initial wrapper

client/client.go

@@ -0,0 +1,101 @@
+package client
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+)
+
+var (
+	defaultAPI = "https://openlibrary.org/api/books"
+)
+
+// Client
+type Client struct {
+	httpClient http.Client
+	apipath    string
+}
+
+// NewClient returns a new Client struct using http.DefaultClient and default api path.
+func NewClient() (*Client, error) {
+	return &Client{
+		apipath: defaultAPI,
+	}, nil
+}
+
+// SetHTTPClient updates the httpClient on the client with a manually-configured one.
+// If unset, the client will fall back to using http.DefaultClient.
+func (c *Client) SetHTTPClient(h http.Client) {
+	c.httpClient = h
+}
+
+// SetAPIPath updates the hostname and path to the API; the default is "https://openlibrary.org/api/books".
+// If APIPath is set to an empty string, the client will fall back to the default option.
+func (c *Client) SetAPIPath(p string) {
+	c.apipath = p
+}
+
+// GetByISBN fetches details for a book based on its ISBN10 or ISBN13.
+func (c *Client) GetByISBN(k string) (*BookDetails, error) {
+	key := "ISBN:" + k
+	return c.fetch(key)
+}
+
+// GetByOCLC fetches details for a book based on its WorldCat OCLC number.
+func (c *Client) GetByOCLC(k string) (*BookDetails, error) {
+	key := "OCLC:" + k
+	return c.fetch(key)
+}
+
+// GetByLCCN fetches details for a book based on its Library of Congress Control Number.
+func (c *Client) GetByLCCN(k string) (*BookDetails, error) {
+	key := "LCCN:" + k
+	return c.fetch(key)
+}
+
+// GetByOLID fetches details for a book based on its OpenLibrary ID number.
+func (c *Client) GetByOLID(k string) (*BookDetails, error) {
+	key := "OLID:" + k
+	return c.fetch(key)
+}
+
+// GetByRawKey fetches details for a book based on an arbitrary key; this method is provided
+// as a future-proof fallback in case the OpenLibrary API adds more "bibkey" request types in the future.
+// Most users should use one of the other lookup functions.
+func (c *Client) GetByRawKey(k string) (*BookDetails, error) {
+	return c.fetch(k)
+}
+
+func (c *Client) fetch(key string) (*BookDetails, error) {
+	path := c.apipath
+	if path == "" {
+		path = defaultAPI
+	}
+
+	resp, err := c.httpClient.Get(path + "?bibkeys=%s&jscmd=data&format=json")
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("received non-200 status code: %d", resp.StatusCode)
+	}
+
+	var result response
+	b, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, err
+	}
+	if err = json.Unmarshal(b, &result); err != nil {
+		return nil, err
+	}
+
+	details, ok := result[key]
+	if !ok {
+		return nil, fmt.Errorf("book not found")
+	}
+
+	return &details, nil
+}