class JsAjaxWizard

# File lib/jsajax_wizard.rb, line 45
def initialize(html='', debug: false)

  @html, @debug = RXFHelper.read(html).first, debug        
  @requests = []
  
  # search for AJAX placeholders
  scan_requests(@html)    

end

# File lib/jsajax_wizard.rb, line 55
def add_request(server: '', element: {}, trigger: nil, target_element: {}, 
                target_eval: false)
  type = element.any? ? [:element, element] : [:trigger, trigger]
  @requests << [server, type, target_element, target_eval ]
end

# File lib/jsajax_wizard.rb, line 61
def to_html()
  
  html = @html.empty? ? build_html : @html
  
  puts 'html: ' + html.inspect if @debug
  
  doc = Rexle.new(html)
  puts 'doc.xml: ' + doc.xml(pretty: true) if @debug
  add_events(doc)
  js = build_js(doc)
  doc.root.element('body').add(Rexle.new(js))    
  
  doc.xml    
end

# File lib/jsajax_wizard.rb, line 78
  def add_element_function(element, i, server, target, target_eval)
    
    puts ('element: ' + element.inspect).debug if @debug
    puts '::' + [element, i, server, target, target_eval].inspect if @debug
    
    a = []
    
    a << if element.is_a?(Hash) then
    
      if element[:type] == 'text' then
    
        if element[:event].to_sym == :on_enter then
      "
function ajaxCall#{i+1}(keyCode, e) {

if (keyCode==13){
  ajaxRequest('#{server}' + e.value, ajaxResponse#{i+1})
}  

}
"
        else
      "
function ajaxCall#{i+1}(e) {
  ajaxRequest('#{server}' + e.value, ajaxResponse#{i+1})
}
"
        end
        
      elsif element[:type] == 'timer'
      "
setInterval(
function() {
  ajaxRequest('#{server}', ajaxResponse#{i+1})
}, #{element[:interval]});
"        
      else
"
function ajaxCall#{i+1}() {
  ajaxRequest('#{server}', ajaxResponse#{i+1})
}
"  
      end
      
    else
      
 "
function ajaxCall#{i+1}(s) {
  ajaxRequest('#{server}' + escape(s), ajaxResponse#{i+1})
}
"     
    end

a << "
function ajaxResponse#{i+1}(xhttp) {
"      

    if target.is_a?(Hash) and target[:id] then
      
      a << "  document.getElementById('#{target[:id]}')" + 
          ".innerHTML = xhttp.responseText;"
    end

    if target_eval then
      
      a << "  eval(xhttp.responseText);"
      
    end

a << "
}
"      

    a.join

  
  end

# File lib/jsajax_wizard.rb, line 156
def add_events(doc)    
  
  @requests.each.with_index do |x,i|
    
    puts ('request x: ' + x.inspect).debug if @debug
    
    method(('modify_' + x[1].first.to_s).to_sym).call(x[1].last, doc, i)
          
  end
  
  doc
end

# File lib/jsajax_wizard.rb, line 169
def build_elements()

  html = @requests.map.with_index do |x,i|

    raw_e, e2 = x[1..-1]
    
    e = raw_e.last
    
    # e = element e.g. {type: 'button', event: 'onclick'}
    # e2 = target_element: {id: '', property: :innerHTML}

    a = if e[:type].to_s == 'button' then
    
      ["<button type='button''>Change Content</button>"]
      
    elsif e[:type].to_s == 'text' then
      
      ["<input type='text'/>"]
      
    else
      ['']
    end
    
    a << "<div id='%s'></div>" % [e2[:id]] if e2.is_a? Hash
    a.join("\n")

  end

  r = html.join("\n")
  puts 'r: ' + r.inspect if @debug
  r

end

# File lib/jsajax_wizard.rb, line 203
def build_html()

  RexleBuilder.build do |xml|
    xml.html do 
      xml.head do
        xml.meta name: "viewport", content: \
            "width=device-width, initial-scale=1"
        xml.style "\nbody {font-family: Arial;}\n\n"
      end
      xml.body build_elements
    end
  end
  
end

# File lib/jsajax_wizard.rb, line 218
  def build_js(doc)


ajax=<<EOF
function ajaxRequest(url, cFunction) {
  var xhttp;
  xhttp = new XMLHttpRequest();
  xhttp.onreadystatechange = function() {
    if (this.readyState == 4 && this.status == 200) {
      cFunction(this);
    }
  };
  xhttp.open("GET", url, true);
  xhttp.send();
}
EOF

    funcs_defined = @requests.map.with_index do |x,i|
      
      puts ('x: ' + x.inspect).debug if @debug
      server, raw_type, target, target_eval = x
      
      if raw_type.first == :trigger then
        modify_trigger_function(raw_type.last, i, server, doc)
      end
      
      add_element_function(raw_type.last, i, server, target, target_eval)
      
    end
    
    s = "\n\n" + ajax + "\n\n" + funcs_defined.join
    "\n  <script>\n%s\n  </script>\n" % s  

  end

# File lib/jsajax_wizard.rb, line 253
def modify_element(element, doc, i)
  
  selector = if element[:id] then
    '#' + element[:id]
  elsif element[:type]
    "*[@type='%s']" % element[:type]
  end
  
  if @debug then
    puts ("selector: %s" % selector.inspect).debug
    puts 'doc: ' + doc.xml(pretty: true).inspect
  end
  
  e = doc.at_css(selector)
  puts ('e: ' + e.inspect).debug if @debug
  return unless e
  puts ('e: ' + e.inspect).debug if @debug
  
  func = 'ajaxCall' + (i+1).to_s
  event = e.attributes[:type] == 'button' ? func + '()' : func + '(this)'
  
  puts ('element: ' + element.inspect).debug if @debug
  
  key = if element[:event] then
  
    if element[:event].to_sym == :on_enter then
      event = func + '(event.keyCode, this)'
      :onkeyup
    else
      element[:event].to_sym
    end
    
  else
    e.attributes[:type] == 'button' ? :onclick : :onkeyup
  end
  
  e.attributes[key] = event    
end

# File lib/jsajax_wizard.rb, line 292
def modify_trigger(element, doc, i)
end

# File lib/jsajax_wizard.rb, line 295
def modify_trigger_function(trigger, i, server, doc)
  
  doc.root.xpath('//script').each do |script|
    puts 'script: ' + script.inspect
    s = script.text.to_s
    
    script.text = s.sub(/#{trigger} = function\(\) {[^}]+/) {|x|
      a = x.lines
      indent = a[1][/\s+/]
      a[0..-2].join + indent + "ajaxCall#{i+1}(event.results[0][0]." + 
                                                     "transcript);\n" + a[-1]
    }
    
  end
  
end

# File lib/jsajax_wizard.rb, line 314
def scan_requests(html)
  

  a = html.scan(/\$\[([^\]]+)?\]\(([^\)]+)/)

  a.each do |var, url|

    #== fetch the trigger element details

    tag = html[/<[^<]+\$\[([^\]]+)?\]\(#{url}[^\>]+>/]
    element_name  = tag[/(?<=<)\w+/]
    event = tag[/(\w+)=["']\$\[([^\]]+)?\]\(#{url}/,1]

    # is there an id?
    id = tag[/(?<=id=["'])[^"']+/]

    h2 = if id then
      {id: id}
    else
      {type: element_name.to_sym }
    end

    element = h2.merge(event: event)

    if var.nil? then
      
      add_request(server: url, element: element, target_eval: true)
      next
      
    end

    #== fetch the target element details

    tag2 = html[/<[^<]+>\$#{var}</]
    # is there an id?
    target_id = tag2[/(?<=id=["'])[^"']+/]

    inner_html = tag2 =~ />\$#{var}</

    property = if inner_html then
    
      html.sub!(/>\$#{var}</,'>&nbsp;<')
      :innerHTML
      
    end

    target_element = {id: target_id, property: property}

    add_request(server: url, element: element, 
                target_element: target_element)
    
  end
  
end