cran.rb

# frozen_string_literal: true

module PackageManager
  class CRAN < Base
    HAS_VERSIONS = true
    HAS_DEPENDENCIES = true
    URL = "https://cran.r-project.org/"
    COLOR = "#198CE7"

    def self.package_link(db_project, _version = nil)
      "https://cran.r-project.org/package=#{db_project.name}"
    end

    def self.download_url(db_project, version = nil)
      "https://cran.r-project.org/src/contrib/#{db_project.name}_#{version}.tar.gz"
    end

    def self.documentation_url(name, _version = nil)
      "http://cran.r-project.org/web/packages/#{name}/#{name}.pdf"
    end

    def self.check_status_url(db_project)
      "http://cran.r-project.org/web/packages/#{db_project.name}/index.html"
    end

    def self.project_names
      html = get_html("https://cran.r-project.org/web/packages/available_packages_by_date.html", request: { timeout: 5 })
      html.css("tr")[1..].map { |tr| tr.css("td")[1].text.strip }
    end

    def self.recent_names
      project_names[0..15].uniq
    end

    def self.project(name)
      html = get_html("https://cran.r-project.org/web/packages/#{name}/index.html", request: { timeout: 5 })
      info = {}
      table = html.css("table")[0]
      return nil if table.nil?

      table.css("tr").each do |tr|
        tds = tr.css("td").map(&:text)
        info[tds[0]] = tds[1]
      end

      { name: name, html: html, info: info }
    end

    def self.mapping(raw_project)
      MappingBuilder.build_hash(
        name: raw_project[:name],
        homepage: raw_project[:info].fetch("URL:", "").split(",").first,
        description: raw_project[:html].css("h2").text.split(":")[1..].join(":").strip,
        licenses: raw_project[:info]["License:"],
        repository_url: repo_fallback("", (raw_project[:info].fetch("URL:", "").split(",").first.presence || raw_project[:info]["BugReports:"])).to_s[0, 255]
      )
    end

    def self.versions(raw_project, _name)
      [VersionBuilder.build_hash(
        number: raw_project[:info]["Version:"],
        published_at: raw_project[:info]["Published:"]
      )] + find_old_versions(raw_project)
    end

    def self.find_old_versions(project)
      archive_page = get_html("https://cran.r-project.org/src/contrib/Archive/#{project[:name]}/", request: { timeout: 5 })
      trs = archive_page.css("table").css("tr").select do |tr|
        tds = tr.css("td")
        tds[1]&.text&.match(/tar\.gz$/)
      end
      trs.map do |tr|
        tds = tr.css("td")
        VersionBuilder.build_hash(
          number: tds[1].text.strip.split("_").last.gsub(".tar.gz", ""),
          published_at: tds[2].text.strip
        )
      end
    end

    def self.dependencies(name, version, _mapped_project)
      dependencies = find_dependencies(name, version)
      return [] unless dependencies&.any?

      dependencies.map do |dependency|
        dependency = dependency.to_h.deep_stringify_keys
        {
          project_name: dependency["name"],
          requirements: dependency["requirement"] || "*",
          kind: dependency["type"],
          platform: db_platform,
        }
      end
    end

    def self.find_dependencies(name, version)
      begin
        url = "https://cran.rstudio.com/src/contrib/#{name}_#{version}.tar.gz"
        head_response = Typhoeus.head(url)
        raise if head_response.code != 200
      rescue StandardError
        url = "https://cran.rstudio.com/src/contrib/Archive/#{name}/#{name}_#{version}.tar.gz"
      end

      folder_name = "#{name}_#{version}"
      tarball_name = "#{folder_name}.tar.gz"
      downloaded_file = File.open "/tmp/#{tarball_name}", "wb"
      request = Typhoeus::Request.new(url)
      request.on_headers do |response|
        return [] if response.code != 200
      end
      request.on_body { |chunk| downloaded_file.write(chunk) }
      request.on_complete { downloaded_file.close }
      request.run

      `mkdir /tmp/#{folder_name} && tar xvzf /tmp/#{tarball_name} -C /tmp/#{folder_name}  --strip-components 1`

      contents = `cat /tmp/#{folder_name}/DESCRIPTION`

      `rm -rf /tmp/#{folder_name} /tmp/#{tarball_name}`

      Bibliothecary.analyse_file("DESCRIPTION", contents).first.fetch(:dependencies)
    ensure
      `rm -rf /tmp/#{folder_name} /tmp/#{tarball_name}`
      []
    end
  end
end