require 'spec_helper'

describe Prawn::Graphics::Transparency do
  def make_transparent(opacity, stroke_opacity = opacity)
    pdf.transparent(opacity, stroke_opacity) do
      yield if block_given?
    end
  end

  let(:pdf) { create_pdf }

  it 'the PDF version should be at least 1.4' do
    make_transparent(0.5)
    str = pdf.render
    expect(str[0, 8]).to eq('%PDF-1.4')
  end

  it 'a new extended graphics state should be created for ' \
    'each unique transparency setting' do
    make_transparent(0.5, 0.2) do
      make_transparent(0.5, 0.75)
    end
    extgstates = PDF::Inspector::ExtGState.analyze(pdf.render).extgstates
    expect(extgstates.length).to eq(2)
  end

  it 'a new extended graphics state should not be created for ' \
    'each duplicate transparency setting' do
    make_transparent(0.5, 0.75) do
      make_transparent(0.5, 0.75)
    end
    extgstates = PDF::Inspector::ExtGState.analyze(pdf.render).extgstates
    expect(extgstates.length).to eq(1)
  end

  it 'setting the transparency with only one parameter sets the ' \
    'transparency for both the fill and the stroke' do
    make_transparent(0.5)
    extgstate = PDF::Inspector::ExtGState.analyze(pdf.render).extgstates[0]
    expect(extgstate[:opacity]).to eq(0.5)
    expect(extgstate[:stroke_opacity]).to eq(0.5)
  end

  it 'setting the transparency with a numerical parameter and ' \
    'a :stroke should set the fill transparency to the numerical parameter ' \
    'and the stroke transparency to the option' do
    make_transparent(0.5, 0.2)
    extgstate = PDF::Inspector::ExtGState.analyze(pdf.render).extgstates[0]
    expect(extgstate[:opacity]).to eq(0.5)
    expect(extgstate[:stroke_opacity]).to eq(0.2)
  end

  it 'does not allow negative values' do
    make_transparent(-0.5, -0.2)
    extgstate = PDF::Inspector::ExtGState.analyze(pdf.render).extgstates[0]
    expect(extgstate[:opacity]).to eq(0.0)
    expect(extgstate[:stroke_opacity]).to eq(0.0)
  end

  it 'does not allow too big values' do
    make_transparent(2.0, 3.0)
    extgstate = PDF::Inspector::ExtGState.analyze(pdf.render).extgstates[0]
    expect(extgstate[:opacity]).to eq(1.0)
    expect(extgstate[:stroke_opacity]).to eq(1.0)
  end

  describe 'with more than one page' do
    it 'the extended graphic state resource should be added to both pages' do
      make_transparent(0.5, 0.2)
      pdf.start_new_page
      make_transparent(0.5, 0.2)
      extgstates = PDF::Inspector::ExtGState.analyze(pdf.render).extgstates
      extgstate = extgstates[0]
      expect(extgstates.length).to eq(2)
      expect(extgstate[:opacity]).to eq(0.5)
      expect(extgstate[:stroke_opacity]).to eq(0.2)
    end
  end
end