ksj_collect_n03.R

zip_n03_url <- function(year, pref_code) {
  
  year <- as.character(year)
  
  year <- rlang::arg_match(year,
                           values = as.character(c(1920L,
                                                   seq.int(1950, 1985, by = 5L),
                                                   seq.int(1995, 2005, by = 5L),
                                                   seq.int(2006, 2018, by = 1L))))
  
  year_dir <-
    dplyr::case_when(
      year == "1920" ~ "200101",
      year == "1950" ~ "501001",
      year == "1955" ~ "551001",
      year == "1960" ~ "601001",
      year == "1965" ~ "651001",
      year == "1970" ~ "701001",
      year == "1975" ~ "751001",
      year == "1980" ~ "801001",
      year == "1985" ~ "851001",
      year == "1995" ~ "951001",
      year == "2000" ~ "001001",
      year == "2005" ~ "05",
      year == "2006" ~ "06",
      year == "2007" ~ "071001",
      year == "2008" ~ "090320",
      year == "2009" ~ "100329",
      year == "2010" ~ "110331",
      year == "2011" ~ "120331",
      year == "2012" ~ "120401",
      year == "2013" ~ "130401",
      year == "2014" ~ "140401",
      year == "2015" ~ "150101",
      year == "2016" ~ "160101",
      year == "2017" ~ "170101",
      year == "2018" ~ "180101"
    )
  
  paste0(
    "http://nlftp.mlit.go.jp/ksj/gml/data/N03/N03-",
    year,
    "/N03-",
    year_dir,
    "_",
    jpndistrict:::collect_prefcode(code = pref_code),
    "_GML.zip"
  )
  
}

read_ksj_n03 <- function(path = NULL, year = NULL, pref_code = NULL, download = FALSE) {
  
  if (is.null(path)) {
    
    dl_zip <-
      zip_n03_url(year, pref_code)
    
    path <- dplyr::if_else(download == TRUE,
                           ".",
                           tempdir())
    zip_path <-
      paste0(path, "/", basename(dl_zip))
    
    dl_zip %>%
      download.file(zip_path)
    
    path <- paste0(path, "/", gsub(".zip", "", basename(dl_zip)))
    
    dir.create(path)
    unzip(zipfile = zip_path,
          exdir = path)
    
  }
  
  if (grepl(".shp$", basename(path))) {
    d <- sf::st_read(dsn = path,
                     options = c("ENCODING=CP932"),
                     as_tibble = TRUE,
                     stringsAsFactors = FALSE)
  } else if (grepl(".geojson$", basename(path))) {
    d <- sf::st_read(dsn = path,
                     as_tibble = TRUE,
                     stringsAsFactors = FALSE)
  }
  
  xml_info <-
    list.files(gsub(pattern = "(.+)/.+$",
                    replacement = "\\1",
                    path),
               pattern = paste0("^N03.+",
                                gsub(basename(path),
                                     "..+", ""),
                                ".xml$"),
               full.names = TRUE)
  
  if (length(xml_info) == 1) {
    xml_info <-
      xml_info %>%
      xml2::read_xml() %>%
      xml2::as_list()
    
    d <-
      d %>%
      purrr::set_names(
        names(xml_info$Dataset$AdministrativeBoundary)[2:6],
        attr(d, "sf_column"))
  }
  d
}