$(document).ready ->
  # Mobile navigation
  toggleSidebar = ->
    $('.navbar-toggler, .row-offcanvas').toggleClass 'show'

  $('[data-toggle="offcanvas"]').click toggleSidebar

  $('[data-action="sidebar-nav"]').click (event) ->
    if $('.navbar-toggler').is(':visible')
      event.preventDefault()
      toggleSidebar()
      setTimeout ->
        window.location = event.target.href
      , 260 # Wait for the sidebar to slide away before navigating

  # Initialize Scrollspy for sidebar navigation; http://v4-alpha.getbootstrap.com/components/scrollspy/
  # See also http://www.codingeverything.com/2014/02/BootstrapDocsSideBar.html and http://jsfiddle.net/KyleMit/v6zhz/
  $('body').scrollspy
    target: '#contents'
    offset: Math.round $('main').css('padding-top').replace('px', '')

  initializeScrollspyFromHash = (hash) ->
    $("#contents a.active[href!='#{hash}']").removeClass 'show'

  $(window).on 'activate.bs.scrollspy', (event, target) -> # Why `window`? https://github.com/twbs/bootstrap/issues/20086
    # We only want one active link in the nav
    $("#contents a.active[href!='#{target.relatedTarget}']").removeClass 'show'
    $target = $("#contents a[href='#{target.relatedTarget}']")
    # Update the browser address bar on scroll or navigation
    window.history.pushState {}, $target.text(), $target.prop('href')


  # Initialize CodeMirror for code examples; https://codemirror.net/doc/manual.html
  editors = []
  lastCompilationElapsedTime = 200
  $('textarea').each (index) ->
    $(@).data 'index', index
    mode = if $(@).hasClass('javascript-output') then 'javascript' else 'coffeescript'

    editors[index] = editor = CodeMirror.fromTextArea @,
      mode: mode
      theme: 'twilight'
      indentUnit: 2
      tabSize: 2
      lineWrapping: on
      lineNumbers: off
      inputStyle: 'contenteditable'
      readOnly: mode isnt 'coffeescript' # Can’t use 'nocursor' if we want the JavaScript to be copyable
      viewportMargin: Infinity

    # Whenever the user edits the CoffeeScript side of a code example, update the JavaScript output
    # If the editor is Try CoffeeScript, also update the hash and save this code in localStorage
    if mode is 'coffeescript'
      pending = null
      editor.on 'change', (instance, change) ->
        clearTimeout pending
        pending = setTimeout ->
          lastCompilationStartTime = Date.now()
          try
            coffee = editor.getValue()
            if index is 0 and $('#try').hasClass('show') # If this is the editor in Try CoffeeScript and it’s still visible
              # Update the hash with the current code
              link = "try:#{encodeURIComponent coffee}"
              window.history.pushState {}, 'CoffeeScript', "#{location.href.split('#')[0]}##{link}"
              # Save this to the user’s localStorage
              try
                if window.localStorage?
                  window.localStorage.setItem 'tryCoffeeScriptCode', coffee
              catch exception
            output = CoffeeScript.compile coffee, bare: yes
            lastCompilationElapsedTime = Math.max(200, Date.now() - lastCompilationStartTime)
          catch exception
            output = "#{exception}"
          editors[index + 1].setValue output
        , lastCompilationElapsedTime

      # Fix the code editors’ handling of tab-indented code
      editor.addKeyMap
        'Tab': (cm) ->
          if cm.somethingSelected()
            cm.indentSelection 'add'
          else if /^\t/m.test cm.getValue()
            # If any lines start with a tab, treat this as tab-indented code
            cm.execCommand 'insertTab'
          else
            cm.execCommand 'insertSoftTab'
        'Shift-Tab': (cm) ->
          cm.indentSelection 'subtract'
        'Enter': (cm) ->
          cm.options.indentWithTabs = /^\t/m.test cm.getValue()
          cm.execCommand 'newlineAndIndent'

  # Handle the code example buttons
  $('[data-action="run-code-example"]').click ->
    run = $(@).data 'run'
    index = $("##{$(@).data('example')}-js").data 'index'
    js = editors[index].getValue()
    js = "#{js}\nalert(#{unescape run});" unless run is yes
    eval js


  # Try CoffeeScript
  toggleTry = (checkLocalStorage = no) ->
    if checkLocalStorage and window.localStorage?
      try
        coffee = window.localStorage.getItem 'tryCoffeeScriptCode'
        if coffee?
          editors[0].setValue coffee
      catch exception
    $('#try, #try-link').toggleClass 'show'
  closeTry = ->
    $('#try, #try-link').removeClass 'show'

  $('[data-toggle="try"]').click toggleTry
  $('[data-close="try"]').click closeTry


  # Configure the initial state
  if window.location.hash?
    if window.location.hash is '#try'
      toggleTry yes
    else if window.location.hash.indexOf('#try') is 0
      editors[0].setValue decodeURIComponent window.location.hash[5..]
      toggleTry()
    else
      initializeScrollspyFromHash window.location.hash
      if window.location.hash.length > 1
        # Initializing the code editors might’ve thrown off our vertical scroll position
        document.getElementById(window.location.hash.slice(1).replace(/try:.*/, '')).scrollIntoView()