require 'spec_helper'

describe Ferver::FileList do
  before { allow(Dir).to receive(:exist?).and_return(true) }
  subject { Ferver::FileList.new('/foo') }

  describe 'creating instance' do
    context 'when empty path argument is passed' do
      it 'should raise exception if no argument passed' do
        expect { Ferver::FileList.new }.to raise_error(ArgumentError)
      end
    end

    context 'when valid path argument is passed' do
      let(:path) { '/foo' }

      it 'should find files in path argument' do
        expect(Dir).to receive(:foreach).with(path).and_return(EMPTY_FILE_LIST)

        Ferver::FileList.new(path)
      end
    end

    context 'when path argument passed does not exist' do
      let(:path) { '/foo' }

      it 'should test if directory exists' do
        expect(Dir).to receive(:exist?).with(path).and_return(true)
        allow(Dir).to receive(:foreach).with(path).and_return(EMPTY_FILE_LIST)

        Ferver::FileList.new(path)
      end

      it 'should raise exception' do
        allow(Dir).to receive(:exist?).with(path).and_return(false)

        expect { Ferver::FileList.new(path) }.to raise_error(Ferver::DirectoryNotFoundError)
      end
    end
  end

  context 'when path directory is empty' do
    before { allow(Dir).to receive(:foreach).and_return(EMPTY_FILE_LIST) }

    it 'should have zero #file_count' do
      expect(subject.size).to eq(0)
    end

    it 'should return empty array of files' do
      expect(subject.all).to eq(EMPTY_FILE_LIST)
    end
  end

  context 'when path directory contains current working dir and parent' do
    before(:each) do
      allow(Dir).to receive(:foreach).and_yield('.').and_yield('.').and_yield('file1')
      allow(File).to receive(:file?).and_return(true)
    end

    it 'should not count current working dir and parent' do
      expect(subject.size).to eq(1)
    end

    it 'should not include current working dir and parent' do
      expect(subject.all).to eq(['file1'])
    end
  end

  context 'when path directory contains file and directory' do
    before(:each) do
      allow(Dir).to receive(:foreach).and_yield('file1').and_yield('a_directory')
      allow(File).to receive(:file?).twice.and_return(true, false)
    end

    it 'should not count the directory' do
      expect(subject.size).to eq(1)
    end

    it 'should not include the directory' do
      expect(subject.all).to eq(['file1'])
    end
  end

  context 'when path directory contains valid files' do
    let(:files) { %w(file1 file2) }
    before do
      allow(Dir).to receive(:foreach).and_yield(files[0]).and_yield(files[1])
      allow(File).to receive(:file?).twice.and_return(true)
    end

    it 'should count all files' do
      expect(subject.size).to eq(2)
    end

    it 'should list all files' do
      expect(subject.all).to eq(files)
    end

    describe 'iterating over files list' do
      it 'should yield files in order' do
        i = 0
        subject.each do | file |
          expect(file).to eq(files[i])
          i += 1
        end
      end
    end
  end

  describe 'requesting files' do
    before(:each) do
      allow(Dir).to receive(:foreach).and_yield('file1').and_yield('file2')
      allow(File).to receive(:file?).and_return(true)
    end

    context 'when requesting valid file_id' do
      # TODO: possible to redesign this

      it '#file_id_is_valid? should return true for first file' do
        expect(subject.file_id_is_valid?(0)).to be_truthy
      end

      it '#file_id_is_valid? should return true for second file' do
        expect(subject.file_id_is_valid?(1)).to be_truthy
      end

      it '#file_by_id should return the correct file for the first file' do
        expect(subject.file_by_id(0)).to eq('file1')
      end

      it '#file_by_id should return the correct file for the second file' do
        expect(subject.file_by_id(1)).to eq('file2')
      end
    end

    context 'when requesting invalid file_id' do
      it 'should return false for invalid file_id' do
        expect(subject.file_id_is_valid?(2)).to be_falsey
      end

      it 'should raise_error if file_by_id is called' do
        expect { subject.file_by_id(2) }.to raise_error(IndexError)
      end
    end
  end
end