class store
{
function sale_item($inventory_id, $item_cost, $user_id)
{
}
function buy_item($item_id, $store_id, $user_id)
{
}
function item_info($item_id, $data_info = false)
{
}
}
class player
{
function init_user_stats ()
{
}
function level_up($xp, $current_level, $user_id)
{
}
function update_stats($user_id, $stats_array)
{
}
}
class inventory
{
function in_inventory($user_id, $item_id)
{
}
function give_item($item_id, $user_id)
{
}
function take_item($inventory_id, $user_id)
{
}
function transfer_item ($source_user, $target_id, $inventory_id)
{
}
}