(ns auto-ap.background.mail
  (:require
   [amazonica.aws.s3 :as s3]
   [amazonica.aws.simpleemail :as ses]
   [amazonica.aws.sqs :as sqs]
   [auto-ap.parse :as parse]
   [auto-ap.routes.invoices :as invoices]
   [auto-ap.utils :refer [heartbeat]]
   [clojure-mail.message :as message]
   [clojure.data.json :as json]
   [clojure.java.io :as io]
   [clojure.string :as str]
   [clojure.tools.logging :as log]
   [config.core :refer [env]]
   [mount.core :as mount]
   [unilog.context :as lc]
   [yang.scheduler :as scheduler])
  (:import
   (java.util Properties UUID)
   (javax.mail Session)
   (javax.mail.internet MimeMessage)))

(defn send-email-about-failed-message [mail-bucket mail-key] 
  (let [target-key (str "failed-emails/" mail-key ".eml")
        target-url (str "http://" (:data-bucket env)
                        ".s3-website-us-east-1.amazonaws.com/"
                        target-key)]
    (log/info "sending email to " (:import-failure-destination-emails env))
    (s3/copy-object mail-bucket mail-key (:data-bucket env) target-key)
    (ses/send-email {:destination {:to-addresses (:import-failure-destination-emails env)}
                     :source      (:invoice-email env)
                     :message     {:subject "An email invoice import failed"
                                   :body    {:html (str "<div>You can download the original email <a href=\"" target-url "\">here</a>.</div>")
                                             :text (str "<div>You can download the original email here: " target-url)}}})))


(defn process-sqs []
  (log/info "Fetching messages from sqs...")
  (doseq [message (:messages (sqs/receive-message {:queue-url              (:invoice-import-queue-url env)
                                                   :wait-time-seconds      5
                                                   :max-number-of-messages 10
                                                   #_#_:attribute-names    ["All"]}))]
    (let [message-body (json/read-str (:body message)
                                      :key-fn keyword)]
      (doseq [r (:Records message-body)] 
        (log/info "Processing record " r)
        (let [props          (Session/getDefaultInstance (Properties.))
              message-stream (-> (s3/get-object {:key         (-> r :s3 :object :key)
                                                 :bucket-name (-> r :s3 :bucket :name)})
                                 :input-stream)
              mail           (message/read-message (MimeMessage. props message-stream))]
          (log/info "reading mail" (->> mail :body (filter :content-type)  (map :body)  ))
          (doseq [pdf-stream (->> (-> mail :body)
                                  (filter :content-type)
                                  #_(filter #(re-find #"application/pdf" (:content-type %)) ))
                  :let       [filename    (str "/tmp/" (UUID/randomUUID) ".pdf")]]
            (try 
              (let [
                    _           (io/copy (:body pdf-stream) (io/file filename))
                    extension   (last (str/split (.getName (io/file filename)) #"\."))
                    s3-location (str "invoice-files/" (str (UUID/randomUUID)) "." extension)
                    _           (s3/put-object :bucket-name (:data-bucket env)
                                               :key s3-location
                                               :input-stream (io/input-stream filename)
                                               :metadata {:content-type "application/pdf"})
                    imports     (->> (parse/parse-file filename filename)
                                     (map #(assoc %
                                                  :source-url (str "http://" (:data-bucket env)
                                                                   ".s3-website-us-east-1.amazonaws.com/"
                                                                   s3-location)
                                                  :import-status :import-status/approved)))]
                (log/info "Found imports" imports)
                (invoices/import-uploaded-invoice {:user/role "admin"} imports ))
              (catch Exception e
                (log/warn e)
                (send-email-about-failed-message (-> r :s3 :bucket :name) (-> r :s3 :object :key)))
              (finally 
                (io/delete-file filename)))))))
    (sqs/delete-message (assoc message :queue-url (:invoice-import-queue-url env) ))))

(mount/defstate import-invoices
  :start (scheduler/every (* 60 5000) (heartbeat process-sqs "import-uploaded-invoices"))
  :stop (scheduler/stop import-invoices))