------
    Write-Log "[4/4] Stopping active 8x8 processes and installing silently..." -Color Cyan

    $targetProcesses = Get-Process | Where-Object { 
        $_.ProcessName -like "*8x8*" -or $_.MainWindowTitle -like "*8x8*" 
    }

    if ($targetProcesses) {
        foreach ($proc in $targetProcesses) {
            Write-Log "Stopping process: $($proc.ProcessName) (PID: $($proc.Id))" -Color Yellow
            Stop-Process -Id $proc.Id -Force -ErrorAction SilentlyContinue
        }
        Start-Sleep -Seconds 3
    }

    $msiLogPath = Join-Path $logDir "8x8_MSI_Install.log"
    $msiArgs    = "/i `"$installerPath`" /quiet /norestart /lv* `"$msiLogPath`""
    
    Write-Log "Executing: msiexec.exe $msiArgs" -Color Cyan
    $installJob = Start-Process msiexec.exe -ArgumentList $msiArgs -Wait -PassThru

    if ($installJob.ExitCode -ne 0 -and $installJob.ExitCode -ne 3010) {
        Write-Log "MSI Installation failed with exit code $($installJob.ExitCode)." -Color Red
        exit $installJob.ExitCode
    }

    Write-Log "MSI Installation completed successfully with ExitCode $($installJob.ExitCode)." -Color Green

    # --------------------------------------------------------------------------
    # Step 5: Relaunch 8x8 Work in Active User Session
    # --------------------------------------------------------------------------
    Write-Log "Launching updated 8x8 Work..." -Color Cyan

    $possiblePaths = @(
        "${env:ProgramFiles}\8x8 Inc\8x8 Work\8x8 Work.exe",
        "${env:ProgramFiles(x86)}\8x8 Inc\8x8 Work\8x8 Work.exe",
        "${env:ProgramFiles}\8x8 Work\8x8 Work.exe",
        "$env:LocalAppData\Programs\8x8 Work\8x8 Work.exe"
    )

    $exePath = $possiblePaths | Where-Object { Test-Path $_ } | Select-Object -First 1

    if ($exePath) {
        if ($explorerProc -and $activeUser) {
            $launchTask = "JCT600_8x8_Launch"
            $launchAction = New-ScheduledTaskAction -Execute "explorer.exe" -Argument "`"$exePath`""
            $launchTrigger = New-ScheduledTaskTrigger -At (Get-Date).AddSeconds(2) -Once
            $launchPrincipal = New-ScheduledTaskPrincipal -UserId $activeUser -LogonType Interactive -RunLevel Limited

            Register-ScheduledTask -TaskName $launchTask -Action $launchAction -Trigger $launchTrigger -Principal $launchPrincipal -Force | Out-Null
            Start-ScheduledTask -TaskName $launchTask | Out-Null

            Start-Sleep -Seconds 4
            Unregister-ScheduledTask -TaskName $launchTask -Confirm:$false -ErrorAction SilentlyContinue
            Write-Log "8x8 Work launched successfully for $activeUser." -Color Green
        } else {
            Start-Process "explorer.exe" -ArgumentList "`"$exePath`""
            Write-Log "8x8 Work started via explorer.exe fallback." -Color Green
        }
    } else {
        Write-Log "Could not locate 8x8 Work executable on disk." -Color Yellow
    }

} catch {
    Write-Log "Unexpected script error: $_" -Color Red
} finally {
    Write-Log "Cleaning up temporary files..." -Color Gray
    if (Test-Path $workDir) {
        Remove-Item $workDir -Recurse -Force -ErrorAction SilentlyContinue
    }
    Write-Log "========== 8x8 Work Update Script Finished ==========" -Color Cyan
}