feat(client): add pagination support

Closes #11

internal/client/client.go

@@ -8,6 +8,7 @@ import (
 	"io"
 	"net/http"
 	"net/url"
+	"strconv"
 	"time"
 )
 
@@ -17,6 +18,9 @@ type Client struct {
 	httpClient *http.Client
 }
 
+const maxItemsPerPage = 50
+const maxItemsPerPageStr = "50"
+
 func NewClient(baseURL *url.URL, apiToken string) *Client {
 	return &Client{
 		baseURI: baseURL,
@@ -31,13 +35,49 @@ func NewClient(baseURL *url.URL, apiToken string) *Client {
 	}
 }
 
-func (c *Client) Send(ctx context.Context, method string, uriRef *url.URL, payload any, response any) error {
+func (c *Client) sendPaginated(ctx context.Context, method string, uriRef *url.URL, payload any, response any) error {
+	query, err := url.ParseQuery(uriRef.RawQuery)
+	if err != nil {
+		return fmt.Errorf("failed to parse query string: %w", err)
+	}
+	query.Set("limit", maxItemsPerPageStr)
+	page := 1
+	var rawResponses []json.RawMessage
+	for {
+		query.Set("page", strconv.Itoa(page))
+		uriRef.RawQuery = query.Encode()
+		var res json.RawMessage
+		count, err := c.Send(ctx, method, uriRef, payload, &res)
+		if err != nil {
+			return fmt.Errorf("failed to send: %w", err)
+		}
+		var oneResponse []json.RawMessage
+		if err := json.Unmarshal(res, &oneResponse); err != nil {
+			return fmt.Errorf("failed to unmarshal message: %w", err)
+		}
+		rawResponses = append(rawResponses, oneResponse...)
+		if count <= page*maxItemsPerPage {
+			break
+		}
+		page++
+	}
+	responses, err := json.Marshal(rawResponses)
+	if err != nil {
+		return fmt.Errorf("failed to marshal raw responses to paginated request: %w", err)
+	}
+	if err := json.Unmarshal(responses, &response); err != nil {
+		return fmt.Errorf("failed to unmarshal paginated request responses: %w", err)
+	}
+	return nil
+}
+
+func (c *Client) Send(ctx context.Context, method string, uriRef *url.URL, payload any, response any) (int, error) {
 	uri := c.baseURI.ResolveReference(uriRef)
 
 	var payloadReader io.Reader
 	if payload != nil {
 		if body, err := json.Marshal(payload); err != nil {
-			return fmt.Errorf("cannot marshal payload: %w", err)
+			return 0, fmt.Errorf("cannot marshal payload: %w", err)
 		} else {
 			payloadReader = bytes.NewReader(body)
 		}
@@ -45,24 +85,28 @@ func (c *Client) Send(ctx context.Context, method string, uriRef *url.URL, paylo
 
 	req, err := http.NewRequestWithContext(ctx, method, uri.String(), payloadReader)
 	if err != nil {
-		return fmt.Errorf("cannot create request: %w", err)
+		return 0, fmt.Errorf("cannot create request: %w", err)
 	}
 	req.Header = *c.headers
 
 	resp, err := c.httpClient.Do(req)
 	if err != nil {
-		return fmt.Errorf("cannot send request: %w", err)
+		return 0, fmt.Errorf("cannot send request: %w", err)
 	}
 	defer resp.Body.Close()
 	body, err := io.ReadAll(resp.Body)
 	if err != nil {
-		return fmt.Errorf("cannot read response body: %w", err)
+		return 0, fmt.Errorf("cannot read response body: %w", err)
 	}
 	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
-		return fmt.Errorf("non 2XX status code received: %d, %q", resp.StatusCode, body)
+		return 0, fmt.Errorf("non 2XX status code received: %d, %q", resp.StatusCode, body)
 	}
 	if err = json.Unmarshal(body, response); err != nil {
-		return fmt.Errorf("response body unmarshal failed: %w", err)
+		return 0, fmt.Errorf("response body unmarshal failed: %w", err)
+	}
+	if count, err := strconv.Atoi(resp.Header.Get("x-total-count")); err != nil {
+		return 0, nil
+	} else {
+		return count, nil
 	}
-	return nil
 }