Class: Bundler::Resolver

# File 'lib/bundler/resolver.rb', line 20

def self.resolve(requirements, source_requirements = {}, base = [], gem_version_promoter = GemVersionPromoter.new, additional_base_requirements = [], platforms = nil)
  base = SpecSet.new(base) unless base.is_a?(SpecSet)
  resolver = new(source_requirements, base, gem_version_promoter, additional_base_requirements, platforms)
  result = resolver.start(requirements)
  SpecSet.new(SpecSet.new(result).for(requirements.reject{|dep| dep.name.end_with?("\0") }))
end

# File 'lib/bundler/resolver.rb', line 231

def amount_constrained(dependency)
  @amount_constrained ||= {}
  @amount_constrained[dependency.name] ||= begin
    if (base = @base[dependency.name]) && !base.empty?
      dependency.requirement.satisfied_by?(base.first.version) ? 0 : 1
    else
      all = index_for(dependency).search(dependency.name).size

      if all <= 1
        all - 1_000_000
      else
        search = search_for(dependency)
        search = @prerelease_specified[dependency.name] ? search.count : search.count {|s| !s.version.prerelease? }
        search - all
      end
    end
  end
end

# File 'lib/bundler/resolver.rb', line 89

def before_resolution
  Bundler.ui.info "Resolving dependencies...", debug?
end

# File 'lib/bundler/resolver.rb', line 72

def debug(depth = 0)
  return unless debug?
  debug_info = yield
  debug_info = debug_info.inspect unless debug_info.is_a?(String)
  puts debug_info.split("\n").map {|s| depth == 0 ? "BUNDLER: #{s}" : "BUNDLER(#{depth}): #{s}" }
end

# File 'lib/bundler/resolver.rb', line 197

def dependencies_equal?(dependencies, other_dependencies)
  dependencies.map(&:dep) == other_dependencies.map(&:dep)
end

# File 'lib/bundler/resolver.rb', line 103

def dependencies_for(specification)
  specification.dependencies_for_activated_platforms
end

# File 'lib/bundler/resolver.rb', line 280

def formatted_versions_with_platforms(versions_with_platforms)
  version_platform_strs = versions_with_platforms.map do |vwp|
    version = vwp.first
    platform = vwp.last
    version_platform_str = String.new(version.to_s)
    version_platform_str << " #{platform}" unless platform.nil? || platform == Gem::Platform::RUBY
    version_platform_str
  end
  version_platform_strs.join(", ")
end

# File 'lib/bundler/resolver.rb', line 165

def index_for(dependency)
  source_for(dependency.name).specs
end

# File 'lib/bundler/resolver.rb', line 97

def indicate_progress
  Bundler.ui.info ".", false unless debug?
end

# File 'lib/bundler/resolver.rb', line 177

def name_for(dependency)
  dependency.name
end

# File 'lib/bundler/resolver.rb', line 181

def name_for_explicit_dependency_source
  Bundler.default_gemfile.basename.to_s
rescue StandardError
  "Gemfile"
end

# File 'lib/bundler/resolver.rb', line 187

def name_for_locking_dependency_source
  Bundler.default_lockfile.basename.to_s
rescue StandardError
  "Gemfile.lock"
end

# File 'lib/bundler/resolver.rb', line 193

def requirement_satisfied_by?(requirement, activated, spec)
  requirement.matches_spec?(spec) || spec.source.is_a?(Source::Gemspec)
end

# File 'lib/bundler/resolver.rb', line 173

def results_for(dependency, base)
  index_for(dependency).search(dependency, base)
end

# File 'lib/bundler/resolver.rb', line 107

def search_for(dependency_proxy)
  platform = dependency_proxy.__platform
  dependency = dependency_proxy.dep
  name = dependency.name
  @search_for[dependency_proxy] ||= begin
    results = results_for(dependency, @base[name])

    if vertex = @base_dg.vertex_named(name)
      locked_requirement = vertex.payload.requirement
    end

    if !@prerelease_specified[name] && (!@use_gvp || locked_requirement.nil?)
      # Move prereleases to the beginning of the list, so they're considered
      # last during resolution.
      pre, results = results.partition {|spec| spec.version.prerelease? }
      results = pre + results
    end

    spec_groups = if results.any?
      nested = []
      results.each do |spec|
        version, specs = nested.last
        if version == spec.version
          specs << spec
        else
          nested << [spec.version, [spec]]
        end
      end
      nested.reduce([]) do |groups, (version, specs)|
        next groups if locked_requirement && !locked_requirement.satisfied_by?(version)

        specs_by_platform = Hash.new do |current_specs, current_platform|
          current_specs[current_platform] = select_best_platform_match(specs, current_platform)
        end

        spec_group_ruby = SpecGroup.create_for(specs_by_platform, [Gem::Platform::RUBY], Gem::Platform::RUBY)
        groups << spec_group_ruby if spec_group_ruby

        next groups if @resolving_only_for_ruby

        spec_group = SpecGroup.create_for(specs_by_platform, @platforms, platform)
        groups << spec_group if spec_group

        groups
      end
    else
      []
    end
    # GVP handles major itself, but it's still a bit risky to trust it with it
    # until we get it settled with new behavior. For 2.x it can take over all cases.
    if !@use_gvp
      spec_groups
    else
      @gem_version_promoter.sort_versions(dependency, spec_groups)
    end
  end
end

# File 'lib/bundler/resolver.rb', line 201

def sort_dependencies(dependencies, activated, conflicts)
  dependencies.sort_by do |dependency|
    name = name_for(dependency)
    vertex = activated.vertex_named(name)
    [
      @base_dg.vertex_named(name) ? 0 : 1,
      vertex.payload ? 0 : 1,
      vertex.root? ? 0 : 1,
      amount_constrained(dependency),
      conflicts[name] ? 0 : 1,
      vertex.payload ? 0 : search_for(dependency).count,
      self.class.platform_sort_key(dependency.__platform),
    ]
  end
end

# File 'lib/bundler/resolver.rb', line 169

def source_for(name)
  @source_requirements[name] || @source_requirements[:default]
end

# File 'lib/bundler/resolver.rb', line 44

def start(requirements)
  @gem_version_promoter.prerelease_specified = @prerelease_specified = {}
  requirements.each {|dep| @prerelease_specified[dep.name] ||= dep.prerelease? }

  verify_gemfile_dependencies_are_found!(requirements)
  dg = @resolver.resolve(requirements, @base_dg)
  dg.
    map(&:payload).
    reject {|sg| sg.name.end_with?("\0") }.
    map(&:to_specs).
    flatten
rescue Molinillo::VersionConflict => e
  message = version_conflict_message(e)
  raise VersionConflict.new(e.conflicts.keys.uniq, message)
rescue Molinillo::CircularDependencyError => e
  names = e.dependencies.sort_by(&:name).map {|d| "gem '#{d.name}'" }
  raise CyclicDependencyError, "Your bundle requires gems that depend" \
    " on each other, creating an infinite loop. Please remove" \
    " #{names.count > 1 ? "either " : ""}#{names.join(" or ")}" \
    " and try again."
end

# File 'lib/bundler/resolver.rb', line 250

def verify_gemfile_dependencies_are_found!(requirements)
  requirements.each do |requirement|
    name = requirement.name
    next if name == "bundler"
    next unless search_for(requirement).empty?

    if (base = @base[name]) && !base.empty?
      version = base.first.version
      message = "You have requested:\n" \
        "  #{name} #{requirement.requirement}\n\n" \
        "The bundle currently has #{name} locked at #{version}.\n" \
        "Try running `bundle update #{name}`\n\n" \
        "If you are updating multiple gems in your Gemfile at once,\n" \
        "try passing them all to `bundle update`"
    else
      source = source_for(name)
      specs = source.specs.search(name)
      versions_with_platforms = specs.map {|s| [s.version, s.platform] }
      cache_message = begin
                          " or in gems cached in #{Bundler.settings.app_cache_path}" if Bundler.app_cache.exist?
                        rescue GemfileNotFound
                          nil
                        end
      message = String.new("Could not find gem '#{SharedHelpers.pretty_dependency(requirement)}' in #{source}#{cache_message}.\n")
      message << "The source contains the following versions of '#{name}': #{formatted_versions_with_platforms(versions_with_platforms)}" if versions_with_platforms.any?
    end
    raise GemNotFound, message
  end
end

# File 'lib/bundler/resolver.rb', line 291

def version_conflict_message(e)
  # only show essential conflicts, if possible
  conflicts = e.conflicts.dup

  if conflicts["bundler"]
    conflicts.replace("bundler" => conflicts["bundler"])
  else
    conflicts.delete_if do |_name, conflict|
      deps = conflict.requirement_trees.map(&:last).flatten(1)
      !Bundler::VersionRanges.empty?(*Bundler::VersionRanges.for_many(deps.map(&:requirement)))
    end
  end

  e = Molinillo::VersionConflict.new(conflicts, e.specification_provider) unless conflicts.empty?

  solver_name = "Bundler"
  possibility_type = "gem"
  e.message_with_trees(
    :solver_name => solver_name,
    :possibility_type => possibility_type,
    :reduce_trees => lambda do |trees|
      # called first, because we want to reduce the amount of work required to find maximal empty sets
      trees = trees.uniq {|t| t.flatten.map {|dep| [dep.name, dep.requirement] } }

      # bail out if tree size is too big for Array#combination to make any sense
      return trees if trees.size > 15
      maximal = 1.upto(trees.size).map do |size|
        trees.map(&:last).flatten(1).combination(size).to_a
      end.flatten(1).select do |deps|
        Bundler::VersionRanges.empty?(*Bundler::VersionRanges.for_many(deps.map(&:requirement)))
      end.min_by(&:size)

      trees.reject! {|t| !maximal.include?(t.last) } if maximal

      trees.sort_by {|t| t.reverse.map(&:name) }
    end,
    :printable_requirement => lambda {|req| SharedHelpers.pretty_dependency(req) },
    :additional_message_for_conflict => lambda do |o, name, conflict|
      if name == "bundler"
        o << %(\n  Current Bundler version:\n    bundler (#{Bundler::VERSION}))

        conflict_dependency = conflict.requirement
        conflict_requirement = conflict_dependency.requirement
        other_bundler_required = !conflict_requirement.satisfied_by?(Gem::Version.new(Bundler::VERSION))

        if other_bundler_required
          o << "\n\n"

          candidate_specs = source_for(:default_bundler).specs.search(conflict_dependency)
          if candidate_specs.any?
            target_version = candidate_specs.last.version
            new_command = [File.basename($PROGRAM_NAME), "_#{target_version}_", *ARGV].join(" ")
            o << "Your bundle requires a different version of Bundler than the one you're running.\n"
            o << "Install the necessary version with `gem install bundler:#{target_version}` and rerun bundler using `#{new_command}`\n"
          else
            o << "Your bundle requires a different version of Bundler than the one you're running, and that version could not be found.\n"
          end
        end
      elsif conflict.locked_requirement
        o << "\n"
        o << %(Running `bundle update` will rebuild your snapshot from scratch, using only\n)
        o << %(the gems in your Gemfile, which may resolve the conflict.\n)
      elsif !conflict.existing
        o << "\n"

        relevant_source = conflict.requirement.source || source_for(name)

        metadata_requirement = name.end_with?("\0")

        o << "Could not find gem '" unless metadata_requirement
        o << SharedHelpers.pretty_dependency(conflict.requirement)
        o << "'" unless metadata_requirement
        if conflict.requirement_trees.first.size > 1
          o << ", which is required by "
          o << "gem '#{SharedHelpers.pretty_dependency(conflict.requirement_trees.first[-2])}',"
        end
        o << " "

        o << if metadata_requirement
          "is not available in #{relevant_source}"
        else
          "in #{relevant_source}.\n"
        end
      end
    end,
    :version_for_spec => lambda {|spec| spec.version },
    :incompatible_version_message_for_conflict => lambda do |name, _conflict|
      if name.end_with?("\0")
        %(#{solver_name} found conflicting requirements for the #{name} version:)
      else
        %(#{solver_name} could not find compatible versions for #{possibility_type} "#{name}":)
      end
    end
  )
end