bundlr-spec.coffee

module.exports = class Bundlr

    FORMAT_TTNITF:       'ttnitf'
    FORMAT_PICTURE:      'bild'     # deliberate to match OFP
    FORMAT_TTNINJS:      'ttninjs'
    FORMAT_INDESIGN:     'indesign'
    FORMAT_CUTPASTE:     'cutpaste' # txt-format in media-moj
    FORMAT_TTNITFXML:    'ttnitfxml'

    # ofp spec is "ttninf", "ttnintf+bild", "ttinjs" etc
    bundleForOfpSpec: (ofpSpec) -> bundleFor ofpSpec.split /\+/g

    # array of [FORMAT_XYZ], returns a Bundle instance
    bundleFor: (arr) ->


# factory method to instantiate a bundlr from search result.
# the seach result is either a single or an array of ttninjs
# entries  as output by search-service 'item' request.
Bundlr.fromSearchResult = (result) ->


Bundlr.Bundle = class Bundle

    # the bundle filename.
    # 150219-blocketbluff-64381
    filename: ->

    # Returns an array of Entry. Caller must loop
    # over entries and decide how to deal with them.
    entries: ->


Bundlr.Entry = class Entry

    format: # one of Bundlr.FORMAT_XYZ

    uri: # uri to entry on the form:
         # http://tt.se/media/text/150219-blocketbluff-64381/a000_NormalHires # association
         # http://tt.se/media/text/150219-blocketbluff-64381/body_ttnitf      # body_ttnitf
         # http://tt.se/media/text/150219-blocketbluff-64381                  # ttninjs

    # each entry have either href or content. for pictures we have a href pointing to the
    # actual file. for ttnitf, xml, ttninjs etc the actual text content is in content.

    href: # where the actual file can be found (if not content)
         # http://spix-bildbank01.driften.net:80/images/dist-fs/ttninjs/hires/705/170/0CC4DC684027411BA2C50E72CC39BE66.jpg

    content: # the textual content of this entry (if not href)

    filename: # the proposed filename for this entry:
        # blocketbluff_a000_NormalHires.jpg               picture
        # 150219-blocketbluff-64381.ttt                   ttnitf
        # 150219-blocketbluff-64381-indesign.txt          indesign
        # 150219-blocketbluff-64381.txt                   cutpaste
        # ...

    # returns a promise for the byte size of the contents. for 'href' 
    # entries this either looks in the ttninjs for size or
    # falls back on a HEAD request to the originating server.
    # for 'content' style entries. it is the string contents
    # size if turned into a Buffer.
    size: ->

    # returns a promise for the mimetype. same rules as for 
    # size() in that it may fall back on a HEAD request to
    # the originating server.
    mimetype: ->

    # return a promise for a readstream with the contents. can be used
    # as an alternative way of getting the contents. works for both
    # href and content.
    readstream: ->


# ######################## EXAMPLE ################
Bundlr = require 'bundlr'

# sigh. global.
bundle = zip = null

@amqpc.rcp('search-service', 'item', msg).then (item) ->
  
  bundlr = Bundlr.fromSearchSearch item
  
  # create a specific bundle
  bundle = bundlr.forOfpSpec 'ttnitf+bild'

  # loop over entries, pick out stuff
  bundle.entries().map (ent) -> Q.all([ent.filename(), ent.readstream()])
      
.all (todo) ->

  zip = new Zip()
  todo.forEach ([filename, readstream]) ->
      f = zip.addFile filename
      readstream.pipe f

.then >
 
  # shipping to the browser...
  response.set 'Content-Length', zip.size()
  response.set 'Content-Type', 'application/zip'
  response.set 'Content-Disposition', "attachment; filename=\"#{bundle.filename()}\";"
  
  zip.pipe response