# ==========================================================
# Clear Outlook AutoComplete Cache (System-Wide)
# ==========================================================
# Description:
# Closes Microsoft Outlook, scans all user profiles in C:\Users,
# removes Outlook AutoComplete cache files (NK2 and
# Stream_Autocomplete files) for every user account.
#
# Outlook automatically rebuilds the cache when reopened.
# ==========================================================

Write-Host "============================================="
Write-Host " Outlook AutoComplete Cache Cleanup (All Users)"
Write-Host "============================================="

# ----------------------------------------------------------
# Stop Outlook Process
# ----------------------------------------------------------

Write-Host "`n[INFO] Closing Outlook..."

Get-Process OUTLOOK -ErrorAction SilentlyContinue | ForEach-Object {

    $_.CloseMainWindow() | Out-Null

    # Wait up to 10 seconds for graceful close
    if (!$_.WaitForExit(10000)) {

        Write-Host "[INFO] Force closing Outlook..."
        $_ | Stop-Process -Force
    }
}

# ----------------------------------------------------------
# Get All User Profiles
# ----------------------------------------------------------
$ExcludedUsers = @(
    "Public",
    "Default",
    "Default User",
    "All Users"
)

# Add users passed through script arguments
for ($i = 0; $i -lt $args.Count; $i++) {

    if (![string]::IsNullOrWhiteSpace($args[$i])) {
        $ExcludedUsers += $args[$i]
    }
}

# Get profiles excluding specified users
$UserProfiles = Get-ChildItem "C:\Users" -Directory |
Where-Object {
    $_.Name -notin $ExcludedUsers
}
if ($UserProfiles.Count -eq 0) {
    Write-Host "[ERROR] No user profiles found."
    exit
}
# ----------------------------------------------------------
# Process Each User Profile
# ----------------------------------------------------------

foreach ($Profile in $UserProfiles) {

    Write-Host "`n============================================="
    Write-Host "[INFO] Processing User: $($Profile.Name)"
    Write-Host "============================================="

    # ------------------------------------------------------
    # NK2 Files
    # ------------------------------------------------------

    $NK2Path = Join-Path $Profile.FullName "AppData\Roaming\Microsoft\Outlook"

    Write-Host "`n[INFO] Checking NK2 files..."

    if (Test-Path $NK2Path) {

        $NK2Files = Get-ChildItem -Path $NK2Path -Filter "*.nk2" -ErrorAction SilentlyContinue

        if ($NK2Files) {

            foreach ($File in $NK2Files) {

                try {
                    Remove-Item $File.FullName -Force -ErrorAction Stop

                    Write-Host "[SUCCESS] Removed NK2 File: $($File.Name)"
                }
                catch {
                    Write-Host "[FAILED] Unable to remove: $($File.Name)"
                }
            }
        }
        else {
            Write-Host "[INFO] No NK2 files found."
        }
    }
    else {
        Write-Host "[INFO] Outlook roaming folder not found."
    }

    # ------------------------------------------------------
    # Stream_Autocomplete Files
    # ------------------------------------------------------

    $RoamCachePath = Join-Path $Profile.FullName "AppData\Local\Microsoft\Outlook\RoamCache"

    Write-Host "`n[INFO] Checking Stream_Autocomplete files..."

    if (Test-Path $RoamCachePath) {

        $AutoCompleteFiles = Get-ChildItem `
            -Path $RoamCachePath `
            -Filter "Stream_Autocomplete*" `
            -ErrorAction SilentlyContinue

        if ($AutoCompleteFiles) {

            foreach ($File in $AutoCompleteFiles) {

                try {
                    Remove-Item $File.FullName -Force -ErrorAction Stop

                    Write-Host "[SUCCESS] Removed AutoComplete File: $($File.Name)"
                }
                catch {
                    Write-Host "[FAILED] Unable to remove: $($File.Name)"
                }
            }
        }
        else {
            Write-Host "[INFO] No Stream_Autocomplete files found."
        }
    }
    else {
        Write-Host "[INFO] RoamCache folder not found."
    }
}

# ----------------------------------------------------------
# Completion Message
# ----------------------------------------------------------

Write-Host "`n============================================="
Write-Host " Outlook AutoComplete Cache Cleanup Completed"
Write-Host "============================================="

Write-Host "`n[INFO] Outlook will rebuild the cache automatically when reopened."