param(
    [Parameter(Mandatory=$true)]
    [string]$url,
    [Parameter(Mandatory=$true)]
    [string]$sourceUrl
)

function Write-File($msg)
{
    ($msg) | Out-File "log-update-emails.txt" -Append
}

function Write-Info($msg)
{
    Write-Host $msg -foregroundcolor green
    Write-File $msg
}

function Write-Warn($msg)
{
    Write-Host $msg -foregroundcolor yellow
    Write-File $msg
}


function ContainsUser($users, $loginName)
{
    foreach ($user in $users)
    {
        if ($user.LoginName.ToLower() -eq $loginName.ToLower())
        {
            return $true
        }
    }
    return $false
}

function Get-User($web, $userName)
{
    if ([System.String]::IsNullOrEmpty($userName))
    {
        return $null
    }
    
    $user = $null
    try
    {
        $user = $web.EnsureUser($userName)
    }
    catch
    {
        return $null
    }
    
    return $user
}

$users = New-Object System.Collections.ArrayList
$site = Get-SPSite $url
foreach ($user in $site.RootWeb.AllUsers)
{
	if ([System.String]::IsNullOrEmpty($user.Email))
	{
		$users.Add($user) > $null
	}
}
foreach ($user in $site.RootWeb.SiteUsers)
{
	$contains = ContainsUser $users $user.LoginName
	if ([System.String]::IsNullOrEmpty($user.Email) -and (-not $contains))
	{
		$users.Add($user) > $null
	}
}

$sourceSite = Get-SPSite $sourceUrl
$sourceWeb = $sourceSite.RootWeb
foreach ($user in $users)
{
    Write-Info($user.LoginName)
	$sourceUser = Get-User $sourceWeb $user.LoginName
	if ($sourceUser -eq $null)
	{
		Write-Warn("  User not found on source")
		continue
	}
	
	if ([System.String]::IsNullOrEmpty($sourceUser.Email))
	{
		Write-Warn("  User email is empty on source")
		continue
	}
	
	$user.Email = $sourceUser.Email
	$user.Update()
	Write-Info("  Email was updated to " + $sourceUser.Email)
}