(ns mailhead.routes.home
  (:require [mailhead.layout :as layout]
            [mailhead.visualize :as v]
            [mailhead.parser :as parser]
            [clj-time.core :as time]
            [compojure.core :refer [defroutes GET POST]]
            [ring.util.response :refer [redirect]]
            [ring.util.http-response :refer [ok content-type]]
            [clojure.java.io :as io]))

(defn home-page []
  (layout/render "home.html"))

(defn about-page []
  (layout/render "about.html"))

(defn find-header [parsed-email header]
  (let [headers (:headers parsed-email)]
    (first (parser/find-headers headers header))))

(defn calculate-travel-time [parsed-email-headers]
  (let [start-date (:time (first (reverse parsed-email-headers)))
        end-date (:time (last (reverse parsed-email-headers)))]
    (if (time/after? end-date start-date)
      (time/in-seconds (time/interval start-date end-date))
      nil)))

(defn show-result [message-string]
  (if (empty? (parser/parse message-string))
    (layout/render "parser-error.html" {:mailheader message-string})
    (let [parsed-email (parser/parse-all message-string)
          parsed-email-headers (parser/parse message-string)
          token (v/draw parsed-email-headers)]
      (layout/render "result.html"
                     {:mailheader message-string
                      :from (:address (first (:from parsed-email)))
                      :to (:address (first (:to parsed-email)))
                      :mailer (find-header parsed-email "X-Mailer")
                      :traveltime (calculate-travel-time parsed-email-headers)
                      :token token}))))

(defn show-sample [index]
  (let [email-content (slurp (str "sample-data/example" index ".eml"))]
    (show-result email-content)))


(defn generated-image [token]
  (-> (clojure.java.io/input-stream (str "generated-images/" token ".svg"))
      ok
      (content-type "image/svg+xml")))

(defroutes home-routes
  (GET "/" [] (home-page))
  (GET "/image/:token" [token] (generated-image token))
  (POST "/analyze" [mailheader] (show-result mailheader))
  (GET "/example/:index" [index] (show-sample index))
  (GET "/about" [] (about-page)))