From 8f265499cd8bec0635967edfb11d56c3fbf49dc1 Mon Sep 17 00:00:00 2001
From: pat-s <patrick.schratz@gmail.com>
Date: Sun, 4 Aug 2024 09:46:03 +0200
Subject: [PATCH] add helper

---
 get-all-pkg-versions.R | 51 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 51 insertions(+)
 create mode 100644 get-all-pkg-versions.R

diff --git a/get-all-pkg-versions.R b/get-all-pkg-versions.R
new file mode 100644
index 0000000..77fc713
--- /dev/null
+++ b/get-all-pkg-versions.R
@@ -0,0 +1,51 @@
+# Load necessary libraries
+library(httr2)
+library(dplyr)
+library(tidyr)
+library(xml2)
+library(tools)
+library(future)
+library(future.apply)
+
+# Define the base URL for the CRAN archive
+base_url <- "https://cran.r-project.org/src/contrib/Archive/"
+
+# Function to get all package names using tools::CRAN_package_db()
+get_package_names <- function() {
+  cran_db <- CRAN_package_db()
+  package_names <- unique(cran_db$Package)
+  return(package_names)
+}
+
+# Function to get all archived versions of a package with error handling
+get_archived_versions <- function(package_name) {
+  package_url <- paste0(base_url, package_name, "/")
+  
+  # Try to perform the request and handle any errors
+  tryCatch({
+    response <- request(package_url) %>% req_perform()
+    page <- response %>% resp_body_string() %>% read_html()
+    version_links <- page %>% xml_find_all("//a") %>% xml_attr("href")
+    # Extract version numbers
+    versions <- gsub(paste0(package_name, "_|\\.tar\\.gz"), "", version_links)
+    # Filter out invalid version strings
+    versions <- versions[grep("^[0-9]+\\.[0-9]+\\.[0-9]+$", versions)]
+    return(data.frame(Package = package_name, Version = versions, stringsAsFactors = FALSE))
+  }, error = function(e) {
+    # If there's an error (e.g., HTTP 404), return NULL
+    return(NULL)
+  })
+}
+
+# Get all package names
+package_names <- get_package_names()
+
+# Set up parallel processing
+plan(multisession, workers = parallel::detectCores())
+
+# Get archived versions for all packages in parallel
+all_packages_df <- future_lapply(package_names, get_archived_versions) %>%
+  bind_rows()
+
+# Display the dataframe
+print(all_packages_df)