(ns pdf-test.core
  (:require [pdfboxing.form :as form]
            [pdfboxing.common :as common])
  (:import [org.apache.pdfbox.pdmodel PDDocumentCatalog PDPage PDPageContentStream]))

(declare draw-line)

(draw-line :input-pdf "edited.pdf" :output-pdf "neco2.pdf"
           :coordinates (merge {:page-number 2}
                               {:x 220 :y 395 :x1 560 :y1 395}))

(defn- get-form-fields
  []
  (let [fields (remove #(clojure.string/includes? % "souhlas") (keys (form/get-fields "cs_fo.pdf")))]
    (form/set-fields "cs_fo.pdf" "edited.pdf" (zipmap fields fields))))

(defn- rename-fields
  []
  (let [fields (keys (form/get-fields "ek_ico.pdf"))]
    (nth (clojure.data/diff fields (remove #(clojure.string/includes? % "souhlas" fields))) 1)))
    ; (form/rename-fields "plna_moc.pdf" "renamed.pdf" (zipmap (sort-by #(Integer/parseInt (subs % 12 (count %))) fields) new-names))))
    ; (form/set-fields "ek_form.pdf" "renamed.pdf" (zipmap new-names fields))))

(defn get-catalog
  "Get a catalog from a PDF document"
  [document]
  (.getDocumentCatalog document))

(defn get-page
  "Get a particular page from a catalog"
  [catalog page-number]
  (.get (.getPages catalog) page-number))

(defn get-content-stream
  "Take the read in PDF document and a page number and return content
  stream which will be manipulated"
  [document page-number]
  (let [catalog (get-catalog document)
        page (get-page catalog page-number)
        content-stream (PDPageContentStream. document page true true)]
    content-stream))

(defn use-rgb-colour
  "Take content-stream and use RGB colour to draw on it.
   By default black colour will be used."
  [content-stream & {:keys [r g b]
                     :or {r 0
                          g 0
                          b 0}}]
  (.setStrokingColor content-stream r g b))

(defn set-line-width
  "The width of the line to be drawn.
   By default it's 3."
  [content-stream & {:keys [line-width]
                     :or {line-width 3}}]
  (.setLineWidth content-stream line-width))

(defn draw-line-at-coordinates
  "Take content-stream and coordinates for line to be drawn.
   Coordinates are a hash map in the format of: x, y, x1, y1."
  [content-stream coordinates]
  (.drawLine content-stream
             (:x coordinates)
             (:y coordinates)
             (:x1 coordinates)
             (:y1 coordinates)))

(defn draw-line
  "Draw a line on input-pdf's page, producing a output-pdf document.
   It takes three arguments input-pdf, output-pdf and
   coordinates. Where coordinates have: page-number, x, y, x1, y1
   points where the line should be drawn."
  [& {:keys [input-pdf output-pdf coordinates]}]
  (with-open [document (common/obtain-document input-pdf)]
    (with-open [content-stream (get-content-stream document (:page-number coordinates))]
      (use-rgb-colour content-stream)
      (set-line-width content-stream)
      (draw-line-at-coordinates content-stream coordinates))
    (.save document output-pdf)))