spine.coffee

# In general, there are many places in the file where you can leave off the parens in function calls, if you like.

unless typeof exports is "undefined"    # `unless ... else` reads poorly in English. Better to stick to `if ... else`.
  Spine = exports
else
  Spine = @Spine = {}
  
Spine.version = "0.0.4"
  
$ = Spine.$ = @jQuery || @Zepto || -> arguments[0]    # In Coffee, `or` is preferred over `||`.

makeArray = Spine.makeArray = (args) ->
  Array.prototype.slice.call(args, 0)    # A shortcut for prototype accessors is: `::`  `Array::slice` will do.
  
isArray = Spine.isArray = (value) ->
  Object.prototype.toString.call(value) == "[object Array]"  # Ditto. `Object::toString`
  
Events = Spine.Events = 
  bind: (ev, callback) ->
    evs   = ev.split(" ")
    calls = @_callbacks || @_callbacks = {}
  
    for name in evs
      @_callbacks[name] ?= []    # `or=` here would be more efficient, if it matters.
      @_callbacks[name].push(callback)
    @

  trigger: (args...) ->
    ev = args.shift()
  
    list = @_callbacks?[ev]
    return false unless list
  
    for callback in list
      if callback.apply(this, args) is false
        break      
    true

  unbind: (ev, callback) ->
    unless ev
      @_callbacks = {}
      return @
  
    list = @_callbacks?[ev]
    return @ unless list
  
    unless callback
      delete @_callbacks[ev]
      return @

    for cb, i in list    # You can use `when` to filter a comp. `for cb, i in list when cb is callback`
      if callback == cb
        list.splice(i, 1)
        break
    @

Log = Spine.Log =
  trace: true

  logPrefix: "(App)"

  log: (args...) ->
    return unless @trace
    return if typeof console == "undefined"    # In Coffee, prefer `is` to `==`.
    if @logPrefix then args.unshift(@logPrefix)
    console.log.apply(console, args)
    @
  
# Classes (or prototypial inheritors)
  
unless typeof Object.create is "function"    # This faux Object.create is not API compatible with the real thing, so be careful.
  Object.create = (o) ->
    F = ->
    F.prototype = o
    new F()
      
moduleKeywords = ["included", "extended"]

Class = Spine.Class = 
  inherited: ->
  created: ->
    
  prototype:
    initialize: ->
    init: ->

  create: (include, extend) ->
    object         = Object.create(@)
    object.parent  = @
    object:: = object.fn = Object.create(@::)

    object.include(include) if include
    object.extend(extend) if extend

    object.created()
    @inherited(object)
    object

  init: ->
    instance        = Object.create(@::)
    instance.parent = @

    instance.initialize.apply(instance, arguments)
    instance.init.apply(instance, arguments)
    instance

  proxy: (func) ->
    => func.apply(this, arguments)
    
  proxyAll: (names...) ->
    @[name] = @proxy(@[name]) for name in names

  include: (obj) ->
    for key, value of obj    # Again, you can use a `when` if you like.
      unless key in moduleKeywords 
        @::[key] = value

    included = obj.included
    included.apply(this) if included
    @

  extend: (obj) ->
    for key, value of obj
      unless key in moduleKeywords 
        @[key] = value
    
    extended = obj.extended
    extended.apply(this) if extended
    @
  
Class::proxy    = Class.proxy
Class::proxyAll = Class.proxyAll
Class.inst      = Class.init
Class.sub       = Class.create

Spine.guid = `function(){
  return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function(c) {
    var r = Math.random()*16|0, v = c == 'x' ? r : (r&0x3|0x8);
    return v.toString(16);
  }).toUpperCase();      
}`    # This shouldn't need to be backtick'd. No?

Model = Spine.Model = Class.create()
  
Model.extend(Events)

Model.extend 
  setup: (name, atts) ->
    model = Model.sub()
    model.name = name if name
    model.attributes = atts if atts
    model
    
  created: (sub) ->
    @records = {}
    if @attributes then makeArray(@attributes)    # Multi-line if/elses should probably use indentation.
    else @attributes = []

  find: (id) ->
    record = @records[id]
    throw("Unknown record") unless record
    record.clone()

  exists: (id) ->
    try
      return @find(id)
    catch e
      return false

  refresh: (values) ->
    values = @fromJSON(values)
    @records = {}

    for record in values
      record.newRecord = false
      @records[record.id] = record
    
    @trigger("refresh")
    @

  select: (callback) ->
    result = (record for id, record of @records when callback(record))
    @cloneArray(result)

  findByAttribute: (name, value) ->
    for id, record of @records
      if record[name] == value
        return record.clone()
    null

  findAllByAttribute: (name, value) ->
    @select (item) ->
      item[name] == value

  each: (callback) ->
    for key, value of @records
      callback(value)

  all: ->
    @cloneArray(@recordsValues())

  first: ->
    record = @recordsValues()[0]
    record?.clone()

  last: ->
    values = @recordsValues()
    record = values[values.length - 1]
    record?.clone()

  count: ->
    @recordsValues().length

  deleteAll: ->
    for key, value of @records
      delete @records[key]

  destroyAll: () ->    # Functions that take no arguments require no parens before the arrow.
    for key, value of @records
      @records[key].destroy()

  update: (id, atts) ->
    @find(id).updateAttributes(atts)

  create: (atts) ->
    record = @init(atts)
    record.save()

  destroy: (id) ->
    @find(id).destroy()

  sync: (callback) ->
    @bind("change", callback)

  fetch: (callbackOrParams) ->
    if typeof(callbackOrParams) == "function"
      @bind("fetch", callbackOrParams)
    else
      @trigger("fetch", callbackOrParams)

  toJSON: ->
    @recordsValues()
  
  fromJSON: (objects) ->
    return unless objects
    if typeof objects == "string"
      objects = JSON.parse(objects)
    if isArray(objects)
      return (@init(value) for value in objects)
    else
      @init(objects)

  # Private

  recordsValues: ->
    result = []
    for key, value of @records
      result.push(value)
    result

  cloneArray: (array) ->
    result = []
    result.push value.clone() for value in array
    result

Model.include 
  model: true
  newRecord: true

  init: (atts) ->
    @load atts if atts
    @trigger("init", this)

  isNew: () ->
    @newRecord
  
  isValid: () ->
    not @validate()

  validate: ->

  load: (atts) ->
    for key, value of atts
      @[key] = value

  attributes: ->
    result = {}
    result[key] = @[key] for key in @parent.attributes
    result.id   = @id
    result

  eql: (rec) ->
    rec && rec.id == @id && rec.parent == @parent

  save: ->
    error = @validate()
    if error
      @trigger("error", @, error)
      return false
    
    @trigger("beforeSave", @)
    if @newRecord then @create() else @update()
    @trigger("save", @)
    return @

  updateAttribute: (name, value) ->
    @[name] = value
    @save()

  updateAttributes: (atts) ->
    @load(atts)
    @save()
  
  destroy: ->
    @trigger("beforeDestroy", @)
    delete @parent.records[@id]
    @destroyed = true
    @trigger("destroy", @)
    @trigger("change", @, "destroy")

  dup: ->
    result = @parent.init(@attributes())
    result.newRecord = @newRecord
    result
  
  clone: ->
    Object.create(@)

  reload: ->
    return @ if @newRecord
    original = @parent.find(@id)
    @load(original.attributes())
    return original

  toJSON: ->
    @attributes()
  
  exists: ->
    @id && @id of @parent.records    # Prefer `and` to `&&`.

  # Private

  update: ->
    @trigger("beforeUpdate", @)
    records = @parent.records
    records[@id].load @attributes()
    clone = records[@id].clone()
    @trigger("update", clone)
    @trigger("change", clone, "update")

  create: ->
    @trigger("beforeCreate", @)
    @id          = Spine.guid() unless @id
    @newRecord   = false
    records      = @parent.records
    records[@id] = @dup()
    clone        = records[@id].clone()
    @trigger("create", clone)
    @trigger("change", clone, "create")
  
  bind: (events, callback) ->
    @parent.bind events, (record) =>
      if record && @eql(record)
        callback.apply(@, arguments)
  
  trigger: ->
    @parent.trigger.apply(@parent, arguments)
  
# Controllers
  
eventSplitter = /^(\w+)\s*(.*)$/

Controller = Spine.Controller = Class.create
  tag: "div"
  
  initialize: (options) ->
    @options = options

    for key, value of @options
      @[key] = value

    @el = document.createElement(@tag) unless @el
    @el = $(@el)

    @events = @parent.events unless @events
    @elements = @parent.elements unless @elements

    @delegateEvents() if @events
    @refreshElements() if @elements
    @proxyAll.apply(@, @proxied) if @proxied
      
  $: (selector) ->
    $(selector, @el)
      
  delegateEvents: ->
    for key of @events
      methodName = @events[key]
      method     = @proxy(@[methodName])
      
      match      = key.match(eventSplitter)
      eventName  = match[1]
      selector   = match[2]

      if selector == ''
        @el.bind(eventName, method)
      else
        @el.delegate(selector, eventName, method)
  
  refreshElements: ->
    for key, value of @elements
      @[value] = @$(key)
  
  delay: (func, timeout) ->
    setTimeout(@proxy(func), timeout || 0)

Controller.include(Events)
Controller.include(Log)

Spine.App = Class.create()
Spine.App.extend(Events)

Controller.fn.App = Spine.App