module FakeFS
  class Dir
    include Enumerable

    def initialize(string)
      raise Errno::ENOENT, string unless FileSystem.find(string)
      @path = string
      @open = true
      @pointer = 0
      @contents = [ '.', '..', ] + FileSystem.find(@path).values
    end

    def close
      @open = false
      @pointer = nil
      @contents = nil
      nil
    end

    def each(&block)
      while f = read
        yield f
      end
    end

    def path
      @path
    end

    def pos
      @pointer
    end

    def pos=(integer)
      @pointer = integer
    end

    def read
      raise IOError, "closed directory" if @pointer == nil
      n = @contents[@pointer]
      @pointer += 1
      n.to_s.gsub(path + '/', '') if n
    end

    def rewind
      @pointer = 0
    end

    def seek(integer)
      raise IOError, "closed directory" if @pointer == nil
      @pointer = integer
      @contents[integer]
    end

    def self.[](pattern)
      glob(pattern)
    end

    def self.chdir(dir, &blk)
      FileSystem.chdir(dir, &blk)
    end

    def self.chroot(string)
      # Not implemented yet
    end

    def self.delete(string)
      raise SystemCallError, "No such file or directory - #{string}" unless FileSystem.find(string).values.empty?
      FileSystem.delete(string)
    end

    def self.entries(dirname)
      raise SystemCallError, dirname unless FileSystem.find(dirname)
      Dir.new(dirname).map { |file| file }
    end

    def self.foreach(dirname, &block)
      Dir.open(dirname) { |file| yield file }
    end

    def self.glob(pattern)
      [FileSystem.find(pattern) || []].flatten.map{|e| e.to_s}.sort
    end

    def self.mkdir(string, integer = 0)
      parent = string.split('/')
      parent.pop
      raise Errno::ENOENT, "No such file or directory - #{string}" unless parent.join == "" || FileSystem.find(parent.join('/'))
      FileUtils.mkdir_p(string)
    end

    def self.open(string, &block)
      if block_given?
        Dir.new(string).each { |file| yield(file) }
      else
        Dir.new(string)
      end
    end

    def self.tmpdir
      '/tmp'
    end

    def self.pwd
      FileSystem.current_dir.to_s
    end

    class << self
      alias_method :getwd, :pwd
      alias_method :rmdir, :delete
      alias_method :unlink, :delete
    end
  end
end