require "zip/zip"
require "zip/zipfilesystem"


module Buildr

  # The ZipTask creates a new ZIP file. You can include any number of files and
  # and directories, use exclusion patterns, and include files into specific
  # directories.
  class ZipTask < Rake::FileTask

    def initialize(*args)
      super
      @paths = {}
      enhance do |task|
        verbose { puts "Creating #{task.name}" }
        # We're here because the Zip file does not exist, or one of the files is
        # newer than the Zip contents; in the later case, opening the Zip file
        # will add to its contents instead of replacing it, so we want the Zip
        # gone before we change it. We also don't want to see any partial updates.
        rm task.name, :verbose=>false rescue nil
        mkpath File.dirname(task.name), :verbose=>false
        begin
          Zip::ZipFile.open(task.name, Zip::ZipFile::CREATE) { |zip| create zip }
        rescue
          rm task.name, :verbose=>false rescue nil
          raise
        end
      end
    end

    # Include the specified files and directories. Returns self.
    #
    # You can specify a path for inclusion by passing :path=> as the
    # last argument. For example:
    #   task.include "src"  # Include the src directory
    #   task.include foobar, :path=>"libs"  # Include under /libs/
    def include(*files)
      if Hash === files.last
        path = files.pop[:path]
      end
      (@paths[path] ||= FileList[]).include *files
      self
    end
    alias :add :include

    # Excludes the specified files and directories. Returns self. Use this
    # in combination with include; make sure to use the same path.
    def exclude(*files)
      if Hash === files.last
        path = files.pop[:path]
      end
      (@paths[path] ||= FileList[]).exclude *files
      self
    end

    # Returns a path to which you can include/exclude files.
    #
    #   zip(..).include("foo", :path=>"bar")
    # is equivalen to:
    #   zip(..).path("bar").include("foo")
    def path(path)
      @paths[path] ||= FileList[]
    end

    # Pass options to the task. Returns self.
    def with(options)
      options.each do |key, value|
        self[key] = value
      end
      self
    end

    def []=(key, value)
      fail "#{self.class} does not support the attribute #{key}"
    end
    
    def invoke_prerequisites()
      super
      @paths.each { |p, files| artifacts(*files).each { |f| file(f).invoke } }
    end

    def needed?()
      # You can do something like:
      #   include("foo", :path=>"foo").exclude("foo/bar", path=>"foo").
      #     include("foo/bar", :path=>"foo/bar")
      # This will play havoc if we handled all the prerequisites together
      # under the task, so instead we handle them individually for each path.
      #@paths.collect{ |p, files| files }.flatten.each { |f| file(f).invoke }
      return true unless File.exist?(name)
      # We need to check that any file we include is not newer than the
      # contents of the ZIP. The file itself but also the directory it's
      # coming from, since some tasks touch the directory, e.g. when the
      # content of target/classes is included into a WAR.
      files = @paths.collect { |path, files| files.map(&:to_s) }.flatten
      files = files.collect { |f| File.directory?(f) ? FileList[File.join(f, "**", "*")].collect | [f] : f }.flatten
      most_recent = files.select { |f| File.exist?(f) }.collect { |f| File.stat(f).mtime }.max
      File.stat(name).mtime < (most_recent || Rake::EARLY)
    end

  protected

    def create(zip)
      zip_map.keys.sort.each do |path|
        puts "Adding #{path}" if Rake.application.options.trace
        zip.add path, zip_map[path]
      end
    end

    def zip_map()
      unless @zip_map
        args = @paths.collect do |path, files|
          if path
            dest_for = proc { |f| File.join(path, f) }
          else
            dest_for = proc { |f| f }
          end
          artifacts(*files).map(&:to_s).collect do |file|
            if File.directory?(file)
              # Include all files inside the directory, with path starting
              # from the directory itself.
              prefix = File.dirname(file) + File::SEPARATOR
              Dir[File.join(file, "**", "*")].sort.
                reject { |file| File.directory?(file) || files.exclude?(file) }.
                collect { |file| [ dest_for[file.sub(prefix, "")], file ] }
            else
              # Include just that one file, sans its diectory path.
              [ dest_for[File.basename(file)], file ]
            end
          end
        end.flatten
        @zip_map = Hash[ *args ]
      end
      @zip_map
    end

  end

  # The ZipTask creates a new ZIP file. You can include any number of files and
  # and directories, use exclusion patterns, and include files into specific
  # directories.
  #
  # For example:
  #   returning(zip("test.zip")) { |task|
  #     task.include "srcs"
  #     task.include "README", "LICENSE"
  #   end
  def zip(file)
    ZipTask.define_task(file)
  end


  # The UnzipTask expands the contents of a ZIP file into a target directory.
  # You can include any number of files and directories, use exclusion patterns,
  # and expand files from relative paths.
  #
  # The file(s) to unzip is the first prerequisite.
  class UnzipTask < Rake::Task

    # The target directory.
    attr_accessor :target

    def initialize(*args)
      super
      @paths = {}
      enhance do |task|
        fail "Where do you want the file unzipped" unless target

        # If no paths specified, then no include/exclude patterns
        # specified. Nothing will happen unless we include all files.
        if @paths.empty?
          @paths[nil] = FromPath.new(nil)
          @paths[nil].include "*"
        end

        # Otherwise, empty unzip creates target as a file when touching.
        mkpath target, :verbose=>false
        prerequisites.each do |file|
          Zip::ZipFile.open(file) do |zip|
            entries = zip.collect
            @paths.each do |path, patterns|
              patterns.map(entries).each do |dest, entry|
                next if entry.directory?
                dest = File.expand_path(dest, target)
                puts "Extracting #{dest}" if Rake.application.options.trace
                mkpath File.dirname(dest), :verbose=>false rescue nil
                entry.extract(dest) { true }
              end
            end
          end
        end
        # Let other tasks know we updated the target directory.
        touch target, :verbose=>false
      end
    end

    # Specifies directory to unzip to and return self.
    def into(target)
      self.target = target
      self
    end

    # Include all files that match the patterns and returns self.
    #
    # Use include if you only want to unzip some of the files, by specifying
    # them instead of using exclusion. You can use #include in combination
    # with #exclude.
    def include(*files)
      if Hash === files.last
        from_path(files.pop[:path]).include *files
      else
        from_path(nil).include *files
      end
      self
    end
    alias :add :include

    # Exclude all files that match the patterns and return self.
    #
    # Use exclude to unzip all files except those that match the pattern.
    # You can use #exclude in combination with #include.
    def exclude(*files)
      if Hash === files.last
        from_path(files.pop[:path]).exclude *files
      else
        from_path(nil).exclude *files
      end
      self
    end

    # Allows you to unzip from a path. Returns an object you can use to
    # specify which files to include/exclude relative to that path.
    # Expands the file relative to that path.
    #
    # For example:
    #   unzip("test.jar").into(Dir.pwd).from_path("etc").include("LICENSE")
    # will unzip etc/LICENSE into ./LICENSE.
    #
    # This is different from:
    #  unzip("test.jar").into(Dir.pwd).include("etc/LICENSE")
    # which unzips etc/LICENSE into ./etc/LICENSE.
    def from_path(path)
      @paths[path] ||= FromPath.new(path)
    end

    def needed?()
      return true unless target && File.exist?(target)
      return true if prerequisites.any? { |prereq| File.stat(prereq).mtime > File.stat(target).mtime }
      false
    end

    # :nodoc:
    class FromPath

      def initialize(path)
        if path
          @path = path[-1] == ?/ ? path : path + "/"
        else
          @path = ""
        end
      end

      # See UnzipTask#include
      def include(*files)
        @include ||= []
        @include |= files
        self
      end

      # See UnzipTask#exclude
      def exclude(*files)
        @exclude ||= []
        @exclude |= files
        self
      end

      # :nodoc:
      def map(entries)
        includes = @include || ["*"]
        excludes = @exclude || []
        entries.inject({}) do |map, entry|
          short = entry.name.sub(@path, "")
          if includes.any? { |pat| File.fnmatch(pat, short) } &&
             !excludes.any? { |pat| File.fnmatch(pat, short) }
            map[short] = entry
          end
          map
        end
      end

    end

  end

  # Defines a task that will unzip the specified file, into the directory
  # specified by calling #into. It is the second call to into that creates
  # and returns the task.
  #
  # You can unzip only some files by specifying an inclusion or exclusion
  # pattern, and unzip files from a path in the ZIP file. See UnzipTask
  # for more information.
  #
  # For example:
  #   unzip("test.zip").into("test")
  #   unzip("test.zip").into("etc").include("README", "LICENSE") 
  #   unzip("test.zip").into("src").from_path("srcs")
  def unzip(file)
    task = nil
    namespace { task = UnzipTask.define_task("unzip"=>file) }
    task
  end

end