Add attachments support

mastodon/mastodon.go

@@ -83,6 +83,32 @@ func (c *Client) doAPI(ctx context.Context, method string, uri string, params in
 			return err
 		}
 		ct = mw.FormDataContentType()
+	} else if file, ok := params.(*multipart.FileHeader); ok {
+		f, err := file.Open()
+		if err != nil {
+			return err
+		}
+		defer f.Close()
+
+		var buf bytes.Buffer
+		mw := multipart.NewWriter(&buf)
+		part, err := mw.CreateFormFile("file", filepath.Base(file.Filename))
+		if err != nil {
+			return err
+		}
+		_, err = io.Copy(part, f)
+		if err != nil {
+			return err
+		}
+		err = mw.Close()
+		if err != nil {
+			return err
+		}
+		req, err = http.NewRequest(method, u.String(), &buf)
+		if err != nil {
+			return err
+		}
+		ct = mw.FormDataContentType()
 	} else if reader, ok := params.(io.Reader); ok {
 		var buf bytes.Buffer
 		mw := multipart.NewWriter(&buf)

mastodon/status.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"fmt"
 	"io"
+	"mime/multipart"
 	"net/http"
 	"net/url"
 	"time"
@@ -295,3 +296,13 @@ func (c *Client) UploadMediaFromReader(ctx context.Context, reader io.Reader) (*
 	}
 	return &attachment, nil
 }
+
+// UploadMediaFromReader uploads a media attachment from a io.Reader.
+func (c *Client) UploadMediaFromMultipartFileHeader(ctx context.Context, fh *multipart.FileHeader) (*Attachment, error) {
+	var attachment Attachment
+	err := c.doAPI(ctx, http.MethodPost, "/api/v1/media", fh, &attachment, nil)
+	if err != nil {
+		return nil, err
+	}
+	return &attachment, nil
+}