levels.go

package nzcovid19cases

import (
	"encoding/json"
	"fmt"
	"regexp"
	"strconv"

	"github.com/anaskhan96/soup"
)

type AlertLevel struct {
	Level     int
	LevelName string
}

var re = regexp.MustCompile(`(?m)Level (\d)`) //nolint:gochecknoglobals
const NumLevelREMatches = 2

func ScrapeLevel() (int, string, error) {
	resp, err := soup.Get("https://uniteforrecovery.govt.nz/covid-19/covid-19-alert-system/alert-system-overview/")
	if err != nil {
		return 0, "", err
	}

	doc := soup.HTMLParse(resp)

	h2s := doc.FindAll("h2", "class", "content-element__title")
	if len(h2s) < 1 {
		return 0, "", fmt.Errorf("could not find h3")
	}

	h2 := h2s[0]

	matches := re.FindStringSubmatch(h2.Text())
	if len(matches) != NumLevelREMatches {
		return 0, "", fmt.Errorf("expected two match elements")
	}

	levelString := matches[1]

	levelInt, err := strconv.Atoi(levelString)
	if err != nil {
		return 0, "", fmt.Errorf("could not convert level (%v) to int: %w", levelString, err)
	}

	levelName, ok := levelLookup[levelInt]
	if !ok {
		return 0, "", fmt.Errorf("could not look up level name from level (%v) : %w", levelInt, err)
	}

	return levelInt, levelName, nil
}

func RenderLevels(levelInt int, levelString, viewType string) (string, error) {
	if viewType != JSONRenderType {
		return "", InvalidUsageError{fmt.Sprintf("unknown view type: %v", viewType)}
	}

	level := AlertLevel{
		Level:     levelInt,
		LevelName: levelString,
	}

	b, err := json.MarshalIndent(level, "", "  ")
	if err != nil {
		return "", err
	}

	return string(b), nil
}