go-extractor/sites/megamillions/megamillions.go

package megamillions

import (
	"context"
	"fmt"
	"io"
	"strconv"
	"strings"
	"time"

	"gitea.stevedudenhoeffer.com/steve/go-extractor"

	"golang.org/x/text/currency"
)

type Config struct{}

var DefaultConfig = Config{}

func (c Config) validate() Config {
	return c
}

type Drawing struct {
	Date      time.Time
	Numbers   [5]int
	MegaBall  int
	Megaplier int
}

type NextDrawing struct {
	Date    string
	Jackpot currency.Amount
}

func deferClose(cl io.Closer) {
	if cl != nil {
		_ = cl.Close()
	}
}

func netTicksToTime(t int64) time.Time {
	return time.Unix(0, t*100).Add(-621355968000000000)
}

func getDrawing(_ context.Context, doc extractor.Document) (*Drawing, error) {
	var drawing Drawing

	// the drawdate is stored as a .net ticks value in the data-playdateticks attribute of a
	// span with the id of "lastestDate"

	date := doc.Select("span#lastestDate")
	if len(date) != 1 {
		return nil, fmt.Errorf("expected 1 date, got %d", len(date))
	}

	txt, err := date[0].Attr("data-playdateticks")
	if err != nil {
		return nil, fmt.Errorf("failed to get date: %w", err)
	}

	ticks, err := strconv.ParseInt(txt, 10, 64)
	if err != nil {
		return nil, fmt.Errorf("failed to parse date: %w", err)
	}

	fmt.Println("ticks", ticks)
	drawing.Date = netTicksToTime(ticks)

	err = doc.ForEach("ul.numbers li.ball", func(n extractor.Node) error {
		classes, err := n.Attr("class")

		if err != nil {
			return err
		}

		txt, err := n.Text()

		if err != nil {
			return err
		}

		val, err := strconv.Atoi(txt)

		if err != nil {
			return err
		}

		if strings.Contains(classes, "winNum1") {
			drawing.Numbers[0] = val
			return nil
		}

		if strings.Contains(classes, "winNum2") {
			drawing.Numbers[1] = val
			return nil
		}

		if strings.Contains(classes, "winNum3") {
			drawing.Numbers[2] = val
			return nil
		}

		if strings.Contains(classes, "winNum4") {
			drawing.Numbers[3] = val
			return nil
		}

		if strings.Contains(classes, "winNum5") {
			drawing.Numbers[4] = val
			return nil
		}

		if strings.Contains(classes, "winNumMB") {
			drawing.MegaBall = val
			return nil
		}
		return fmt.Errorf("unknown li.ball class: %s", classes)
	})
	if err != nil {
		return nil, fmt.Errorf("failed to get numbers: %w", err)
	}

	megaplier := doc.Select("span.megaplier span.winNumMP")

	if len(megaplier) != 1 {
		return nil, fmt.Errorf("expected 1 megaplier, got %d", len(megaplier))
	}

	// megaplier is in the format of "2X" or "3X" etc.

	txt, err = megaplier[0].Text()

	if err != nil {
		return nil, fmt.Errorf("failed to get megaplier: %w", err)
	}

	val, err := strconv.Atoi(strings.ReplaceAll(strings.ReplaceAll(txt, "X", ""), "x", ""))

	if err != nil {
		return nil, fmt.Errorf("failed to convert megaplier to int: %w", err)
	}
	drawing.Megaplier = val

	return &drawing, nil
}

func getNextDrawing(_ context.Context, doc extractor.Document) (*NextDrawing, error) {
	var nextDrawing NextDrawing

	date := doc.Select("div.nextEstGroup span.nextDrawDate")
	if len(date) != 1 {
		return nil, fmt.Errorf("expected 1 date, got %d", len(date))
	}

	var err error
	nextDrawing.Date, err = date[0].Text()

	if err != nil {
		return nil, fmt.Errorf("failed to get date: %w", err)
	}

	jackpot := doc.Select("div.nextEstGroup span.nextEstVal")

	if len(jackpot) != 1 {
		return nil, fmt.Errorf("expected 1 jackpot, got %d", len(jackpot))
	}

	txt, err := jackpot[0].Text()

	if err != nil {
		return nil, fmt.Errorf("failed to get jackpot: %w", err)
	}

	// jackpot is in the format of "$1.5 billion", "$100 million", or "$200,000" etc

	// make one filter to only get the numeric part of the jackpot

	numericOnly := func(in string) float64 {
		var out string
		for _, r := range in {
			if r >= '0' && r <= '9' {
				out += string(r)
			}

			if r == '.' {
				out += string(r)
			}
		}

		val, err := strconv.ParseFloat(out, 64)

		if err != nil {
			return 0
		}

		return val
	}

	numeric := numericOnly(txt)

	set := false
	if strings.Contains(txt, "Billion") {
		amt := currency.USD.Amount(numeric * 1000000000)
		nextDrawing.Jackpot = amt
		set = true
	} else if strings.Contains(txt, "Million") {
		amt := currency.USD.Amount(numeric * 1000000)
		nextDrawing.Jackpot = amt
		set = true
	} else {
		amt := currency.USD.Amount(numeric)
		nextDrawing.Jackpot = amt
		set = true
	}

	if !set {
		return nil, fmt.Errorf("failed to convert jackpot to currency: %w", err)
	}

	return &nextDrawing, nil
}

func (c Config) GetCurrent(ctx context.Context, b extractor.Browser) (*Drawing, *NextDrawing, error) {
	c = c.validate()

	doc, err := b.Open(ctx, "https://www.megamillions.com/", extractor.OpenPageOptions{})

	if err != nil {
		return nil, nil, err
	}

	defer deferClose(doc)

	d, err := getDrawing(ctx, doc)

	if err != nil {
		return nil, nil, err
	}

	nd, err := getNextDrawing(ctx, doc)

	if err != nil {
		return nil, nil, err
	}

	return d, nd, nil
}

func GetCurrent(ctx context.Context, b extractor.Browser) (*Drawing, *NextDrawing, error) {
	return DefaultConfig.GetCurrent(ctx, b)
}