Check PPM for a binary

check.R

library(shiny)
library(httr)

check_binary <- function(pkg, 
                         version,
                         distro, # one of windows, xenial, bionic, centos7, centos8, opensuse42, opensuse15
                         r_version,
                         repo_base = "https://packagemanager.rstudio.com/cran/", 
                         verbose = FALSE){
  
  pkg_url <- get_pkgurl(pkg, version, repo_base, distro, r_version)
  ua <- sprintf("R/%s R (%s %s)", r_version, r_version, "x86_64-pc-linux-gnu x86_64 linux-gnu")
  #ua <- "R/3.6.2 R (3.6.2 x86_64-pc-linux-gnu x86_64 linux-gnu)"
  if (verbose) {
    print(sprintf("User Agent: %s", ua))
    print(sprintf("Package URL: %s", pkg_url))
  }
  res <- HEAD(url = pkg_url, httr::add_headers(`User-Agent`=ua))
  if(res[["status_code"]] != 200) {
    "failed"
  } else {
    res[["headers"]][["x-package-type"]]  
  }
}

get_pkgurl <- function(pkg, version, repo_base, distro, r_version){
  
  if(is_latest(pkg, version, repo_base)) {
    if (distro == "windows") {
      r_majmin <- substr(r_version, 1, 3)
      return(sprintf("%slatest/bin/windows/contrib/%s/%s_%s.zip", repo_base, r_majmin, pkg, version))
    } else {
      return(sprintf("%s__linux__/%s/latest/src/contrib/%s_%s.tar.gz", repo_base, distro, pkg, version))
    }
  } else {
    if (distro == "windows") {
      return(sprintf("%slatest/src/contrib/Archive/%s/%s_%s.tar.gz", repo_base, pkg, pkg, version))
    } else {
      return(sprintf("%s__linux__/%s/latest/src/contrib/Archive/%s/%s_%s.tar.gz", repo_base, distro, pkg, pkg, version))
    }
  }
}

is_latest <- function(pkg, version, repo_base){
  ap <- available.packages(repos = paste0(repo_base,"latest"), type = "source", ignore_repo_cache = TRUE)
  pkgid <- which(rownames(ap) == pkg)
  latest_vers <- ap[pkg, colnames(ap) == "Version"]
  latest_vers == version
}