require 'spec_helper'

describe ActiveRecord::Relation do
  before(:each) do
    Economist.delete_all
    EconomicSchool.delete_all
  end

  describe "#to_structs" do
    it 'responds to :to_structs' do
      expect(Economist.all.respond_to?(:to_structs)).to eq(true)
    end

    it 'raises an error when the relation has no select_values' do
      expect do
        Economist.all.to_structs(Struct.new(:test_struct))
      end.to raise_error(ArgumentError, 'Expected select_values to be present')
    end

    it 'returns an empty array when no results are returned' do
      expect(Economist.where('1 = 0').select(:id).to_structs(Struct.new(:test_struct))).to eq([])
    end

    it 'returns an array with struct instances' do
      hayek = Economist.create!(name: 'F.A. Hayek')
      id_struct = Struct.new(:id)
      expect(Economist.all.select(:id).to_structs(id_struct)).to eq([id_struct.new(hayek.id)])
    end

    it 'handles joined elements properly' do
      austrian = EconomicSchool.create!(name: 'Austrian Economics')
      hayek = Economist.create!(name: 'F.A. Hayek', economic_school: austrian)
      test_struct = Struct.new(:name, :school)
      expect(
        Economist
          .joins(:economic_school)
          .select('economists.name', 'economic_schools.name as school_name')
          .to_structs(test_struct)
      ).to eq([test_struct.new(hayek.name, austrian.name)])
    end

    it 'incorporates both integer and text where bind parameters' do
      hayek = Economist.create!(name: 'F.A. Hayek')
      test_struct = Struct.new(:id, :name)

      structs = Economist
        .where(
          :id => [hayek.id],
          :name => hayek.name,
        )
        .select(:id, :name)
        .to_structs(test_struct)

      expect(structs).to eq([test_struct.new(hayek.id, hayek.name)])
    end

    it 'properly casts values from arbitrary calculated columns' do
      hayek = Economist.create!(name: 'F.A. Hayek')
      scope = Economist.all
      pluck_results = scope.pluck(Arel.sql("date('now')"))
      pluck_column_klass = pluck_results.first.class

      date_struct = Struct.new(:date)
      struct_scope = scope.select("date('now')")
      structs_results = struct_scope.to_structs(date_struct)
      struct_column_klass = structs_results.first.date.class
      expect(pluck_column_klass).to eq(struct_column_klass)
    end

    it 'properly casts a single array column' do
      Economist.create!(name: 'F.A. Hayek')

      if active_record_supports_arrays?
        test_struct = Struct.new(:names)
        structs_results = Economist.select('array[name]').to_structs(test_struct)
        expect(structs_results.first.names).to eq(['F.A. Hayek'])
      else
        skip "DB selection doesn't support ARRAY[]"
      end
    end

    it 'raises an error when column count does not match struct size' do
      expect do
        test_struct = Struct.new(:id, :name, :extra_field)
        Economist.select('id, name').to_structs(test_struct)
      end.to raise_error(ArgumentError, 'Expected struct fields and columns lengths to be equal')
    end

    it 'raises an error when column names are not unique' do
      expect do
        test_struct = Struct.new(:id, :id2)
        Economist.select('id, id').to_structs(test_struct)
      end.to raise_error(ArgumentError, 'Expected column names to be unique')
    end
  end
end