api,db: add comments count endpoint

Closes https://gitlab.com/commento/commento-ce/issues/27

api/comment_count.go

@@ -0,0 +1,43 @@
+package main
+
+import (
+	"net/http"
+)
+
+func commentCount(domain string, path string) (int, error) {
+	// path can be empty
+	if domain == "" {
+		return 0, errorMissingField
+	}
+
+	p, err := pageGet(domain, path)
+	if err != nil {
+		return 0, errorInternal
+	}
+
+	return p.CommentCount, nil
+}
+
+func commentCountHandler(w http.ResponseWriter, r *http.Request) {
+	type request struct {
+		Domain         *string `json:"domain"`
+		Path           *string `json:"path"`
+	}
+
+	var x request
+	if err := bodyUnmarshal(r, &x); err != nil {
+		bodyMarshal(w, response{"success": false, "message": err.Error()})
+		return
+	}
+
+	domain := domainStrip(*x.Domain)
+	path := *x.Path
+
+	count, err := commentCount(domain, path)
+	if err != nil {
+		bodyMarshal(w, response{"success": false, "message": err.Error()})
+		return
+	}
+
+	bodyMarshal(w, response{"success": true, "count": count})
+}

api/comment_count_test.go

@@ -0,0 +1,54 @@
+package main
+
+import (
+	"testing"
+	"time"
+)
+
+func TestCommentCountBasics(t *testing.T) {
+	failTestOnError(t, setupTestEnv())
+
+	commenterHex, _ := commenterNew("test@example.com", "Test", "undefined", "http://example.com/photo.jpg", "google", "")
+
+	commentNew(commenterHex, "example.com", "/path.html", "root", "**foo**", "approved", time.Now().UTC())
+	commentNew(commenterHex, "example.com", "/path.html", "root", "**bar**", "approved", time.Now().UTC())
+	commentNew(commenterHex, "example.com", "/path.html", "root", "**baz**", "unapproved", time.Now().UTC())
+
+	count, err := commentCount("example.com", "/path.html")
+	if err != nil {
+		t.Errorf("unexpected error counting comments: %v", err)
+		return
+	}
+
+	if count != 2 {
+		t.Errorf("expected count=2 got count=%d", count)
+		return
+	}
+}
+
+func TestCommentCountNewPage(t *testing.T) {
+	failTestOnError(t, setupTestEnv())
+
+	count, err := commentCount("example.com", "/path.html")
+	if err != nil {
+		t.Errorf("unexpected error counting comments: %v", err)
+		return
+	}
+
+	if count != 0 {
+		t.Errorf("expected count=0 got count=%d", count)
+		return
+	}
+}
+
+func TestCommentCountEmpty(t *testing.T) {
+	if _, err := commentCount("example.com", ""); err != nil {
+		t.Errorf("unexpected error counting comments on empty path: %v", err)
+		return
+	}
+
+	if _, err := commentCount("", ""); err == nil {
+		t.Errorf("expected error not found counting comments with empty everything")
+		return
+	}
+}

api/page.go

@@ -6,4 +6,5 @@ type page struct {
 	Domain           string `json:"domain"`
 	Path             string `json:"path"`
 	IsLocked         bool   `json:"isLocked"`
+	CommentCount     int    `json:"commentCount"`
 }

api/page_get.go

@@ -11,19 +11,20 @@ func pageGet(domain string, path string) (page, error) {
 	}
 
 	statement := `
-		SELECT isLocked
+		SELECT isLocked, commentCount
 		FROM pages
 		WHERE domain=$1 AND path=$2;
 	`
 	row := db.QueryRow(statement, domain, path)
 
 	p := page{Domain: domain, Path: path}
-	if err := row.Scan(&p.IsLocked); err != nil {
+	if err := row.Scan(&p.IsLocked, &p.CommentCount); err != nil {
 		if err == sql.ErrNoRows {
 			// If there haven't been any comments, there won't be a record for this
 			// page. The sane thing to do is return defaults.
 			// TODO: the defaults are hard-coded in two places: here and the schema
 			p.IsLocked = false
+			p.CommentCount = 0
 		} else {
 			logger.Errorf("error scanning page: %v", err)
 			return page{}, errorInternal

api/page_update.go

@@ -9,6 +9,8 @@ func pageUpdate(p page) error {
 		return errorMissingField
 	}
 
+	// fields to not update:
+	//   commentCount
 	statement := `
 		INSERT INTO
 		pages  (domain, path, isLocked)

db/20180923002745-comment-count.sql

@@ -0,0 +1,15 @@
+ALTER TABLE pages
+  ADD commentCount INTEGER NOT NULL DEFAULT 0;
+
+CREATE OR REPLACE FUNCTION commentsInsertTriggerFunction() RETURNS TRIGGER AS $trigger$
+BEGIN
+  UPDATE pages
+  SET commentCount = commentCount + 1
+  WHERE domain = new.domain AND path = new.path;
+
+  RETURN NEW;
+END;
+$trigger$ LANGUAGE plpgsql;
+
+CREATE TRIGGER commentsInsertTrigger AFTER INSERT ON comments
+FOR EACH ROW EXECUTE PROCEDURE commentsInsertTriggerFunction();