$ErrorActionPreference = 'silentlycontinue'

Add-PSSnapin Microsoft.SharePoint.PowerShell

# Variables
$siteCollection = "https://*SharePointUrl"
$majorVersionCount = 5 # Sets the limit on how many major version to retain
$majorVersionsDraftsCount = 1 # Sets the limit on how many major versions we should keep all drafts of
$exclusions = @("Customized Reports", "Form Templates", "Translation Packages", "Converted Forms", "Master Page Gallery", "Reusable Content", "Site Assets", "Site Collection Documents", "Site Collection Images", "Style Library", "Suggested Content Browser Locations", "User Information List", "wfpub", "Pages", "Site Pages")

$foundLibraries = @()
$countOfFoundLibraries = 0

# Get the Site Collection
$Site = Get-SPSite $siteCollection
$spWebApp = $Site.WebApplication

write-host "Locating all Libraries that will be affected by this change.." -foregroundcolor "yellow"

# Locate all lists in all sites, filtering as required
foreach ($allSites in $spWebApp.Sites) {
    foreach ($Web in $allSites.AllWebs) { # loop through all sites
        foreach ($list in $Web.Lists) { # loop through every list in sites
            if ((-not ($exclusions -contains $list.Title)) -and ($list.BaseTemplate -eq "DocumentLibrary")) { 
            # If the found list's name isn't in the exclusions list and it's a document library
                $countOfFoundLibraries++
                $foundLibraries += $list # Add it to the foundLibraries array
            }
        }
    }
}

# Show all found lists
write-host "Found the following libraries -" -foregroundcolor "yellow"
$foundLibraries | format-Table -Property Title, @{Label="URL"; Expression={$_.ParentWeb.Url + "/" + $_.RootFolder.Url}} -AutoSize

# Confirm that lists will be modified
write-host "This will enable version history on $countOfFoundLibraries libraries, confirm? (Y/N)`n" -foregroundcolor "yellow"
$confirmation = Read-Host

# If user confirmed
if ($confirmation -eq 'y' -or 'Y') {
    # Loop through all lists and update title
    foreach ($item in $foundLibraries) {
        try {
            $url = $item.ParentWeb.Url + "/" + $item.RootFolder.Url
            
            $list.EnableVersioning = $true  # Enabled document versioning
            $item.EnableMinorVersions = $true # Enables minor (draft) versioning of documents

            $item.MajorVersionLimit = $majorVersionsCount # Sets the limit on how many major version to retain
            $item.MajorWithMinorVersionsLimit = $majorVersionsDraftsCount # Sets the limit on how many major versions we should keep all drafts of

            $item.Update() # Updates the list
            write-host "Updated $url library sucessfully" -foregroundcolor "Green"
        } catch {
            write-host "Failed to update $url library" -foregroundcolor "Red"
        }
    }
} else {
    write-host "Libraries will not be updated" -foregroundcolor "yellow"
}