Merge pull request #1 from matrix-org/kegan/github

Add a github service with issue/PR expansion

src/github.com/matrix-org/go-neb/goneb.go

@@ -6,6 +6,7 @@ import (
 	"github.com/matrix-org/go-neb/database"
 	"github.com/matrix-org/go-neb/server"
 	_ "github.com/matrix-org/go-neb/services/echo"
+	_ "github.com/matrix-org/go-neb/services/github"
 	_ "github.com/mattn/go-sqlite3"
 	"net/http"
 	_ "net/http/pprof"

src/github.com/matrix-org/go-neb/services/github/github.go

@@ -0,0 +1,97 @@
+package services
+
+import (
+	"fmt"
+	log "github.com/Sirupsen/logrus"
+	"github.com/google/go-github/github"
+	"github.com/matrix-org/go-neb/database"
+	"github.com/matrix-org/go-neb/matrix"
+	"github.com/matrix-org/go-neb/plugin"
+	"golang.org/x/oauth2"
+	"regexp"
+	"strconv"
+)
+
+// Matches alphanumeric then a /, then more alphanumeric then a #, then a number.
+// E.g. owner/repo#11 (issue/PR numbers) - Captured groups for owner/repo/number
+var ownerRepoIssueRegex = regexp.MustCompile("([A-z0-9-_]+)/([A-z0-9-_]+)#([0-9]+)")
+
+type githubService struct {
+	id     string
+	UserID string
+	Rooms  []string
+}
+
+func (s *githubService) ServiceUserID() string { return s.UserID }
+func (s *githubService) ServiceID() string     { return s.id }
+func (s *githubService) ServiceType() string   { return "github" }
+func (s *githubService) RoomIDs() []string     { return s.Rooms }
+func (s *githubService) Plugin(roomID string) plugin.Plugin {
+	return plugin.Plugin{
+		Commands: []plugin.Command{},
+		Expansions: []plugin.Expansion{
+			plugin.Expansion{
+				Regexp: ownerRepoIssueRegex,
+				Expand: func(roomID, matchingText string) interface{} {
+					cli := githubClient("")
+					owner, repo, num, err := ownerRepoNumberFromText(matchingText)
+					if err != nil {
+						log.WithError(err).WithField("text", matchingText).Print(
+							"Failed to extract owner,repo,number from matched string")
+						return nil
+					}
+
+					i, _, err := cli.Issues.Get(owner, repo, num)
+					if err != nil {
+						log.WithError(err).WithFields(log.Fields{
+							"owner":  owner,
+							"repo":   repo,
+							"number": num,
+						}).Print("Failed to fetch issue")
+						return nil
+					}
+
+					return &matrix.TextMessage{
+						"m.notice",
+						fmt.Sprintf("%s : %s", *i.HTMLURL, *i.Title),
+					}
+				},
+			},
+		},
+	}
+}
+
+// githubClient returns a github Client which can perform Github API operations.
+// If `token` is empty, a non-authenticated client will be created. This should be
+// used sparingly where possible as you only get 60 requests/hour like that (IP locked).
+func githubClient(token string) *github.Client {
+	var tokenSource oauth2.TokenSource
+	if token != "" {
+		tokenSource = oauth2.StaticTokenSource(
+			&oauth2.Token{AccessToken: token},
+		)
+	}
+	httpCli := oauth2.NewClient(oauth2.NoContext, tokenSource)
+	return github.NewClient(httpCli)
+}
+
+// ownerRepoNumberFromText parses a GH issue string that looks like 'owner/repo#11'
+// into its constituient parts. Returns: owner, repo, issue#.
+func ownerRepoNumberFromText(ownerRepoNumberText string) (string, string, int, error) {
+	// [full_string, owner, repo, issue_number]
+	groups := ownerRepoIssueRegex.FindStringSubmatch(ownerRepoNumberText)
+	if len(groups) != 4 {
+		return "", "", 0, fmt.Errorf("No match found for '%s'", ownerRepoNumberText)
+	}
+	num, err := strconv.Atoi(groups[3])
+	if err != nil {
+		return "", "", 0, err
+	}
+	return groups[1], groups[2], num, nil
+}
+
+func init() {
+	database.RegisterService(func(serviceID string) database.Service {
+		return &githubService{id: serviceID}
+	})
+}