# frozen_string_literal: true

require "rubygems/installer"

module Bundler
  class RubyGemsGemInstaller < Gem::Installer
    # Cap how many jobserver slots a single gem's `make` may grab so that one
    # gem with many recipes doesn't starve the others sharing the pool. Beyond
    # a handful of jobs the extra parallelism rarely pays off in practice.
    MAX_JOBS_PER_GEM = 3

    def check_executable_overwrite(filename)
      # Bundler needs to install gems regardless of binstub overwriting
    end

    def install
      pre_install_checks

      run_pre_install_hooks

      spec.loaded_from = spec_file

      # Completely remove any previous gem files
      strict_rm_rf gem_dir
      strict_rm_rf spec.extension_dir

      SharedHelpers.filesystem_access(gem_dir, :create) do
        FileUtils.mkdir_p gem_dir
      end

      SharedHelpers.filesystem_access(gem_dir, :write) do
        extract_files
      end

      build_extensions if spec.extensions.any?
      write_build_info_file
      run_post_build_hooks

      SharedHelpers.filesystem_access(bin_dir, :write) do
        generate_bin
      end

      generate_plugins

      write_spec

      SharedHelpers.filesystem_access("#{gem_home}/cache", :write) do
        write_cache_file
      end

      say spec.post_install_message unless spec.post_install_message.nil?

      run_post_install_hooks

      spec
    end

    if Bundler.rubygems.provides?("< 3.5")
      def pre_install_checks
        super
      rescue Gem::FilePermissionError
        # Ignore permission checks in RubyGems. Instead, go on, and try to write
        # for real. We properly handle permission errors when they happen.
        nil
      end
    end

    def ensure_writable_dir(dir)
      super
    rescue Gem::FilePermissionError
      # Ignore permission checks in RubyGems. Instead, go on, and try to write
      # for real. We properly handle permission errors when they happen.
      nil
    end

    def generate_plugins
      return unless Gem::Installer.method_defined?(:generate_plugins, false)

      ensure_writable_dir @plugins_dir

      if spec.plugins.empty?
        remove_plugins_for(spec, @plugins_dir)
      else
        regenerate_plugins_for(spec, @plugins_dir)
      end
    end

    if Bundler.rubygems.provides?("< 3.5.19")
      def generate_bin_script(filename, bindir)
        bin_script_path = File.join bindir, formatted_program_filename(filename)

        Gem.open_file_with_lock(bin_script_path) do
          require "fileutils"
          FileUtils.rm_f bin_script_path # prior install may have been --no-wrappers

          File.open(bin_script_path, "wb", 0o755) do |file|
            file.write app_script_text(filename)
            file.chmod(options[:prog_mode] || 0o755)
          end
        end

        verbose bin_script_path

        generate_windows_script filename, bindir
      end
    end

    def build_jobs
      @jobserver_read_io&.read_nonblock(MAX_JOBS_PER_GEM, @jobserver_tokens)
      acquired_jobs = @jobserver_tokens.empty? ? nil : @jobserver_tokens.size

      acquired_jobs || Bundler.settings[:jobs] || super
    rescue IO::WaitReadable, EOFError
      1
    end

    def build_extensions
      @jobserver_tokens = +""
      @jobserver_read_io, @jobserver_write_io = connect_to_jobserver

      extension_cache_path = options[:bundler_extension_cache_path]
      extension_dir = spec.extension_dir
      unless extension_cache_path && extension_dir
        prepare_extension_build(extension_dir)
        return super
      end

      build_complete = SharedHelpers.filesystem_access(extension_cache_path.join("gem.build_complete"), :read, &:file?)
      if build_complete && !options[:force]
        SharedHelpers.filesystem_access(File.dirname(extension_dir)) do |p|
          FileUtils.mkpath p
        end
        SharedHelpers.filesystem_access(extension_cache_path) do
          FileUtils.cp_r extension_cache_path, extension_dir
        end
      else
        prepare_extension_build(extension_dir)
        super
        SharedHelpers.filesystem_access(extension_cache_path.parent, &:mkpath)
        SharedHelpers.filesystem_access(extension_cache_path) do
          FileUtils.cp_r extension_dir, extension_cache_path
        end
      end
    ensure
      unless @jobserver_tokens.empty?
        @jobserver_write_io.write(@jobserver_tokens)
        @jobserver_write_io.flush
      end
    end

    def spec
      if Bundler.rubygems.provides?("< 3.3.12") # RubyGems implementation rescues and re-raises errors before 3.3.12 and we don't want that
        @package.spec
      else
        super
      end
    end

    def gem_checksum
      Checksum.from_gem_package(@package)
    end

    private

    def connect_to_jobserver
      return unless ENV["MAKEFLAGS"]
      # We append our own --jobserver-auth, so read the last one. Otherwise a
      # parent jobserver's descriptors (e.g. `bundle install` run under
      # `make -j`) would be picked up instead of the pool ParallelInstaller created.
      read_fd, write_fd = ENV["MAKEFLAGS"].scan(/--jobserver-auth=(\d+),(\d+)/).last

      return unless read_fd && write_fd

      # Pass explicit modes. On POSIX, IO.new detects the descriptor's access
      # mode, but on Windows it can't, so the write end would default to read
      # mode and raise "IOError: not opened for writing" when releasing slots.
      [IO.new(read_fd.to_i, "r", autoclose: false), IO.new(write_fd.to_i, "w", autoclose: false)]
    end

    def prepare_extension_build(extension_dir)
      SharedHelpers.filesystem_access(extension_dir, :create) do
        FileUtils.mkdir_p extension_dir
      end
    end

    def strict_rm_rf(dir)
      return unless File.exist?(dir)
      return if Dir.empty?(dir)

      parent = File.dirname(dir)
      parent_st = File.stat(parent)

      if parent_st.world_writable? && !parent_st.sticky?
        raise InsecureInstallPathError.new(spec.full_name, dir)
      end

      begin
        FileUtils.remove_entry_secure(dir)
      rescue StandardError => e
        raise unless File.exist?(dir)

        raise DirectoryRemovalError.new(e, "Could not delete previous installation of `#{dir}`")
      end
    end
  end
end
