Add tpl/site and tpl/hugo

This means that the current `.Site` and ´.Hugo` is available as a globals, so you can do `site.IsServer`, `hugo.Version` etc.

Fixes #5470
Fixes #5467
Fixes #5503

35 files changed, 518 insertions, 162 deletions

diff --git a/.gitignore b/.gitignore
index 568492d85..89244f128 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,4 @@
-hugo
+/hugo
 docs/public*
 /.idea
 hugo.exe
diff --git a/commands/commandeer.go b/commands/commandeer.go
index cd2866a27..b722991ab 100644
--- a/commands/commandeer.go
+++ b/commands/commandeer.go
@@ -17,10 +17,11 @@ import (
 	"bytes"
 	"errors"
 
-	"github.com/gohugoio/hugo/common/herrors"
-
 	"io/ioutil"
 
+	"github.com/gohugoio/hugo/common/herrors"
+	"github.com/gohugoio/hugo/common/hugo"
+
 	jww "github.com/spf13/jwalterweatherman"
 
 	"os"
@@ -105,7 +106,7 @@ func (c *commandeer) getErrorWithContext() interface{} {
 	m := make(map[string]interface{})
 
 	m["Error"] = errors.New(removeErrorPrefixFromLog(c.logger.Errors()))
-	m["Version"] = hugoVersionString()
+	m["Version"] = hugo.BuildVersionString()
 
 	fe := herrors.UnwrapErrorWithFileContext(c.buildErr)
 	if fe != nil {
@@ -379,7 +380,7 @@ func (c *commandeer) loadConfig(mustHaveConfigFile, running bool) error {
 	if themeVersionMismatch {
 		name := filepath.Base(dir)
 		cfg.Logger.ERROR.Printf("%s theme does not support Hugo version %s. Minimum version required is %s\n",
-			strings.ToUpper(name), helpers.CurrentHugoVersion.ReleaseVersion(), minVersion)
+			strings.ToUpper(name), hugo.CurrentVersion.ReleaseVersion(), minVersion)
 	}
 
 	return nil
diff --git a/commands/genman.go b/commands/genman.go
index ac4eaf8d1..720046289 100644
--- a/commands/genman.go
+++ b/commands/genman.go
@@ -17,6 +17,7 @@ import (
 	"fmt"
 	"strings"
 
+	"github.com/gohugoio/hugo/common/hugo"
 	"github.com/gohugoio/hugo/helpers"
 	"github.com/gohugoio/hugo/hugofs"
 	"github.com/spf13/cobra"
@@ -45,7 +46,7 @@ in the "man" directory under the current directory.`,
 			header := &doc.GenManHeader{
 				Section: "1",
 				Manual:  "Hugo Manual",
-				Source:  fmt.Sprintf("Hugo %s", helpers.CurrentHugoVersion),
+				Source:  fmt.Sprintf("Hugo %s", hugo.CurrentVersion),
 			}
 			if !strings.HasSuffix(cc.genmandir, helpers.FilePathSeparator) {
 				cc.genmandir += helpers.FilePathSeparator
diff --git a/commands/hugo.go b/commands/hugo.go
index 0bb15c3d1..759efc17b 100644
--- a/commands/hugo.go
+++ b/commands/hugo.go
@@ -23,6 +23,7 @@ import (
 	"sort"
 	"sync/atomic"
 
+	"github.com/gohugoio/hugo/common/hugo"
 	"github.com/pkg/errors"
 
 	"github.com/gohugoio/hugo/common/herrors"
@@ -1041,7 +1042,7 @@ func (c *commandeer) isThemeVsHugoVersionMismatch(fs afero.Fs) (dir string, mism
 		}
 
 		if minVersion, ok := tomlMeta["min_version"]; ok {
-			if helpers.CompareVersion(minVersion) > 0 {
+			if hugo.CompareVersion(minVersion) > 0 {
 				return absThemeDir, true, fmt.Sprint(minVersion)
 			}
 		}
diff --git a/commands/version.go b/commands/version.go
index b85f53725..287950a2d 100644
--- a/commands/version.go
+++ b/commands/version.go
@@ -14,16 +14,9 @@
 package commands
 
 import (
-	"fmt"
-	"runtime"
-	"strings"
-
-	jww "github.com/spf13/jwalterweatherman"
-
-	"github.com/gohugoio/hugo/helpers"
-	"github.com/gohugoio/hugo/hugolib"
-	"github.com/gohugoio/hugo/resource/tocss/scss"
+	"github.com/gohugoio/hugo/common/hugo"
 	"github.com/spf13/cobra"
+	jww "github.com/spf13/jwalterweatherman"
 )
 
 var _ cmder = (*versionCmd)(nil)
@@ -47,29 +40,5 @@ func newVersionCmd() *versionCmd {
 }
 
 func printHugoVersion() {
-	jww.FEEDBACK.Println(hugoVersionString())
-}
-
-func hugoVersionString() string {
-	program := "Hugo Static Site Generator"
-
-	version := "v" + helpers.CurrentHugoVersion.String()
-	if hugolib.CommitHash != "" {
-		version += "-" + strings.ToUpper(hugolib.CommitHash)
-	}
-	if scss.Supports() {
-		version += "/extended"
-	}
-
-	osArch := runtime.GOOS + "/" + runtime.GOARCH
-
-	var buildDate string
-	if hugolib.BuildDate != "" {
-		buildDate = hugolib.BuildDate
-	} else {
-		buildDate = "unknown"
-	}
-
-	return fmt.Sprintf("%s %s %s BuildDate: %s", program, version, osArch, buildDate)
-
+	jww.FEEDBACK.Println(hugo.BuildVersionString())
 }
diff --git a/hugolib/hugo_info.go b/common/hugo/hugo.go
index 303231edb..b93b10bf1 100644
--- a/hugolib/hugo_info.go
+++ b/common/hugo/hugo.go
@@ -11,13 +11,11 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package hugolib
+package hugo
 
 import (
 	"fmt"
 	"html/template"
-
-	"github.com/gohugoio/hugo/helpers"
 )
 
 var (
@@ -29,21 +27,19 @@ var (
 	BuildDate string
 )
 
-var hugoInfo *HugoInfo
-
-// HugoInfo contains information about the current Hugo environment
-type HugoInfo struct {
-	Version    helpers.HugoVersionString
+// Info contains information about the current Hugo environment
+type Info struct {
+	Version    VersionString
 	Generator  template.HTML
 	CommitHash string
 	BuildDate  string
 }
 
-func init() {
-	hugoInfo = &HugoInfo{
-		Version:    helpers.CurrentHugoVersion.Version(),
+func NewInfo() Info {
+	return Info{
+		Version:    CurrentVersion.Version(),
 		CommitHash: CommitHash,
 		BuildDate:  BuildDate,
-		Generator:  template.HTML(fmt.Sprintf(`<meta name="generator" content="Hugo %s" />`, helpers.CurrentHugoVersion.String())),
+		Generator:  template.HTML(fmt.Sprintf(`<meta name="generator" content="Hugo %s" />`, CurrentVersion.String())),
 	}
 }
diff --git a/hugolib/hugo_info_test.go b/common/hugo/hugo_test.go
index 0a34330ac..18a9b594f 100644
--- a/hugolib/hugo_info_test.go
+++ b/common/hugo/hugo_test.go
@@ -11,21 +11,22 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package hugolib
+package hugo
 
 import (
 	"fmt"
 	"testing"
 
-	"github.com/gohugoio/hugo/helpers"
 	"github.com/stretchr/testify/require"
 )
 
 func TestHugoInfo(t *testing.T) {
 	assert := require.New(t)
 
-	assert.Equal(helpers.CurrentHugoVersion.Version(), hugoInfo.Version)
-	assert.IsType(helpers.HugoVersionString(""), hugoInfo.Version)
+	hugoInfo := NewInfo()
+
+	assert.Equal(CurrentVersion.Version(), hugoInfo.Version)
+	assert.IsType(VersionString(""), hugoInfo.Version)
 	assert.Equal(CommitHash, hugoInfo.CommitHash)
 	assert.Equal(BuildDate, hugoInfo.BuildDate)
 	assert.Contains(hugoInfo.Generator, fmt.Sprintf("Hugo %s", hugoInfo.Version))
diff --git a/common/hugo/site.go b/common/hugo/site.go
new file mode 100644
index 000000000..08391858a
--- /dev/null
+++ b/common/hugo/site.go
@@ -0,0 +1,24 @@
+// Copyright 2018 The Hugo Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package hugo
+
+import "github.com/gohugoio/hugo/langs"
+
+// Site represents a site in the build. This is currently a very narrow interface,
+// but the actual implementation will be richer, see hugolib.SiteInfo.
+type Site interface {
+	Language() *langs.Language
+	IsServer() bool
+	Hugo() Info
+}
diff --git a/common/hugo/vars_extended.go b/common/hugo/vars_extended.go
new file mode 100644
index 000000000..20683b804
--- /dev/null
+++ b/common/hugo/vars_extended.go
@@ -0,0 +1,18 @@
+// Copyright 2018 The Hugo Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build extended
+
+package hugo
+
+var isExtended = true
diff --git a/common/hugo/vars_regular.go b/common/hugo/vars_regular.go
new file mode 100644
index 000000000..e1ece83fb
--- /dev/null
+++ b/common/hugo/vars_regular.go
@@ -0,0 +1,18 @@
+// Copyright 2018 The Hugo Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build !extended
+
+package hugo
+
+var isExtended = false
diff --git a/helpers/hugo.go b/common/hugo/version.go
index 3ad4f9379..204f8f747 100644
--- a/helpers/hugo.go
+++ b/common/hugo/version.go
@@ -1,4 +1,4 @@
-// Copyright 2015 The Hugo Authors. All rights reserved.
+// Copyright 2018 The Hugo Authors. All rights reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -11,18 +11,20 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package helpers
+package hugo
 
 import (
 	"fmt"
+
+	"runtime"
 	"strings"
 
 	"github.com/gohugoio/hugo/compare"
 	"github.com/spf13/cast"
 )
 
-// HugoVersion represents the Hugo build version.
-type HugoVersion struct {
+// Version represents the Hugo build version.
+type Version struct {
 	// Major and minor version.
 	Number float32
 
@@ -35,34 +37,34 @@ type HugoVersion struct {
 }
 
 var (
-	_ compare.Eqer     = (*HugoVersionString)(nil)
-	_ compare.Comparer = (*HugoVersionString)(nil)
+	_ compare.Eqer     = (*VersionString)(nil)
+	_ compare.Comparer = (*VersionString)(nil)
 )
 
-func (v HugoVersion) String() string {
-	return hugoVersion(v.Number, v.PatchLevel, v.Suffix)
+func (v Version) String() string {
+	return version(v.Number, v.PatchLevel, v.Suffix)
 }
 
 // Version returns the Hugo version.
-func (v HugoVersion) Version() HugoVersionString {
-	return HugoVersionString(v.String())
+func (v Version) Version() VersionString {
+	return VersionString(v.String())
 }
 
-// HugoVersionString represents a Hugo version string.
-type HugoVersionString string
+// VersionString represents a Hugo version string.
+type VersionString string
 
-func (h HugoVersionString) String() string {
+func (h VersionString) String() string {
 	return string(h)
 }
 
 // Compare implements the compare.Comparer interface.
-func (h HugoVersionString) Compare(other interface{}) int {
-	v := MustParseHugoVersion(h.String())
+func (h VersionString) Compare(other interface{}) int {
+	v := MustParseVersion(h.String())
 	return compareVersionsWithSuffix(v.Number, v.PatchLevel, v.Suffix, other)
 }
 
 // Eq implements the compare.Eqer interface.
-func (h HugoVersionString) Eq(other interface{}) bool {
+func (h VersionString) Eq(other interface{}) bool {
 	s, err := cast.ToStringE(other)
 	if err != nil {
 		return false
@@ -72,9 +74,9 @@ func (h HugoVersionString) Eq(other interface{}) bool {
 
 var versionSuffixes = []string{"-test", "-DEV"}
 
-// ParseHugoVersion parses a version string.
-func ParseHugoVersion(s string) (HugoVersion, error) {
-	var vv HugoVersion
+// ParseVersion parses a version string.
+func ParseVersion(s string) (Version, error) {
+	var vv Version
 	for _, suffix := range versionSuffixes {
 		if strings.HasSuffix(s, suffix) {
 			vv.Suffix = suffix
@@ -90,10 +92,10 @@ func ParseHugoVersion(s string) (HugoVersion, error) {
 	return vv, nil
 }
 
-// MustParseHugoVersion parses a version string
+// MustParseVersion parses a version string
 // and panics if any error occurs.
-func MustParseHugoVersion(s string) HugoVersion {
-	vv, err := ParseHugoVersion(s)
+func MustParseVersion(s string) Version {
+	vv, err := ParseVersion(s)
 	if err != nil {
 		panic(err)
 	}
@@ -101,36 +103,54 @@ func MustParseHugoVersion(s string) HugoVersion {
 }
 
 // ReleaseVersion represents the release version.
-func (v HugoVersion) ReleaseVersion() HugoVersion {
+func (v Version) ReleaseVersion() Version {
 	v.Suffix = ""
 	return v
 }
 
 // Next returns the next Hugo release version.
-func (v HugoVersion) Next() HugoVersion {
-	return HugoVersion{Number: v.Number + 0.01}
+func (v Version) Next() Version {
+	return Version{Number: v.Number + 0.01}
 }
 
 // Prev returns the previous Hugo release version.
-func (v HugoVersion) Prev() HugoVersion {
-	return HugoVersion{Number: v.Number - 0.01}
+func (v Version) Prev() Version {
+	return Version{Number: v.Number - 0.01}
 }
 
 // NextPatchLevel returns the next patch/bugfix Hugo version.
 // This will be a patch increment on the previous Hugo version.
-func (v HugoVersion) NextPatchLevel(level int) HugoVersion {
-	return HugoVersion{Number: v.Number - 0.01, PatchLevel: level}
+func (v Version) NextPatchLevel(level int) Version {
+	return Version{Number: v.Number - 0.01, PatchLevel: level}
 }
 
-// CurrentHugoVersion represents the current build version.
-// This should be the only one.
-var CurrentHugoVersion = HugoVersion{
-	Number:     0.53,
-	PatchLevel: 0,
-	Suffix:     "-DEV",
+// BuildVersionString creates a version string. This is what you see when
+// running "hugo version".
+func BuildVersionString() string {
+	program := "Hugo Static Site Generator"
+
+	version := "v" + CurrentVersion.String()
+	if CommitHash != "" {
+		version += "-" + strings.ToUpper(CommitHash)
+	}
+	if isExtended {
+		version += "/extended"
+	}
+
+	osArch := runtime.GOOS + "/" + runtime.GOARCH
+
+	var buildDate string
+	if BuildDate != "" {
+		buildDate = BuildDate
+	} else {
+		buildDate = "unknown"
+	}
+
+	return fmt.Sprintf("%s %s %s BuildDate: %s", program, version, osArch, buildDate)
+
 }
 
-func hugoVersion(version float32, patchVersion int, suffix string) string {
+func version(version float32, patchVersion int, suffix string) string {
 	if patchVersion > 0 {
 		return fmt.Sprintf("%.2f.%d%s", version, patchVersion, suffix)
 	}
@@ -142,7 +162,7 @@ func hugoVersion(version float32, patchVersion int, suffix string) string {
 // It returns -1 if the given version is less than, 0 if equal and 1 if greater than
 // the running version.
 func CompareVersion(version interface{}) int {
-	return compareVersionsWithSuffix(CurrentHugoVersion.Number, CurrentHugoVersion.PatchLevel, CurrentHugoVersion.Suffix, version)
+	return compareVersionsWithSuffix(CurrentVersion.Number, CurrentVersion.PatchLevel, CurrentVersion.Suffix, version)
 }
 
 func compareVersions(inVersion float32, inPatchVersion int, in interface{}) int {
@@ -168,7 +188,7 @@ func compareVersionsWithSuffix(inVersion float32, inPatchVersion int, suffix str
 			return -1
 		}
 
-		v, err := ParseHugoVersion(s)
+		v, err := ParseVersion(s)
 		if err != nil {
 			return -1
 		}
diff --git a/common/hugo/version_current.go b/common/hugo/version_current.go
new file mode 100644
index 000000000..0a42f3023
--- /dev/null
+++ b/common/hugo/version_current.go
@@ -0,0 +1,22 @@
+// Copyright 2018 The Hugo Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package hugo
+
+// CurrentVersion represents the current build version.
+// This should be the only one.
+var CurrentVersion = Version{
+	Number:     0.53,
+	PatchLevel: 0,
+	Suffix:     "-DEV",
+}
diff --git a/helpers/hugo_test.go b/common/hugo/version_test.go
index 1c2d89619..fb28750ec 100644
--- a/helpers/hugo_test.go
+++ b/common/hugo/version_test.go
@@ -11,7 +11,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package helpers
+package hugo
 
 import (
 	"testing"
@@ -21,10 +21,10 @@ import (
 )
 
 func TestHugoVersion(t *testing.T) {
-	assert.Equal(t, "0.15-DEV", hugoVersion(0.15, 0, "-DEV"))
-	assert.Equal(t, "0.15.2-DEV", hugoVersion(0.15, 2, "-DEV"))
+	assert.Equal(t, "0.15-DEV", version(0.15, 0, "-DEV"))
+	assert.Equal(t, "0.15.2-DEV", version(0.15, 2, "-DEV"))
 
-	v := HugoVersion{Number: 0.21, PatchLevel: 0, Suffix: "-DEV"}
+	v := Version{Number: 0.21, PatchLevel: 0, Suffix: "-DEV"}
 
 	require.Equal(t, v.ReleaseVersion().String(), "0.21")
 	require.Equal(t, "0.21-DEV", v.String())
@@ -62,9 +62,9 @@ func TestCompareVersions(t *testing.T) {
 }
 
 func TestParseHugoVersion(t *testing.T) {
-	require.Equal(t, "0.25", MustParseHugoVersion("0.25").String())
-	require.Equal(t, "0.25.2", MustParseHugoVersion("0.25.2").String())
-	require.Equal(t, "0.25-test", MustParseHugoVersion("0.25-test").String())
-	require.Equal(t, "0.25-DEV", MustParseHugoVersion("0.25-DEV").String())
+	require.Equal(t, "0.25", MustParseVersion("0.25").String())
+	require.Equal(t, "0.25.2", MustParseVersion("0.25.2").String())
+	require.Equal(t, "0.25-test", MustParseVersion("0.25-test").String())
+	require.Equal(t, "0.25-DEV", MustParseVersion("0.25-DEV").String())
 
 }
diff --git a/deps/deps.go b/deps/deps.go
index de6d8b52a..46f4f7730 100644
--- a/deps/deps.go
+++ b/deps/deps.go
@@ -7,6 +7,7 @@ import (
 	"github.com/pkg/errors"
 
 	"github.com/gohugoio/hugo/cache/filecache"
+	"github.com/gohugoio/hugo/common/hugo"
 	"github.com/gohugoio/hugo/common/loggers"
 	"github.com/gohugoio/hugo/config"
 	"github.com/gohugoio/hugo/helpers"
@@ -62,8 +63,12 @@ type Deps struct {
 	// The translation func to use
 	Translate func(translationID string, args ...interface{}) string `json:"-"`
 
+	// The language in use. TODO(bep) consolidate with site
 	Language *langs.Language
 
+	// The site building.
+	Site hugo.Site
+
 	// All the output formats available for the current site.
 	OutputFormatsConfig output.Formats
 
@@ -230,6 +235,7 @@ func New(cfg DepsCfg) (*Deps, error) {
 		ResourceSpec:        resourceSpec,
 		Cfg:                 cfg.Language,
 		Language:            cfg.Language,
+		Site:                cfg.Site,
 		FileCaches:          fileCaches,
 		BuildStartListeners: &Listeners{},
 		Timeout:             time.Duration(timeoutms) * time.Millisecond,
@@ -245,7 +251,7 @@ func New(cfg DepsCfg) (*Deps, error) {
 
 // ForLanguage creates a copy of the Deps with the language dependent
 // parts switched out.
-func (d Deps) ForLanguage(cfg DepsCfg) (*Deps, error) {
+func (d Deps) ForLanguage(cfg DepsCfg, onCreated func(d *Deps) error) (*Deps, error) {
 	l := cfg.Language
 	var err error
 
@@ -259,6 +265,8 @@ func (d Deps) ForLanguage(cfg DepsCfg) (*Deps, error) {
 		return nil, err
 	}
 
+	d.Site = cfg.Site
+
 	// The resource cache is global so reuse.
 	// TODO(bep) clean up these inits.
 	resourceCache := d.ResourceSpec.ResourceCache
@@ -271,6 +279,12 @@ func (d Deps) ForLanguage(cfg DepsCfg) (*Deps, error) {
 	d.Cfg = l
 	d.Language = l
 
+	if onCreated != nil {
+		if err = onCreated(&d); err != nil {
+			return nil, err
+		}
+	}
+
 	if err := d.translationProvider.Clone(&d); err != nil {
 		return nil, err
 	}
@@ -299,6 +313,9 @@ type DepsCfg struct {
 	// The language to use.
 	Language *langs.Language
 
+	// The Site in use
+	Site hugo.Site
+
 	// The configuration to use.
 	Cfg config.Provider
 
diff --git a/goreleaser-extended.yml b/goreleaser-extended.yml
index 31b52d7ba..004e94953 100644
--- a/goreleaser-extended.yml
+++ b/