# frozen_string_literal: true

require_relative "worker"
require_relative "installer/parallel_installer"
require_relative "installer/standalone"
require_relative "installer/gem_installer"

module Bundler
  class Installer
    attr_reader :post_install_messages, :definition

    # Begins the installation process for Bundler.
    # For more information see the #run method on this class.
    def self.install(root, definition, options = {})
      installer = new(root, definition)
      Plugin.hook(Plugin::Events::GEM_BEFORE_INSTALL_ALL, definition.dependencies)
      installer.run(options)
      Plugin.hook(Plugin::Events::GEM_AFTER_INSTALL_ALL, definition.dependencies)
      installer
    end

    def initialize(root, definition)
      @root = root
      @definition = definition
      @post_install_messages = {}
    end

    # Runs the install procedures for a specific Gemfile.
    #
    # Firstly, this method will check to see if `Bundler.bundle_path` exists
    # and if not then Bundler will create the directory. This is usually the same
    # location as RubyGems which typically is the `~/.gem` directory
    # unless other specified.
    #
    # Secondly, it checks if Bundler has been configured to be "frozen".
    # Frozen ensures that the Gemfile and the Gemfile.lock file are matching.
    # This stops a situation where a developer may update the Gemfile but may not run
    # `bundle install`, which leads to the Gemfile.lock file not being correctly updated.
    # If this file is not correctly updated then any other developer running
    # `bundle install` will potentially not install the correct gems.
    #
    # Thirdly, Bundler checks if there are any dependencies specified in the Gemfile.
    # If there are no dependencies specified then Bundler returns a warning message stating
    # so and this method returns.
    #
    # Fourthly, Bundler checks if the Gemfile.lock exists, and if so
    # then proceeds to set up a definition based on the Gemfile and the Gemfile.lock.
    # During this step Bundler will also download information about any new gems
    # that are not in the Gemfile.lock and resolve any dependencies if needed.
    #
    # Fifthly, Bundler resolves the dependencies either through a cache of gems or by remote.
    # This then leads into the gems being installed, along with stubs for their executables,
    # but only if the --binstubs option has been passed or Bundler.options[:bin] has been set
    # earlier.
    #
    # Sixthly, a new Gemfile.lock is created from the installed gems to ensure that the next time
    # that a user runs `bundle install` they will receive any updates from this process.
    #
    # Finally, if the user has specified the standalone flag, Bundler will generate the needed
    # require paths and save them in a `setup.rb` file. See `bundle standalone --help` for more
    # information.
    def run(options)
      Bundler.create_bundle_path

      ProcessLock.lock do
        # Invalidate any stale gem specification cache from before we acquired the lock.
        # Another process may have installed gems while we were waiting.
        Gem::Specification.reset
        @definition.sources.clear_cache

        @definition.ensure_equivalent_gemfile_and_lockfile(options[:deployment])

        if @definition.dependencies.empty?
          Bundler.ui.warn "The Gemfile specifies no dependencies"
          lock
          return
        end

        if @definition.setup_domain!(options)
          ensure_specs_are_compatible!
          load_plugins
        end
        install(options)

        Gem::Specification.reset # invalidate gem specification cache so that installed gems are immediately available

        lock
        Standalone.new(options[:standalone], @definition).generate if options[:standalone]
      end
    end

    def generate_bundler_executable_stubs(spec, options = {})
      if spec.name == "bundler"
        Bundler.ui.warn "Bundler itself does not use binstubs because its version is selected by RubyGems"
        return
      end

      if options[:binstubs_cmd] && spec.executables.empty?
        options = {}
        spec.runtime_dependencies.each do |dep|
          bins = @definition.specs[dep].first.executables
          options[dep.name] = bins unless bins.empty?
        end
        if options.any?
          Bundler.ui.warn "#{spec.name} has no executables, but you may want " \
            "one from a gem it depends on."
          options.each {|name, bins| Bundler.ui.warn "  #{name} has: #{bins.join(", ")}" }
        else
          Bundler.ui.warn "There are no executables for the gem #{spec.name}."
        end
        return
      end

      # double-assignment to avoid warnings about variables that will be used by ERB
      bin_path = Bundler.bin_path
      bin_path = bin_path
      relative_gemfile_path = Bundler.default_gemfile.relative_path_from(bin_path)
      relative_gemfile_path = relative_gemfile_path
      ruby_command = Thor::Util.ruby_command
      ruby_command = ruby_command
      template_path = File.expand_path("templates/Executable", __dir__)
      template = File.read(template_path)

      exists = []
      spec.executables.each do |executable|
        binstub_path = "#{bin_path}/#{executable}"
        if File.exist?(binstub_path) && !options[:force]
          exists << executable
          next
        end

        mode = Gem.win_platform? ? "wb:UTF-8" : "w"
        require "erb"
        content = ERB.new(template, trim_mode: "-").result(binding)

        File.write(binstub_path, content, mode: mode, perm: 0o777 & ~File.umask)
        if Gem.win_platform? || options[:all_platforms]
          prefix = "@ruby -x \"%~f0\" %*\n@exit /b %ERRORLEVEL%\n\n"
          File.write("#{binstub_path}.cmd", prefix + content, mode: mode)
        end
      end

      if options[:binstubs_cmd] && exists.any?
        case exists.size
        when 1
          Bundler.ui.warn "Skipped #{exists[0]} since it already exists."
        when 2
          Bundler.ui.warn "Skipped #{exists.join(" and ")} since they already exist."
        else
          items = exists[0...-1].empty? ? nil : exists[0...-1].join(", ")
          skipped = [items, exists[-1]].compact.join(" and ")
          Bundler.ui.warn "Skipped #{skipped} since they already exist."
        end
        Bundler.ui.warn "If you want to overwrite skipped stubs, use --force."
      end
    end

    def generate_standalone_bundler_executable_stubs(spec, options = {})
      # double-assignment to avoid warnings about variables that will be used by ERB
      bin_path = Bundler.bin_path
      unless path = Bundler.settings[:path]
        raise "Can't standalone without an explicit path set"
      end
      standalone_path = Bundler.root.join(path).relative_path_from(bin_path)
      standalone_path = standalone_path
      template = File.read(File.expand_path("templates/Executable.standalone", __dir__))
      ruby_command = Thor::Util.ruby_command
      ruby_command = ruby_command

      spec.executables.each do |executable|
        next if executable == "bundle"
        executable_path = Pathname(spec.full_gem_path).join(spec.bindir, executable).relative_path_from(bin_path)
        executable_path = executable_path

        mode = Gem.win_platform? ? "wb:UTF-8" : "w"
        require "erb"
        content = ERB.new(template, trim_mode: "-").result(binding)

        File.write("#{bin_path}/#{executable}", content, mode: mode, perm: 0o755)
        if Gem.win_platform? || options[:all_platforms]
          prefix = "@ruby -x \"%~f0\" %*\n@exit /b %ERRORLEVEL%\n\n"
          File.write("#{bin_path}/#{executable}.cmd", prefix + content, mode: mode)
        end
      end
    end

    private

    # the order that the resolver provides is significant, since
    # dependencies might affect the installation of a gem.
    # that said, it's a rare situation (other than rake), and parallel
    # installation is SO MUCH FASTER. so we let people opt in.
    def install(options)
      standalone = options[:standalone]
      force = options[:force]
      local = options[:local] || options[:"prefer-local"]
      jobs = Bundler.settings.installation_parallelization
      specs = @definition.specs
      # Installing default gems may need the remote index again to cache
      # their .gem files, so keep resolution memory around in that case.
      # The bundler spec itself is excluded because it comes from the
      # metadata source and never goes through that path.
      @definition.release_resolution_memory! if specs.none? {|s| s.default_gem? && s.source.is_a?(Source::Rubygems) }
      spec_installations = ParallelInstaller.call(self, specs, jobs, standalone, force, local: local)
      spec_installations.each do |installation|
        post_install_messages[installation.name] = installation.post_install_message if installation.has_post_install_message?
      end
    end

    def load_plugins
      Gem.load_plugins

      requested_path_gems = @definition.specs.select {|s| s.source.is_a?(Source::Path) }
      path_plugin_files = requested_path_gems.flat_map do |spec|
        spec.matches_for_glob("rubygems_plugin#{Bundler.rubygems.suffix_pattern}")
      rescue TypeError
        error_message = "#{spec.name} #{spec.version} has an invalid gemspec"
        raise Gem::InvalidSpecificationException, error_message
      end
      Gem.load_plugin_files(path_plugin_files)
      Gem.load_env_plugins
    end

    def ensure_specs_are_compatible!
      overrides = @definition.overrides
      @definition.specs.each do |spec|
        unless spec.matches_current_ruby_with_overrides?(overrides)
          raise InstallError, incompatibility_message(spec, "requires ruby version #{spec.required_ruby_version}, " \
            "which is incompatible with the current version, #{Gem.ruby_version}")
        end
        unless spec.matches_current_rubygems_with_overrides?(overrides)
          raise InstallError, incompatibility_message(spec, "requires rubygems version #{spec.required_rubygems_version}, " \
            "which is incompatible with the current version, #{Gem.rubygems_version}")
        end
      end
    end

    # Build the error raised when a locked spec can't run on the current Ruby or
    # RubyGems. When the offending spec is a platform-specific variant locked in
    # frozen mode, point users at the fix: re-resolving outside frozen mode adds
    # the Ruby (non platform-specific) fallback variant to the lockfile.
    def incompatibility_message(spec, reason)
      message = "#{spec.full_name} #{reason}"
      return message unless Bundler.frozen_bundle? && spec.platform != Gem::Platform::RUBY

      message + "\n\nThe lockfile only includes the #{spec.platform} variant of #{spec.name}. " \
        "If a compatible Ruby variant is available, run `bundle install` outside of frozen/deployment mode " \
        "to add it to the lockfile as a fallback, then commit the updated #{SharedHelpers.relative_lockfile_path}."
    end

    def lock
      @definition.lock
    end
  end
end
