local v = require 'semver'

local function checkVersion(ver, major, minor, patch, prerelease, build)
  assert_equal(major, ver.major)
  assert_equal(minor, ver.minor)
  assert_equal(patch, ver.patch)
  assert_equal(prerelease, ver.prerelease)
  assert_equal(build, ver.build)
end

context('semver', function()

  context('creation', function()

    context('from numbers', function()
      it('parses 3 numbers correctly', function()
        checkVersion(v(1,2,3), 1,2,3)
      end)

      it('parses 2 numbers correctly', function()
        checkVersion(v(1,2), 1,2,0)
      end)

      it('parses 1 number correctly', function()
        checkVersion(v(1), 1,0,0)
      end)

      it('parses prereleases', function()
        checkVersion(v(1,2,3,"-alpha"), 1,2,3,"alpha")
      end)
      it('parses builds', function()
        checkVersion(v(1,2,3,"+build.1"), 1,2,3,nil,"build.1")
      end)
    end)

    describe("from strings", function()
      test("1.2.3", function()
        checkVersion( v'1.2.3', 1,2,3)
      end)
      test("10.20.123", function()
        checkVersion( v'10.20.123', 10,20,123)
      end)
      test("2.0", function()
        checkVersion( v'2.0', 2,0,0)
      end)
      test("5", function()
        checkVersion( v'5', 5,0,0)
      end)
      test("1.2.3-alpha", function()
        checkVersion( v'1.2.3-alpha', 1,2,3,'alpha' )
      end)
      test("1.2.3+build.15", function()
        checkVersion( v'1.2.3+build.15', 1,2,3,nil,'build.15' )
      end)
    end)

    describe('errors', function()
      test('no parameters are passed', function()
        assert_error(function() v() end)
      end)
      test('negative numbers', function()
        assert_error(function() v(-1, 0, 0) end)
        assert_error(function() v( 0,-1, 0) end)
        assert_error(function() v( 0, 0,-1) end)
      end)
      test('floats', function()
        assert_error(function() v(.1, 0, 0) end)
        assert_error(function() v( 0,.1, 0) end)
        assert_error(function() v( 0, 0,.1) end)
      end)
      test('empty string', function()
        assert_error(function() v("") end)
      end)
      test('garbage at the beginning of the string', function()
        assert_error(function() v("foobar1.2.3") end)
      end)
      test('garbage at the end of the string', function()
        assert_error(function() v("1.2.3foobar") end)
      end)
      test('a non-string or number is passed', function()
        assert_error(function() v({}) end)
      end)
    end)
  end)

  describe("tostring", function()
    it("works with major, minor and patch", function()
      assert_equal("1.2.3", tostring(v(1,2,3)))
    end)

    it("works with a prerelease", function()
      assert_equal("1.2.3-beta", tostring(v(1,2,3,'-beta')))
    end)
    it("works with a build", function()
      assert_equal("1.2.3+foobar", tostring(v(1,2,3, '+foobar')))
    end)
  end)

  describe("==", function()
    it("is true when major, minor and patch are the same", function()
      assert_equal(v(1,2,3), v'1.2.3')
    end)
    it("is false when major, minor and patch are not the same", function()
      assert_not_equal(v(1,2,3), v(4,5,6))
    end)
    it("false if all is the same except the prerelease", function()
      assert_not_equal(v(1,2,3), v'1.2.3-alpha')
    end)
    it("false if all is the same except the build", function()
      assert_not_equal(v(1,2,3), v'1.2.3+peter.1')
    end)
  end)

  describe("<", function()
    test("true if major < minor", function()
      assert_less_than(v'1.100.10', v'2.0.0')
    end)
    test("false if major > minor", function()
      assert_greater_than(v'2', v'1')
    end)
    test("true if major = major but minor < minor", function()
      assert_less_than(v'1.2.0', v'1.3.0')
    end)
    test("false if minor < minor", function()
      assert_greater_than(v'1.1', v'1.0')
    end)
    test("true if major =, minor =, but patch <", function()
      assert_less_than(v'0.0.1', v'0.0.10')
    end)
    test("false if major =, minor =, but patch >", function()
      assert_greater_than(v'0.0.2', v'0.0.1')
    end)
    describe("prereleases", function()
      test("false if exact same prerelease", function()
        assert_false(v'1.0.0-beta' < v'1.0.0-beta')
      end)
      test("a prerelease version is less than the official version", function()
        assert_less_than(v'1.0.0-rc1', v'1.0.0')
      end)
      test("identifiers with only digits are compared numerically", function()
        assert_less_than(v'1.0.0-1', v'1.0.0-2')
        assert_less_than(v'1.0.0-2', v'1.0.0-10')
      end)
      test("itendifiers with letters or dashes are compared lexiconumerically", function()
        assert_less_than(v'1.0.0-alpha', v'1.0.0-beta')
        assert_less_than(v'1.0.0-alpha-10', v'1.0.0-alpha-2')
      end)
      test("numerical ids always have less priority than lexiconumericals", function()
        assert_less_than(v'1.0.0-1', v'1.0.0-alpha')
        assert_less_than(v'1.0.0-2', v'1.0.0-1asdf')
      end)
      test("identifiers can be separated by colons; they must be compared individually", function()
        assert_less_than(v'1.0.0-alpha',   v'1.0.0-alpha.1')
        assert_less_than(v'1.0.0-alpha.1', v'1.0.0-beta.2')
        assert_less_than(v'1.0.0-beta.2',  v'1.0.0-beta.11')
        assert_less_than(v'1.0.0-beta.11', v'1.0.0-rc.1')
      end)
    end)
    describe("builds", function()
      test("false if exact same build", function()
        assert_false(v'1.0.0+build1' < v'1.0.0+build1')
      end)
      test("a regular (not-build) version is always less than a build version", function()
        assert_less_than(v'1.0.0', v'1.0.0+12')
      end)
      test("identifiers with only digits are compared numerically", function()
        assert_less_than(v'1.0.0+1', v'1.0.0+2')
        assert_less_than(v'1.0.0+2', v'1.0.0+10')
      end)
      test("idendifiers with letters or dashes are compared lexiconumerically", function()
        assert_less_than(v'1.0.0+build1',  v'1.0.0+build2')
        assert_less_than(v'1.0.0+build10', v'1.0.0+build2')
      end)
      test("numerical ids always have less priority than lexiconumericals", function()
        assert_less_than(v'1.0.0+1', v'1.0.0+build1')
        assert_less_than(v'1.0.0+2', v'1.0.0+1build')
      end)
      test("identifiers can be separated by colons; they must be compared individually", function()
        assert_less_than(v'1.0.0+0.3.7', v'1.3.7+build')
        assert_less_than(v'1.3.7+build', v'1.3.7+build.2.b8f12d7')
        assert_less_than(v'1.3.7+build.2.b8f12d7', v'1.3.7+build.11.e0f985a')
      end)
    end)
  end)

  describe("nextPatch", function()
    it("increases the patch number by 1", function()
      assert_equal(v'1.0.1', v'1.0.0':nextPatch())
    end)
  end)

  describe("nextMinor", function()
    it("increases the minor number by 1", function()
      assert_equal(v'1.2.0', v'1.1.0':nextMinor())
    end)
    it("resets the patch number", function()
      assert_equal(v'1.2.0', v'1.1.7':nextMinor())
    end)
  end)

  describe("nextMajor", function()
    it("increases the major number by 1", function()
      assert_equal(v'2.0.0', v'1.0.0':nextMajor())
    end)
    it("resets the patch number", function()
      assert_equal(v'2.0.0', v'1.2.3':nextMajor())
    end)
  end)


  -- This works like the "pessimisstic operator" in Rubygems.
  -- if a and b are versions, a ^ b means "b is backwards-compatible with a"
  -- in other words, "it's safe to upgrade from a to b"
  describe("^", function()
    test("true for self", function()
      assert_true(v(1,2,3) ^ v(1,2,3))
    end)
    test("different major versions mean it's always unsafe", function()
      assert_false(v(2,0,0) ^ v(3,0,0))
      assert_false(v(2,0,0) ^ v(1,0,0))
    end)

    test("patch versions are always compatible", function()
      assert_true(v(1,2,3) ^ v(1,2,0))
      assert_true(v(1,2,3) ^ v(1,2,5))
    end)

    test("it's safe to upgrade to a newer minor version", function()
      assert_true(v(1,2,0) ^ v(1,5,0))
    end)
    test("it's unsafe to downgrade to an earlier minor version", function()
      assert_false(v(1,5,0) ^ v(1,2,0))
    end)
  end)

end)