up

internal/services/team_service/receipt.go

@@ -103,6 +103,9 @@ func (s *TeamService) teamReceipt(ctx context.Context, gameID int, teamID string
 }
 
 func renderReceipt(card team_qr_pdf.Card) (*image.Gray, error) {
+	if err := team_qr_pdf.ValidateWiFi(card.WiFiName, card.WiFiPassword); err != nil {
+		return nil, fmt.Errorf("%w: %w", ErrInvalidReceipt, err)
+	}
 	name := strings.Join(strings.Fields(card.Name), " ")
 	if name == "" || len([]rune(name)) > 255 {
 		return nil, ErrInvalidReceipt
@@ -111,17 +114,34 @@ func renderReceipt(card team_qr_pdf.Card) (*image.Gray, error) {
 	if err != nil {
 		return nil, fmt.Errorf("parse receipt font: %w", err)
 	}
-	face, err := opentype.NewFace(ttf, &opentype.FaceOptions{Size: 26, DPI: 72, Hinting: font.HintingFull})
+	nameSize, nameLineHeight := 26.0, 34
+	if card.WiFiName != "" {
+		nameSize, nameLineHeight = 20, 26
+	}
+	face, err := opentype.NewFace(ttf, &opentype.FaceOptions{Size: nameSize, DPI: 72, Hinting: font.HintingFull})
 	if err != nil {
 		return nil, fmt.Errorf("open receipt font: %w", err)
 	}
-	defer face.Close()
+	defer func() {
+		if face != nil {
+			_ = face.Close()
+		}
+	}()
 	for _, r := range name {
 		if _, ok := face.GlyphAdvance(r); !ok {
 			return nil, ErrInvalidReceipt
 		}
 	}
 	lines := wrapReceiptName(name, face)
+	instructionFace, err := opentype.NewFace(ttf, &opentype.FaceOptions{Size: 20, DPI: 72, Hinting: font.HintingFull})
+	if err != nil {
+		return nil, fmt.Errorf("open Wi-Fi receipt font: %w", err)
+	}
+	defer instructionFace.Close()
+	var instructions []string
+	for _, paragraph := range team_qr_pdf.WiFiInstructions(card.WiFiName, card.WiFiPassword) {
+		instructions = append(instructions, wrapReceiptText(paragraph, instructionFace)...)
+	}
 	qr, err := qrcode.New(card.URL, qrcode.Medium)
 	if err != nil {
 		return nil, ErrInvalidReceipt
@@ -132,8 +152,20 @@ func renderReceipt(card team_qr_pdf.Card) (*image.Gray, error) {
 		return nil, ErrInvalidReceipt
 	}
 	qrSize := len(bitmap) * scale
-	qrY := 16 + len(lines)*34 + 16
-	height := qrY + qrSize + 24
+	qrY := 16 + len(lines)*nameLineHeight + 16
+	height := qrY + qrSize + 24 + len(instructions)*26
+	for card.WiFiName != "" && height > receiptMaxHeight && nameSize > 16 {
+		_ = face.Close()
+		nameSize -= 2
+		nameLineHeight = int(nameSize) + 6
+		face, err = opentype.NewFace(ttf, &opentype.FaceOptions{Size: nameSize, DPI: 72, Hinting: font.HintingFull})
+		if err != nil {
+			return nil, fmt.Errorf("resize receipt font: %w", err)
+		}
+		lines = wrapReceiptName(name, face)
+		qrY = 16 + len(lines)*nameLineHeight + 16
+		height = qrY + qrSize + 24 + len(instructions)*26
+	}
 	if height > receiptMaxHeight {
 		return nil, ErrInvalidReceipt
 	}
@@ -142,7 +174,7 @@ func renderReceipt(card team_qr_pdf.Card) (*image.Gray, error) {
 	drawer := font.Drawer{Dst: img, Src: image.Black, Face: face}
 	for i, line := range lines {
 		width := drawer.MeasureString(line).Ceil()
-		drawer.Dot = fixed.P((receiptWidth-width)/2, 16+face.Metrics().Ascent.Ceil()+i*34)
+		drawer.Dot = fixed.P((receiptWidth-width)/2, 16+face.Metrics().Ascent.Ceil()+i*nameLineHeight)
 		drawer.DrawString(line)
 	}
 	x := (receiptWidth - qrSize) / 2
@@ -153,6 +185,11 @@ func renderReceipt(card team_qr_pdf.Card) (*image.Gray, error) {
 			}
 		}
 	}
+	drawer.Face = instructionFace
+	for i, line := range instructions {
+		drawer.Dot = fixed.P(16, qrY+qrSize+instructionFace.Metrics().Ascent.Ceil()+i*26)
+		drawer.DrawString(line)
+	}
 	for i, pixel := range img.Pix {
 		if pixel < 128 {
 			img.Pix[i] = 0
@@ -211,3 +248,25 @@ func validateReceiptRaster(data []byte) error {
 	}
 	return nil
 }
+
+// Preserve spaces in credentials when wrapping the printed instructions.
+func wrapReceiptText(text string, face font.Face) []string {
+	var lines []string
+	line := ""
+	for _, r := range text {
+		for line != "" && font.MeasureString(face, line+string(r)).Ceil() > receiptWidth-32 {
+			if space := strings.LastIndexByte(line, ' '); space >= 0 {
+				lines = append(lines, line[:space+1])
+				line = line[space+1:]
+			} else {
+				lines = append(lines, line)
+				line = ""
+			}
+		}
+		line += string(r)
+	}
+	if line != "" {
+		lines = append(lines, line)
+	}
+	return lines
+}