# frozen_string_literal: true

require_relative "cooldown"
require_relative "vendored_tsort"

##
# A RequestSet groups a request to activate a set of dependencies.
#
#   nokogiri = Gem::Dependency.new 'nokogiri', '>= 1.6'
#   pg = Gem::Dependency.new 'pg', '>= 0.14'
#
#   set = Gem::RequestSet.new nokogiri, pg
#
#   requests = set.resolve
#
#   p requests.map { |r| r.full_name }
#   #=> ["nokogiri-1.6.0", "mini_portile-0.5.1", "pg-0.17.0"]

class Gem::RequestSet
  include Gem::TSort

  ##
  # Array of gems to install even if already installed

  attr_accessor :always_install

  ##
  # The Gem::Cooldown applied to release candidates, if any.

  attr_accessor :cooldown

  attr_reader :dependencies

  attr_accessor :development

  ##
  # Errors fetching gems during resolution.

  attr_reader :errors

  ##
  # Set to true if you want to install only direct development dependencies.

  attr_accessor :development_shallow

  ##
  # The set of git gems imported via load_gemdeps.

  attr_reader :git_set # :nodoc:

  ##
  # When true, dependency resolution is not performed, only the requested gems
  # are installed.

  attr_accessor :ignore_dependencies

  attr_reader :install_dir # :nodoc:

  ##
  # If true, allow dependencies to match prerelease gems.

  attr_accessor :prerelease

  ##
  # When false no remote sets are used for resolving gems.

  attr_accessor :remote

  attr_reader :resolver # :nodoc:

  ##
  # Sets used for resolution

  attr_reader :sets # :nodoc:

  ##
  # Treat missing dependencies as silent errors

  attr_accessor :soft_missing

  ##
  # The set of vendor gems imported via load_gemdeps.

  attr_reader :vendor_set # :nodoc:

  ##
  # The set of source gems imported via load_gemdeps.

  attr_reader :source_set

  ##
  # Creates a RequestSet for a list of Gem::Dependency objects, +deps+.  You
  # can then #resolve and #install the resolved list of dependencies.
  #
  #   nokogiri = Gem::Dependency.new 'nokogiri', '>= 1.6'
  #   pg = Gem::Dependency.new 'pg', '>= 0.14'
  #
  #   set = Gem::RequestSet.new nokogiri, pg

  def initialize(*deps)
    @dependencies = deps

    @always_install      = []
    @conservative        = false
    @cooldown            = nil
    @dependency_names    = {}
    @development         = false
    @development_shallow = false
    @errors              = []
    @git_set             = nil
    @ignore_dependencies = false
    @install_dir         = Gem.dir
    @prerelease          = false
    @remote              = true
    @requests            = []
    @sets                = []
    @soft_missing        = false
    @sorted_requests     = nil
    @specs               = nil
    @vendor_set          = nil
    @source_set          = nil

    yield self if block_given?
  end

  ##
  # Declare that a gem of name +name+ with +reqs+ requirements is needed.

  def gem(name, *reqs)
    if dep = @dependency_names[name]
      dep.requirement.concat reqs
    else
      dep = Gem::Dependency.new name, *reqs
      @dependency_names[name] = dep
      @dependencies << dep
    end
  end

  ##
  # Add +deps+ Gem::Dependency objects to the set.

  def import(deps)
    @dependencies.concat deps
  end

  ##
  # Installs gems for this RequestSet using the Gem::Installer +options+.
  #
  # If a +block+ is given an activation +request+ and +installer+ are yielded.
  # The +installer+ will be +nil+ if a gem matching the request was already
  # installed.

  def install(options, &block) # :yields: request, installer
    if dir = options[:install_dir]
      requests = install_into dir, false, options, &block
      return requests
    end

    @prerelease = options[:prerelease]

    requests = []
    download_queue = Thread::Queue.new

    # Create a thread-safe list of gems to download
    sorted_requests.each do |req|
      download_queue << req
    end

    # Create N threads in a pool, have them download all the gems
    threads = Array.new(Gem.configuration.concurrent_downloads) do
      # When a thread pops this item, it knows to stop running. The symbol
      # is queued here so that there will be one symbol per thread.
      download_queue << :stop

      Thread.new do
        # The pop method will block waiting for items, so the only way
        # to stop a thread from running is to provide a final item that
        # means the thread should stop.
        while req = download_queue.pop
          break if req == :stop
          req.spec.download options unless req.installed?
        end
      end
    end

    # Wait for all the downloads to finish before continuing
    threads.each(&:value)

    # Install requested gems after they have been downloaded
    sorted_requests.each do |req|
      if req.installed? && @always_install.none? {|spec| spec == req.spec.spec }
        req.spec.spec.build_extensions unless options[:build_extension] == false
        yield req, nil if block_given?
        next
      end

      spec =
        begin
          req.spec.install options do |installer|
            yield req, installer if block_given?
          end
        rescue Gem::RuntimeRequirementNotMetError => e
          suggestion = "There are no versions of #{req.request} compatible with your Ruby & RubyGems"
          suggestion += ". Maybe try installing an older version of the gem you're looking for?" unless @always_install.include?(req.spec.spec)
          e.suggestion = suggestion
          raise
        end

      requests << spec
    end

    return requests if options[:gemdeps]

    install_hooks requests, options

    requests
  end

  ##
  # Installs from the gem dependencies files in the +:gemdeps+ option in
  # +options+, yielding to the +block+ as in #install.
  #
  # If +:without_groups+ is given in the +options+, those groups in the gem
  # dependencies file are not used.  See Gem::Installer for other +options+.

  def install_from_gemdeps(options, &block)
    gemdeps = options[:gemdeps]

    @install_dir = options[:install_dir] || Gem.dir
    @prerelease  = options[:prerelease]
    @remote      = options[:domain] != :local
    @conservative = true if options[:conservative]
    @cooldown = Gem::Cooldown.from_options options

    gem_deps_api = load_gemdeps gemdeps, options[:without_groups], true

    resolve

    if options[:explain]
      puts "Gems to install:"

      sorted_requests.each do |spec|
        puts "  #{spec.full_name}"
      end
    else
      installed = install options, &block

      if options.fetch :lock, true
        lockfile =
          Gem::RequestSet::Lockfile.build self, gemdeps, gem_deps_api.dependencies
        lockfile.write
      end

      installed
    end
  end

  def install_into(dir, force = true, options = {})
    gem_home = ENV["GEM_HOME"]
    ENV["GEM_HOME"] = dir

    existing = force ? [] : specs_in(dir)
    existing.delete_if {|s| @always_install.include? s }

    dir = File.expand_path dir

    installed = []

    options[:development] = false
    options[:install_dir] = dir
    options[:only_install_dir] = true
    @prerelease = options[:prerelease]

    sorted_requests.each do |request|
      spec = request.spec

      if existing.find {|s| s.full_name == spec.full_name }
        yield request, nil if block_given?
        next
      end

      spec.install options do |installer|
        yield request, installer if block_given?
      end

      installed << request
    end

    install_hooks installed, options

    installed
  ensure
    ENV["GEM_HOME"] = gem_home
  end

  ##
  # Call hooks on installed gems

  def install_hooks(requests, options)
    specs = requests.map do |request|
      case request
      when Gem::Resolver::ActivationRequest then
        request.spec.spec
      else
        request
      end
    end

    require_relative "dependency_installer"
    inst = Gem::DependencyInstaller.new options
    inst.installed_gems.replace specs

    Gem.done_installing_hooks.each do |hook|
      hook.call inst, specs
    end unless Gem.done_installing_hooks.empty?
  end

  ##
  # Load a dependency management file.

  def load_gemdeps(path, without_groups = [], installing = false)
    @git_set    = Gem::Resolver::GitSet.new
    @vendor_set = Gem::Resolver::VendorSet.new
    @source_set = Gem::Resolver::SourceSet.new

    @git_set.root_dir = @install_dir

    lock_file = "#{File.expand_path(path)}.lock"
    if File.exist?(lock_file)
      load_lockfile lock_file
    end

    gf = Gem::RequestSet::GemDependencyAPI.new self, path
    gf.installing = installing
    gf.without_groups = without_groups if without_groups
    gf.load
  end

  def load_lockfile(lock_file) # :nodoc:
    require "bundler"
    require "bundler/lockfile_parser"

    # Bundler::Source::Path resolves relative `remote:` paths against
    # Bundler.root, which raises when there is no Gemfile in the working
    # directory. Anchor it to the lockfile's directory so PATH sections in a
    # `gem install -g` lockfile can be parsed without a Bundler environment.
    previous_root = Bundler.instance_variable_get(:@root)
    Bundler.instance_variable_set(:@root, Pathname.new(File.expand_path(File.dirname(lock_file))))

    parser = Bundler::LockfileParser.new(File.read(lock_file), lockfile_path: lock_file)

    parser.specs.group_by(&:source).each do |source, specs|
      case source
      when Bundler::Source::Rubygems
        remotes = source.remotes.map {|remote| Gem::Source.new(remote.to_s) }
        remotes << Gem::Source.new(Gem::DEFAULT_HOST) if remotes.empty?
        lock_set = Gem::Resolver::LockSet.new(remotes)
        specs.each do |spec|
          added = lock_set.add(spec.name, spec.version.to_s, spec.platform)
          spec.dependencies.each do |dep|
            added.each {|s| s.add_dependency dep }
          end
        end
        @sets << lock_set
      when Bundler::Source::Git
        git_set = Gem::Resolver::GitSet.new
        git_set.root_dir = @install_dir
        specs.each do |spec|
          git_spec = git_set.add_git_spec(
            spec.name,
            spec.version.to_s,
            source.uri.to_s,
            source.revision,
            source.submodules || false
          )
          spec.dependencies.each {|dep| git_spec.add_dependency dep }
        end
        @sets << git_set
      when Bundler::Source::Path
        vendor_set = Gem::Resolver::VendorSet.new
        specs.each do |spec|
          loaded = vendor_set.add_vendor_gem(spec.name, source.path.to_s)
          spec.dependencies.each {|dep| loaded.dependencies << dep }
        end
        @sets << vendor_set
      end
    end

    parser.dependencies.each_value do |dep|
      gem dep.name, *dep.requirement.as_list
    end
  ensure
    Bundler.instance_variable_set(:@root, previous_root) if defined?(previous_root)
  end

  def pretty_print(q) # :nodoc:
    q.group 2, "[RequestSet:", "]" do
      q.breakable

      if @remote
        q.text "remote"
        q.breakable
      end

      if @prerelease
        q.text "prerelease"
        q.breakable
      end

      if @development_shallow
        q.text "shallow development"
        q.breakable
      elsif @development
        q.text "development"
        q.breakable
      end

      if @soft_missing
        q.text "soft missing"
      end

      q.group 2, "[dependencies:", "]" do
        q.breakable
        @dependencies.map do |dep|
          q.text dep.to_s
          q.breakable
        end
      end

      q.breakable
      q.text "sets:"

      q.breakable
      q.pp @sets.map(&:class)
    end
  end

  ##
  # Resolve the requested dependencies and return an Array of Specification
  # objects to be activated.

  def resolve(set = Gem::Resolver::BestSet.new)
    @sets << set
    @sets << @git_set
    @sets << @vendor_set
    @sets << @source_set

    set = Gem::Resolver.compose_sets(*@sets)
    set.remote = @remote
    set.prerelease = @prerelease

    resolver = Gem::Resolver.new @dependencies, set
    resolver.cooldown            = @cooldown
    resolver.development         = @development
    resolver.development_shallow = @development_shallow
    resolver.ignore_dependencies = @ignore_dependencies
    resolver.soft_missing        = @soft_missing

    if @conservative
      installed_gems = {}
      Gem::Specification.find_all do |spec|
        (installed_gems[spec.name] ||= []) << spec
      end
      resolver.skip_gems = installed_gems
    end

    @resolver = resolver

    @requests = resolver.resolve

    @errors = set.errors

    @requests
  end

  ##
  # Resolve the requested dependencies against the gems available via Gem.path
  # and return an Array of Specification objects to be activated.

  def resolve_current
    resolve Gem::Resolver::CurrentSet.new
  end

  def sorted_requests
    @sorted_requests ||= strongly_connected_components.flatten
  end

  def specs
    @specs ||= @requests.map(&:full_spec)
  end

  def specs_in(dir)
    Gem::Util.glob_files_in_dir("*.gemspec", File.join(dir, "specifications")).map do |g|
      Gem::Specification.load g
    end
  end

  def tsort_each_node(&block) # :nodoc:
    @requests.each(&block)
  end

  def tsort_each_child(node) # :nodoc:
    node.spec.dependencies.each do |dep|
      next if dep.type == :development && !@development

      match = @requests.find do |r|
        dep.match?(r.spec.name, r.spec.version, r.spec.is_a?(Gem::Resolver::InstalledSpecification) || @prerelease)
      end

      unless match
        next if dep.type == :development && @development_shallow
        next if @soft_missing
        raise Gem::DependencyError,
              "Unresolved dependency found during sorting - #{dep} (requested by #{node.spec.full_name})"
      end

      yield match
    end
  end
end

require_relative "request_set/gem_dependency_api"
require_relative "request_set/lockfile"
