#coding: utf-8
module BootstrapTabHelper
  extend ActiveSupport::Concern

  include BootstrapHelper

  class TabBuilder
    attr_accessor :tabs, :default_index, :options, :template

    def initialize(index, template, options={})
      @default_index, @options, @template = index, options, template
      @tabs = {}
    end

    # tab label and content of tabs
    #
    # label - label of tab
    # options -
    #   disabled  - true, false default: false
    #   clickable - true, false default: true
    #   other options that can be accpted by li
    #   pane_options -
    #     every option that can be accepted by div
    def tab(label, options={}, &proc)
      default_options = {disabled: false, clickable: true}
      pane_options = options.delete(:pane_options) || {}
      @tabs[label] = [options.reverse_merge!(default_options), pane_options, proc]
    end

    def to_s

      style = @options.delete(:style)
      inline = @options.delete(:inline)
      position = @options.delete(:position)
      #align = @options.delete(:align)
      stacked = @options.delete(:stacked)

      @options[:class] ||= ''
      @options[:class] << ' nav-stacked' if stacked
      #@options[:class] << " pull-#{align}" if align
      @options[:class] << ' nav nav-tabs' if style == 'tab'
      @options[:class] << ' nav nav-pills' if style == 'pill'

      wrap_options = {style: "display: #{inline ? 'inline-block' : 'block'};", class: " tabbable tabs-#{position}"}

      content_options = @options.delete(:content_options) || {}
      content_options[:class] ||= ''
      content_options[:class] << ' tab-content'

      @template.div(wrap_options) do
        tab_content = ''
        tab_content << @template.list(@options) do |li|
          @tabs.keys.each do |k|
            render_label(li, style,
                         k,
                         @tabs.keys.index(k) == @default_index.to_i,
                         "#{@options[:id]}-tab-#{@tabs.keys.index(k)}",
                         @tabs[k][0])
          end
        end

        tab_content << @template.div(content_options) do
          tab_panes = ''
          @tabs.values.each do |v|

            tab_panes << render_content(@tabs.values.index(v) == @default_index.to_i,
                                        "#{@options[:id]}-tab-#{@tabs.values.index(v)}",
                                        v[1],
                                        &v[2])

          end
          tab_panes.html_safe
        end

        tab_content.html_safe
      end

    end

    private

    def render_label(li, style, title, show, link_id, options={})
      tab_class = show ? 'active' : ''
      tab_class << ' disabled' if options.delete(:disabled)

      clickable = options.delete(:clickable)

      li.add @template.link_to(title.html_safe, "##{clickable ? link_id : ''}", data: {toggle: style}),
             options.merge!({class: tab_class})
    end

    def render_content(show, link_id, options={}, &proc)

      options[:class] ||= ''
      options[:class] << " tab-pane #{show ? 'active' : ''}"
      options[:id] = link_id

      @template.div(options) do
        @template.capture(&proc) if proc
      end
    end
  end

  #显示tab页
  #index: 默认显示第几个标签
  #options:
  #  style: pill, tab  default: tab
  #  position: below, left, right direction of tab
  #  align: left, right. the alignment of tab, NOT AVAILABLE NOW
  #  inline: true ,false default: false
  #  stacked: true, false default: false
  #  content_options
  #    every option that can be accepted by div
  def tabs(index=0, options={}, &proc)
    default_options = {inline: false, stacked: false, id: 'tabs', style: 'tab'}
    index, options = 0, index if index.is_a?(Hash)

    builder = TabBuilder.new(index, self, options.reverse_merge!(default_options))
    capture(builder, &proc)
    builder.to_s
  end


end