Initial commit

internal/monkeyuser/monkeyuser.go

@@ -0,0 +1,124 @@
+package monkeyuser
+
+import (
+	"aleesa-webapp-go/internal/config"
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"math/rand/v2"
+	"strings"
+
+	"github.com/carlmjohnson/requests"
+	"golang.org/x/net/html"
+)
+
+// MonkeyUsers описывает структуру json-массива ответа www.monkeyusers.com.
+type MonkeyUsers []struct {
+	Title string `json:"title"`
+	URL   string `json:"url"`
+}
+
+func APIClient(cfg *config.MyConfig) (string, error) {
+	var (
+		ctx       = context.Background()
+		respBody  bytes.Buffer
+		respBytes []byte
+		body      string
+		userAgent = cfg.UserAgents[rand.IntN(len(cfg.UserAgents))]
+		baseURL   = "https://www.monkeyuser.com"
+		indexURL  = fmt.Sprintf("%s/index.json", baseURL)
+	)
+
+	err := requests.
+		URL(indexURL).
+		UserAgent(userAgent).
+		ToBytesBuffer(&respBody).
+		Fetch(ctx)
+
+	if err != nil {
+		return "", fmt.Errorf("unable to GET %s: %w", indexURL, err)
+	}
+
+	// На всякий случай валидируем utf-8.
+	respBytes = bytes.ToValidUTF8(respBody.Bytes(), []byte{0xef, 0xbf, 0xbd})
+
+	var monkeyusers MonkeyUsers
+
+	if err := json.Unmarshal(respBytes, &monkeyusers); err != nil {
+		err = fmt.Errorf("unable to to parse response from %s: %w", indexURL, err)
+
+		return "", err
+	}
+
+	amountOfUsers := len(monkeyusers)
+
+	if amountOfUsers == 0 {
+		err = fmt.Errorf("no links found in %s", indexURL)
+
+		return "", err
+	}
+
+	ofChoice := rand.IntN(amountOfUsers)
+	pageURL := fmt.Sprintf("%s%s", baseURL, monkeyusers[ofChoice].URL)
+
+	// Делаем второй запрос к серверу.
+	err = requests.
+		URL(pageURL).
+		UserAgent(userAgent).
+		ToString(&body).
+		Fetch(ctx)
+
+	if err != nil {
+		return "", fmt.Errorf("unable to GET %s: %w", pageURL, err)
+	}
+
+	// Парсим body ответа от сервера
+	doc, err := html.Parse(strings.NewReader(body))
+
+	if err != nil {
+		return "", err
+	}
+
+	var (
+		hyperlink string
+		link      func(*html.Node)
+	)
+
+	link = func(n *html.Node) {
+		if n.Type == html.ElementNode && n.Data == "img" {
+			for _, a_href := range n.Attr { //nolint: revive,stylecheck
+				// Если у нас class == "lazyload small-image", то после него ключ data-src должен содержать
+				// искомый relative url
+				if a_href.Key == "class" && a_href.Val == "logo" {
+					continue
+				}
+
+				var v = a_href.Val
+				if a_href.Key == "src" && v != "/images/logo.png" {
+					hyperlink = v
+
+					break
+				}
+			}
+		}
+
+		// traverses the HTML of the webpage from the first child node
+		for c := n.FirstChild; c != nil; c = c.NextSibling {
+			link(c)
+		}
+	}
+
+	link(doc)
+
+	// Возвращаем ссылку на картинку buni comic
+	if hyperlink != "" {
+		return fmt.Sprintf("%s%s", baseURL, hyperlink), nil
+	}
+
+	err = fmt.Errorf("no links found on monkeyusers.com")
+
+	return "", err
+}
+
+/* vim: set ft=go noet ai ts=4 sw=4 sts=4: */