module CompatTables
  require 'json'
  require 'net/http'

  BROWSERS = {
    'chrome' => 'Chrome',
    'edge' => 'Edge',
    'firefox' => 'Firefox',
    'ie' => 'Internet Explorer',
    'opera' => 'Opera',
    'safari' => 'Safari',
    'webview_android' => 'WebView Android',
    'chrome_android' => 'Chrome Android',
    'firefox_android' => 'Firefox for Android',
    'opera_android' => 'Opera Android',
    'safari_ios' => 'Safari on IOS',
    'samsunginternet_android' => 'Samsung Internet'
  }

  def generate_compatibility_table()
    json_files_uri = request_bcd_uris()

    compat_tables = []

    json_files_uri.each do |uri|
      compat_tables.push(generate_compatibility_table_wrapper(uri))
    end

    return compat_tables
  end

  def request_bcd_uris
    index_json = JSON.load(Net::HTTP.get(URI(current_url.to_s + '/index.json')))

    uris = []

    index_json['doc']['body'].each do |element|
      uris.push(element['value']['dataURL']) if element['type'] == 'browser_compatibility' and element['value']['dataURL']
    end

    uris.map! do |uri|
      tmp_uri = URI.parse(base_url.to_s)
      tmp_uri.path = uri
      uri = tmp_uri.to_s
    end

    return uris
  end

  def generate_compatibility_table_wrapper(uri)

    @json_data = JSON.load(Net::HTTP.get(URI(uri)))['data']

    html_table = generate_basic_html_table()

    @json_data.keys.each do |key|
      if key == '__compat' or @json_data[key]['__compat']
        add_entry_to_table(html_table, key)
      else
      end
    end

    return html_table
  end

  def generate_basic_html_table
    table = Nokogiri::XML::Node.new('table', doc)

    table.add_child('<thead><tr id=bct-browser-type><tr id=bct-browsers><tbody>')

    table.css('#bct-browser-type').each do |node|
      node.add_child('<th>')
      %w(Desktop Mobile).each do |browser_type|
        node.add_child("<th colspan=6>#{browser_type}")
      end
    end

    table.css('#bct-browsers').each do |node|
      node.add_child('<th>')

      BROWSERS.values.each do |browser|
        node.add_child("<th>#{browser}")
      end
    end

    return table
  end

  def add_entry_to_table(html_table, key)
    json = @json_data[key]

    html_table.at_css('tbody').add_child('<tr>')

    last_table_entry = html_table.at_css('tbody').last_element_child

    if key == '__compat'
      tmp = slug.split('/')
      last_table_entry.add_child("<th><code>#{tmp.last}")
    else
      last_table_entry.add_child("<th><code>#{key}")
    end


    BROWSERS.keys.each do |browser_key|
      if key == '__compat'
        add_data_to_entry(json['support'][browser_key], last_table_entry)
      else
        add_data_to_entry(json['__compat']['support'][browser_key], last_table_entry)
      end

    end
  end

  def add_data_to_entry(json, entry)
    version_added = []
    version_removed = []
    notes = []

    if json
      if json.is_a?(Array)
        json.each do |element|

          if element['version_added']
            version_added.push(element['version_added'])
          else
            version_added.push(false)
          end

          if element['version_removed']
            version_removed.push(element['version_removed'])
          else
            version_removed.push(false)
          end

          if element['notes']
            notes.push(element['notes'])
          else
            notes.push(false)
          end

        end
      else
        version_added.push(json['version_added'])
        version_removed.push(json['version_removed'])
        notes.push(json['notes'])
      end

      version_added.map! do |version|
        if version == true
          version = 'Yes'
        elsif version == false
          version = 'No'
        elsif version.is_a?(Numeric)
        else
          version = '?'
        end

        version
      end

      if version_removed[0]
        format_string = "<td class=bc-supports-no>"
      else
        if version_added[0] == 'No'
          format_string = "<td class=bc-supports-no>"
        else
          format_string = "<td class=bc-supports-yes>"
        end
      end

      for value in (0..version_added.length-1) do
        if version_removed[value]
          format_string += "<div>#{version_added[value]}-#{version_removed[value]}</div>"
        else
          if version_added[value] == 'No'
            format_string += "<div>#{version_added[value]}</div>"
          else
            format_string += "<div>#{version_added[value]}</div>"
          end
        end

        if notes[value]
          format_string += "<div>#{notes[value]}</div>"
        end
      end

    else
      format_string = "<td class=bc-supports-no><div>?</div></td>"
    end

    entry.add_child(format_string)
  end

end