{-# LANGUAGE Arrows, NoMonomorphismRestriction #-}
import ShadowLibrary.Core

import Text.XML.HXT.Core
import Text.XML.HXT.XPath
import Data.List
import Data.List.Utils (replace)

import Text.Regex.Posix
import Text.Printf


extractRecords = extractLinksWithText "//div[@class='artifact-title']/a"  -- pary adres-tytuł

extractPages = extractLinksWithText "//div[@class='pagination-masked clearfix top']//a[@class='next-page-link']" -- pary adres-tytuł

extractPublicationFiles = extractLinksWithText "//div[@class='file-link']/a" -- pary adres-tytuł

runExtractor url = runX $ (arr (const url) >>> setTraceLevel 1 >>> extractPages)

runDocumentsExtractor url = runX $ (arr (const url) >>> setTraceLevel 1 >>> extractRecords)

runFileExtractor url = runX $ (arr (const url) >>> setTraceLevel 1 >>> extractPublicationFiles)


mapToUrl :: ([Char], [Char]) -> [Char]
mapToUrl (url, title) = url


merge [] ys = ys
merge (x:xs) ys = x:merge ys xs


toShadowItem :: (([Char], [Char]), ([Char], [Char])) -> ShadowItem
toShadowItem ((fileUrl, fileTitle), (publicationUrl, publicationTitle)) =
  (defaultShadowItem fileUrl title) {
    itype = "periodical",
    format = Just "pdf",
    finalUrl = fileUrl
    }
  where title = "Polskie Towarzystwo Botaniczne " ++ publicationTitle


withEmptyCheck current [] = do 
  publications <- runDocumentsExtractor current
  let publicationUrls = map mapToUrl publications
  publicationFiles <- mapM runFileExtractor publicationUrls
  let publicationFileItems = map toShadowItem (zip (map head publicationFiles) publications)
  return publicationFileItems
  
withEmptyCheck current nextUrls = do
  let single = head nextUrls
  publications <- runDocumentsExtractor current
  let publicationUrls = map mapToUrl publications
  publicationFiles <- mapM runFileExtractor publicationUrls
  let publicationFileItems = map toShadowItem (zip (map head publicationFiles) publications)
  recursive <- getAllPages single
  let results = merge publicationFileItems recursive
  return results


getAllPages url = do
  items <- runExtractor url
  let urls = map mapToUrl items
  results <- (withEmptyCheck url urls)
  return results


main = do
    let start = "https://pbsociety.org.pl/repository/discover?filtertype=has_content_in_original_bundle&filter_relational_operator=equals&filter=true"
    results <- getAllPages start
    print results