## Here we define all the "chunks" that a message is parsed
## into. Chunks are used by ThreadViewMode to render a message. Chunks
## are used for both MIME stuff like attachments, for Sup's parsing of
## the message body into text, quote, and signature regions, and for
## notices like "this message was decrypted" or "this message contains
## a valid signature"---basically, anything we want to differentiate
## at display time.
##
## A chunk can be inlineable, expandable, or viewable. If it's
## inlineable, #color and #lines are called and the output is treated
## as part of the message text. This is how Text and one-line Quotes
## and Signatures work.
##
## If it's not inlineable but is expandable, #patina_color and
## #patina_text are called to generate a "patina" (a one-line widget,
## basically), and the user can press enter to toggle the display of
## the chunk content, which is generated from #color and #lines as
## above. This is how Quote, Signature, and most widgets
## work. Exandable chunks can additionally define #initial_state to be
## :open if they want to start expanded (default is to start collapsed).
##
## If it's not expandable but is viewable, a patina is displayed using
###patina_color and #patina_text, but no toggling is allowed. Instead,
##if #view! is defined, pressing enter on the widget calls view! and
##(if that returns false) #to_s. Otherwise, enter does nothing. This
##is how non-inlineable attachments work.

module Redwood
module Chunk
  class Attachment
    HookManager.register "mime-decode", <<EOS
Executes when decoding a MIME attachment.
Variables:
   content_type: the content-type of the message
       filename: the filename of the attachment as saved to disk (generated
                 on the fly, so don't call more than once)
  sibling_types: if this attachment is part of a multipart MIME attachment,
                 an array of content-types for all attachments. Otherwise,
                 the empty array.
Return value:
  The decoded text of the attachment, or nil if not decoded.
EOS
#' stupid ruby-mode

    ## raw_content is the post-MIME-decode content. this is used for
    ## saving the attachment to disk.
    attr_reader :content_type, :filename, :lines, :raw_content

    def initialize content_type, filename, encoded_content, sibling_types
      @content_type = content_type
      @filename = filename
      @raw_content =
        if encoded_content.body
          encoded_content.decode
        else
          "For some bizarre reason, RubyMail was unable to parse this attachment.\n"
        end

      @lines =
        case @content_type
        when /^text\/plain\b/
          Message.convert_from(@raw_content, encoded_content.charset).split("\n")
        else
          text = HookManager.run "mime-decode", :content_type => content_type,
                                 :filename => lambda { write_to_disk },
                                 :sibling_types => sibling_types
          text.split("\n") if text
        end
    end

    def color; :none end
    def patina_color; :attachment_color end
    def patina_text
      if expandable?
        "Attachment: #{filename} (#{lines.length} lines)"
      else
        "Attachment: #{filename} (#{content_type})"
      end
    end

    ## an attachment is exapndable if we've managed to decode it into
    ## something we can display inline. otherwise, it's viewable.
    def inlineable?; false end
    def expandable?; !viewable? end
    def initial_state; :open end
    def viewable?; @lines.nil? end
    def view!
      path = write_to_disk
      system "/usr/bin/run-mailcap --action=view #{@content_type}:#{path} >& /dev/null"
      $? == 0
    end

    def write_to_disk
      file = Tempfile.new "redwood.attachment"
      file.print @raw_content
      file.close
      file.path
    end

    ## used when viewing the attachment as text
    def to_s
      @lines || @raw_content
    end
  end

  class Text
    WRAP_LEN = 80 # wrap at this width

    attr_reader :lines
    def initialize lines
      @lines = lines.map { |l| l.chomp.wrap WRAP_LEN }.flatten # wrap

      ## trim off all empty lines except one
      lines.pop while lines.last =~ /^\s*$/ 
    end

    def inlineable?; true end
    def expandable?; false end
    def viewable?; false end
    def color; :none end
  end

  class Quote
    attr_reader :lines
    def initialize lines
      @lines = lines
    end
    
    def inlineable?; @lines.length == 1 end
    def expandable?; !inlineable? end
    def viewable?; false end

    def patina_color; :quote_patina_color end
    def patina_text; "(#{lines.length} quoted lines)" end
    def color; :quote_color end
  end

  class Signature
    attr_reader :lines
    def initialize lines
      @lines = lines
    end

    def inlineable?; @lines.length == 1 end
    def expandable?; !inlineable? end
    def viewable?; false end

    def patina_color; :sig_patina_color end
    def patina_text; "(#{lines.length}-line signature)" end
    def color; :sig_color end
  end

  class EnclosedMessage
    attr_reader :lines
    def initialize from, body
      @from = from
      @lines = body.split "\n"
    end

    def from
      @from ? @from.longname : "unknown sender"
    end

    def inlineable?; false end
    def expandable?; true end
    def initial_state; :open end
    def viewable?; false end

    def patina_color; :generic_notice_patina_color end
    def patina_text; "Begin enclosed message from #{from} (#{@lines.length} lines)" end

    def color; :quote_color end
  end

  class CryptoNotice
    attr_reader :lines, :status, :patina_text

    def initialize status, description, lines=[]
      @status = status
      @patina_text = description
      @lines = lines
    end

    def patina_color
      case status
      when :valid: :cryptosig_valid_color
      when :invalid: :cryptosig_invalid_color
      else :cryptosig_unknown_color
      end
    end
    def color; patina_color end

    def inlineable?; false end
    def expandable?; !@lines.empty? end
    def viewable?; false end
  end
end
end