(do ;; required for arcane scoping
  (defn check-param-exists [param-name]
    #[f[test "$(echo '{{' '{param-name}' '}}' | sed 's/ //g')" != '{{{param-name}}}']f])

  (defn if-param-then-else [param-name param-defined otherwise [echo True]]
    #[f[ {(check-param-exists param-name)} && {(if echo "echo " "")}{param-defined} || {(if echo "echo " "")}{otherwise} ]f])

  (defn param-if-param-else [param-name otherwise]
    (if-param-then-else param-name f"'{{{param-name}}}'" otherwise))

  (defn get-thought-param-field [field]
    #[f[ cat www/data/thought-registry | grep -P "\t{{thought}}\t" | awk -v FS=$'\t' '{{print ${(get (dict :tags "1" :file-name "2" :title "3" :date "4" :description "5") field)}}}' ]f])

  (defn subshell [#* lines]
    #[f[({(.join "; " lines)})]f])

  (setv thought-tag-format (form->html
    `(a (:href "?filter-tag=${tag}") "${tag}")))

  (setv thought-tag-list-format
    #[f[tags: $(while read -r tag{";"} do echo "{thought-tag-format}"{";"} done <<< "${{tags//{#[[;]]}/$'\n'}}")]f])

  (setv thought-list-entry-format (form->html 
    `(div (:id "${file_name}" :class thought-list-entry)
      (div (:class title) (a (:href "\\?thought=${file_name}") "${title}"))
      (div (:class date) "${date}")
      (div (:class description) "${description}")
      (div (:class categories) ~#[f[$(echo {thought-tag-list-format})]f]))))

  (setv thought-display-meta-format (form->html
    `(div (:class thought-meta)
      (div (:class date) "${date}")
      (div (:class tags) ~#[f[$(echo "{thought-tag-list-format}")]f]))))

  (defn thought [[title "empty title"] [description ""] [date "1970-01-01"] [tags []] [content '(p "no content provided")]]
    (inherit page-name)
    (with [thought-registry (open "../data/thought-registry" "a")]
      (.write thought-registry f"{(.join #[[;]] tags)}\t{(get page-name -1)}\t{title}\t{date}\t{description}\n"))
              
    `(
      ~content
      ~(run "put-footnotes")
      ~(comments f"/html/thought/view-thought.html?thought={(get page-name -1)}")))

  (run "echo -n > ../data/thought-registry")

  (page
    :title #[f[$[{(param-if-param-else "thought" "natalie thoughts")}]]f] 
    :description #[f[
      $[{(if-param-then-else "thought" #[f["$({(get-thought-param-field "description")})"]f] #[f[
        $({(if-param-then-else 
          "filter-tag" 
          "'thoughts filtered for &quot;{filter-tag}&quot;'" 
          "an enumeration of natalie thoughts. it is functionally a blog")})]f])}]]f]

    `(section 
       (h1 ~#[f[
        $[{(if-param-then-else "thought" #[f[$({(get-thought-param-field "title")})]f] #[f[
          $({(if-param-then-else 
            "filter-tag" 
            "'thoughts filtered for &quot;{filter-tag}&quot;'" 
            "natalie thoughts. functionally a blog")})]f])}]]f])
        
        (div (:class ~#[f[$[{(if-param-then-else "thought" "thought" "thought-list")}]]f]) 
          ~#[f[$[{(if-param-then-else 
            "thought" 
            #[f[{(subshell
              #[f[tags=$({(get-thought-param-field "tags")})]f]
              #[f[date=$({(get-thought-param-field "date")})]f]
              #[f[echo "{thought-display-meta-format}"]f]
              #[f[include ./www/site/html/html/thoughts/$({(get-thought-param-field "file_name")}).html]f])}]f]
            #[f[cat www/data/thought-registry | eval $({(if-param-then-else 
              "filter-tag" 
              #[-[grep '{filter-tag}']-] 
              #[-["grep -E '.*'"]-])}) | sort -t$'\t' -k4 -nr | while IFS=$'\t' read -r tags file_name title date description{";"} do echo "{thought-list-entry-format}"{";"} done]f] 
            :echo False)}]]f]))))