Add open library API call when search has no result

internal/openlibrary/openlibrary.go

@@ -0,0 +1,70 @@
+package openlibrary
+
+import (
+	"encoding/json"
+	"io"
+	"net/http"
+	"net/url"
+	"strconv"
+	"strings"
+)
+
+type OpenLibraryQueryResult struct {
+	Books    []OpenLibraryBook `json:"docs"`
+	NumFound int               `json:"numFound"`
+}
+
+type OpenLibraryBook struct {
+	Title         string   `json:"title"`
+	Authors       []string `json:"author_name"`
+	OpenLibraryId string   `json:"cover_edition_key"`
+}
+
+func CallOpenLibrary(searchterm string, limit int, offset int) (OpenLibraryQueryResult, error) {
+	var queryResult OpenLibraryQueryResult
+	baseUrl := "https://openlibrary.org"
+	booksApiUrl := "search.json"
+	u, err := url.Parse(baseUrl)
+	if err != nil {
+		return queryResult, err
+	}
+	u = u.JoinPath(booksApiUrl)
+	if limit != 0 {
+		addQueryParamInt(u, "limit", limit)
+	}
+	if offset != 0 {
+		addQueryParamInt(u, "offset", offset)
+	}
+	addQueryParam(u, "q", searchterm)
+	client := &http.Client{}
+	req, err := http.NewRequest("GET", u.String(), nil)
+	if err != nil {
+		return queryResult, err
+	}
+	req.Header.Add("Accept", "application/json")
+	req.Header.Add("User-Agent", "PersonalLibraryManager/0.1 (artlef@protonmail.com)")
+	resp, err := client.Do(req)
+	if err != nil {
+		return queryResult, err
+	}
+	defer resp.Body.Close()
+
+	bodyBytes, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return queryResult, err
+	}
+	bodyString := string(bodyBytes)
+	decoder := json.NewDecoder(strings.NewReader(bodyString))
+	err = decoder.Decode(&queryResult)
+	return queryResult, err
+}
+
+func addQueryParamInt(u *url.URL, paramName string, paramValue int) {
+	addQueryParam(u, paramName, strconv.Itoa(paramValue))
+}
+
+func addQueryParam(u *url.URL, paramName string, paramValue string) {
+	q := u.Query()
+	q.Set(paramName, paramValue)
+	u.RawQuery = q.Encode()
+}