implement "index" subcommand

1 files changed, 180 insertions, 0 deletions

diff --git a/repo.go b/repo.go
new file mode 100644
index 0000000..f0c2491
--- /dev/null
+++ b/repo.go
@@ -0,0 +1,180 @@
+/*******************************************************************************
+*
+* Copyright 2017 Stefan Majewsky <majewsky@gmx.net>
+*
+* This program is free software: you can redistribute it and/or modify it under
+* the terms of the GNU General Public License as published by the Free Software
+* Foundation, either version 3 of the License, or (at your option) any later
+* version.
+*
+* This program is distributed in the hope that it will be useful, but WITHOUT ANY
+* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+* A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+*
+* You should have received a copy of the GNU General Public License along with
+* this program. If not, see <http://www.gnu.org/licenses/>.
+*
+*******************************************************************************/
+
+package main
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"regexp"
+	"strings"
+)
+
+//RootPath is the directory below which all repositories are located. Its value
+//is $GOPATH/src to match the repository layout created by `go get`.
+var RootPath string
+
+func init() {
+	gopath := os.Getenv("GOPATH")
+	if gopath == "" {
+		FatalIfError(errors.New("$GOPATH is not set (rtree needs the GOPATH variable to know where to look for and place repos)"))
+	}
+	RootPath = filepath.Join(gopath, "src")
+}
+
+//Repo describes the entry for a repository in the index file.
+type Repo struct {
+	//CheckoutPath shall be relative to the RootPath.
+	CheckoutPath string `yaml:"path"`
+	//Remotes maps remote names (as noted in the .git/config of the repo) to
+	//remote URLs (as they appear in the .git/config of the repo, i.e. possibly
+	//abbreviated).
+	Remotes []Remote `yaml:"remotes"`
+}
+
+//Remote describes a remote that is configured in a Repo.
+type Remote struct {
+	Name string `yaml:"name"`
+	URL  string `yaml:"url"`
+}
+
+//AbsolutePath returns the absolute CheckoutPath of this repo.
+func (r Repo) AbsolutePath() string {
+	return filepath.Join(RootPath, r.CheckoutPath)
+}
+
+//NewRepoFromAbsolutePath initializes a Repo instance by scanning the existing
+//checkout at the given path.
+func NewRepoFromAbsolutePath(path string) (repo Repo, err error) {
+	repo.CheckoutPath, err = filepath.Rel(RootPath, path)
+	if err != nil {
+		return
+	}
+
+	//list remotes
+	cmd := exec.Command("git", "-C", path, "config", "-l")
+	var buf bytes.Buffer
+	cmd.Stdout = &buf
+	cmd.Stderr = os.Stderr
+	err = cmd.Run()
+	if err != nil {
+		return repo, fmt.Errorf("exec `git config -l` in %s: %s", path, err.Error())
+	}
+
+	for _, line := range strings.Split(string(buf.Bytes()), "\n") {
+		match := remoteConfigRx.FindStringSubmatch(line)
+		if match == nil {
+			continue
+		}
+		repo.Remotes = append(repo.Remotes, Remote{
+			Name: match[1],
+			URL:  match[2],
+		})
+	}
+	return
+}
+
+var remoteConfigRx = regexp.MustCompile(`remote\.([^=]+)\.url=(.+)`)
+
+//ForeachPhysicalRepo walks over the repository tree, executing the action
+//function once for every repo encountered (but *not* for repos contained
+//within other repos, e.g. submodules).
+func ForeachPhysicalRepo(action func(repo Repo) error) error {
+	return filepath.Walk(RootPath, func(path string, info os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+		//look for repos, i.e. directories containing a .git directory
+		if !info.IsDir() {
+			return nil
+		}
+		_, err = os.Stat(filepath.Join(path, ".git"))
+		if err != nil {
+			return nil
+		}
+
+		//appears to be a repo
+		repo, err := NewRepoFromAbsolutePath(path)
+		if err == nil {
+			err = action(repo)
+		}
+		if err != nil {
+			return err
+		}
+		//do not traverse further down into submodules etc.
+		return filepath.SkipDir
+	})
+}
+
+//Checkout creates the repo in the given path with the given remotes. The
+//working copy will only be initialized if there is an "origin" remote.
+func (r Repo) Checkout() error {
+	//check if we have an "origin" remote to clone from
+	var originURL string
+	for _, remote := range r.Remotes {
+		if remote.Name == "origin" {
+			originURL = remote.URL
+			break
+		}
+	}
+
+	if originURL == "" {
+		cmd := exec.Command("git", "init", r.AbsolutePath())
+		cmd.Stdout = os.Stdout
+		cmd.Stderr = os.Stderr
+		err := cmd.Run()
+		if err != nil {
+			return err
+		}
+		fmt.Fprintln(os.Stderr, "warning: will not checkout anything since there is no remote named \"origin\"")
+	} else {
+		cmd := exec.Command("git", "clone", originURL, r.AbsolutePath())
+		cmd.Stdout = os.Stdout
+		cmd.Stderr = os.Stderr
+		err := cmd.Run()
+		if err != nil {
+			return err
+		}
+	}
+
+	remotesAdded := false
+	for _, remote := range r.Remotes {
+		if remote.Name != "origin" {
+			cmd := exec.Command("git", "-C", r.AbsolutePath(), "remote", "add", remote.Name, remote.URL)
+			cmd.Stdout = os.Stdout
+			cmd.Stderr = os.Stderr
+			err := cmd.Run()
+			if err != nil {
+				return err
+			}
+			remotesAdded = true
+		}
+	}
+	if remotesAdded {
+		cmd := exec.Command("git", "-C", r.AbsolutePath(), "remote", "update")
+		cmd.Stdout = os.Stdout
+		cmd.Stderr = os.Stderr
+		return cmd.Run()
+	}
+
+	return nil
+}