ImageGrid/ui (gen4)/features/collections.js

/**********************************************************************
* 
*
*
**********************************************************************/
((typeof define)[0]=='u'?function(f){module.exports=f(require)}:define)
(function(require){ var module={} // make module AMD/node compatible...
/*********************************************************************/

var data = require('imagegrid/data')

var toggler = require('lib/toggler')
var actions = require('lib/actions')
var features = require('lib/features')

var browse = require('lib/widget/browse')

var core = require('features/core')
var widgets = require('features/ui-widgets')



/*********************************************************************/
// 
// XXX might be a good idea to make collection loading part of the 
// 		.load(..) protocol...
// 		...this could be done via a url suffix, as a shorthand.
// 		something like:
// 			/path/to/index:collection
// 				-> /path/to/index/sub/path/.ImageGrid/collections/collection
// XXX loading collections by direct path would require us to look 
// 		in the containing index for missing parts (*images.json, ...)
// XXX saving a local collection would require us to save to two 
// 		locations:
// 			- collection specific stuff (data) to collection path
// 			- global stuff (images, tags, ...) to base index...
// XXX local tags:
// 		- save		- done
// 		- load		- done
// 		- save/merge use...
// XXX merge data -- collection/crop/all
// 		- vertical only
// 		- horizontal only
// 		- both
// XXX external / linked collections (.location)...
//
//

var MAIN_COLLECTION_TITLE = '$ALL'
var MAIN_COLLECTION_GID = '0'

// XXX undo...
var CollectionActions = actions.Actions({
	config: {
		// can be:
		// 	'all'		- save crop state for all collections (default)
		// 	'main'		- save crop state for main state only
		// 	'none'		- do not save crop state
		'collection-save-crop-state': 'all',


		// XXX should this be in config???
		// 		...technically no, but we need shit to resolve correctly 
		// 		to a relevant feature...
		'collection-transfer-changes': ['data'],
	},

	// Format:
	// 	{
	// 		<title>: {
	// 			title: <title>,
	// 			gid: <gid>,
	//
	// 			crop_stack: [ .. ],
	//
	// 			// base collection format -- raw data...
	// 			data: <data>,
	//
	// 			...
	// 		},
	// 		...
	// 	}
	collections: null,

	get collectionGIDs(){
		var res = {}
		var c = this.collections || {}
		Object.keys(c)
			.forEach(function(title){
				res[c[title].gid || title] = title
			})
		return res
	},

	get collection(){
		return this.location.collection },
	set collection(value){
		this.loadCollection(value) },
	get collectionGID(){
		return ((this.collections || {})[this.collection] || {}).gid 
			|| MAIN_COLLECTION_GID },
	set collectionGID(value){
		this.collection = value },

	// XXX should this check consistency???
	get collection_order(){
		if(this.collections == null){
			return null
		}

		var collections = this.collections
		var keys = Object.keys(collections)
		var order = this.__collection_order = this.__collection_order || []

		// add unsorted things to the head of the list...
		var res = keys
			.concat(order)
			.reverse()
			.unique()
			.reverse()

		// keep MAIN_COLLECTION_TITLE out of the collection order...
		var m = res.indexOf(MAIN_COLLECTION_TITLE)
		m >= 0
			&& res.splice(m, 1)

		// remove stuff not present...
		if(res.length > keys.length){
			res = res.filter(function(e){ return e in collections })
		}

		this.__collection_order.splice(0, this.__collection_order.length, ...res)

		return this.__collection_order
	},
	set collection_order(value){
		this.__collection_order = value },

	get collections_length(){
		var c = (this.collections || {})
		return MAIN_COLLECTION_TITLE in c ? 
			Object.keys(c).length - 1
			: Object.keys(c).length
	},

	// Format:
	// 	{
	// 		// NOTE: this is always the first handler...
	// 		'data': <action-name>,
	// 		'gid': <gid>,
	//
	// 		<format>: <action-name>,
	// 		...
	// 	}
	//
	get collection_handlers(){
		var handlers = this.__collection_handlers = this.__collection_handlers || {}

		if(Object.keys(handlers).length == 0){
			var that = this
			handlers['data'] = null
			this.actions.forEach(function(action){
				var fmt = that.getActionAttr(action, 'collectionFormat')
				if(fmt){
					handlers[fmt] = action
				}
			})
		}

		// cleanup...
		if(handlers['data'] == null){
			delete handlers['data']
		}

		return handlers
	},


	// Collection events...
	//
	collectionLoading: ['- Collections/',
		core.doc`This is called by .loadCollection(..) or one of the 
		overloading actions when collection load is done...

		The .pre phase is called just before the load and the .post phase 
		just after.
		
		`,
		core.notUserCallable(function(collection){
			// This is the window resize event...
			//
			// Not for direct use.
		})],
	collectionUnloaded: ['- Collections/',
		core.doc`This is called when unloading a collection.
		`,
		core.notUserCallable(function(collection){
			// This is the window resize event...
			//
			// Not for direct use.
		})],
	collectionCreated: ['- Collections/',
		core.doc`This is called when a collection is created.

		NOTE: this is not triggered for the "${MAIN_COLLECTION_TITLE}" collection...
		`,
		core.notUserCallable(function(collection){
			// This is the window resize event...
			//
			// Not for direct use.
		})],
	collectionRemoved: ['- Collections/',
		core.doc`This is called when a collection is removed.

		NOTE: this is not triggered for the "${MAIN_COLLECTION_TITLE}" collection...
		`,
		core.notUserCallable(function(collection){
			// This is the window resize event...
			//
			// Not for direct use.
		})],


	// Collection life-cycle...
	//
	loadCollection: ['- Collections/',
		core.doc`Load collection...

			Load collection...
			.loadCollection(collection)
			.loadCollection(gid)
				-> this
			
			Force reload current collection...
			.loadCollection('!')
				-> this
				NOTE: this will not call .saveCollection(..) before 
					reloading, thus potentially losing some state that 
					was not explicitly saved.


		When loading a collection, previous state is saved.

		If .data for a collection is not available this will do nothing, 
		this enables extending actions to handle the collection in 
		different ways.

		Protocol:
		- collection format handlers: .collection_handlers
			- built from actions that define .collectionFormat attr to 
			  contain the target format string.
		- format is determined by matching it to a key in .collections[collection]
			e.g. 'data' is applicable if .collections[collection].data is not null
		- the format key's value is passed to the handler action
		- the handler is expected to return a promise
		- only the first matching handler is called
		- the data handler is always first to get checked

		Example loader action:
			collectionXLoader: [
				// handle .x
				{collectionFormat: 'x'}
				function(title, state){
					return new Promise(function(resolve){ 
						var x = state.x
		
						// do stuff with .x
		
						resolve() 
					}) }],


		The .data handler is always first to enable caching, i.e. once some
		non-data handler is done, it can set the .data which will be loaded
		directly the next time.
		To invalidate such a cache .data should simply be deleted.


		NOTE: cached collection state is persistent.
		NOTE: when current collection is removed from .collections this 
			will not save state when loading another collection...
		`,
		function(collection){
			var that = this
			var force = collection == '!'
			collection = collection == '!' ? 
				this.collection 
				: collection
			// if collection is a gid, get the title...
			collection = this.collectionGIDs[collection] || collection 
			if(collection == null 
					|| this.collections == null 
					|| !(collection in this.collections)){
				return
			}
			var crop_mode = this.config['collection-save-crop-state'] || 'all'

			var current = this.current
			var ribbon = this.current_ribbon

			var prev = this.collection
			var collection_data = this.collections[collection]
			var handlers = this.collection_handlers

			// save current collection state...
			//
			// main view...
			// NOTE: we save here unconditionally because MAIN_COLLECTION_TITLE
			// 		is stored ONLY when we load some other collection...
			if(this.collection == null){
				this.saveCollection(
					MAIN_COLLECTION_TITLE, 
					crop_mode == 'none' ?  'base' : 'crop', 
					true)

			// collection...
			// NOTE: we only save if the current collection exists, it 
			// 		may not exist if it was just removed...
			} else if(this.collection in this.collections
					// prevent saving over changed current state...
					&& !force){
				this.saveCollection(
					this.collection, 
					crop_mode == 'all' ? 'crop': null)
			}

			// load collection...
			Promise
				.all(Object.keys(handlers)
					// filter relevant handlers...
					.filter(function(format){ 
						return format == '*' || collection_data[format] })
					// run handlers...
					.map(function(format){
						return that[handlers[format]](collection, collection_data) }))
				.then(function(){
					var data = collection_data.data

					if(!data){
						return
					}

					// current...
					data.current = data.getImage(current) 
						// current is not in collection -> try and keep 
						// the ribbon context...
						|| that.data.getImage(
							current, 
							data.getImages(that.data.getImages(ribbon)))
						// get closest image from collection...
						|| that.data.getImage(current, data.order)
						|| data.current

					that
						.collectionLoading.chainCall(that, 
							function(){
								// do the actual load...
								that.load.chainCall(that, 
									function(){
										that.collectionUnloaded(
											prev || MAIN_COLLECTION_TITLE)
									}, {
										location: that.location,

										data: data,

										crop_stack: collection_data.crop_stack
											&& collection_data.crop_stack.slice(),

										// NOTE: we do not need to pass collections 
										// 		and order here as they stay in from 
										// 		the last .load(..) in merge mode...
										//collections: that.collections,
										//collection_order: that.collection_order,
									}, true)

								// maintain the .collection state...
								if(collection == MAIN_COLLECTION_TITLE){
									// no need to maintain the main data in two 
									// locations...
									delete that.collections[MAIN_COLLECTION_TITLE]
									delete this.location.collection

								} else {
									that.data.collection = 
										that.location.collection = 
										collection
									// cleanup...
									if(collection == null){
										delete this.location.collection
									}
								}
							}, 
							collection)
				})
		}],
	// XXX should this call .loadCollection('!') when saving to current
	// 		collection???
	// 		This would reaload the view to a consistent (just saved) 
	// 		state...
	// 		...see comments inside...
	// XXX it feels like we need two levels of actions, low-level that 
	// 		just do their job and user actions that take care of 
	// 		consistent state and the like...
	// XXX do we need to handle collection gids here???
	saveCollection: ['- Collections/',
		core.doc`Save current state to collection

			Save current state to current collection
			.saveCollection()
			.saveCollection('current')
				-> this
				NOTE: this will do nothing if no collection is loaded.

			Save state as collection...
			.saveCollection(collection)
				-> this
				NOTE: if saving to self the default mode is 'crop' else
					it is 'current' (see below for info on respective 
					modes)...

			Save current state as collection ignoring crop stack
			.saveCollection(collection, 0)
			.saveCollection(collection, 'current')
				-> this

			Save new empty collection
			.saveCollection(collection, 'empty')
				-> this

			Save current crop state to collection
			.saveCollection(collection, 'crop')
				-> this

			Save top depth crops from current crop stack to collection
			.saveCollection(collection, depth)
				-> this

			Save base crop state to collection
			.saveCollection(collection, 'base')
				-> this


		NOTE: this will overwrite collection .data and .crop_stack only, 
			the rest of the data is untouched...
		NOTE: when saving to current collection and maintain consistent 
			state it may be necessary to .loadCollection('!')
		`,
		function(collection, mode, force){
			var that = this
			collection = collection || this.collection
			collection = collection == 'current' ? this.collection : collection

			if(!force 
					&& (collection == null || collection == MAIN_COLLECTION_TITLE)){
				return
			}

			var collections = this.collections = this.collections || {}
			var depth = typeof(mode) == typeof(123) ? mode : null
			mode = depth == 0 ? 'current' 
				: depth ? 'crop' 
				: mode
			// default mode -- if saving to self then 'crop' else 'current'
			if(!mode){
				mode = ((collection in collections 
							&& collection == this.collection) 
						|| collection == MAIN_COLLECTION_TITLE) ? 
					'crop' 
					: 'current'
			}
			var new_collection = 
				!collections[collection] 
				&& collection != MAIN_COLLECTION_TITLE


			// save the data...
			var state = collections[collection] = collections[collection] || {}
			state.title = state.title || collection
			state.gid = state.gid 
				// maintain the GID of MAIN_COLLECTION_TITLE as MAIN_COLLECTION_GID...
				|| (collection == MAIN_COLLECTION_TITLE ? 
					MAIN_COLLECTION_GID 
					: this.data.newGID())
			// NOTE: we do not need to care about tags here as they 
			// 		will get overwritten on load...
			state.data = (mode == 'empty' ? 
					(new this.data.constructor())
				: mode == 'base' && this.crop_stack ? 
					(this.crop_stack[0] || this.data.clone())
				: mode == 'crop' ? 
					this.data.clone()
				// current...
				: this.data.clone()
					.run(function(){
						var d = this
						this.collection = collection
					})
					.clear('unloaded'))

			// crop mode -> handle crop stack...
			if(mode == 'crop' && this.crop_stack && depth != 0){
				depth = depth || this.crop_stack.length
				depth = this.crop_stack.length - Math.min(depth, this.crop_stack.length)

				state.crop_stack = this.crop_stack.slice(depth)

			// other modes...
			} else {
				delete state.crop_stack
			}


			// XXX this leads to recursion????
			// 		.loadCollection('X')
			// 			-> .saveCollection('current')
			// 				-> .loadCollection('!')
			// XXX should we be doing this here or on case by case basis externally...
			//collection == this.collection
			//	&& this.loadCollection('!')

			new_collection
				&& this.collectionCreated(collection)
		}],
	newCollection: ['- Collections/',
		core.doc` Shorthand to .saveCollection(collection, 'empty')`,
		function(collection){ return this.saveCollection(collection, 'empty') }],
	removeCollection: ['- Collections/',
		core.doc`

			.removeCollection(collection)
			.removeCollection(gid)
				-> this
		
		NOTE: when removing the currently loaded collection this will 
			just remove it from .collections and do nothing...`,
		function(collection){
			if(!this.collections || collection == MAIN_COLLECTION_TITLE){
				return
			}
			collection = this.collectionGIDs[collection] || collection
			if(collection in this.collections){
				delete this.collections[collection]
				this.collectionRemoved(collection)
			}
		}],


	// Introspection...
	//
	inCollections: ['- Image/',
		core.doc`Get list of collections containing item`,
		function(gid){
			var that = this
			gid = this.data.getImage(gid)
			//return Object.keys(this.collections || {})
			return (this.collection_order || [])
				.filter(function(c){
					return c != MAIN_COLLECTION_TITLE
						&& (!gid 
							|| that.collections[c].data.getImage(gid)) })
		}],


	// Collection editing....
	//
	collect: ['- Collections/',
		core.doc`Add items to collection

			Add current image to collection...
			.collect('current', collection)
				-> this

			Add current ribbon to collection...
			.collect('ribbon', collection)
				-> this

			Add loaded images to collection...
			.collect('loaded', collection)
				-> this

			
			Add gid(s) to collection...
			.collect(gid, collection)
			.collect([gid, ,. ], collection)
				-> this


		NOTE: this will not account for item topology. To merge accounting
			for topology use .joinCollect(..)
		NOTE: if an image gid is not found locally it will be searched in
			base data...
		`,
		function(gids, collection){
			var that = this
			collection = collection || this.collection
			collection = this.collectionGIDs[collection] || collection 
			if(collection == null || collection == MAIN_COLLECTION_TITLE){
				return
			}

			// create collection if needed...
			(!this.collections 
					|| !(collection in this.collections))
				&& this.newCollection(collection)

			gids = gids == 'loaded' ? 
					this.data.getImages('loaded')
				: gids == 'ribbon' ?
					[this.current_ribbon]
				: gids instanceof Array ? 
					gids 
				: [gids]
			gids = gids
				.map(function(gid){ 
					return gid in that.data.ribbons ? 
						// when adding a ribbon gid expand to images...
						that.data.ribbons[gid].compact()
						: [ that.data.getImage(gid) 
							// check base data for image gid...
							|| that.collections[MAIN_COLLECTION_TITLE].data.getImage(gid) ] })
				.reduce(function(a, b){ return a.concat(b) }, [])

			// add to collection...
			var data = this.data.constructor.fromArray(gids)

			return this.joinCollect(null, collection, data)
		}],
	joinCollect: ['- Collections/Merge to collection',
		core.doc`Merge/Join current state to collection

			Join current state into collection
			.joinCollect(collection)
				-> this

			Join current state with specific alignment into collection
			.joinCollect(align, collection)
				-> this

			Join data to collection with specific alignment
			.joinCollect(align, collection, data)
				-> this

		This is like .collect(..) but will preserve topology.
		
		NOTE: for align docs see Data.join(..)
		NOTE: if align is set to null or not given then it will be set 
			to default value.
		NOTE: this will join to the left (prepend) of the collections, this is 
			different from how basic .join(..) works (appends)
		`,
		function(align, collection, data){
			collection = arguments.length == 1 ? align : collection
			collection = this.collectionGIDs[collection] || collection 
			if(collection == null || collection == MAIN_COLLECTION_TITLE){
				return
			}

			(!this.collections 
					|| !(collection in this.collections))
				&& this.newCollection(collection)

			// if only collection is given, reset align to null...
			align = align === collection ? null : align

			if(this.collections && this.collections[collection]){
				//this.collections[collection].data.join(align, data || this.data.clone())
				var res = this.collections[collection].data = (data || this.data)
					.clone()
					.join(align, this.collections[collection].data)

				// joining into the current collection...
				if(collection == this.collection){
					var cur = this.current
					this.data = res 
					this.data.current = cur
				}

			} else {
				this.saveCollection(collection)
			}
		}],
	uncollect: ['Collections|Image/Remove from collection',
		core.doc`Remove gid(s) from collection...

			Remove current image from current collection...
			.uncollect()
			.uncollect('current')
				-> this

			Remove gid(s) from current collection...
			.uncollect(gid)
			.uncollect([gid, ..])
				-> this

			Remove gid(s) from collection...
			.uncollect(gid, collection)
			.uncollect([gid, ..], collection)
				-> this


		NOTE: this will remove any gid, be it image or ribbon.
		`,
		{browseMode: function(){ return !this.collection && 'disabled' }},
		function(gids, collection){
			collection = collection || this.collection
			collection = this.collectionGIDs[collection] || collection 
			if(collection == null 
					|| collection == MAIN_COLLECTION_TITLE
					|| !this.collections 
					|| !(collection in this.collections)){
				return
			}

			var that = this

			gids = gids == 'loaded' ? this.data.getImages('loaded')
				: gids instanceof Array ? gids 
				: [gids]
			gids = gids
				.map(function(gid){ 
					return gid in that.data.ribbons ? 
						// when adding a ribbon gid expand to images...
						that.data.ribbons[gid].compact()
						: [that.data.getImage(gid)] })
				.reduce(function(a, b){ return a.concat(b) }, [])

			// remove from the loaded state...
			this.collection == collection
				&& this.data.clear(gids)

			// NOTE: we do both this and the above iff data is cloned...
			// NOTE: if tags are saved to the collection it means that 
			// 		those tags are local to the collection and we do not 
			// 		need to protect them...
			if(this.data !== this.collections[collection].data){
				this.collections[collection].data
					.clear(gids)
			}
		}],
	uncollectRibbon: ['Collections|Ribbon/Remove ribbon from collection',
		core.doc`Remove ribbons from collection...

			Remove current ribbon from current collection...
			.uncollectRibbon()
			.uncollectRibbon('current')
				-> this

			Remove gid(s) from current collection...
			.uncollectRibbon(gid)
			.uncollectRibbon([gid, .. ])
				-> this

			Remove gid(s) from collection...
			.uncollectRibbon(gid, collection)
			.uncollectRibbon([gid, .. ], collection)
				-> this


		NOTE: this is the same as .uncollect(..) but removes whole ribbons, 
			i.e. each gid given will be resolved to a ribbon which will be
			removed.
		`,
		{browseMode: function(){ return !this.collection && 'disabled' }},
		function(gids, collection){
			var that = this
			gids = gids || 'current'
			gids = gids instanceof Array ? gids : [gids]
			gids = gids.map(function(gid){ return that.data.getRibbon(gid) })
			return this.uncollect(gids, collection) 
		}],


	// Serialization...
	//
	// NOTE: this will handle collection title and data only, the rest 
	// 		is copied in as-is.
	// 		It is the responsibility of the extending features to transform
	// 		their data on load as needed.
	load: [function(json){
		var that = this

		var collections = {}
		var c = json.collections || {}
		var order = json.collection_order || Object.keys(c)

		if((json.location || {}).collection){
			this.location.collection = json.location.collection
		}
			
		Object.keys(c).forEach(function(title){
			var state = collections[title] = { title: title }

			// load data...
			var d = c[title].data == null ?
					null
				: c[title].data instanceof data.Data ?
					c[title].data
				: data.Data.fromJSON(c[title].data)
			if(d){
				state.data = d
			}

			// NOTE: this can be done lazily when loading each collection
			// 		but doing so will make the system more complex and 
			// 		confuse (or complicate) some code that expects 
			// 		.collections[*].crop_stack[*] to be instances of Data.
			if(c[title].crop_stack){
				state.crop_stack = c[title].crop_stack
					.map(function(c){ 
						return c instanceof data.Data ? 
							c 
							: data.Data(c) })
			}

			// copy the rest of collection data as-is...
			Object.keys(c[title])
				.forEach(function(key){
					if(key in state){
						return
					}

					state[key] = c[title][key]
				})
		})

		return function(){
			if(Object.keys(collections).length > 0){
				this.collection_order = order
				this.collections = collections
			}
		}
	}],
	//
	// Supported modes:
	// 	current (default) 	- ignore collections
	// 	base				- save only base data in each collection and
	// 							the main collection is saved as current
	// 	full				- full current state.
	// 	
	// NOTE: we do not store .collection_order here, because we order 
	// 		the collections in the object.
	// 		...when saving a partial collection set, for example in
	// 		.prepareIndexForWrite(..) it would be necessary to add it 
	// 		in to maintain the correct order when merging... (XXX)
	// NOTE: currently this only stores title and data, it is the 
	// 		responsibility of extending features to store their specific 
	// 		data in collections...
	// 		XXX is this the right way to go???
	json: [function(mode){ return function(res){
		mode = mode || 'current'

		var collections = this.collections

		// NOTE: if mode is 'current' ignore collections...
		if(mode != 'current' && collections){
			var order = this.collection_order
			// NOTE: .collection_order does not return MAIN_COLLECTION_TITLE 
			// 		so we have to add it in manually...
			order = MAIN_COLLECTION_TITLE in collections ?
				order.concat([MAIN_COLLECTION_TITLE])
				: order

			// in base mode save the main view as current...
			if(mode == 'base' && this.collection){
				var main = collections[MAIN_COLLECTION_TITLE]
				res.data =  (main.crop_stack ? 
						(main.crop_stack[0] || main.data)
						: main.data)
					.dumpJSON()

				delete res.location.collection
			}

			res.collections = {}
			order.forEach(function(title){
				// in base mode skip the main collection...
				if(mode == 'base' && title == MAIN_COLLECTION_TITLE){
					return
				}

				var state = collections[title]

				// build the JSON...
				var s = res.collections[title] = { title: title }
				if(state.gid){
					s.gid = state.gid
				}
				var data = ((mode == 'base' && state.crop_stack) ? 
						(state.crop_stack[0] || state.data)
						: state.data)
				if(data){
					s.data = data.dumpJSON()
				}

				// handle .crop_stack of collection...
				// NOTE: in base mode, crop_stack is ignored...
				if(mode != 'base' && state.crop_stack){
					s.crop_stack = state.crop_stack
						.map(function(d){ return d.dumpJSON() })
				}
			})
		}
	} }],
	clone: [function(full){
		return function(res){
			if(this.collections){
				var cur = this.collections

				if(this.collection){
					res.location.collection = this.collection
				}

				collections = res.collections = {}
				this.collection_order
					.forEach(function(title){
						var c = collections[title] = {
							title: title,
						}

						if(cur[title].data){
							c.data = cur[title].data.clone()
						}

						if(cur[title].crop_stack){
							c.crop_stack = cur[title].crop_stack
								.map(function(d){ return d.clone() })
						}
					})
			}

		} }],

	clear: [function(){
		this.collection
			&& this.collectionUnloaded('*')
		delete this.collections
		delete this.__collection_order
		delete this.location.collection
	}],


	// Config and interface stuff...
	//
	toggleCollectionCropRetention: ['Interface/Collection crop save mode',
		core.makeConfigToggler(
			'collection-save-crop-state', 
			[
				'all',
				'main', 
				'none',
			])],
	toggleCollections: ['- Collections/Collections',
		toggler.Toggler(null,
			function(_, state){
				return state == null ?
					// cur state...
					(this.collection 
						|| MAIN_COLLECTION_TITLE)
					// new state...
					: (this.loadCollection(state) 
						&& state) },
			function(){ 
				return [MAIN_COLLECTION_TITLE].concat(this.collection_order || []) })],
})


var Collection = 
module.Collection = core.ImageGridFeatures.Feature({
	title: '',
	doc: '',

	tag: 'collections',
	depends: [
		'base',
		'location',
		'crop',
	],
	suggested: [
		'collection-tags',
		'auto-collections',

		'ui-collections',
		'fs-collections',
	],

	actions: CollectionActions, 

	handlers: [
		// XXX do we need this???
		['json.pre',
			function(){ this.saveCollection() }],

		// changes...
		//
		// format:
		// 	'collections'		- collection list changes
		// 	'collection: <gid>'	- holds collection-specific changes
		//
		// collection-list...
		[[
			'collectionCreated',
			'collectionRemoved',
		],
			function(_, collection){
				// collection list changed...
				this.markChanged('collections')
				// collection changed...
				collection in this.collections
					&& this.markChanged(
						'collection: '
							+JSON.stringify(this.collections[collection].gid || collection))
			}],
		// basic collection edits...
		[[
			'collect',
			'joinCollect',
			'uncollect',
		], 
			function(_, collection){
				this.markChanged(
					'collection: '
						+JSON.stringify(
							this.collections[collection || this.collection].gid || collection),
					['data'])
			}],
		// transfer changes on load/unload collection...
		['collectionLoading.pre',
			function(to){
				var that = this
				var from = this.collection || MAIN_COLLECTION_TITLE
				if(from == to || this.changes === undefined || this.changes === true){
					return
				}

				// XXX this should not be in config...
				var change_tags = this.config['collection-transfer-changes'] || ['data']

				var from_changes = change_tags
					.filter(function(item){
						return that.changes === true || (that.changes || {})[item] })

				return function(){
					if(to == from){
						return
					}
					var gid = (this.collections[to] || {}).gid || to
					var changes = this.changes !== false ? 
						this.changes['collection: '+JSON.stringify(gid)] 
						: []
					var from_id = 'collection: '
						+JSON.stringify(from == MAIN_COLLECTION_TITLE ?
							MAIN_COLLECTION_GID
							: this.collections[from].gid || from)

					// everything has changed, no need to bother with details...
					if(changes === true){
						return
					}

					// save changes to 'from'...
					from_changes.length > 0
						&& this.markChanged(from_id, from_changes)

					// load changes from 'to'..
					change_tags.forEach(function(item){
						if(changes && changes.indexOf(item) >= 0){
							that.markChanged(item)

						} else if(that.changes && that.changes[item]){
							delete that.changes[item]
						}
					})
				}
			}],


		// XXX account for 'base' mode changes...
		// 		use : .config['collection-transfer-changes']
		['prepareIndexForWrite', 
			function(res, _, full){
				var changed = full == true 
					|| res.changes === true
					|| res.changes.collections
				var collections = this.collections

				if(changed && res.raw.collections){
					// select the actual changed collection list...
					changed = changed === true ? 
						Object.keys(res.raw.collections)
						: changed

					// collection index...
					// XXX should this be at root or in collections/???
					// 		...root seems better as it will let us lazy-load
					// 		collection list without any extra effort...
					//var index = res.index['collections/index'] = {}
					var index = res.index['collection-index'] = {}
					Object.keys(collections)
						.forEach(function(title){ 
							index[collections[title].gid || title] = title  })

					changed
						// skip the raw field...
						.filter(function(k){ return changed.indexOf(k) >= 0 })
						.forEach(function(k){
							var gid = res.raw.collections[k].gid || k
							var path = 'collections/'+ gid
							var raw = res.raw.collections[k]

							// collections/<gid>/metadata
							var metadata = res.index[path +'/metadata'] = {}
							Object.keys(raw)
								.forEach(function(key){ metadata[key] = raw[key] })

							// collections/<gid>/data
							if(metadata.data){
								res.index[path +'/data'] = metadata.data
								delete metadata.data
							}
						})
				}
			}],
		// XXX
		['prepareJSONForLoad',
			function(res, json, base_path){
				// XXX
			}],
	],
})


//---------------------------------------------------------------------

var CollectionTagsActions = actions.Actions({
	config: {
		// List of tags to be stored in a collection, unique to it...
		//
		// NOTE: the rest of the tags are shared between all collections
		// NOTE: to disable local tags either delete this, set it to null
		// 		or to an empty list.
		'collection-local-tags': [
			'bookmark',
			'selected',
		],
		
		// XXX this should not be in config -- see CollectionActions.config for details...
		'collection-transfer-changes': CollectionActions.config['collection-transfer-changes']
			.concat([
				'bookmarked', 
				'selected',
			]),
	},

	collectTagged: ['- Collections|Tag/',
		function(tags, collection){
			return this.collect(this.data.getTaggedByAll(tags), collection) }],
	uncollectTagged: ['- Collections|Tag/',
		function(tags, collection){
			return this.uncollect(this.data.getTaggedByAll(tags), collection) }],

	// marked...
	collectMarked: ['- Collections|Mark/',
		function(collection){
			return this.collectTagged('selected', collection) }],
	uncollectMarked: ['Collections|Mark/Remove marked from collection',
		{browseMode: function(){ 
			return (!this.collection || this.marked.length == 0) && 'disabled' }},
		function(collection){
			return this.uncollectTagged('selected', collection) }],

	// bookmarked...
	collectBookmarked: ['- Collections|Bookmark/',
		function(collection){
			return this.collectTagged('bookmark', collection) }],
	uncollectBookmarked: ['Collections|Bookmark/Remove bookmarked from collection',
		{browseMode: function(){ 
			return (!this.collection || this.bookmarked.length == 0) && 'disabled' }},
		function(collection){
			return this.uncollectTagged('bookmark', collection) }],
})

var CollectionTags = 
module.CollectionTags = core.ImageGridFeatures.Feature({
	title: 'Collection tag handling',
	doc: core.doc`
	What this does:
	- Makes tags global through all collections
	- Handles local tags per collection


	Global tags:
	------------

	Global tags are shared through all the collections, this helps keep
	image-specific tags, keywords and meta-information stored in tags 
	global, i.e. connected to specific image and not collection. 

	Global tags are stored in .data.tags and cleared out of from the 
	collection's: 
		.collections[<title>].data


	Collection local tags:
	----------------------

	Local tags are listed in .config['collection-local-tags'], this makes
	selection, bookmarking and other process related tags local to each 
	collection.

	Collection-local tags are stored in .collections[<title>].local_tags
	and overwrite the corresponding tags in .data.tags on collection load.

	`,

	tag: 'collection-tags',

	depends: [
		'collections',
		'tags',

		// XXX
		'image-marks',
		'image-bookmarks',
	],

	actions: CollectionTagsActions,

	handlers: [
		// move tags between collections...
		['collectionLoading.pre',
			function(title){
				var that = this
				var local_tag_names = this.config['collection-local-tags'] || []
				var tags = this.data.tags

				// NOTE: this is done at the .pre stage as we need to grab 
				// 		the tags BEFORE the data gets cleared (in the case 
				// 		of MAIN_COLLECTION_TITLE)...
				var local_tags = (this.collections[title] || {}).local_tags || {}

				return function(){
					// load local_tags...
					local_tag_names
						.forEach(function(tag){ 
							tags[tag] = local_tags[tag] || [] 
						})

					;(this.crop_stack || [])
						.forEach(function(d){ d.tags = tags })
					this.data.tags = tags
					this.data.sortTags()
				}
			}],
		// remove tags from unloaded collections...
		['collectionUnloaded',
			function(_, title){
				if(title in this.collections 
						&& 'data' in this.collections[title]){
					delete this.collections[title].data.tags
				}
			}],
		// remove tags when saving...
		['saveCollection.pre',
			function(title, mode, force){
				var that = this
				title = title || this.collection || MAIN_COLLECTION_TITLE
				var local_tag_names = this.config['collection-local-tags'] || []

				// do not do anything for main collection unless force is true...
				if(title == MAIN_COLLECTION_TITLE && !force){
					return
				}

				// we need this to prevent copy of tags on first save...
				var new_set = !(title in (this.collections || {}))

				return function(){
					// save local tags...
					var local_tags = this.collections[title].local_tags = {}
					local_tag_names
						.forEach(function(tag){ 
							local_tags[tag] = (!new_set || title == MAIN_COLLECTION_TITLE) ? 
								(that.data.tags[tag] || []) 
								: []
						})

					delete (this.collections[title].data || {}).tags
				}
			}],
		// prevent .uncollect(..) from removing global tags...
		// XXX this seems a bit hacky (???)
		['uncollect.pre',
			function(_, gids, title){
				var that = this
				var local_tag_names = this.config['collection-local-tags'] || []

				// prevent global tag removal...
				var tags = this.data.tags
				delete this.data.tags

				return function(){
					// update local tags...
					local_tag_names.forEach(function(tag){
						tags[tag] = that.data.makeSparseImages(tags[tag], true) })

					this.data.tags = tags
					this.data.sortTags()
				}
			}],
		// save .local_tags to json...
		// NOTE: we do not need to explicitly load anything as .load() 
		// 		will load everything we need and .collectionLoading(..)
		// 		will .sortTags() for us...
		['json',
			function(res, mode){
				var c = this.collections
				var rc = res.collections

				// in 'base' mode set .data.tags and .local_tags to 
				// the base collection data...
				if(mode == 'base' 
						&& this.collection != null
						&& this.collection != MAIN_COLLECTION_TITLE){
					// NOTE: at this point .crop_stack is handled, so we 
					// 		do not need to care about it...
					var tags = c[MAIN_COLLECTION_TITLE].local_tags || {}
					var rtags = 
						res.data.tags = 
						res.collections[this.collection].data.tags || {}

					// compact and overwrite the local tags for the base...
					Object.keys(tags)
						.forEach(function(tag){
							rtags[tag] = tags[tag].compact() })
				}

				// clear and compact tags for all collections...
				rc
					&& Object.keys(rc || {})
						.forEach(function(title){
							var tags = c[title].local_tags || {}
							var rtags = rc[title].local_tags = {}

							// compact the local tags...
							Object.keys(tags)
								.forEach(function(tag){
									rtags[tag] = tags[tag].compact() })

							// no need to save the tags in more than the
							// root .data...
							if(rc[title].data){
								delete rc[title].data.tags
							}
						})
			}],


		// XXX should we be a bit more atomic and save tags iff
		// 		they were changed only???
		['prepareIndexForWrite', 
			function(res, _, full){
				var raw = res.raw.collections

				// NOTE: we are cheating here, we do not need to check 
				// 		for changes as this is already taken care off by
				// 		the main collections feature, here we just update 
				// 		the stuff it created...
				// XXX should we be a bit more atomic and save tags iff
				// 		they were changed only???
				Object.keys(this.collections || {}).forEach(function(title){
					var path = 'collections/'+ raw[title].gid
					var metadata = res.index[path + '/metadata']

					if(metadata && 'local_tags' in metadata){
						res.index[path +'/tags'] = metadata.local_tags
						delete metadata.local_tags
					}
				})
			}],
		// XXX
		['prepareJSONForLoad',
			function(res, json, base_path){
				// XXX
			}],
	],
})



//---------------------------------------------------------------------

// XXX add UI...
// XXX removing items from auto-collection has no effect as it will be 
// 		reconstructed on next load -- is this the right way to go???
var AutoCollectionsActions = actions.Actions({
	collectionAutoLevelLoader: ['- Collections/',
		core.doc`

		`,
		{collectionFormat: 'level_query'},
		function(title, state){ 
			return new Promise((function(resolve){
				var source = state.source || MAIN_COLLECTION_TITLE
				source = source == MAIN_COLLECTION_TITLE ? 
					((this.crop_stack || [])[0] 
						|| this.data)
					// XXX need a way to preload collection data...
					: ((this.collection[source].crop_stack || [])[0] 
						|| this.collections[source].data)

				var query = state.level_query
				query = query == 'top' ? 
						[0, 1]
					: query == 'bottom' ?
						[-1]
					: query instanceof Array ? 
						query
					: typeof(query) == typeof('str') ? 
						query.split('+').map(function(e){ return e.trim() })
					: query > 0 ? 
						[0, query]
					: [query]
				query = query[0] == 'top' ?
						[0, parseInt(query[1])+1]
					: query[0] == 'bottom' ?
						[-parseInt(query[1])-1]
					: query

				var levels = source.ribbon_order.slice.apply(source.ribbon_order, query)

				var gids = []
				levels.forEach(function(gid){
					source.makeSparseImages(source.ribbons[gid], gids) })
				gids = gids.compact()

				// get items that topped matching the query...
				var remove = state.data ?
					state.data.order
						.filter(function(gid){ return gids.indexOf(gid) < 0 })
					: []

				// build data...
				state.data = data.Data.fromArray(gids)
					// join with saved state...
					.join(state.data || data.Data())
					// remove unmatching...
					.clear(remove)

				resolve()
			}).bind(this)) }],
	makeAutoLevelCollection: ['- Collections/',
		core.doc`Make level auto-collection...

		`,
		function(title, source, a, b){
			// XXX query 
			var query = b != null ? [a, b] : a

			this.saveCollection(title, 'empty')

			this.collections[title].level_query = query
			this.collections[title].source = source
		}],

	// XXX do we need real tag queries???
	collectionAutoTagsLoader: ['- Collections/',
		core.doc`

		NOTE: this will ignore local tags.
		NOTE: this will prepend new matching items to the saved state.
		`,
		{collectionFormat: 'tag_query'},
		function(title, state){ 
			return new Promise((function(resolve){
				var local_tag_names = this.config['collection-local-tags'] || []

				var tags = (state.tag_query || [])
					.filter(function(tag){ 
						return local_tag_names.indexOf(tag) < 0 })

				// XXX should this be a real tag query???
				var gids = this.data.getTaggedByAll(tags)

				// get items that topped matching the query...
				var remove = state.data ?
					state.data.order
						.filter(function(gid){ return gids.indexOf(gid) < 0 })
					: []

				// build data...
				state.data = data.Data.fromArray(gids)
					// join with saved state...
					.join(state.data || data.Data())
					// remove unmatching...
					.clear(remove)

				resolve()
			}).bind(this)) }],
	makeAutoTagCollection: ['- Collections/',
		core.doc`Make tag auto-collection...

			Make a tag auto-collection...
			.makeAutoTagCollection(title, tag)
			.makeAutoTagCollection(title, tag, tag, ..)
			.makeAutoTagCollection(title, [tag, tag, ..])
				-> this

		NOTE: at least one tag must be supplied...
		`,
		function(title, tags){
			tags = arguments.length > 2 ? [].slice.call(arguments, 1) : tags
			tags = tags instanceof Array ? tags : [tags]

			if(tags.length == 0){
				return
			}

			this.saveCollection(title, 'empty')

			this.collections[title].tag_query = tags
		}],
})

var AutoCollections =
module.AutoCollections = core.ImageGridFeatures.Feature({
	title: 'Auto collections',
	doc: core.doc`
	A collection is different from a crop in that it:
		- preserves ribbon state
		- preserves order
		- preserves local tags

	Tag changes are handled by removing images that were untagged (no 
	longer matching) from the collection and adding newly tagged/matching 
	images to collection.
	`,

	tag: 'auto-collections',
	depends: [
		'collections',
	],

	actions: AutoCollectionsActions,

	handlers: [
		['json',
			function(res){
				var c = this.collections || {}
				var rc = res.collections || {}

				Object.keys(rc)
					.forEach(function(title){
						var cur = c[title]
						var r = rc[title]

						// XXX is this the right way to go???
						if('tag_query' in cur){
							r.tag_query = cur.tag_query

						} else if('level_query' in cur){
							r.level_query = cur.level_query
							if(cur.source){
								r.source = cur.source
							}
						}
					})
			}],
	],
})



//---------------------------------------------------------------------

// XXX show collections in image metadata... (???)
var UICollectionActions = actions.Actions({
	config: {
		// Global default collections...
		//
		// NOTE: delete or set to null for none...
		//'default-collections': null,
	},

	editDefaultCollections: ['Interface/Edit default collections...',
		widgets.makeConfigListEditorDialog(
			'default-collections', 
			{
				cls: 'collection-list',

				unique: true,
				sortable: 'y',

				normalize: function(title){ 
					return title.trim() },
				check: function(title){ 
					return title.length > 0 
						&& title != MAIN_COLLECTION_TITLE },
			})],

	// XXX edit collection title here???
	browseCollections: ['Collections/$Collec$tions...',
		core.doc`Collection list...

		NOTE: collections are added live and not on dialog close...
		`,
		widgets.makeUIDialog(function(action){
			var that = this
			var to_remove = []

			var collections = that.collection_order = 
				(that.collection_order || []).slice()

			var defaults = this.config['default-collections']
			if(defaults){
				collections = collections.concat(defaults).unique()
			}

			return browse.makeLister(null, 
				function(path, make){
					var dialog = this
						.on('update', function(){
							that.collection
								&& dialog.filter(JSON.stringify(that.collection))
									.addClass('highlighted')
						})

					var openHandler = function(_, title){
						var title = $(this).find('.text').attr('text') || title
						// create collection if it does not exist...
						if(!that.collections 
								|| !(title in that.collections)){
							that.newCollection(title)
						}

						var gid = that.current
						action ?
							action.call(that, title)
							: that.loadCollection(title)
						that.focusImage(gid)
						dialog.close()
					}
					var setItemState = function(title){
						var gid = ((that.collections || {})[title] || {}).gid || title
						// handle main collection changes...
						gid = title == MAIN_COLLECTION_TITLE ? 
							MAIN_COLLECTION_GID 
							: gid

						var text = this.find('.text').last()

						// saved state...
						var unsaved = that.changes === true 
							|| (that.changes || {})['collection: '+ JSON.stringify(gid)]
							|| (that.collectionGID == gid 
								&& (that.config['collection-transfer-changes'] || [])
									.filter(function(a){ 
										return !!(that.changes || {})[a] }).length > 0)
						unsaved
							&& text.attr('unsaved', true)

						// indicate collection crop...
						var cs = 
							title == (that.collection || MAIN_COLLECTION_TITLE) ? 
								that.crop_stack
							: (that.collections || {})[title] ?
								that.collections[title].crop_stack
							: null
						cs
							&& text.attr('cropped', cs.length)
					}

					// update collection list if changed externally...
					// XXX do we need this???
					collections.splice.apply(collections, [0, collections.length].concat(
						collections
							.concat(this.collection_order || [])
							.unique()))

					// main collection...
					!action 
						&& collections.indexOf(MAIN_COLLECTION_TITLE) < 0
						&& make([
								MAIN_COLLECTION_TITLE,
							], 
							{ events: {
								update: function(_, title){
									// make this look almost like a list element...
									// XXX hack???
									$(this).find('.text:first-child')
										.before($('<span>')
											.css('color', 'transparent')
											.addClass('sort-handle')
											.html('&#x2630;'))
									setItemState
										//.call($(this), title)
										.call($(this), $(this).find('.text').attr('text'))
								},
								open: openHandler,
							}})

					// collection list...
					make.EditableList(collections, 
						{
							unique: true,
							sortable: 'y',
							to_remove: to_remove,

							itemopen: openHandler,

							normalize: function(title){ 
								return title.trim() },
							check: function(title){ 
								return title.length > 0 },

							each: setItemState, 

							itemadded: function(title){
								action ?
									that.newCollection(title)
									: that.saveCollection(title) },

							disabled: action ? [MAIN_COLLECTION_TITLE] : false,
						})
				}, {
					cls: 'collection-list',
					// focus current collection...
					selected: JSON.stringify(
						(that.collection || MAIN_COLLECTION_TITLE)
							// XXX not sure it is good that we have to do this...
							.replace(/\$/g, '')),
				})
				.close(function(){
					that.collection_order = collections

					to_remove
						.forEach(function(title){ that.removeCollection(title) }) 
				})
		})],
	browseImageCollections: ['Collections|Image/Image $collections...',
		widgets.makeUIDialog(function(gid){
			var that = this
			gid = this.data.getImage(gid)

			var defaults = this.config['default-collections']

			var all
			var collections
			var to_remove

			return browse.makeLister(null, 
				function(path, make){
					var dialog = this
						.on('update', function(){
							that.collection
								&& dialog.filter(JSON.stringify(that.collection))
									.addClass('highlighted')
						})

					//all = Object.keys(that.collections || {})
					all = that.collection_order = that.collection_order || []

					if(defaults){
						all = all.concat(defaults).unique()
					}

					collections = collections 
						|| that.inCollections(gid || null)

					// build the disabled list...
					if(!to_remove){
						to_remove = []
						all.forEach(function(title){
							collections.indexOf(title) < 0
								&& to_remove.push(title)
						})
					}

					all.length > 0 ?
						make.EditableList(all, 
							{
								new_item: false,
								to_remove: to_remove,
								itemopen: function(_, title){
									var i = to_remove.indexOf(title)

									i >= 0 ? 
										to_remove.splice(i, 1) 
										: to_remove.push(title)

									dialog.update()
								},
							})
						: make.Empty('No collections...')
				})
				.close(function(){
					all.forEach(function(title){
						collections.indexOf(title) < 0
							&& to_remove.indexOf(title) < 0
							&& that.collect(gid, title)
					})
					to_remove.forEach(function(title){ 
						that.uncollect(gid, title)
					}) 
				})
		})],

	// Collection actions with collection selection...
	//
	// XXX should we warn the user when overwriting???
	saveAsCollection: ['Collections/$Save as collection...',
		widgets.uiDialog(function(){
			return this.browseCollections(function(title){
				this.saveCollection(title, 'current') 
				// XXX should we be doing this manually here or in .saveCollection(..)
				title == this.collection
					&& this.loadCollection('!')
			}) })],
	addToCollection: ['Collections|Image/Add $image to collection...',
		widgets.uiDialog(function(gids){
			return this.browseCollections(function(title){
				this.collect(gids || 'current', title) }) })],
	addRibbonToCollection: ['Collections|Ribbon/Add $ribbon to collection...',
		widgets.uiDialog(function(){ return this.addToCollection('ribbon') })],
	addLoadedToCollection: ['Collections/$Add loaded images to collection...',
		widgets.uiDialog(function(){ return this.addToCollection('loaded') })],
	joinToCollection: ['Collections/$Merge view to collection...',
		widgets.uiDialog(function(){
			return this.browseCollections(function(title){
				this.joinCollect(title) }) })],

	// XXX should this be here???
	addMarkedToCollection: ['Collections|Mark/Add marked to $collection...',
		{browseMode: function(){ 
			return this.marked.length == 0 && 'disabled' }},
		widgets.uiDialog(function(gids){
			return this.browseCollections(function(title){
				this.collectMarked(gids || this.current, title) }) })],

	/*/ XXX this is not used by metadata yet...
	metadataSection: ['- Image/',
		function(gid, make){
		}],
	//*/
})

var UICollection = 
module.UICollection = core.ImageGridFeatures.Feature({
	title: '',
	doc: '',

	tag: 'ui-collections',
	depends: [
		'ui',
		'collections',

		// XXX needed only for .addMarkedToCollection(..)
		'collection-tags',
	],

	actions: UICollectionActions, 

	handlers: [
		// we need to do this as we transfer tags after everything is 
		// loaded...
		['collectionLoading',
			function(){
				this.reload() 
			}],

		// update view when editing current collection...
		[[
			'uncollect', 
			'joinCollect',
		],
			function(_, gids, collection){
				(collection == null || this.collection == collection)
					&& this.reload(true)
			}],

		// maintain crop viewer state when loading/unloading collections...
		['load clear reload collectionLoading collectionUnloaded',
			function(){
				if(!this.dom){
					return
				}
				this.dom[this.collection ? 
					'addClass' 
					: 'removeClass']('collection-mode')

				this.dom[this.cropped ? 
					'addClass' 
					: 'removeClass']('crop-mode')
			}],
	],
})



//---------------------------------------------------------------------
// XXX collection id...
// XXX Things to try/do:
// 		- save collection on exit/write (?)
// 		- lazy load collections (load list, lazy-load data)
// 			- collection index
// 		- load directories as collections (auto?)...
// 		- export collections to directories...
// 		- auto-export collections (on save)...
// 			- add new images
// 			- remove old images...
// 		- collection history (same as ctrl-shift-h)...

var FileSystemCollectionActions = actions.Actions({

	// Format:
	// 	{
	// 		path: <string>,
	// 		...
	// 	}
	collections: null,

	collectionPathLoader: ['- Collections/',
		{collectionFormat: 'path'},
		function(data, loader){ 
			// XXX
		}],

	importCollectionsFromPath: ['- Collections|File/Import collections from path',
		function(path){
			// XXX
		}],
})


// XXX manage format...
// XXX manage changes...
var FileSystemCollection = 
module.FileSystemCollection = core.ImageGridFeatures.Feature({
	title: '',
	doc: '',

	tag: 'fs-collections',
	depends: [
		'index-format',
		'fs',
		'collections',
	],

	actions: FileSystemCollectionActions,

	handlers: [
	],
})



//---------------------------------------------------------------------
// XXX localstorage-collections (???)




/**********************************************************************
* vim:set ts=4 sw=4 :                               */ return module })