$user_names = "My User", "Another User"
$search_since = "2017-03-01"

$global:zendesk_user_name = "username"
$global:zendesk_password = "password"
$global:zendesk_address = "zendesk_address"

function CreateAuthorizationHeader()
{
    $pair = "$($zendesk_user_name):$($zendesk_password)"

    $encodedCreds = [System.Convert]::ToBase64String([System.Text.Encoding]::ASCII.GetBytes($pair))

    $basicAuthValue = "Basic $encodedCreds"

    $Headers = @{
        Authorization = $basicAuthValue
    }

    return $Headers
}

function GetUserIdForUsers($users)
{
    $header = CreateAuthorizationHeader
    $users_objects = @()
    foreach ($user in $users)
    {
        $user_info = Invoke-RestMethod -Uri "$zendesk_address/api/v2/users/autocomplete.json?name=$user" -Headers $header
        $number_of_users = $user_info.users.Count
        if ($number_of_users -gt 1)
        {
            write-host "User: $user found $number_of_users times in the zendesk portal"
            foreach ($u in $user_info.users)
            {
                write-host "Name:" $u.name ", Email: " $u.email ", id: " $u.id -ForegroundColor Magenta
            }
            $use_all_users = Read-Host "Do you want to use all users for the query? (yes / no)"
            if ($use_all_users -match "yes")
            {
                foreach ($u in $user_info.users)
                {
                    $properties = @{'username'=$user_info.users[0].name;
                                    'id'=$user_info.users[0].id;
                                    'email'=$user_info.users[0].email}
                    $new_user = New-Object psobject -Property $properties
                    $users_objects += $new_user
                }
            }
            else
            {
                throw "There is more then one user with the same name!"
            }
        }
        else
        {
            $properties = @{'username'=$user_info.users[0].name;
                            'id'=$user_info.users[0].id;
                            'email'=$user_info.users[0].email}
            $new_user = New-Object psobject –Prop $properties
            $users_objects += $new_user
        }
    }
    return $users_objects

}

function GetTickets($search_since, $next_page)
{
    $result = @()
    $header = CreateAuthorizationHeader
    $tickets = Invoke-RestMethod -Uri "$zendesk_address/api/v2/search.json?query=type:ticket created>$search_since custom_field_21803188:False" -Headers $header
    Write-Host "HI! Found" $tickets.count "tickets in the provided period" -ForegroundColor Yellow
    $result += $tickets.results

    while ($tickets.next_page -ne $null)
    {
        $tickets = Invoke-RestMethod -Uri $tickets.next_page -Headers $header
        $result += $tickets.results
    }

    return $result
}

function GetTicketAudits($ticketId)
{
    $header = CreateAuthorizationHeader
    $ticket_information = Invoke-RestMethod -Uri "$zendesk_address/api/v2/tickets/$ticketId/audits.json" -Headers $header
    return $ticket_information.audits |  select -Property author_id | Select-Object -ExpandProperty author_id | select -uniq
}

function execute(){
    $user_ids = GetUserIdForUsers $user_names
    $all_tickets = GetTickets $search_since

    $proceed = Read-Host "would you like to proceed? (yes / no)"
    if ($proceed -ne "yes") {throw "stopped by the user..."}

    $counter = 1
    $results = @()
    foreach ($ticket in $all_tickets)
    {
        $precentage = [math]::Round(($counter/$all_tickets.Count)*100)
        $counter++
        Write-Progress -Activity "Search in Progress" -Status "$precentage% Complete:" -PercentComplete $precentage
        $audits = GetTicketAudits $ticket.id
        foreach ($audit in $audits){
            foreach ($user in $user_ids)
            {
                if ($audit -eq $user.id)
                {
                    $properties = @{'ticket_id'=$ticket.id;
                                    'ticket_url'=$ticket.url;
                                    'ticket_subject'=$ticket.subject;
                                    'username'=$user.username;
                                    'id'= $user.id;
                                    'email'= $user.email}
                    $record = New-Object psobject -Property $properties
                    $results += $record
                    write-host "match!" $ticket.id ", user: " $user.username
                }
            }
        }
    }
    return $results
}

execute | Export-Csv -Path "c:\a\results.csv"