require 'spec_helper'

describe TfIdfSimilarity::TermCountModel do
  let :text do
    "FOO-foo BAR bar \r\n\t 123 !@#"
  end

  let :tokens do
    ['FOO-foo', 'BAR', 'bar', "\r\n\t", '123', '!@#']
  end

  let :document_without_text do
    TfIdfSimilarity::Document.new('')
  end

  let :document do
    TfIdfSimilarity::Document.new(text)
  end

  let :document_with_tokens do
    TfIdfSimilarity::Document.new(text, :tokens => tokens)
  end

  let :document_with_term_counts do
    TfIdfSimilarity::Document.new(text, :term_counts => {'bar' => 5, 'baz' => 10})
  end

  context 'without documents', :unless => lambda{MATRIX_LIBRARY == :gsl} do
    let :model do
      TfIdfSimilarity::TermCountModel.new([], :library => MATRIX_LIBRARY)
    end

    describe '#documents' do
      it 'should be empty' do
        model.documents.should be_empty
      end
    end

    describe '#terms' do
      it 'should be empty' do
        model.terms.should be_empty
      end
    end

    describe '#average_document_size' do
      it 'should be zero' do
        model.average_document_size.should == 0
      end
    end

    describe '#document_count' do
      it 'should be zero' do
        model.document_count('xxx').should == 0
      end
    end

    describe '#term_count' do
      it 'should be zero' do
        model.term_count('xxx').should == 0
      end
    end
  end

  context 'with documents' do
    let :documents do
      [
        document, # 4 tokens
        document_with_tokens, # 3 tokens
        document_without_text, # 0 tokens
        document_with_term_counts, # 15 tokens
      ]
    end

    let :model do
      TfIdfSimilarity::TermCountModel.new(documents, :library => MATRIX_LIBRARY)
    end

    describe '#documents' do
      it 'should return the documents' do
        model.documents.should == documents
      end
    end

    describe '#terms' do
      it 'should return the terms' do
        model.terms.to_a.sort.should == ['bar', 'baz', 'foo', 'foo-foo']
      end
    end

    describe '#average_document_size' do
      it 'should return the average number of tokens in a document' do
        model.average_document_size.should == 5.5
      end
    end

    describe '#document_count' do
      it 'should return the number of documents the term appears in' do
        model.document_count('bar').should == 3
      end
    end

    describe '#term_count' do
      it 'should return the number of times the term appears in the corpus' do
        model.term_count('bar').should == 9
      end
    end
  end
end