clear pdf

internal/modules/pdf/interface.go

@@ -0,0 +1,7 @@
+package pdf
+
+import "evening_detective/internal/models"
+
+type IPDFGenerator interface {
+	CreateTeamsPDF(teams []*models.Team) ([]byte, error)
+}

internal/modules/pdf/service.go

@@ -0,0 +1,135 @@
+package pdf
+
+import (
+	"bytes"
+	"embed"
+	"evening_detective/internal/models"
+	"strings"
+
+	"github.com/signintech/gopdf"
+	"github.com/skip2/go-qrcode"
+)
+
+//go:embed JetBrainsMono-Medium.ttf
+var f embed.FS
+
+type service struct{}
+
+func NewPDFGenerator() IPDFGenerator {
+	return &service{}
+}
+
+func (s *service) CreateTeamsPDF(teams []*models.Team) ([]byte, error) {
+	pdf := &gopdf.GoPdf{}
+	pdf.Start(gopdf.Config{PageSize: *gopdf.PageSizeA4}) // W: 595, H: 842
+	file, err := f.Open("JetBrainsMono-Medium.ttf")
+	if err != nil {
+		return nil, err
+	}
+	if err := pdf.AddTTFFontByReader("main", file); err != nil {
+		return nil, err
+	}
+	if err := pdf.SetFont("main", "", 10); err != nil {
+		return nil, err
+	}
+
+	countOnPage := 9
+	padding := 17.
+	xDelta := 187.
+	yDelta := 260.
+	for i, team := range teams {
+		if i%countOnPage == 0 {
+			pdf.AddPage()
+			pdf.SetPage(1 + i/countOnPage)
+		}
+		y := (padding + 15) + yDelta*float64(i%countOnPage/3)
+		x := padding + xDelta*float64(i%3)
+
+		if err := printTextCenter(pdf, "Подключите Wi-Fi", xDelta-6, x+3, y); err != nil {
+			return nil, err
+		}
+		if err := printTextCenter(pdf, "Имя: evening_detective", xDelta-6, x+3, 15+y); err != nil {
+			return nil, err
+		}
+		if err := printTextCenter(pdf, "Пароль: 12345678", xDelta-6, x+3, 30+y); err != nil {
+			return nil, err
+		}
+		if err := printQR(pdf, team.Link, x+21, 65+y); err != nil {
+			return nil, err
+		}
+		if err := printTextCenter(pdf, "Войдите в приложение по qr", xDelta-6, x+3, 55+y); err != nil {
+			return nil, err
+		}
+		if err := printTextCenter(pdf, team.Name, xDelta-6, x+3, 55+y+150); err != nil {
+			return nil, err
+		}
+	}
+	buffer := &bytes.Buffer{}
+	_, err = pdf.WriteTo(buffer)
+	return buffer.Bytes(), err
+}
+
+func printQR(pdf *gopdf.GoPdf, url string, x, y float64) error {
+	png, err := qrcode.Encode(url, qrcode.Medium, 256)
+	if err != nil {
+		return err
+	}
+	imgHolder, err := gopdf.ImageHolderByBytes(png)
+	if err != nil {
+		return err
+	}
+	err = pdf.ImageByHolder(imgHolder, x, y, &gopdf.Rect{W: 145, H: 145})
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func printTextCenter(pdf *gopdf.GoPdf, text string, pageWidth, x, y float64) error {
+	lines := splitTextByWords(pdf, text, pageWidth)
+	for i, line := range lines {
+		lineWidth, err := pdf.MeasureTextWidth(line)
+		if err != nil {
+			return err
+		}
+
+		xLine := x + (pageWidth-lineWidth)/2
+		yLine := y + 15*float64(i)
+		pdf.SetXY(xLine, yLine)
+
+		pdf.Cell(nil, line)
+	}
+	return nil
+}
+
+func splitTextByWords(pdf *gopdf.GoPdf, text string, maxWidth float64) []string {
+	words := strings.Fields(text)
+	var lines []string
+	var currentLine string
+
+	for _, word := range words {
+		testLine := currentLine
+		if testLine != "" {
+			testLine += " " + word
+		} else {
+			testLine = word
+		}
+
+		width, _ := pdf.MeasureTextWidth(testLine)
+
+		if width <= maxWidth {
+			currentLine = testLine
+		} else {
+			if currentLine != "" {
+				lines = append(lines, currentLine)
+			}
+			currentLine = word
+		}
+	}
+
+	if currentLine != "" {
+		lines = append(lines, currentLine)
+	}
+
+	return lines
+}