append metadata tags after saving tracks

also rewrite requests to monochrome using 2 helper methods

monochrome/client.go

@@ -1,5 +1,12 @@
 package monochrome
 
+import (
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+)
+
 type ClientConfig struct {
 	ApiURL string
 }
@@ -13,3 +20,41 @@ func NewClient(config ClientConfig) *Client {
 		config: config,
 	}
 }
+
+func (c *Client) makeRequest(method string, path string, body io.Reader, params map[string]string) (*http.Request, error) {
+	req, err := http.NewRequest(method, c.config.ApiURL+path, body)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create request: %v", err)
+	}
+
+	p := url.Values{}
+	for key, value := range params {
+		p.Add(key, value)
+	}
+	req.URL.RawQuery = p.Encode()
+
+	return req, nil
+}
+
+func (c *Client) do(req *http.Request) ([]byte, error) {
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("failed to send request: %v", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode == http.StatusTooManyRequests {
+		return nil, fmt.Errorf("rate limited")
+	}
+
+	data, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read response: %v", err)
+	}
+
+	if resp.StatusCode >= 400 {
+		return data, fmt.Errorf("got error from api, data is filled with response")
+	}
+
+	return data, nil
+}