// isBranch returns true if the given string is a branch in VCS.
func isBranch(branch string, repo v.Repo) (bool, error) {
	branches, err := repo.Branches()
	if err != nil {
		return false, err
	}
	for _, b := range branches {
		if b == branch {
			return true, nil
		}
	}
	return false, nil
}

// Get all the references for a repo. This includes the tags and branches.
func getAllVcsRefs(repo vcs.Repo) ([]string, error) {
	tags, err := repo.Tags()
	if err != nil {
		return []string{}, err
	}

	branches, err := repo.Branches()
	if err != nil {
		return []string{}, err
	}

	return append(branches, tags...), nil
}

func displayCommitInfo(repo vcs.Repo, dep *cfg.Dependency) {
	c, err := repo.CommitInfo(dep.Reference)
	ref := dep.Reference

	if err == nil {
		tgs, err2 := repo.TagsFromCommit(c.Commit)
		if err2 == nil && len(tgs) > 0 {
			if tgs[0] != dep.Reference {
				ref = ref + " (" + tgs[0] + ")"
			}
		}
		singleInfo(displayCommitInfoTemplate, dep.Name, ref, c.Author, c.Date.Format(time.RFC1123Z), commitSubjectFirstLine(c.Message))
	}
}

func findCurrentBranch(repo vcs.Repo) string {
	msg.Debug("Attempting to find current branch for %s", repo.Remote())
	// Svn and Bzr don't have default branches.
	if repo.Vcs() == vcs.Svn || repo.Vcs() == vcs.Bzr {
		return ""
	}

	if repo.Vcs() == vcs.Git || repo.Vcs() == vcs.Hg {
		ver, err := repo.Current()
		if err != nil {
			msg.Debug("Unable to find current branch for %s, error: %s", repo.Remote(), err)
			return ""
		}
		return ver
	}

	return ""
}

// From a local repo find out the current branch name if there is one.
func findCurrentBranch(repo v.Repo) string {
	Debug("Attempting to find current branch for %s", repo.Remote())
	// Svn and Bzr don't have default branches.
	if repo.Vcs() == v.Svn || repo.Vcs() == v.Bzr {
		return ""
	}

	if repo.Vcs() == v.Git {
		c := exec.Command("git", "symbolic-ref", "--short", "HEAD")
		c.Dir = repo.LocalPath()
		c.Env = envForDir(c.Dir)
		out, err := c.CombinedOutput()
		if err != nil {
			Debug("Unable to find current branch for %s, error: %s", repo.Remote(), err)
			return ""
		}
		return strings.TrimSpace(string(out))
	}

	if repo.Vcs() == v.Hg {
		c := exec.Command("hg", "branch")
		c.Dir = repo.LocalPath()
		c.Env = envForDir(c.Dir)
		out, err := c.CombinedOutput()
		if err != nil {
			Debug("Unable to find current branch for %s, error: %s", repo.Remote(), err)
			return ""
		}
		return strings.TrimSpace(string(out))
	}

	return ""
}

// Some repos will have multiple branches in them (e.g. Git) while others
// (e.g. Svn) will not.
// TODO(mattfarina): Add API calls to github, bitbucket, etc.
func defaultBranch(repo v.Repo, home string) string {

	// Svn and Bzr use different locations (paths or entire locations)
	// for branches so we won't have a default branch.
	if repo.Vcs() == v.Svn || repo.Vcs() == v.Bzr {
		return ""
	}

	// Check the cache for a value.
	key, kerr := cacheCreateKey(repo.Remote())
	var d cacheRepoInfo
	if kerr == nil {
		d, err := cacheRepoData(key, home)
		if err == nil {
			if d.DefaultBranch != "" {
				return d.DefaultBranch
			}
		}
	}

	// If we don't have it in the store try some APIs
	r := repo.Remote()
	u, err := url.Parse(r)
	if err != nil {
		return ""
	}
	if u.Scheme == "" {
		// Where there is no scheme we try urls like [email protected]:foo/bar
		r = strings.Replace(r, ":", "/", -1)
		r = "ssh://" + r
		u, err = url.Parse(r)
		if err != nil {
			return ""
		}
		u.Scheme = ""
	}
	if u.Host == "github.com" {
		parts := strings.Split(u.Path, "/")
		if len(parts) != 2 {
			return ""
		}
		api := fmt.Sprintf("https://api.github.com/repos/%s/%s", parts[0], parts[1])
		resp, err := http.Get(api)
		if err != nil {
			return ""
		}
		defer resp.Body.Close()
		if resp.StatusCode >= 300 || resp.StatusCode < 200 {
			return ""
		}
		body, err := ioutil.ReadAll(resp.Body)
		var data interface{}
		err = json.Unmarshal(body, &data)
		if err != nil {
			return ""
		}
		gh := data.(map[string]interface{})
		db := gh["default_branch"].(string)
		if kerr == nil {
			d.DefaultBranch = db
			saveCacheRepoData(key, d, home)
		}
		return db
	}

	if u.Host == "bitbucket.org" {
		parts := strings.Split(u.Path, "/")
		if len(parts) != 2 {
			return ""
		}
		api := fmt.Sprintf("https://bitbucket.org/api/1.0/repositories/%s/%s/main-branch/", parts[0], parts[1])
		resp, err := http.Get(api)
		if err != nil {
			return ""
		}
		defer resp.Body.Close()
		if resp.StatusCode >= 300 || resp.StatusCode < 200 {
			return ""
		}
		body, err := ioutil.ReadAll(resp.Body)
		var data interface{}
		err = json.Unmarshal(body, &data)
		if err != nil {
			return ""
		}
		bb := data.(map[string]interface{})
		db := bb["name"].(string)
		if kerr == nil {
			d.DefaultBranch = db
			saveCacheRepoData(key, d, home)
		}
		return db
	}

	return ""
}