90 lines
2.0 KiB
Go
90 lines
2.0 KiB
Go
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package pdf
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import (
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"context"
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"fmt"
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"io"
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"time"
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"github.com/chromedp/cdproto/page"
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"github.com/chromedp/chromedp"
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)
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// Generator handles PDF generation using headless Chrome
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type Generator struct {
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timeout time.Duration
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}
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// NewGenerator creates a new PDF generator with the specified timeout
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func NewGenerator(timeout time.Duration) *Generator {
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if timeout == 0 {
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timeout = 30 * time.Second
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}
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return &Generator{
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timeout: timeout,
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}
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}
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// GenerateFromURL generates a PDF from a given URL
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func (g *Generator) GenerateFromURL(ctx context.Context, url string) ([]byte, error) {
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// Create context with timeout
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ctx, cancel := context.WithTimeout(ctx, g.timeout)
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defer cancel()
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// Create chromedp context
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allocCtx, allocCancel := chromedp.NewContext(ctx)
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defer allocCancel()
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// Buffer to store PDF
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var pdfBuffer []byte
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// Run chromedp tasks
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err := chromedp.Run(allocCtx,
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// Navigate to URL
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chromedp.Navigate(url),
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// Wait for page to be ready
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chromedp.WaitReady("body"),
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// Small delay to ensure all content is loaded
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chromedp.Sleep(500*time.Millisecond),
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// Generate PDF with print-optimized settings
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chromedp.ActionFunc(func(ctx context.Context) error {
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var err error
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pdfBuffer, _, err = page.PrintToPDF().
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WithPrintBackground(true).
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WithPreferCSSPageSize(true).
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WithMarginTop(0).
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WithMarginBottom(0).
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WithMarginLeft(0).
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WithMarginRight(0).
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WithPaperWidth(8.27). // A4 width in inches
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WithPaperHeight(11.69). // A4 height in inches
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Do(ctx)
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return err
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}),
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)
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if err != nil {
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return nil, fmt.Errorf("chromedp execution failed: %w", err)
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}
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if len(pdfBuffer) == 0 {
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return nil, fmt.Errorf("generated PDF is empty")
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}
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return pdfBuffer, nil
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}
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// StreamFromURL generates a PDF and writes it to the provided writer
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func (g *Generator) StreamFromURL(ctx context.Context, url string, w io.Writer) error {
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pdfData, err := g.GenerateFromURL(ctx, url)
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if err != nil {
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return err
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}
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_, err = w.Write(pdfData)
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return err
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}
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