(ns utils
  (:import java.text.SimpleDateFormat
           java.util.Date
           java.net.URLDecoder
           org.antlr.stringtemplate.StringTemplateGroup)
  (:use clojure.contrib.json.write
        clojure.contrib.sql))

(let [db-host "localhost"
      db-port 5432
      db-name "dumpfm"]
  (def *db* {:classname "org.postgresql.Driver"
             :subprotocol "postgresql"
             :subname (str "//" db-host ":" db-port "/" db-name)
             :user "postgres"
             :password "root"}))

;;  moved this to here which doesn't seem right... maybe a 'settings.clj' or something?
(def *dumps-per-page* 20)

;; Misc

(defn no-args-adaptor [f]
  (fn [& more] (f)))

(defn ms-in-future [ms]
  (+ ms (System/currentTimeMillis)))

(defn swap [f]
  (fn [& more] (apply f (reverse more))))

(def YYYYMMDD-format (new SimpleDateFormat "yyyyMMdd"))

(defn today []
  (.format YYYYMMDD-format (new Date)))

(def formatter (new SimpleDateFormat "h:mm a EEE M/d"))

(defn non-empty-string? [s]
  (cond (string? s) (> (count s) 0)
        :else s))

(defn seconds [t] (* t 1000))
(defn minutes [t] (* t 60 1000))

(defn kbytes [b] (* b 1024))
(defn mbytes [b] (* b 1024 1024))

;; JSON responses

(def yyyy-mm-dd-formatter (new SimpleDateFormat "yyyy-MM-dd"))

(defmethod print-json Date
  [d]
  (print-json (.format yyyy-mm-dd-formatter d)))

(defn resp-error [message]
  {:status 400 :headers {} :body message})

(defn resp-success [message]
  {:status 200 :headers {} :body (json-str message)})

;; Database

(defn do-cmds [query]
  (with-connection *db*
    (do-commands query)))

(defn do-select [query]
  (with-connection *db*
    (with-query-results rs query
      (doall rs))))

(defn do-count [query]
  ((first (with-connection *db*
	    (with-query-results rs query
	      (doall rs))))
   :count))

(defn do-delete [table query]
  (with-connection *db*
    (delete-rows table query)))

(defn do-insert [table cols values]
  (with-connection *db*
    (insert-values table cols values)))

;; Parsing

(defn maybe-parse-int 
  ([s] (Integer/parseInt s))
  ([s default]
     (try (Integer/parseInt s)
          (catch NumberFormatException _ default))))

(defn maybe-parse-long [s f]
  (if s (Long/parseLong s) f))

(defn url-decode [text]
  (URLDecoder/decode text "UTF-8"))

(defn #^String lower-case
  "Converts string to all lower-case."
  [#^String s]
  (.toLowerCase s))

;; 404

(defn unknown-page [& more]
  [404 "Page not Found"])

;; Templates

(def template-group (new StringTemplateGroup "dumpfm" "template"))
(.setRefreshInterval template-group 3)

;; TODO: handle exception
(defn fetch-template [template session]
  (let [st (.getInstanceOf template-group template)]
    (if (session :nick)
      (do (.setAttribute st "user_email" (session :email))
          (.setAttribute st "user_nick" (session :nick))
          (if (non-empty-string? (session :avatar)) (.setAttribute st "user_avatar" (session :avatar)))
          (.setAttribute st "isadmin" (session :is_admin)))) ;; TODO: consolidate session/user code
    st))

(defn serve-template [template session]
  (.toString (fetch-template template session)))


;; User authentication
; TODO: create user module

(defn first-or-nil [l]
  (if (empty? l) nil (first l)))

(def nick-regex #"^[A-Za-z0-9\-_∆˚†]*$")

(defn is-invalid-nick? [n]
  (cond
   (< (count n) 3) "NICK_TOO_SHORT"
   (not (re-matches nick-regex n)) "NICK_INVALID_CHARS"))

(defn check-nick [nick]
  (let [query "SELECT * FROM users WHERE LOWER(nick) = ? LIMIT 1"]
    (> (count (do-select [query (lower-case nick)])) 0)))

(defn fetch-nick [nick]
  (let [q1 "SELECT * FROM users WHERE nick = ? LIMIT 1"
        ; ORDER BY ensures consistent retrieval of ambiguious names
        q2 "SELECT * FROM users WHERE lower(nick) = ? ORDER BY nick LIMIT 1"]
    (or (first-or-nil (do-select [q1 nick]))
        (first-or-nil (do-select [q2 (lower-case nick)])))))

(defn authorize-nick-hash [nick hash]
  (let [db-user (fetch-nick nick)]
    (and db-user (= (db-user :hash) hash) db-user)))

(defn is-vip? [session]
  (session :is_admin))

(defmacro if-vip [e]
  "Evaluates expr if user is vipm otherwise returns 404 string. Can only be used
   where session is defined."
  `(if (is-vip? ~'session) ~e (unknown-page)))