require 'minitest/autorun'
require 'nokogiri'
require_relative '../lib/devcenter-parser/header_id_generator'

describe 'HeaderIdGeneratorTest' do
  it 'respects existing ids in non-header elements' do
    html = '<strong id="foo">clean</strong>'
    assert_equal html, result(html)
  end

  it 'inserts ids in subheaders' do
    html = '<h2>Foo Bar Header 123</h2>'
    assert_id result(html), 'h2', 'foo-bar-header-123'
  end

  it 'generates ids replacing inner non-alphanum chars with dashes' do
    ['Foo Bar', 'Foo-Bar', 'Foo#bar', 'Foo##Bar', 'Foo##Bar', '-$Foo##Bar$-'].each do |title|
      html = "<h2>#{title}</h2>"
      assert_id result(html), 'h2', 'foo-bar'
    end
  end


  describe 'ensures that there are not collisions between ids in subheaders' do
    describe 'by prepending the id of the previous headers as long as necessary' do
      it 'when there are conflicts on headers from different sections' do
        html = <<-HTML
          <h2>A</h2>
            <h3>B</h3>
              <h4>Z</h4>

          <h2>C</h2>
            <h3>B</h3>
              <h4>Z</h4>
        HTML
        result = result(html)
        %w{ a c }.each{ |id| assert_id(result, 'h2', id) }
        %w{ a-b c-b }.each{ |id| assert_id(result, 'h3', id) }
        %w{ a-b-z c-b-z }.each{ |id| assert_id(result, 'h4', id) }
      end

      it 'when there are conflicts on headers from different sections where some headers are missing' do
        html = <<-HTML
          <h2>A</h2>
            <h4>Z</h4>

          <h2>C</h2>
            <h3>Z</h3>
        HTML
        result = result(html)
        %w{ a c }.each{ |id| assert_id(result, 'h2', id) }
        %w{ c-z }.each{ |id| assert_id(result, 'h3', id) }
        %w{ a-z }.each{ |id| assert_id(result, 'h4', id) }
      end

      it 'when there are conflicts inside the same section' do
        html = <<-HTML
          <h2>D</h2>
            <h3>X</h3>
              <h4>Z</h4>
            <h3>Y</h3>
              <h4>Z</h4>
        HTML
        result = result(html)
        %w{ d }.each{ |id| assert_id(result, 'h2', id) }
        %w{ x y }.each{ |id| assert_id(result, 'h3', id) }
        %w{ x-z y-z }.each{ |id| assert_id(result, 'h4', id) }
      end
    end

    it 'by appending numbers for those subheaders with same nesting level and parent header name' do
      html = <<-HTML
        <h2>A</h2>
          <h3>B</h3>
          <h3>B</h3>

        <h2>C</h2>
        <h2>C</h2>
      HTML
      result = result(html)
      %w{ a c-1 c-2 }.each{ |id| assert_id(result, 'h2', id) }
      %w{ a-b-1 a-b-2 }.each{ |id| assert_id(result, 'h3', id) }
    end
  end

  def assert_id(html, tag, id)
    assert html.include?("<#{tag} id=\"#{id}\">"), "<#{tag} id=\"#{id}\"> not found"
  end

  def result(html)
    doc = Nokogiri::HTML::DocumentFragment.parse(html)
    HeaderIdGenerator.new(doc)
    doc.to_html
  end
end