# batch rename a list<string> as path
export def rename [renamer,--dry-run] {
    let paths = ($in)
    let new_paths = ($paths | each { | old_path | $old_path | path parse }
    | do $renamer)
    let plan = $paths | zip $new_paths

    if ($dry_run) {
        return $plan
    }
    $plan | batch rename
}

# in: list<list<string>> and rename first to second for every list. 
export def "batch rename" [] {
    each { | row | 
        mkdir ($row.1 | path parse | get parent)
        mv $row.0 $row.1 -i
    }
}

# set the parent dir of a list<path>
export def "append dir" [new_dir:string] {
    update parent {|p| $p.parent | path join $new_dir }
}

# set the filename of a list<path>
export def "set filename" [new_name:string] {
    each { |p| $p.parent | path join $new_name }
}