Reply with errors

chess/board.go

@@ -730,12 +730,12 @@ func getXY(position string) (int, int, error) {
 	posX = runes[0]
 	posY = runes[1]
 
-	if posX < 'a' && posX > 'h' {
+	if posX < 'a' || posX > 'h' {
-		return -1, -1, fmt.Errorf("invalid posX: %s", position)
+		return -1, -1, fmt.Errorf("invalid move: %s", position)
 	}
 
-	if posY < '1' && posY > '8' {
+	if posY < '1' || posY > '8' {
-		return -1, -1, fmt.Errorf("invalid posY: %s", position)
+		return -1, -1, fmt.Errorf("invalid move: %s", position)
 	}
 
 	// image origin (0,0) is at top-left corner (a8)

db/db.go

@@ -57,8 +57,9 @@ func ItemHasReply(parentId int, userId int) (bool, error) {
 }
 
 func InsertItem(item *sn.Item) error {
-	if _, err := db.Exec(
+	if _, err := db.Exec(``+
-		`INSERT INTO items(id, user_id, text, parent_id) VALUES (?, ?, ?, NULLIF(?, 0))`,
+		`INSERT INTO items(id, user_id, text, parent_id) VALUES (?, ?, ?, NULLIF(?, 0)) `+
+		`ON CONFLICT DO UPDATE SET text = EXCLUDED.text, updated_at = CURRENT_TIMESTAMP`,
 		item.Id, item.User.Id, item.Text, item.ParentId); err != nil {
 		return err
 	}

main.go

@@ -33,7 +33,7 @@ func tickGameStart(c *sn.Client) {
 	)
 
 	if mentions, err = c.Mentions(); err != nil {
-		log.Printf("mentions error: %v\n", err)
+		log.Printf("failed to fetch mentions: %v\n", err)
 		return
 	}
 
@@ -42,53 +42,23 @@ func tickGameStart(c *sn.Client) {
 	for _, n := range mentions {
 
 		if exists, err := db.ItemHasReply(n.Item.Id, meId); err != nil {
-			log.Printf("error during game start check: %v\n", err)
+			log.Printf("failed to check for existing reply to game start in item %d: %v\n", n.Item.Id, err)
 			continue
 		} else if exists {
 			// TODO: check if move changed
-			log.Printf("game start already exists: id=%d\n", n.Item.Id)
+			log.Printf("reply to game start in item %d already exists\n", n.Item.Id)
 			continue
 		}
 
-		move := strings.Trim(strings.ReplaceAll(n.Item.Text, "@chess", ""), " ")
+		if err = handleGameStart(&n.Item); err != nil {
-
+			if _, err2 := createComment(n.Item.Id, fmt.Sprintf("`%v`", err)); err2 != nil {
-		var b *chess.Board
+				log.Printf("failed to reply with error to item %d: %v\n", n.Item.Id, err2)
-		if b, err = chess.NewGame(move); err != nil {
+			} else {
-			log.Printf("error creating new game: %v: id=%d\n", err, n.Item.Id)
+				log.Printf("replied to game start in item %d with error: %v\n", n.Item.Id, err)
-			continue
+			}
+		} else {
+			log.Printf("started new game via item %d\n", n.Item.Id)
 		}
-
-		img := b.Image()
-		var imgUrl string
-		if imgUrl, err = c.UploadImage(img); err != nil {
-			log.Printf("error uploading image: %v\n", err)
-			continue
-		}
-
-		n.Item.ParentId = 0
-		if err = db.InsertItem(&n.Item); err != nil {
-			log.Printf("error inserting item into db: %v: id=%d\n", err, n.Item.Id)
-			continue
-		}
-
-		text := strings.Trim(fmt.Sprintf("%s\n\n%s", b.AlgebraicNotation(), imgUrl), " ")
-		var cId int
-		if cId, err = c.CreateComment(n.Item.Id, text); err != nil {
-			log.Printf("error creating reply: %v\n", err)
-			continue
-		}
-
-		var item *sn.Item
-		if item, err = c.Item(cId); err != nil {
-			log.Printf("error fetching item: %v: id=%d\n", cId)
-			continue
-		}
-		if err = db.InsertItem(item); err != nil {
-			log.Printf("error inserting item into db: %v: id=%d\n", err, item.Id)
-			continue
-		}
-
-		log.Printf("started new game: id=%d\n", n.Item.Id)
 	}
 }
 
@@ -99,7 +69,7 @@ func tickGameProgress(c *sn.Client) {
 	)
 
 	if replies, err = c.Replies(); err != nil {
-		log.Printf("replies error: %v\n", err)
+		log.Printf("failed to fetch replies: %v\n", err)
 		return
 	}
 
@@ -108,75 +78,134 @@ func tickGameProgress(c *sn.Client) {
 	for _, n := range replies {
 
 		if exists, err := db.ItemHasReply(n.Item.Id, meId); err != nil {
-			log.Printf("error during game update check: %v\n", err)
+			log.Printf("failed to check for existing reply to game update in item %d: %v\n", n.Item.Id, err)
 			continue
 		} else if exists {
 			// TODO: check if move changed
-			log.Printf("game update already exists: id=%d\n", n.Item.Id)
+			log.Printf("reply to game update in item %d already exists\n", n.Item.Id)
 			continue
 		}
 
-		var thread []sn.Item
+		if err = handleGameProgress(&n.Item); err != nil {
-		if thread, err = db.GetThread(n.Item.ParentId); err != nil {
+			if _, err2 := createComment(n.Item.Id, fmt.Sprintf("`%v`", err)); err2 != nil {
-			log.Printf("error fetching thread: %v: id=%d\n", err, n.Item.ParentId)
+				log.Printf("failed to reply with error to item %d: %v\n", n.Item.Id, err2)
-			continue
+			} else {
-		}
+				log.Printf("replied to game start in item %d with error: %v\n", n.Item.Id, err)
-
-		b := chess.NewBoard()
-		// TODO: better parsing of moves in replies using regexp for example or enforce a specific format
-		// since players might include more than just the move in their replies
-		move := strings.Trim(n.Item.Text, " ")
-		for _, item := range thread {
-			if item.User.Id == meId {
-				continue
-			}
-
-			moves := strings.Trim(strings.ReplaceAll(item.Text, "@chess", ""), " ")
-			if err = b.Parse(moves); err != nil {
-				log.Printf("error moving piece: %v: id=%d\n", err, item.Id)
-				break
 			}
+		} else {
+			log.Printf("updated game via item %d\n", n.Item.Id)
 		}
-
-		// continue with next reply if the thread loop failed
-		if err != nil {
-			continue
-		}
-
-		if err = b.Parse(move); err != nil {
-			log.Printf("error moving piece: %v: id=%d\n", err, n.Item.ParentId)
-			continue
-		}
-
-		img := b.Image()
-		var imgUrl string
-		if imgUrl, err = c.UploadImage(img); err != nil {
-			log.Printf("error uploading image: %v\n", err)
-			continue
-		}
-
-		if err = db.InsertItem(&n.Item); err != nil {
-			log.Printf("error inserting item into db: %v: id=%d\n", err, n.Item.Id)
-			continue
-		}
-
-		text := fmt.Sprintf("`%s`\n\n%s", b.AlgebraicNotation(), imgUrl)
-		var cId int
-		if cId, err = c.CreateComment(n.Item.Id, text); err != nil {
-			log.Printf("error creating reply: %v\n", err)
-			continue
-		}
-
-		var item *sn.Item
-		if item, err = c.Item(cId); err != nil {
-			log.Printf("error fetching item: %v: id=%d\n", cId)
-			continue
-		}
-		if err = db.InsertItem(item); err != nil {
-			log.Printf("error inserting item into db: %v: id=%d\n", err, item.Id)
-			continue
-		}
-
-		log.Printf("continued game: move=%s id=%d\n", move, cId)
 	}
 }
+
+func handleGameStart(req *sn.Item) error {
+	var (
+		move   = strings.Trim(strings.ReplaceAll(req.Text, "@chess", ""), " ")
+		b      *chess.Board
+		imgUrl string
+		res    string
+		err    error
+	)
+
+	// Immediately save game start request to db so we can store our reply to it in case of error.
+	// We set parentId to 0 such that parent_id will be NULL in the db and not hit foreign key constraints.
+	req.ParentId = 0
+
+	if err = db.InsertItem(req); err != nil {
+		return fmt.Errorf("failed to insert item %d into db: %v\n", req.Id, err)
+	}
+
+	// create board with initial move(s)
+	if b, err = chess.NewGame(move); err != nil {
+		return fmt.Errorf("failed to create new game from item %d: %v\n", req.Id, err)
+	}
+
+	// upload image of board
+	if imgUrl, err = c.UploadImage(b.Image()); err != nil {
+		return fmt.Errorf("failed to upload image for item %d: %v\n", req.Id, err)
+	}
+
+	// reply with algebraic notation and image
+	res = strings.Trim(fmt.Sprintf("%s\n\n%s", b.AlgebraicNotation(), imgUrl), " ")
+	if _, err = createComment(req.Id, res); err != nil {
+		return fmt.Errorf("failed to reply to item %d: %v\n", req.Id, err)
+	}
+
+	return nil
+}
+
+func handleGameProgress(req *sn.Item) error {
+	var (
+		thread []sn.Item
+		b             = chess.NewBoard()
+		move   string = strings.Trim(req.Text, " ")
+		imgUrl string
+		res    string
+		err    error
+	)
+
+	// immediately save game update request to db so we can store our reply to it in case of error
+	if err = db.InsertItem(req); err != nil {
+		return fmt.Errorf("failed to insert item %d into db: %v\n", req.Id, err)
+	}
+
+	// fetch thread to reconstruct all moves so far
+	if thread, err = db.GetThread(req.ParentId); err != nil {
+		return fmt.Errorf("failed to fetch thread for item %d: %v\n", req.ParentId, err)
+	}
+
+	for _, item := range thread {
+		if item.User.Id == meId {
+			continue
+		}
+
+		// TODO: better parsing of moves in replies using regexp for example or enforce a specific format
+		// since players might include more than just the move in their replies
+		moves := strings.Trim(strings.ReplaceAll(item.Text, "@chess", ""), " ")
+
+		// parse and execute existing moves
+		if err = b.Parse(moves); err != nil {
+			return fmt.Errorf("failed to parse move %s: %v\n", moves, err)
+		}
+	}
+
+	// parse and execute new move
+	if err = b.Parse(move); err != nil {
+		return fmt.Errorf("failed to parse move %s: %v\n", move, err)
+	}
+
+	// upload image of updated board
+	if imgUrl, err = c.UploadImage(b.Image()); err != nil {
+		return fmt.Errorf("failed to upload image for item %d: %v\n", req.Id, err)
+	}
+
+	// reply with algebraic notation and image
+	res = strings.Trim(fmt.Sprintf("%s\n\n%s", b.AlgebraicNotation(), imgUrl), " ")
+	if _, err = createComment(req.Id, res); err != nil {
+		return fmt.Errorf("failed to reply to item %d: %v\n", req.Id, err)
+	}
+
+	return nil
+}
+
+func createComment(parentId int, text string) (*sn.Item, error) {
+	var (
+		commentId int
+		err       error
+	)
+
+	if commentId, err = c.CreateComment(parentId, text); err != nil {
+		return nil, fmt.Errorf("failed to reply to item %d: %v\n", parentId, err)
+	}
+
+	var comment *sn.Item
+	if comment, err = c.Item(commentId); err != nil {
+		return nil, fmt.Errorf("failed to fetch item %d: %v\n", commentId, err)
+	}
+
+	if err = db.InsertItem(comment); err != nil {
+		return nil, fmt.Errorf("failed to insert item %d into db: %v\n", err, comment.Id)
+	}
+
+	return comment, nil
+}