First working proof of concept

lib/psd.coffee

-File = require './psd/file.coffee'
+fs    = require 'fs'
+RSVP  = require 'rsvp'
+
+File  = require './psd/file.coffee'
+Header = require './psd/header.coffee'
 
 module.exports = class PSD
+  @fromFile: (file) -> new PSD fs.readFileSync(file)
+
   constructor: (data) ->
-    @file = new File(data)
+    @file = new File(data)
\ No newline at end of file
+    @parsed = false
+    @header = null
+
+  parse: ->
+    new RSVP.Promise (resolve, reject) =>
+      return resolve(@) if @parsed
+      
+      @parseHeader().then (header) =>
+        @header = header
+        resolve(@)
+
+  parseHeader: -> new Header(@file).parse()

lib/psd/file.coffee

 module.exports = class File
-  constructor: (data) ->
+  constructor: (@data) ->
\ No newline at end of file
+    @pos = 0
+
+  tell: -> @pos
+  read: (length) ->
+    data = @data[@pos...@pos+length]
+    @pos += length
+    return data
+
+  seek: (amt, rel = false) -> if rel then @pos += amt else @pos = amt
+
+  readString: (length) -> @read(length).toString()
\ No newline at end of file

lib/psd/header.coffee

+RSVP = require ('rsvp')
+
+module.exports = class Header
+  constructor: (@file) ->
+    @version = null
+    @channels = null
+    @rows = null
+    @cols = null
+    @depth = null
+    @mode = null
+
+  parse: ->
+    new RSVP.Promise (resolve, reject) =>
+      sig = @file.readString(4)
+      console.log sig
+      resolve(@)
\ No newline at end of file

package.json

@@ -2,7 +2,8 @@
   "name": "psd",
   "version": "0.0.1",
   "dependencies": {
-    "coffee-script": "~ 1.7.1"
+    "coffee-script": "~ 1.7.1",
+    "rsvp": "~ 3.0.6"
   },
   "devDependencies": {
     "coffeeify": "~ 0.6.0"