Refactor the GitInfo into the date handlers

Fixes gohugoio#4495

hugolib/gitinfo.go

@@ -19,10 +19,47 @@ import (
 	"strings"
 
 	"github.com/bep/gitmap"
+	"github.com/gohugoio/hugo/config"
 	"github.com/gohugoio/hugo/helpers"
 )
 
+type gitInfo struct {
+	contentDir string
+	repo       *gitmap.GitRepo
+}
+
+func (g *gitInfo) forPage(p *Page) *gitmap.GitInfo {
+	name := path.Join(g.contentDir, filepath.ToSlash(p.Path()))
+	return g.repo[filename]
+}
+
+func newGitInfo(cfg config.Provider) (*gitInfo, error) {
+	var (
+		workingDir = cfg.GetString("workingDir")
+		contentDir = cfg.GetString("contentDir")
+	)
+
+	gitRepo, err := gitmap.Map(workingDir, "")
+	if err != nil {
+		return err
+	}
+
+	repoPath := filepath.FromSlash(gitRepo.TopLevelAbsPath)
+	// The Hugo site may be placed in a sub folder in the Git repo,
+	// one example being the Hugo docs.
+	// We have to find the root folder to the Hugo site below the Git root.
+	contentRoot := strings.TrimPrefix(workingDir, repoPath)
+	contentRoot = strings.TrimPrefix(contentRoot, helpers.FilePathSeparator)
+	contentDir = path.Join(filepath.ToSlash(contentRoot), contentDir))
+
+	return &gitInfo{contentDir: contentDir, repo: gitRepo.Files}
+}
+
 func (h *HugoSites) assembleGitInfo() {
+	// TODO(bep) gitinfo remove this
+	if true {
+		return
+	}
 	if !h.Cfg.GetBool("enableGitInfo") {
 		return
 	}