Application to generate a pdf file of the netflix web page

cdp_test.go

package main

import (
	"context"
	"fmt"
	"io/ioutil"
	"log"
	"time"

	"github.com/mafredri/cdp"
	"github.com/mafredri/cdp/devtool"
	"github.com/mafredri/cdp/protocol/page"
	"github.com/mafredri/cdp/rpcc"
)

func main() {
	err := run(15 * time.Second)
	if err != nil {
		log.Fatal(err)
	}
}

func run(timeout time.Duration) error {
	ctx, cancel := context.WithTimeout(context.Background(), timeout)
	defer cancel()

	// Initialize cdp
	c, conn, err := initCDP(ctx, timeout)
	if err != nil {
		return err
	}
	defer conn.Close() // Leaving connections open will leak memory.

	// Enable lifecycle events...
	err = c.Page.SetLifecycleEventsEnabled(ctx, page.NewSetLifecycleEventsEnabledArgs(true))
	if err != nil {
		return err
	}
	events, err := c.Page.LifecycleEvent(ctx)
	if err != nil {
		return err
	}
	defer events.Close()

	// Enable events on the Page domain, it's often preferrable to create
	// event clients before enabling events so that we don't miss any.
	if err = c.Page.Enable(ctx); err != nil {
		return err
	}

	// Create the Navigate arguments with the optional Referrer field set.
	// url := "https://www.google.com"
	url := "https://www.netflix.com/mx/"
	navArgs := page.NewNavigateArgs(url)
	nav, err := c.Page.Navigate(ctx, navArgs)
	if err != nil {
		return err
	}

	for {
		ev, err := events.Recv()
		if err != nil {
			return err
		}
		fmt.Println(ev.Name)
		if ev.Name == "networkIdle" {
			break
		}
	}

	fmt.Printf("Page loaded with frame ID: %s\n", nav.FrameID)

	// Generating the pdf
	printPDF(ctx, c)

	return nil
}

func printPDF(ctx context.Context, c *cdp.Client) error {
	pdfName := "output.pdf"
	printToPDFArgs := page.NewPrintToPDFArgs().
		SetPrintBackground(true).
		SetLandscape(true).
		SetMarginTop(0).
		SetMarginBottom(0).
		SetMarginLeft(0).
		SetMarginRight(0)

	print, _ := c.Page.PrintToPDF(ctx, printToPDFArgs)
	if err := ioutil.WriteFile(pdfName, print.Data, 0644); err != nil {
		return err
	}
	fmt.Printf("Saved pdf: %s\n", pdfName)
	return nil
}

func initCDP(ctx context.Context, timeout time.Duration) (*cdp.Client, *rpcc.Conn, error) {
	// Use the DevTools HTTP/JSON API to manage targets (e.g. pages, webworkers).
	devt := devtool.New("http://127.0.0.1:9222")
	pt, err := devt.Get(ctx, devtool.Page)
	if err != nil {
		pt, err = devt.Create(ctx)
		if err != nil {
			return nil, nil, err
		}
	}

	// Initiate a new RPC connection to the Chrome DevTools Protocol target.
	conn, err := rpcc.DialContext(ctx, pt.WebSocketDebuggerURL)
	if err != nil {
		return nil, nil, err
	}

	c := cdp.NewClient(conn)
	return c, conn, nil
}