(page "index.html"
  (:import goog.html.sanitizer.HtmlSanitizer
           goog.html.sanitizer.HtmlSanitizer.Builder
           goog.html.sanitizer.unsafe
           goog.html.sanitizer.AttributeWhitelist
           goog.string.Const
           goog.functions
           goog.html.SafeUrl
           goog.html.SafeHtml)
  (:require [cljs.pprint :refer [cl-format] :rename {cl-format format}])
  (:require-macros [feed-archive.let-promise :refer [let-promise]]))

(defc state
  {"base-url" "http://roachnotes.com"
   "pull-time" ""
   "feeds" []
   :items {}})

(defc= base-url
  (get state "base-url")
  #(swap! state assoc-in ["base-url"] %))

(defc= pull-time
  (get state "pull-time"))

(defc= feeds
  (get state "feeds"))

(defn setup-state [base-url]
  (let-promise [[resp (js/fetch (str base-url
                                     "/current"))]
                [data (.json resp)]]
    (swap! state merge
           (js->clj data))))

(cell= (when base-url
         (setup-state base-url)))

(defn make-feed-getter [out-cell]
  (fn [base-url path]
    (let-promise [[resp (js/fetch (str base-url "/" path))]
                  [data (.json resp)]]
      (reset! out-cell (js->clj data)))))

(defn get-feed-entry-cells [base-url feed]
  (let [feed-cell (cell {})
        items (cell= (get feed-cell "items"))
        item-count (cell= (count items))
        get-feed (make-feed-getter feed-cell)
        path (cell= (get feed "path" "<No PATH>"))
        url (cell= (get feed "url" "<No URL>"))
        title (cell= (get feed "title" "<No TITLE>"))]
    (cell= (get-feed base-url path))
    [url title path feed-cell items item-count]))

(defn get-sanitizer []
  (let [r (Builder.)
        justification (.from Const "Because images are ok, silly")]
    (.alsoAllowAttributes unsafe justification
                          r #js [#js {:tagName "img" :attributeName "src" :policy nil}])
    (.build r)))

(defn sanitize-html [html]
  (let [result (.sanitize (get-sanitizer) html)]
    (.unwrap SafeHtml result)))

(defn make-item-getter [out-cell content]
  (fn [base-url feed-path item-path]
    (let-promise [[resp (js/fetch (str base-url "/" feed-path item-path))]
                  [data (.json resp)]]
      (let [data (js->clj data)]
        (reset! content (sanitize-html (get data "content")))
        (reset! out-cell data)))))
(defn get-item-cells [item content]
  (let* [key (get @item "path")
         item-cell (cell= (get (:items state) key)
                          #(swap! state assoc-in [:items key] %))
         get-item (make-item-getter item-cell content)]
    [get-item
     (cell= (get item "title"))
     (cell= (get item "path"))
     (cell= (get item-cell "link"))
     (cell= (sanitize-html (get item-cell "content")))]))

(cell= (.log js/console (clj->js base-url)))

(defn column-width [len]
  (letfn [(divisible-by [x] (= 0 (mod len x)))]
    (format nil "~d%"
            (- (cond (divisible-by 5) 20
                     (divisible-by 4) 25
                     (divisible-by 3) 33
                     (> len 30) 20
                     (> len 20) 25
                     (> len 10) 33
                     true       50)
               0.5))))

(defelem feed-item [{item :item path :path css :my/css overlay :overlay content-cell :content-cell :as attrs} _]
  (let [[get-item title item-path link content] (get-item-cells item content-cell)
        toggled (cell false)
        leftover-attrs (dissoc attrs :item :path :my/css :overlay :content-cell)]
    (cell= (get-item base-url path item-path))
    (article leftover-attrs :css css
             :class "summary"
             (div :html content)
             (header (h3 (a :href link title)) " "
                     (button :class "show-article"
                             :click #(dosync (get-item @base-url @path @item-path)
                                             (reset! overlay true)
                                             (swap! toggled not))
                             ">>")))))

(defelem feed-view [{feed :feed} _]
  (let [[url title path feed-cell items item-count] (get-feed-entry-cells base-url feed)
        child-width (cell= (column-width item-count))
        overlay-visible (cell false)
        content-cell (cell "")]
    (section :class (cell= {"displayed" overlay-visible})
     (div :class (cell= {"article-overlay" true "displayed" overlay-visible})
          (header (button :click #(reset! overlay-visible false)
                          "X"))
          (article :html content-cell))
     (if-tpl (cell= (> item-count 0))
       (div 
        (header (h2 title) (p url))
        (loop-tpl :bindings [item items]
          (feed-item :path path :item item :overlay overlay-visible :content-cell content-cell :my/css (cell= {:width child-width}))))))))

(html
 (head
  (link :href "app.css" :rel "stylesheet" :type "text/css"))
 (body
  (header
   (h1 "Roach Notes " (div :class "beta" :html "&beta;"))
   (input :type "text" :value base-url
          :change #(reset! base-url (.-value (.-target %)))))
  (main
   (loop-tpl :bindings [feed feeds]
     (feed-view :feed feed)))))