# frozen_string_literal: true

# File: engine_spec.rb
require_relative '../../spec_helper'

# Load the class under test
require_relative '../../../lib/macros4cuke/templating/engine'


module Macros4Cuke
module Templating # Open this namespace to get rid of module qualifier prefixes
describe Engine do
  # Sample template (consisting of a sequence of steps)
  let(:sample_template) do
    source = <<-SNIPPET
  Given I landed in the homepage
  And I fill in "Username" with "<userid>"
  And I fill in "Password" with "<password>"
  And I click "Sign in"
SNIPPET

    source
  end

  # Template containing two conditional sections
  let(:sophisticated_template) do
    source = <<-SNIPPET
  When I fill in "firstname" with "<firstname>"
  And I fill in "lastname" with "<lastname>"
  # Next line defines a comment
<?address>  And I fill in "address" with "<address>"</address>
  <?birthdate>
  And I fill in "birthdate" with "<birthdate>"
  </birthdate>
<?dummy></dummy>
  And I click "Register"
SNIPPET

    source
  end



  # Rule for default instantiation
  subject { Engine.new sample_template }


  context 'Class services:' do
    # Helper method.
    # Remove enclosing chevrons <..> (if any)
    def strip_chevrons(aText)
      return aText.gsub(/^<|>$/, '')
    end

    it 'should parse an empty text line' do
      # Expectation: result should be an empty array.
      expect(Engine.parse('')).to be_empty
    end

    it 'should parse a text line without tag' do
      sample_text = 'Mary has a little lamb'
      result = Engine.parse(sample_text)

      # Expectation: an array with one couple:
      # [:static, the source text]
      expect(result.size).to eq(1)
      expect(result[0]).to eq([:static, sample_text])
    end

    it 'should parse a text line that consists of just a tag' do
      sample_text = '<some_tag>'
      result = Engine.parse(sample_text)

      # Expectation: an array with one couple:
      # [:static, the source text]
      expect(result.size).to eq(1)
      expect(result[0]).to eq([:dynamic, strip_chevrons(sample_text)])
    end

    it 'should parse a text line with a tag at the start' do
      sample_text = '<some_tag>some text'
      result = Engine.parse(sample_text)

      # Expectation: an array with two couples:
      # [dynamic, 'some_tag'][:static, some text]
      expect(result.size).to eq(2)
      expect(result[0]).to eq([:dynamic, 'some_tag'])
      expect(result[1]).to eq([:static,  'some text'])
    end

    it 'should parse a text line with a tag at the end' do
      sample_text = 'some text<some_tag>'
      result = Engine.parse(sample_text)

      # Expectation: an array with two couples:
      # [:static, some text] [dynamic, 'some_tag']
      expect(result.size).to eq(2)
      expect(result[0]).to eq([:static,  'some text'])
      expect(result[1]).to eq([:dynamic, 'some_tag'])
    end

    it 'should parse a text line with a tag in the middle' do
      sample_text = 'begin <some_tag> end'
      result = Engine.parse(sample_text)

      # Expectation: an array with three couples:
      expect(result.size).to eq(3)
      expect(result[0]).to eq([:static,  'begin '])
      expect(result[1]).to eq([:dynamic, 'some_tag'])
      expect(result[2]).to eq([:static,  ' end'])
    end

    it 'should parse a text line with two tags in the middle' do
      sample_text = 'begin <some_tag>middle<another_tag> end'
      result = Engine.parse(sample_text)

      # Expectation: an array with items couples:
      expect(result.size).to eq(5)
      expect(result[0]).to eq([:static,  'begin '])
      expect(result[1]).to eq([:dynamic, 'some_tag'])
      expect(result[2]).to eq([:static, 'middle'])
      expect(result[3]).to eq([:dynamic, 'another_tag'])
      expect(result[4]).to eq([:static, ' end'])

      # Case: two consecutive tags
      sample_text = 'begin <some_tag><another_tag> end'
      result = Engine.parse(sample_text)

      # Expectation: an array with four couples:
      expect(result.size).to eq(4)
      expect(result[0]).to eq([:static,  'begin '])
      expect(result[1]).to eq([:dynamic, 'some_tag'])
      expect(result[2]).to eq([:dynamic, 'another_tag'])
      expect(result[3]).to eq([:static,  ' end'])
    end

    it 'should parse a text line with escaped chevrons' do
      sample_text = 'Mary has a \<little\> lamb'
      result = Engine.parse(sample_text)

      # Expectation: an array with one couple: [:static, the source text]
      expect(result.size).to eq(1)
      expect(result[0]).to eq([:static, sample_text])
    end

    it 'should parse a text line with escaped chevrons in a tag' do
      sample_text = 'begin <some_\<\\>weird\>_tag> end'
      result = Engine.parse(sample_text)

      # Expectation: an array with three couples:
      expect(result.size).to eq(3)
      expect(result[0]).to eq([:static,  'begin '])
      expect(result[1]).to eq([:dynamic, 'some_\<\\>weird\>_tag'])
      expect(result[2]).to eq([:static,  ' end'])
    end

    it 'should complain if a tag misses an closing chevron' do
      sample_text = 'begin <some_tag\> end'
      exc = StandardError
      err_msg = "Missing closing chevron '>'."
      expect { Engine.parse(sample_text) }.to raise_error(exc, err_msg)
    end

    it 'should complain if a text misses an opening chevron' do
      sample_text = 'begin <some_tag> > end'
      exc = StandardError
      err_msg = "Missing opening chevron '<'."
      expect { Engine.parse(sample_text) }.to raise_error(exc, err_msg)
    end

    it 'should complain if a text has nested opening chevrons' do
      sample_text = 'begin <<some_tag> > end'
      exc = StandardError
      err_msg = "Nested opening chevron '<'."
      expect { Engine.parse(sample_text) }.to raise_error(exc, err_msg)
    end
  end # context

  context 'Creation and initialization:' do
    it 'should accept an empty template text' do
      expect { Engine.new '' }.not_to raise_error
    end

    it 'should be created with a template text' do
      expect { Engine.new sample_template }.not_to raise_error
    end

    it 'should know the source text' do
      expect(subject.source).to eq(sample_template)

      # Case of an empty template
      instance = Engine.new ''
      expect(instance.source).to be_empty
    end

    it 'should accept conditional section' do
      expect { Engine.new sophisticated_template }.not_to raise_error
      instance = Engine.new sophisticated_template
      elements = instance.instance_variable_get(:@representation)
      sections = elements.select { |e| e.is_a?(Section) }
      names = sections.map(&:to_s)
      expect(names).to eq(%w[<?address> <?birthdate> <?dummy>])
    end

    it 'should complain when a placeholder is empty or blank' do
      text_w_empty_arg = sample_template.sub(/userid/, '')
      exc = Macros4Cuke::EmptyArgumentError
      msg = %(An empty or blank argument occurred in\
 'And I fill in "Username" with "<>"'.)
      expect { Engine.new text_w_empty_arg }.to raise_error(exc, msg)
    end

    it 'should complain when a placeholder contains an invalid character' do
      text_w_empty_arg = sample_template.sub(/userid/, 'user%id')
      exc = Macros4Cuke::InvalidCharError
      msg = "The invalid sign '%' occurs in the argument 'user%id'."
      expect { Engine.new text_w_empty_arg }.to raise_error(exc, msg)
    end

    it 'should complain when a section has no closing tag' do
      # Removing an end of section tag...
      text_w_open_section = sophisticated_template.sub(%r{</address>}, '')
      exc = StandardError
      msg = 'Unterminated section <?address>.'
      expect { Engine.new text_w_open_section }.to raise_error(exc, msg)
    end

    it 'should complain when a closing tag has no corresponding opening tag' do
      # Replacing an end of section tag by another...
      text_w_wrong_end = sophisticated_template.sub(%r{</address>}, '</foobar>')
      exc = StandardError
      msg = "End of section</foobar> doesn't match current section 'address'."
      expect { Engine.new text_w_wrong_end }.to raise_error(exc, msg)
    end

    it 'should complain when a closing tag is found without opening tag' do
      # Replacing an end of section tag by another...
      wrong_end = sophisticated_template.sub(/<\?birthdate>/, '</foobar>')
      msg = 'End of section</foobar> found'\
      ' while no corresponding section is open.'
      expect { Engine.new wrong_end }.to raise_error(StandardError, msg)
    end
  end # context

  context 'Provided services:' do
    it 'should know the variable(s) it contains' do
      # Case using the sample template
      expect(subject.variables).to be == %w[userid password]

      # Case of an empty source template text
      instance = Engine.new ''
      expect(instance.variables).to be_empty
    end


    it 'should render the text given the actuals' do
      locals = { 'userid' => 'johndoe' }

      rendered_text = subject.render(Object.new, locals)
      expected = <<-SNIPPET
  Given I landed in the homepage
  And I fill in "Username" with "johndoe"
  And I fill in "Password" with ""
  And I click "Sign in"
SNIPPET
      expect(rendered_text).to eq(expected)

      # Case of an actual that's not a String
      locals = { 'userid' => 'johndoe', 'password' => 12345 }
      rendered_text = subject.render(Object.new, locals)
      expected = <<-SNIPPET
  Given I landed in the homepage
  And I fill in "Username" with "johndoe"
  And I fill in "Password" with "12345"
  And I click "Sign in"
SNIPPET
      expect(rendered_text).to eq(expected)

      # Place actual value in context object
      Context = Struct.new(:userid, :password)
      context = Context.new('sherlock', 'holmes')
      rendered_text = subject.render(context, 'userid' => 'susan')
      expected = <<-SNIPPET
  Given I landed in the homepage
  And I fill in "Username" with "susan"
  And I fill in "Password" with "holmes"
  And I click "Sign in"
SNIPPET

      expect(rendered_text).to eq(expected)


      # Case of an empty source template text
      instance = Engine.new ''
      expect(instance.render(nil, {})).to be_empty
    end


    it 'should render conditional sections' do
      instance = Engine.new(sophisticated_template)

      locals = {
        'firstname' => 'Anon',
        'lastname' => 'Eemoos',
        'birthdate' => '1976-04-21'
      }
      rendered_text = instance.render(Object.new, locals)
      expected = <<-SNIPPET
  When I fill in "firstname" with "Anon"
  And I fill in "lastname" with "Eemoos"
  And I fill in "birthdate" with "1976-04-21"
  And I click "Register"
SNIPPET

      expect(rendered_text).to eq(expected)

      # Redo with another context
      locals['birthdate'] = nil
      locals['address'] = '122, Mercer Street'

      rendered_text = instance.render(Object.new, locals)
      expected = <<-SNIPPET
  When I fill in "firstname" with "Anon"
  And I fill in "lastname" with "Eemoos"
  And I fill in "address" with "122, Mercer Street"
  And I click "Register"
SNIPPET

      expect(rendered_text).to eq(expected)
    end


    it 'should render multivalued actuals' do
      locals = { 'userid' => %w[johndoe yeti] } # Silly case

      rendered_text = subject.render(Object.new, locals)
      expected = <<-SNIPPET
  Given I landed in the homepage
  And I fill in "Username" with "johndoe<br/>yeti"
  And I fill in "Password" with ""
  And I click "Sign in"
SNIPPET

      expect(rendered_text).to eq(expected)
    end
  end # context
end # describe
end # module
end # module

# End of file