module Maven
  module Tools
    class Gemify

      BASE_GOAL = "de.saumya.mojo:gemify-maven-plugin:0.22.0"

      require 'java'

      bin = nil
      if ENV['M2_HOME'] # use M2_HOME if set
        bin = File.join(ENV['M2_HOME'], "bin")
      else
        ENV['PATH'].split(java.lang.System.getProperty("path.separator")).detect do |path|
          mvn = File.join(path, "mvn")
          if File.exists?(mvn)
            if File.symlink?(mvn)
              link = File.readlink(mvn)
              if link =~ /^\// # is absolute path
                bin = File.dirname(File.expand_path(link))
              else # is relative path so join with dir of the maven command
                bin = File.dirname(File.expand_path(File.join(File.dirname(mvn), link)))
              end
            else # is no link so just expand it
              bin = File.expand_path(path)
            end
          else
            nil
          end
        end
      end
      bin = "/usr/share/maven2/bin" if bin.nil? # OK let's try debian default
      if File.exists?(bin) &&
          Dir.glob(File.join(bin, "..", "lib", "maven-core-3.*jar")).size == 0
        begin
          gem 'ruby-maven', ">=0"
          bin = File.dirname(Gem.bin_path('ruby-maven', "rmvn"))
        rescue LoadError
          bin = nil
        end
      end
      raise "can not find maven3 installation. install ruby-maven with\n\n\tjruby -S gem install ruby-maven --pre\n\n" if bin.nil?
      warn "using #{bin}"
      boot = File.join(bin, "..", "boot")
      lib = File.join(bin, "..", "lib")
      ext = File.join(bin, "..", "ext")
      classpath = (Dir.glob(lib + "/*jar")  + Dir.glob(boot + "/*jar"))

      java.lang.System.setProperty("classworlds.conf", File.join(bin, "m2.conf"))

      java.lang.System.setProperty("maven.home", File.join(bin, ".."))
      classpath.each do |path|
        require path
      end

      private

      def self.create_maven
        puts "create maven instance"

        import "org.codehaus.plexus.classworlds"
        classWorld = ClassWorld.new("plexus.core", java.lang.Thread.currentThread().getContextClassLoader());
        config = org.codehaus.plexus.DefaultContainerConfiguration.new
        config.setClassWorld(classWorld)
        config.setName("ruby-tools")
        container = org.codehaus.plexus.DefaultPlexusContainer.new(config);
        container.lookup(org.apache.maven.Maven.java_class)
      end

      def self.maven
        @maven ||= create_maven
      end

      def self.temp_dir
        @temp_dir ||=
          begin
            f = java.io.File.createTempFile("gemify", "")
            f.delete
            f.mkdir
            f.deleteOnExit
            f.absolute_path
          end
      end

      def self.execute(goal, gemname, version, props = {})
        r = org.apache.maven.execution.DefaultMavenExecutionRequest.new
        r.setShowErrors( true )
        r.getUserProperties.put("gemify.skipDependencies", "true")
        r.getUserProperties.put("gemify.tempDir", temp_dir)
        r.getUserProperties.put("gemify.gemname", gemname)
        r.getUserProperties.put("gemify.version", version.to_s) if version
        props.each do |k,v|
          r.getUserProperties.put(k.to_s, v.to_s)
        end
        r.setGoals( [goal] )
        r.setLoggingLevel(0)

#p r.goals.to_s
#p r.getUserProperties.map
        out = java.lang.System.out
        string_io = java.io.ByteArrayOutputStream.new
        java.lang.System.setOut(java.io.PrintStream.new(string_io))
        result = maven.execute( r );
        java.lang.System.setOut(out)
        result.getExceptions.each { |e| e.printStackTrace }
        string_io.to_s
      end

      public

      def self.get_versions(gemname)
#        p "versions"
#        p gemname
        result = execute("#{BASE_GOAL}:versions", gemname, nil)

        result.gsub(/\n/, '').sub(/.*\[/, "").sub(/\]/, '').gsub(/ /, '').split(',')
      end

      def self.generate_spec(gemname, version)
    #     puts "generate spec"
    #     p gemname
    #     p version
        result = execute("#{BASE_GOAL}:gemify", gemname, version, {"gemify.onlySpecs" => true })
        path = result.gsub(/\n/, '')
        if path =~ /gemspec: /
          path = path.sub(/.*gemspec: /, '')
          if path.size > 0
            result = File.expand_path(path)
            java.io.File.new(result).deleteOnExit
            result
          end
        end
      end

      def self.generate_gem(gemname, version)
    #    p "generate gem"
    #    p gemname
    #    p version.to_s

        result = execute("#{BASE_GOAL}:gemify", gemname, version)
        path = result.gsub(/\n/, '')
        if path =~ /gem: /

          path = path.sub(/.*gem: /, '')
          if path.size > 0
            result = File.expand_path(path)
            java.io.File.new(result).deleteOnExit
            result
          end
        end
      end
    end
  end
end