#--
# Copyright 2006 by Chad Fowler, Rich Kilmer, Jim Weirich and others.
# All rights reserved.
# See LICENSE.txt for permissions.
#++

require 'rubygems/specification'
require 'rubygems/deprecate'

##
# The SourceIndex object indexes all the gems available from a
# particular source (e.g. a list of gem directories, or a remote
# source).  A SourceIndex maps a gem full name to a gem
# specification.
#
# NOTE:: The class used to be named Cache, but that became
#        confusing when cached source fetchers where introduced. The
#        constant Gem::Cache is an alias for this class to allow old
#        YAMLized source index objects to load properly.

class Gem::SourceIndex

  include Enumerable

  attr_reader :gems # :nodoc:

  ##
  # Directories to use to refresh this SourceIndex when calling refresh!

  attr_accessor :spec_dirs

  ##
  # Factory method to construct a source index instance for a given
  # path.
  #
  # deprecated::
  #   If supplied, from_installed_gems will act just like
  #   +from_gems_in+.  This argument is deprecated and is provided
  #   just for backwards compatibility, and should not generally
  #   be used.
  #
  # return::
  #   SourceIndex instance

  def self.from_installed_gems(*deprecated)
    if deprecated.empty?
      from_gems_in(*installed_spec_directories)
    else
      warn "NOTE: from_installed_gems(arg) is deprecated. From #{caller.first}"
      from_gems_in(*deprecated) # HACK warn
    end
  end

  ##
  # Returns a list of directories from Gem.path that contain specifications.

  def self.installed_spec_directories
    # TODO: move to Gem::Utils
    Gem.path.collect { |dir| File.join(dir, "specifications") }
  end

  ##
  # Creates a new SourceIndex from the ruby format gem specifications in
  # +spec_dirs+.

  def self.from_gems_in(*spec_dirs)
    new spec_dirs
  end

  ##
  # Loads a ruby-format specification from +file_name+ and returns the
  # loaded spec.

  def self.load_specification(file_name)
    Gem::Deprecate.skip_during do
      Gem::Specification.load Gem::Path.new(file_name)
    end
  end

  ##
  # Constructs a source index instance from the provided specifications, which
  # is a Hash of gem full names and Gem::Specifications.

  def initialize specs_or_dirs = []
    @gems = {}
    @spec_dirs = nil

    case specs_or_dirs
    when Hash then
      specs_or_dirs.each do |full_name, spec|
        add_spec spec
      end
    when Array, String then
      self.spec_dirs = Array(specs_or_dirs)
      refresh!
    else
      arg = specs_or_dirs.inspect
      warn "NOTE: SourceIndex.new(#{arg}) is deprecated; From #{caller.first}."
    end
  end

  def all_gems
    gems
  end

  def prerelease_gems
    @gems.reject { |name, gem| !gem.version.prerelease? }
  end

  def released_gems
    @gems.reject { |name, gem| gem.version.prerelease? }
  end

  ##
  # Reconstruct the source index from the specifications in +spec_dirs+.

  def load_gems_in(*spec_dirs)
    @gems.clear

    spec_dirs.reverse_each do |spec_dir|
      spec_files = Dir[File.join(spec_dir, "*.gemspec")]

      spec_files.each do |spec_file|
        gemspec = Gem::Deprecate.skip_during do
          Gem::Specification.load spec_file
        end
        add_spec gemspec if gemspec
      end
    end

    self
  end

  ##
  # Returns an Array specifications for the latest released versions
  # of each gem in this index.

  def latest_specs(include_prerelease=false)
    result = Hash.new { |h,k| h[k] = [] }
    latest = {}

    sort.each do |_, spec|
      name = spec.name
      curr_ver = spec.version
      prev_ver = latest.key?(name) ? latest[name].version : nil

      next if !include_prerelease && curr_ver.prerelease?
      next unless prev_ver.nil? or curr_ver >= prev_ver or
                  latest[name].platform != Gem::Platform::RUBY

      if prev_ver.nil? or
         (curr_ver > prev_ver and spec.platform == Gem::Platform::RUBY) then
        result[name].clear
        latest[name] = spec
      end

      if spec.platform != Gem::Platform::RUBY then
        result[name].delete_if do |result_spec|
          result_spec.platform == spec.platform
        end
      end

      result[name] << spec
    end

    result.values.flatten
  end

  ##
  # An array including only the prerelease gemspecs

  def prerelease_specs
    prerelease_gems.values
  end

  ##
  # An array including only the released gemspecs

  def released_specs
    released_gems.values
  end

  ##
  # Add a gem specification to the source index.

  def add_spec(gem_spec, name = gem_spec.full_name)
    # No idea why, but the Indexer wants to insert them using original_name
    # instead of full_name. So we make it an optional arg.
    @gems[name] = gem_spec
  end

  ##
  # Add gem specifications to the source index.

  def add_specs(*gem_specs)
    Gem::Deprecate.skip_during do
      gem_specs.each do |spec|
        add_spec spec
      end
    end
  end

  ##
  # Remove a gem specification named +full_name+.

  def remove_spec(full_name)
    @gems.delete full_name
  end

  ##
  # Iterate over the specifications in the source index.

  def each(&block) # :yields: gem.full_name, gem
    @gems.each(&block)
  end

  ##
  # The gem specification given a full gem spec name.

  def specification(full_name)
    @gems[full_name]
  end

  ##
  # The signature for the source index.  Changes in the signature indicate a
  # change in the index.

  def index_signature
    require 'digest'

    Digest::SHA256.new.hexdigest(@gems.keys.sort.join(',')).to_s
  end

  ##
  # The signature for the given gem specification.

  def gem_signature(gem_full_name)
    require 'digest'

    Digest::SHA256.new.hexdigest(@gems[gem_full_name].to_yaml).to_s
  end

  def size
    @gems.size
  end
  alias length size

  ##
  # Find a gem by an exact match on the short name.

  def find_name(gem_name, requirement = Gem::Requirement.default)
    dep = Gem::Dependency.new gem_name, requirement

    Gem::Deprecate.skip_during do
      search dep
    end
  end

  ##
  # Search for a gem by Gem::Dependency +gem_pattern+.  If +only_platform+
  # is true, only gems matching Gem::Platform.local will be returned.  An
  # Array of matching Gem::Specification objects is returned.
  #
  # For backwards compatibility, a String or Regexp pattern may be passed as
  # +gem_pattern+, and a Gem::Requirement for +platform_only+.  This
  # behavior is deprecated and will be removed.

  def search(gem_pattern, platform_or_requirement = false)
    requirement = nil
    only_platform = false # FIX: WTF is this?!?

    # TODO - Remove support and warning for legacy arguments after 2008/11
    unless Gem::Dependency === gem_pattern
      warn "#{Gem.location_of_caller.join ':'}:Warning: Gem::SourceIndex#search support for #{gem_pattern.class} patterns is deprecated, use #find_name"
    end

    case gem_pattern
    when Regexp then
      requirement = platform_or_requirement || Gem::Requirement.default
    when Gem::Dependency then
      only_platform = platform_or_requirement
      requirement = gem_pattern.requirement

      gem_pattern = if Regexp === gem_pattern.name then
                      gem_pattern.name
                    elsif gem_pattern.name.empty? then
                      //
                    else
                      /^#{Regexp.escape gem_pattern.name}$/
                    end
    else
      requirement = platform_or_requirement || Gem::Requirement.default
      gem_pattern = /#{gem_pattern}/i
    end

    unless Gem::Requirement === requirement then
      requirement = Gem::Requirement.create requirement
    end

    specs = @gems.values.select do |spec|
      spec.name =~ gem_pattern and
        requirement.satisfied_by? spec.version
    end

    if only_platform then
      specs = specs.select do |spec|
        Gem::Platform.match spec.platform
      end
    end

    specs.sort_by { |s| s.sort_obj }
  end

  ##
  # Replaces the gems in the source index from specifications in the
  # directories this source index was created from.  Raises an exception if
  # this source index wasn't created from a directory (via from_gems_in or
  # from_installed_gems, or having spec_dirs set).

  def refresh!
    raise 'source index not created from disk' if @spec_dirs.nil?
    load_gems_in(*@spec_dirs)
  end

  ##
  # Returns an Array of Gem::Specifications that are not up to date.

  def outdated
    outdateds = []

    latest_specs.each do |local|
      dependency = Gem::Dependency.new local.name, ">= #{local.version}"

      fetcher = Gem::SpecFetcher.fetcher
      remotes = fetcher.find_matching dependency
      remotes = remotes.map { |(_, version, _), _| version }

      latest = remotes.sort.last

      outdateds << local.name if latest and local.version < latest
    end

    outdateds
  end

  def ==(other) # :nodoc:
    self.class === other and @gems == other.gems
  end

  def dump
    Marshal.dump(self)
  end
end

# :stopdoc:
module Gem

  ##
  # Cache is an alias for SourceIndex to allow older YAMLized source index
  # objects to load properly.

  Cache = SourceIndex

end

class Gem::SourceIndex
  extend Gem::Deprecate

  deprecate :all_gems,         :none,                        2011, 10

  deprecate :==,               :none,                        2011, 11 # noisy
  deprecate :add_specs,        :none,                        2011, 11 # noisy
  deprecate :each,             :none,                        2011, 11
  deprecate :gems,             :none,                        2011, 11
  deprecate :load_gems_in,     :none,                        2011, 11
  deprecate :refresh!,         :none,                        2011, 11
  deprecate :spec_dirs=,       "Specification.dirs=",        2011, 11 # noisy
  deprecate :add_spec,         "Specification.add_spec",     2011, 11
  deprecate :find_name,        "Specification.find_by_name", 2011, 11
  deprecate :gem_signature,    :none,                        2011, 11
  deprecate :index_signature,  :none,                        2011, 11
  deprecate :initialize,       :none,                        2011, 11
  deprecate :latest_specs,     "Specification.latest_specs", 2011, 11
  deprecate :length,           "Specification.all.length",   2011, 11
  deprecate :outdated,         :none,                        2011, 11
  deprecate :prerelease_gems,  :none,                        2011, 11
  deprecate :prerelease_specs, :none,                        2011, 11
  deprecate :released_gems,    :none,                        2011, 11
  deprecate :released_specs,   :none,                        2011, 11
  deprecate :remove_spec,      "Specification.remove_spec",  2011, 11
  deprecate :search,           :none,                        2011, 11
  deprecate :size,             "Specification.all.size",     2011, 11
  deprecate :spec_dirs,        "Specification.dirs",         2011, 11
  deprecate :specification,    "Specification.find",         2011, 11

  class << self
    extend Gem::Deprecate

    deprecate :from_gems_in,               :none,                2011, 10
    deprecate :from_installed_gems,        :none,                2011, 10
    deprecate :installed_spec_directories, "Specification.dirs", 2011, 11
    deprecate :load_specification,         :none,                2011, 10
  end
end

# :startdoc: