add new Nature method to Record interface

internal/open_figi.go

@@ -0,0 +1,60 @@
+package internal
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"time"
+)
+
+type OpenFIGI struct {
+	client http.Client
+
+	cache map[string]string
+}
+
+func NewOpenFIGI() *OpenFIGI {
+	return &OpenFIGI{
+		client: http.Client{
+			Timeout: 5 * time.Second,
+		},
+	}
+}
+
+func (of *OpenFIGI) Category(ctx context.Context, isin, ticker string) (string, error) {
+	rawBody, err := json.Marshal(mappingRequestBody{
+		IdType:  "ID_ISIN",
+		IdValue: isin,
+	})
+	if err != nil {
+		return "", fmt.Errorf("marshal mapping request body: %w", err)
+	}
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, "https://api.openfigi.com/v3/mapping", bytes.NewBuffer(rawBody))
+	if err != nil {
+		return "", fmt.Errorf("create mapping request: %w", err)
+	}
+
+	res, err := of.client.Do(req)
+	if err != nil {
+		return "", fmt.Errorf("make mapping request: %w", err)
+	}
+	defer res.Body.Close()
+
+	var resBody mappingResponseBody
+	err = json.NewDecoder(res.Body).Decode(&resBody)
+	if err != nil {
+		return "", fmt.Errorf("unmarshal response: %w", err)
+	}
+
+	return "", nil
+}
+
+type mappingRequestBody struct {
+	IdType  string `json:"idType"`
+	IdValue string `json:"idValue"`
+}
+
+type mappingResponseBody struct{}