class Bundler::Resolver

# File lib/bundler/resolver.rb, line 26
def initialize(index, source_requirements, base, gem_version_promoter, additional_base_requirements, platforms)
  @index = index
  @source_requirements = source_requirements
  @base = base
  @resolver = Molinillo::Resolver.new(self, self)
  @search_for = {}
  @base_dg = Molinillo::DependencyGraph.new
  @base.each do |ls|
    dep = Dependency.new(ls.name, ls.version)
    @base_dg.add_vertex(ls.name, DepProxy.new(dep, ls.platform), true)
  end
  additional_base_requirements.each {|d| @base_dg.add_vertex(d.name, d) }
  @platforms = platforms
  @gem_version_promoter = gem_version_promoter
  @allow_bundler_dependency_conflicts = Bundler.feature_flag.allow_bundler_dependency_conflicts?
  @lockfile_uses_separate_rubygems_sources = Bundler.feature_flag.lockfile_uses_separate_rubygems_sources?
  @use_gvp = Bundler.feature_flag.use_gem_version_promoter_for_major_updates? || !@gem_version_promoter.major?
end

# File lib/bundler/resolver.rb, line 222
def self.platform_sort_key(platform)
  return ["", "", ""] if Gem::Platform::RUBY == platform
  platform.to_a.map {|part| part || "" }
end

# File lib/bundler/resolver.rb, line 18
def self.resolve(requirements, index, source_requirements = {}, base = [], gem_version_promoter = GemVersionPromoter.new, additional_base_requirements = [], platforms = nil)
  platforms = Set.new(platforms) if platforms
  base = SpecSet.new(base) unless base.is_a?(SpecSet)
  resolver = new(index, source_requirements, base, gem_version_promoter, additional_base_requirements, platforms)
  result = resolver.start(requirements)
  SpecSet.new(result)
end

# File lib/bundler/resolver.rb, line 216
def self.sort_platforms(platforms)
  platforms.sort_by do |platform|
    platform_sort_key(platform)
  end
end

# File lib/bundler/resolver.rb, line 87
def after_resolution
  Bundler.ui.info ""
end

# File lib/bundler/resolver.rb, line 83
def before_resolution
  Bundler.ui.info "Resolving dependencies...", debug?
end

# File lib/bundler/resolver.rb, line 71
def debug(depth = 0)
  return unless debug?
  debug_info = yield
  debug_info = debug_info.inspect unless debug_info.is_a?(String)
  STDERR.puts debug_info.split("\n").map {|s| "  " * depth + s }
end

# File lib/bundler/resolver.rb, line 78
def debug?
  return @debug_mode if defined?(@debug_mode)
  @debug_mode = ENV["DEBUG_RESOLVER"] || ENV["DEBUG_RESOLVER_TREE"] || false
end

# File lib/bundler/resolver.rb, line 97
def dependencies_for(specification)
  specification.dependencies_for_activated_platforms
end

# File lib/bundler/resolver.rb, line 149
def index_for(dependency)
  source = @source_requirements[dependency.name]
  if source
    source.specs
  elsif @lockfile_uses_separate_rubygems_sources
    Index.build do |idx|
      if dependency.all_sources
        dependency.all_sources.each {|s| idx.add_source(s.specs) if s }
      else
        idx.add_source @source_requirements[:default].specs
      end
    end
  else
    @index
  end
end

# File lib/bundler/resolver.rb, line 91
def indicate_progress
  Bundler.ui.info ".", false unless debug?
end

# File lib/bundler/resolver.rb, line 166
def name_for(dependency)
  dependency.name
end

# File lib/bundler/resolver.rb, line 170
def name_for_explicit_dependency_source
  Bundler.default_gemfile.basename.to_s
rescue
  "Gemfile"
end

# File lib/bundler/resolver.rb, line 176
def name_for_locking_dependency_source
  Bundler.default_lockfile.basename.to_s
rescue
  "Gemfile.lock"
end

# File lib/bundler/resolver.rb, line 188
def relevant_sources_for_vertex(vertex)
  if vertex.root?
    [@source_requirements[vertex.name]]
  elsif @lockfile_uses_separate_rubygems_sources
    vertex.recursive_predecessors.map do |v|
      @source_requirements[v.name]
    end << @source_requirements[:default]
  end
end

# File lib/bundler/resolver.rb, line 182
def requirement_satisfied_by?(requirement, activated, spec)
  return false unless requirement.matches_spec?(spec) || spec.source.is_a?(Source::Gemspec)
  spec.activate_platform!(requirement.__platform) if !@platforms || @platforms.include?(requirement.__platform)
  true
end

# File lib/bundler/resolver.rb, line 101
def search_for(dependency)
  platform = dependency.__platform
  dependency = dependency.dep unless dependency.is_a? Gem::Dependency
  search = @search_for[dependency] ||= begin
    index = index_for(dependency)
    results = index.search(dependency, @base[dependency.name])

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

    if !@prerelease_specified[dependency.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)
        spec_group = SpecGroup.new(specs)
        spec_group.ignores_bundler_dependencies = @allow_bundler_dependency_conflicts
        groups << spec_group
      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
  search.select {|sg| sg.for?(platform) }.each {|sg| sg.activate_platform!(platform) }
end

# File lib/bundler/resolver.rb, line 198
def sort_dependencies(dependencies, activated, conflicts)
  dependencies.sort_by do |dependency|
    dependency.all_sources = relevant_sources_for_vertex(activated.vertex_named(dependency.name))
    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 45
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 235
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 291
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 254
def verify_gemfile_dependencies_are_found!(requirements)
  requirements.each do |requirement|
    name = requirement.name
    next if name == "bundler"
    next unless search_for(requirement).empty?

    cache_message = begin
                        " or in gems cached in #{Bundler.settings.app_cache_path}" if Bundler.app_cache.exist?
                      rescue GemfileNotFound
                        nil
                      end

    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`"
    elsif source = @source_requirements[name]
      specs = source.specs[name]
      versions_with_platforms = specs.map {|s| [s.version, s.platform] }
      message = String.new("Could not find gem '#{SharedHelpers.pretty_dependency(requirement)}' in #{source}#{cache_message}.\n")
      message << if versions_with_platforms.any?
                   "The source contains '#{name}' at: #{formatted_versions_with_platforms(versions_with_platforms)}"
                 else
                   "The source does not contain any versions of '#{name}'"
                 end
    else
      message = "Could not find gem '#{requirement}' in any of the gem sources " \
        "listed in your Gemfile#{cache_message}."
    end
    raise GemNotFound, message
  end
end

# File lib/bundler/resolver.rb, line 302
def version_conflict_message(e)
  e.message_with_trees(
    :solver_name => "Bundler",
    :possibility_type => "gem",
    :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 = trees.sort_by {|t| t.flatten.map(&:to_s) }
      trees.uniq! {|t| t.flatten.map {|dep| [dep.name, dep.requirement] } }

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

      if name == "bundler" && other_bundler_required
        o << "\n"
        o << "This Gemfile requires a different version of Bundler.\n"
        o << "Perhaps you need to update Bundler by running `gem install bundler`?\n"
      end
      if 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_sources = if conflict.requirement.source
          [conflict.requirement.source]
        elsif conflict.requirement.all_sources
          conflict.requirement.all_sources
        elsif @lockfile_uses_separate_rubygems_sources
          # every conflict should have an explicit group of sources when we
          # enforce strict pinning
          raise "no source set for #{conflict}"
        else
          []
        end.compact.map(&:to_s).uniq.sort

        o << "Could not find gem '#{SharedHelpers.pretty_dependency(conflict.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 relevant_sources.empty?
               "in any of the sources.\n"
             else
               "in any of the relevant sources:\n  #{relevant_sources * "\n  "}\n"
             end
      end
    end,
    :version_for_spec => lambda {|spec| spec.version }
  )
end