iRule help with HOST:header and URI path pool selection

I'm looking for a way to make maintaining/managing an existing iRule I have. I'm having a blank moment on trying to organize the HTTP host and uri path match logic. The iRule is similar to this:

Code when HTTP_REQUEST {
set pool_select_value [class lookup [string tolower [HTTP::host]] HOST_2_POOL_DG]
if {[active_members $pool_select_value] > 0 } {
    log local0.notice "Available pool members in Pool: $pool_select_value"
    switch [string tolower [HTTP::host]] {
        "hostdev" -
        "hostdev.domain.name" -
        "hostdev.sub.domain.name" {
            if uri is root then redirect to the subdirectory
            switch [HTTP::uri] {
                "/" { HTTP::redirect "/host-DEV/"
                }
            }
        }
        "host2sdev" -
        "host2dev.domain.name" - 
        "host2dev.sub.domain.name" {
            ir uri does not contain /name/ at the begining, insert name
            switch -glob ![string tolower [HTTP::uri]] {
                "/host2-services-dev/*" { HTTP::redirect "/host2-services-DEV[HTTP::uri]" 
                }
            }
        }
    }
    pool $pool_select_value
} else {
    log local0.notice "NO Available members in Pool: $pool_select_value
    set IFILE_RAW_ERROR_PAGE [ifile get "NoPoolMembers.html"]
    set POOL_VAR_NAME_REPLACEMENT [list "pool_select_value" $pool_select_value]
    set IFILE_FINAL_ERROR_PAGE [string map $POOL_VAR_NAME_REPLACEMENT $IFILE_RAW_ERROR_PAGE]
    HTTP::respond 503 content $IFILE_FINAL_ERROR_PAGE
}
            }

I guess i'm looking for a method/ideas on using data groups to organize matches and appropriate responses. HELP!!!