More idiomatic line-by-line handling of a file in Clojure

More idiomatic line-by-line handling of a file in Clojure

I'm trying to read a file that (may or may not) have YAML frontmatter
line-by-line using Clojure, and return a hashmap with two vectors, one
containing the frontmatter lines and one containing everything else (i.e.,
the body).
And example input file would look like this:
---
key1: value1
key2: value2
---
Body text paragraph 1
Body text paragraph 2
Body text paragraph 3
I have functioning code that does this, but to my (admittedly
inexperienced with Clojure) nose, it reeks of code smell.
(defn process-file [f]
(with-open [rdr (java.io.BufferedReader. (java.io.FileReader. f))]
(loop [lines (line-seq rdr) in-fm 0 frontmatter [] body []]
(if-not (empty? lines)
(let [line (string/trim (first lines))]
(cond
(zero? (count line))
(recur (rest lines) in-fm frontmatter body)
(and (< in-fm 2) (= line "---"))
(recur (rest lines) (inc in-fm) frontmatter body)
(= in-fm 1)
(recur (rest lines) in-fm (conj frontmatter line) body)
:else
(recur (rest lines) in-fm frontmatter (conj body line))))
(hash-map :frontmatter frontmatter :body body)))))
Can someone point me to a more elegant way to do this? I'm going to be
doing a decent amount of line-by-line parsing in this project, and I'd
like a more idiomatic way of going about it if possible.