(ns mailhead.parser
  (:require [clojure.string :as st]
            [clj-time.core :as time]
            [clj-time.coerce :as timec]
            [clojure-mail.core :refer :all]
            [clojure-mail.message :refer :all]))

(defn received-headers [all-headers]
  (map #(first (vals %))
       (filter (fn [header] (= "Received" (first (keys header)))) all-headers)))

(defn parse-received-headers [received-header]
  (let [datetime (st/trim (last (st/split received-header #";")))
        ;; Hacky hacky, but no time to make this proper ...
        cleaned-date (st/trim (st/replace datetime #"(\(.*\)|  )" " "))]
    {:sender (nth (re-find #"\s*from ([^ ]+)" received-header) 1)
     :receiver (nth (re-find #"\s*by ([^ ]+)" received-header) 1)
     :time (timec/from-string cleaned-date)}))

(defn parse-from-file [filename]
  (->> filename
       file->message
       read-message
       :headers
       received-headers
       (map parse-received-headers)))