library("SPARQL")
library("stringi")

### Konfiguration einbinden
source("config/config.R")

### Gets the bibliographicCitations which are currently in the db ##################

read_current_geoera_lit_db <- function() {
  
## http verwenden - https funktioniert nicht ##
endpoint = "http://resource.geolba.ac.at/PoolParty/sparql/geoera"
  
query <- 
    "PREFIX skos:<http://www.w3.org/2004/02/skos/core#>
PREFIX dcterms:<http://purl.org/dc/terms/>
select *
where {
?uri a skos:Concept; skos:prefLabel ?L; dcterms:bibliographicCitation ?citation . 
filter(regex(str(?uri),\"/ref/\")) filter(lang(?L)=\"en\")
optional {?uri dcterms:source ?downloadLink}
}
order by ?L
"


qd <- SPARQL(endpoint, query)
inDB <- qd$results

for (j in 1:length (inDB[1, ])) {
  
  for (i in 1:length(inDB[, j])) {
    Encoding(inDB[i, j]) <-  "UTF-8"
  }
}


pfad <- paste(PFAD_DB_OUT, "inDB-", format(Sys.Date(), "%Y_%m_%d"), ".xlsx", sep="")

write_xlsx(inDB, pfad)

}


get_current_geoera_lit_db <- function() {
  
  pfad <- paste(PFAD_DB_OUT, "inDB-", format(Sys.Date(), "%Y_%m_%d"), ".xlsx", sep="")
  
  if (file.exists(pfad)) {
    inDB <- read_excel(pfad)
    return(inDB)
  }
  
  else {
    read_current_geoera_lit_db()
    
    get_current_geoera_lit_db()
  }
  
}

## nicht meine Funktion - eingebunden von https://rdrr.io/cran/retractcheck/src/R/utils.R
find_doi <- function (strings) {
  regex <- '10\\.\\d{4,9}/[-._;()/:A-Z0-9]+'
  doiLoc <- gregexpr(text = strings, pattern = regex, perl = TRUE, ignore.case = TRUE)
  
  i <- 1
  res <- NULL
  
  # for each in the doiLoc list check whether match (!-1)
  for ( i in 1:length(doiLoc) ) {
    if ( doiLoc[[i]][1] != -1 ) {
      for ( j in 1:length(doiLoc[[i]]) ) {
        res <- c(res,
                 substring(strings[i], doiLoc[[i]][j], doiLoc[[i]][j] + attr(doiLoc[[i]], 'match.length')[j] - 1))
      }
    }
  }
  
  return(res)
}


## nicht meine Funktion - eingebunden von https://stackoverflow.com/questions/52911812/check-if-url-exists-in-r
valid_url <- function(url_in,t=2){
  con <- url(url_in)
  check <- suppressWarnings(try(open.connection(con,open="rt",timeout=t),silent=T)[1])
  suppressWarnings(try(close.connection(con),silent=T))
  ifelse(is.null(check),TRUE,FALSE)
}