store.coffee

#Store('score') # undefined
#Store('score',1)
#Store('score') # 1
#Store('score','',-1) # expires
#Store('score') # undefined
#Store('score', 1) # 1
#Store('score', -> 2 ) # 1 only calls function if 'score' not found
#Store('score','',-1)
#Store('score', -> 2 ) # 2

window.Store = ->
  localStorageSupported = localStorage?

  createCookie = (name, value, days=3650) ->
    if days
      date = new Date
      date.setTime(date.getTime() + (days*24*60*60*1000))
      expires = "; expires=" + date.toGMTString()
    else
      expires =  ""
    document.cookie = name + "=" + value + expires + "; path=/"

  getCookie = (key) ->
    key += "="
    for c in document.cookie.split(';')
      c.substring(1, c.length) while c.charAt(0) is ' '
      return c.substring(key.length, c.length) if c.indexOf(key) == 0
    return null

  methods = if localStorageSupported
    set: (key, value) -> localStorage[key] = value
    get: (key) -> localStorage[key]
    expire: (key) -> localStorage.removeItem(key)
  else
    set: (key, value) -> createCookie(key, value, 1)
    get: getCookie
    expire: (key) -> createCookie(key, "", -1)

  switch (a = arguments).length
    when 0 then methods
    when 1 then methods.get(a[0])
    when 2
      if _.isFunction a[1]
        if methods.get(a[0])
          methods.get(a[0])
        else
          methods.set(a[0], a[1]())
      else
        methods.set(a[0],a[1])
    when 3 then methods.expire(a[0])