Types used in couchDb
=====================

reference
---------

This type is used when one document points to another document. The
advantage of using this type as opposed to a raw string with a document
id is that it is possible, using a view, to figure out all relationships
between documents.

{
	nunaliit_type: 'reference'
	,doc: <string: identifier of the document in reference>
}

actionstamp
-----------

This type is used to keep track of an action performed by a user at a
specific time. Usual keys: nunaliit_created and nunaliit_last_updated 

{
	nunaliit_type: 'actionstamp'
	,name: <string: valid name of user that performed action>
	,time: <int: javascript time>
	,action: <string: action taken (e.g. 'created', lastUpdated'>
}

geometry
--------

This type is used to store a geometry. This type is saved under the key: nunaliit_geometry 

{
	nunaliit_type: 'geometry'
	,wkt: <string: WKT version of geometry in EPSG:4326>
	,bbox: [
		<int: minX>
		,<int: minY>
		,<int: maxX>
		,<int: maxY>
	]
}

layers
------

Layers are associated with documents in an array under the key: nunaliit_layers

{
	nunaliit_layers: [
		<string: layer name>
		,...
	]
}

layerDefinition
---------------

Objects of type layerDefinition are used to define layers that are store in the
database. A layer definition object is saved under the key nunaliit_layer_definition
and follows the following pattern:

{
	nunaliit_layer_definition: {
		nunaliit_type: 'layerDefinition'
		,id: <string: identifier for layer>
		,name: <string: label used to present layer to user>
		,bbox: [
			<int: minX>
			,<int: minY>
			,<int: maxX>
			,<int: maxY>
		]
	}
}

contribution
------------

This type is used when comments are to be applied to other document. These
comments are called 'contributions'. Contributions are saved under the
key: 'nunaliit_contribution'

{
	nunaliit_type: 'contribution'
	,title: <string: title of the comment>
	,description: <string: longer description containing the body of the comment>
	,reference: <reference: points to the original document for which the contribution is meant>
	,reply: <reference: if this contribution is a reply to another, then the replied document 
	                    is pointed here>
}

attachment_descriptions
-----------------------

This is an object under the key 'nunaliit_attachments'. The keys under
nunaliit_attachments.files match the keys found under _attachments. This
object is used to store meta data about the files attached to the document.

{
	nunaliit_type: 'attachment_descriptions'
	,files: {
		<attachmentName>: {
			attachmentName: <attachmentName>
			,fileClass: <string: 'image', 'video', 'audio' or 'gpx'>
			,mimeType: <string: mime type detected>
			,mimeEncoding: <string: mime encoding detected>
			,status: <string: 'submitted', 'analyzed', 'waiting for approval', 'approved', 'denied', 'attached'>
			,mediaFile: <string: name of file on disk in media directory>
			,originalName: <string: name under which file was uploaded>
			,width: <int: width in pixel of image or video>
			,height: <int: height in pixel of image or video> 
			,size: <int: size in bytes of file> 
			,conversionPerformed: <boolean>
			,thumbnail: <string: attachmentName of generated thumbnail, if available>
			,original: <object: description of original file, if applicable> {
				mediaFile: <string: name of file on disk in media directory>
				,width: <int: width in pixel of image or video>
				,height: <int: height in pixel of image or video> 
				,size: <int: size in bytes of file> 
				,mimeType: <string: mime type detected>
				,mimeEncoding: <string: mime encoding detected>
			}
			,source: <string: attachmentName of file for which this is a thumbnail>
			,data: <object: object containing the parameters that were sent with the request 
			                when the attached file was uploaded. Common keys: 'title' and 
			                'description'>
		}
		,...
	}
}

The upload process is as follows:

- file is uploaded and saved in a directory, called the media directory

- the document where the file is destined is updated with the following information:
  - an attachmentName is computed
  - a file description is created and attached to nunaliit_attachments.files[attachmentName]
    - originalName
    - status: 'submitted'
    - original.mediaFile
    - original.size
    
- server detects that a new file was submitted and the file is analyzed
  - fileClass
  - status: 'analyzed'
  - original.width
  - original.height
  - original.mimeType
  - original.mimeEncoding
  
- server detects that a file has been analyzed. It calls the appropriate plugin for conversion.
  In the case of a multimedia file (fileClass: image,audio,video), the file is converted to
  appropriate codec with needed dimensions. Then, if needed, a thumbnail is created. The file 
  descriptor is updated appropriately:
  - status: 'waiting for approval'
  - mimeType
  - mimeEncoding
  - mediaFile
  - width
  - height
  - size
  - conversionPerformed: true
  - thumbnail (set to attachmentName that is the thumbnail, if appropriate)
  
  If a thumbnail is created, a new file descriptor is created:
  - originalName (same as uploaded file)
  - fileClass: 'image'
  - status: 'waiting for approval'
  - mimeType
  - mimeEncoding
  - mediaFile
  - width
  - height
  - size
  - source (set to attachmentName that is the original file)
  
- Administrator approves the file
  - status: 'approved'
   
- server detects a a file was approved and updates the document. Uploads the file
  from the media directory to the document, using the appropriate attachmentName
  - status: 'attached'