add nipb0/blossom helpers.

nipb0/blossom/download.go

@@ -0,0 +1,70 @@
+package blossom
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+
+	"github.com/nbd-wtf/go-nostr"
+)
+
+// Download downloads a file from the media server by its hash
+func (c *Client) Download(ctx context.Context, hash string) ([]byte, error) {
+	if !nostr.IsValid32ByteHex(hash) {
+		return nil, fmt.Errorf("%s is not a valid 32-byte hex string", hash)
+	}
+
+	req, err := http.NewRequestWithContext(ctx, "GET", c.mediaserver+"/"+hash, nil)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create request: %w", err)
+	}
+
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("failed to call %s for %s: %w", c.mediaserver, hash, err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode >= 300 {
+		return nil, fmt.Errorf("%s is not present in %s: %d", hash, c.mediaserver, resp.StatusCode)
+	}
+
+	return io.ReadAll(resp.Body)
+}
+
+// DownloadToFile downloads a file from the media server and saves it to the specified path
+func (c *Client) DownloadToFile(ctx context.Context, hash string, filePath string) error {
+	if !nostr.IsValid32ByteHex(hash) {
+		return fmt.Errorf("%s is not a valid 32-byte hex string", hash)
+	}
+
+	req, err := http.NewRequestWithContext(ctx, "GET", c.mediaserver+"/"+hash, nil)
+	if err != nil {
+		return fmt.Errorf("failed to create request: %w", err)
+	}
+
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return fmt.Errorf("failed to call %s for %s: %w", c.mediaserver, hash, err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode >= 300 {
+		return fmt.Errorf("%s is not present in %s: %d", hash, c.mediaserver, resp.StatusCode)
+	}
+
+	file, err := os.OpenFile(filePath, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0644)
+	if err != nil {
+		return fmt.Errorf("failed to create file %s for %s: %w", filePath, hash, err)
+	}
+	defer file.Close()
+
+	_, err = io.Copy(file, resp.Body)
+	if err != nil {
+		return fmt.Errorf("failed to write to file %s for %s: %w", filePath, hash, err)
+	}
+
+	return nil
+}