require 'rubygems/command'
require 'rubygems/local_remote_options'
require 'rubygems/spec_fetcher'
require 'rubygems/version_option'
require 'rubygems/text'

class Gem::Commands::QueryCommand < Gem::Command

  include Gem::Text
  include Gem::LocalRemoteOptions
  include Gem::VersionOption

  def initialize(name = 'query',
                 summary = 'Query gem information in local or remote repositories')
    super name, summary,
         :name => //, :domain => :local, :details => false, :versions => true,
         :installed => false, :version => Gem::Requirement.default

    add_option('-i', '--[no-]installed',
               'Check for installed gem') do |value, options|
      options[:installed] = value
    end

    add_option('-I', 'Equivalent to --no-installed') do |value, options|
      options[:installed] = false
    end

    add_version_option command, "for use with --installed"

    add_option('-n', '--name-matches REGEXP',
               'Name of gem(s) to query on matches the',
               'provided REGEXP') do |value, options|
      options[:name] = /#{value}/i
    end

    add_option('-d', '--[no-]details',
               'Display detailed information of gem(s)') do |value, options|
      options[:details] = value
    end

    add_option(      '--[no-]versions',
               'Display only gem names') do |value, options|
      options[:versions] = value
      options[:details] = false unless value
    end

    add_option('-a', '--all',
               'Display all gem versions') do |value, options|
      options[:all] = value
    end

    add_option(      '--[no-]prerelease',
               'Display prerelease versions') do |value, options|
      options[:prerelease] = value
    end

    add_local_remote_options
  end

  def defaults_str # :nodoc:
    "--local --name-matches // --no-details --versions --no-installed"
  end

  def execute
    exit_code = 0

    name = options[:name]
    prerelease = options[:prerelease]

    if options[:installed] then
      if name.source.empty? then
        alert_error "You must specify a gem name"
        exit_code |= 4
      elsif installed? name, options[:version] then
        say "true"
      else
        say "false"
        exit_code |= 1
      end

      terminate_interaction exit_code
    end

    req = Gem::Requirement.default
    # TODO: deprecate for real
    dep = Gem::Deprecate.skip_during { Gem::Dependency.new name, req }
    dep.prerelease = prerelease

    if local? then
      if prerelease and not both? then
        alert_warning "prereleases are always shown locally"
      end

      if ui.outs.tty? or both? then
        say
        say "*** LOCAL GEMS ***"
        say
      end

      specs = Gem::Specification.find_all { |s|
        s.name =~ name and req =~ s.version
      }

      spec_tuples = specs.map do |spec|
        [spec.name_tuple, spec]
      end

      output_query_results spec_tuples
    end

    if remote? then
      if ui.outs.tty? or both? then
        say
        say "*** REMOTE GEMS ***"
        say
      end

      fetcher = Gem::SpecFetcher.fetcher

      type = if options[:all]
               if options[:prerelease]
                 :complete
               else
                 :released
               end
             elsif options[:prerelease]
               :prerelease
             else
               :latest
             end

      if options[:name].source.empty?
        spec_tuples = fetcher.detect(type) { true }
      else
        spec_tuples = fetcher.detect(type) do |name_tuple|
          options[:name] === name_tuple.name
        end
      end

      output_query_results spec_tuples
    end
  end

  private

  ##
  # Check if gem +name+ version +version+ is installed.

  def installed?(name, req = Gem::Requirement.default)
    Gem::Specification.any? { |s| s.name =~ name and req =~ s.version }
  end

  def output_query_results(spec_tuples)
    output = []
    versions = Hash.new { |h,name| h[name] = [] }

    spec_tuples.each do |spec_tuple, source|
      versions[spec_tuple.name] << [spec_tuple, source]
    end

    versions = versions.sort_by do |(n,_),_|
      n.downcase
    end

    output_versions output, versions

    say output.join(options[:details] ? "\n\n" : "\n")
  end

  def output_versions output, versions
    versions.each do |gem_name, matching_tuples|
      matching_tuples = matching_tuples.sort_by { |n,_| n.version }.reverse

      platforms = Hash.new { |h,version| h[version] = [] }

      matching_tuples.each do |n, _|
        platforms[n.version] << n.platform if n.platform
      end

      seen = {}

      matching_tuples.delete_if do |n,_|
        if seen[n.version] then
          true
        else
          seen[n.version] = true
          false
        end
      end

      output << make_entry(matching_tuples, platforms)
    end
  end

  def entry_details entry, detail_tuple, specs, platforms
    return unless options[:details]

    name_tuple, spec = detail_tuple

    spec = spec.fetch_spec name_tuple unless Gem::Specification === spec

    entry << "\n"

    spec_platforms   entry, platforms
    spec_authors     entry, spec
    spec_homepage    entry, spec
    spec_license     entry, spec
    spec_loaded_from entry, spec, specs
    spec_summary     entry, spec
  end

  def entry_versions entry, name_tuples, platforms
    return unless options[:versions]

    list =
      if platforms.empty? or options[:details] then
        name_tuples.map { |n| n.version }.uniq
      else
        platforms.sort.reverse.map do |version, pls|
          if pls == [Gem::Platform::RUBY] then
            version
          else
            ruby = pls.delete Gem::Platform::RUBY
            platform_list = [ruby, *pls.sort].compact
            "#{version} #{platform_list.join ' '}"
          end
        end
      end

    entry << " (#{list.join ', '})"
  end

  def make_entry entry_tuples, platforms
    detail_tuple = entry_tuples.first

    name_tuples, specs = entry_tuples.flatten.partition do |item|
      Gem::NameTuple === item
    end

    entry = [name_tuples.first.name]

    entry_versions entry, name_tuples, platforms
    entry_details  entry, detail_tuple, specs, platforms

    entry.join
  end

  def spec_authors entry, spec
    authors = "Author#{spec.authors.length > 1 ? 's' : ''}: "
    authors << spec.authors.join(', ')
    entry << format_text(authors, 68, 4)
  end

  def spec_homepage entry, spec
    return if spec.homepage.nil? or spec.homepage.empty?

    entry << "\n" << format_text("Homepage: #{spec.homepage}", 68, 4)
  end

  def spec_license entry, spec
    return if spec.license.nil? or spec.license.empty?

    licenses = "License#{spec.licenses.length > 1 ? 's' : ''}: "
    licenses << spec.licenses.join(', ')
    entry << "\n" << format_text(licenses, 68, 4)
  end

  def spec_loaded_from entry, spec, specs
    return unless spec.loaded_from

    if specs.length == 1 then
      default = spec.default_gem? ? ' (default)' : nil
      entry << "\n" << "    Installed at#{default}: #{spec.base_dir}"
    else
      label = 'Installed at'
      specs.each do |s|
        version = s.version.to_s
        version << ', default' if s.default_gem?
        entry << "\n" << "    #{label} (#{version}): #{s.base_dir}"
        label = ' ' * label.length
      end
    end
  end

  def spec_platforms entry, platforms
    non_ruby = platforms.any? do |_, pls|
      pls.any? { |pl| pl != Gem::Platform::RUBY }
    end

    return unless non_ruby

    if platforms.length == 1 then
      title = platforms.values.length == 1 ? 'Platform' : 'Platforms'
      entry << "    #{title}: #{platforms.values.sort.join ', '}\n"
    else
      entry << "    Platforms:\n"
      platforms.sort_by do |version,|
        version
      end.each do |version, pls|
        label = "        #{version}: "
        data = format_text pls.sort.join(', '), 68, label.length
        data[0, label.length] = label
        entry << data << "\n"
      end
    end
  end

  def spec_summary entry, spec
    entry << "\n\n" << format_text(spec.summary, 68, 4)
  end

end