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

require 'find'

require 'rubygems/digest/md5'
require 'rubygems/format'
require 'rubygems/installer'

module Gem

  ##
  # Validator performs various gem file and gem database validation
  class Validator
    include UserInteraction

    ##
    # Given a gem file's contents, validates against its own MD5 checksum
    # gem_data:: [String] Contents of the gem file
    def verify_gem(gem_data)
      raise VerificationError, 'empty gem file' if gem_data.size == 0

      unless gem_data =~ /MD5SUM/ then
        return # Don't worry about it...this sucks.  Need to fix MD5 stuff for
               # new format
               # FIXME
      end

      sum_data = gem_data.gsub(/MD5SUM = "([a-z0-9]+)"/,
                               "MD5SUM = \"#{"F" * 32}\"")

      unless Gem::MD5.hexdigest(sum_data) == $1.to_s then
        raise VerificationError, 'invalid checksum for gem file'
      end
    end

    ##
    # Given the path to a gem file, validates against its own MD5 checksum
    # 
    # gem_path:: [String] Path to gem file
    def verify_gem_file(gem_path)
      File.open gem_path, 'rb' do |file|
        gem_data = file.read
        verify_gem gem_data
      end
    rescue Errno::ENOENT
      raise Gem::VerificationError.new("missing gem file #{gem_path}")
    end

    private
    def find_files_for_gem(gem_directory)
      installed_files = []
      Find.find(gem_directory) {|file_name|
        fn = file_name.slice((gem_directory.size)..(file_name.size-1)).sub(/^\//, "")
        if(!(fn =~ /CVS/ || File.directory?(fn) || fn == "")) then 
          installed_files << fn
        end
        
      }
      installed_files
    end
 

    public 
    ErrorData = Struct.new(:path, :problem)

    ##
    # Checks the gem directory for the following potential 
    # inconsistencies/problems:
    # * Checksum gem itself
    # * For each file in each gem, check consistency of installed versions
    # * Check for files that aren't part of the gem but are in the gems directory
    # * 1 cache - 1 spec - 1 directory.  
    # 
    # returns a hash of ErrorData objects, keyed on the problem gem's name.
    def alien
      errors = {}
      Gem::SourceIndex.from_installed_gems.each do |gem_name, gem_spec|
        errors[gem_name] ||= []
        gem_path = File.join(Gem.dir, "cache", gem_spec.full_name) + ".gem"
        spec_path = File.join(Gem.dir, "specifications", gem_spec.full_name) + ".gemspec"
        gem_directory = File.join(Gem.dir, "gems", gem_spec.full_name)
        installed_files = find_files_for_gem(gem_directory)
    
        if(!File.exist?(spec_path)) then
          errors[gem_name] << ErrorData.new(spec_path, "Spec file doesn't exist for installed gem")
        end
    
        begin
          verify_gem_file(gem_path)
          File.open(gem_path, 'rb') do |file|
            format = Gem::Format.from_file_by_path(gem_path)
            format.file_entries.each do |entry, data|
              # Found this file.  Delete it from list
              installed_files.delete remove_leading_dot_dir(entry['path'])

              next unless data # HACK `gem check -a mkrf`

              File.open(File.join(gem_directory, entry['path']), 'rb') do |f|
                unless Gem::MD5.hexdigest(f.read).to_s ==
                       Gem::MD5.hexdigest(data).to_s then
                  errors[gem_name] << ErrorData.new(entry['path'], "installed file doesn't match original from gem")
                end
              end
            end
          end
        rescue VerificationError => e
          errors[gem_name] << ErrorData.new(gem_path, e.message)
        end
        # Clean out directories that weren't explicitly included in the gemspec
        # FIXME: This still allows arbitrary incorrect directories.
        installed_files.delete_if {|potential_directory|        
          File.directory?(File.join(gem_directory, potential_directory))
        }
        if(installed_files.size > 0) then
          errors[gem_name] << ErrorData.new(gem_path, "Unmanaged files in gem: #{installed_files.inspect}")
        end
      end
      errors
    end

    class TestRunner
      def initialize(suite, ui)
        @suite = suite
        @ui = ui
      end

      def self.run(suite, ui)
        require 'test/unit/ui/testrunnermediator'
        return new(suite, ui).start
      end

      def start
        @mediator = Test::Unit::UI::TestRunnerMediator.new(@suite)
        @mediator.add_listener(Test::Unit::TestResult::FAULT, &method(:add_fault))
        return @mediator.run_suite
      end

      def add_fault(fault)
        if Gem.configuration.verbose then
          @ui.say fault.long_display
        end
      end
    end

    autoload :TestRunner, 'test/unit/ui/testrunnerutilities'
   
    ##
    # Runs unit tests for a given gem specification
    def unit_test(gem_spec)
     start_dir = Dir.pwd
     Dir.chdir(gem_spec.full_gem_path)
      $: << File.join(Gem.dir, "gems", gem_spec.full_name)
        # XXX: why do we need this gem_spec when we've already got 'spec'?
      test_files = gem_spec.test_files
      if test_files.empty?
        say "There are no unit tests to run for #{gem_spec.full_name}"
        require 'test/unit/ui/console/testrunner'
        return Test::Unit::TestResult.new
      end
      gem gem_spec.name, "= #{gem_spec.version.version}"
      test_files.each do |f| require f end
      suite = Test::Unit::TestSuite.new("#{gem_spec.name}-#{gem_spec.version}")
      ObjectSpace.each_object(Class) do |klass|
        suite << klass.suite if (klass < Test::Unit::TestCase)
      end
      result = TestRunner.run(suite, ui())
      unless result.passed?
        alert_error(result.to_s)
        #unless ask_yes_no(result.to_s + "...keep Gem?", true) then
          #Gem::Uninstaller.new(gem_spec.name, gem_spec.version.version).uninstall
        #end
      end
      result
    ensure
      Dir.chdir(start_dir)
    end

    def remove_leading_dot_dir(path)
      path.sub(/^\.\//, "")
    end
  end
end