Implement file deletion

assets/templates/html/deletePasteSuccess.html.tmpl

@@ -0,0 +1,3 @@
+{{define "title"}}
+Success - rushlink
+{{end}}

assets/templates/txt/deletePasteSuccess.txt.tmpl

@@ -0,0 +1 @@
+<{{.Request.Host}}/{{.Paste.Key}}> was succesfully deleted

assets/templates/txt/newFileUploadPasteSuccess.txt.tmpl

@@ -1,4 +1,5 @@
-https://{{.Request.Host}}/{{.Paste.Key}}
 {{if .Request.PostForm.deleteToken -}}
 https://{{.Request.Host}}/{{.Paste.Key}}?deleteToken={{.Paste.DeleteToken | urlquery}}
+{{else -}}
+https://{{.Request.Host}}/{{.Paste.Key}}
 {{end -}}

assets/templates/txt/newRedirectPasteSuccess.txt.tmpl

@@ -1,4 +1,5 @@
-https://{{.Request.Host}}/{{.Paste.Key}}
 {{if .Request.PostForm.deleteToken -}}
 https://{{.Request.Host}}/{{.Paste.Key}}?deleteToken={{.Paste.DeleteToken | urlquery}}
+{{else -}}
+https://{{.Request.Host}}/{{.Paste.Key}}
 {{end -}}

fileupload.go

@@ -79,7 +79,7 @@ func (t fileUploadState) String() string {
 
 func OpenFileStore(path string) error {
 	if path == "" {
-		return errors.New("file store path not set")
+		return errors.New("file-store not set")
 	}
 
 	// Try to create the file store directory if it does not yet exist
@@ -158,11 +158,23 @@ func (fu *fileUpload) save(tx *bolt.Tx) error {
 }
 
 func (fu *fileUpload) delete(tx *bolt.Tx) error {
-	// Replace the old paste with a new empty paste
-	return (&fileUpload{
+	// Remove the file in the backend
+	filePath := fileStorePath(fu.ID, fu.FileName)
+	if err := os.Remove(filePath); err != nil {
+		return err
+	}
+
+	// Update the file in the server
+	if err := (&fileUpload{
 		ID:    fu.ID,
 		State: fileUploadStateDeleted,
-	}).save(tx)
+	}).save(tx); err != nil {
+		return err
+	}
+
+	// Cleanup the parent directory
+	wrap := "deletion succeeded, but removing the file directory has failed"
+	return errors.Wrap(os.Remove(path.Dir(filePath)), wrap)
 }
 
 func (fu *fileUpload) url() *url.URL {

handlers.go

@@ -173,47 +173,34 @@ func viewPasteHandlerInner(w http.ResponseWriter, r *http.Request, flags viewPas
 }
 
 func newPasteHandler(w http.ResponseWriter, r *http.Request) {
-	newPasteHandlerMultipart(w, r, func(w http.ResponseWriter, r *http.Request) {
-		newPasteHandlerURLEncoded(w, r, func(w http.ResponseWriter, r *http.Request) {
-			renderError(w, r, http.StatusBadRequest, "no form data in request\n")
-		})
-	})
-}
-
-// Try to parse the new-paste request as multi-part form.
-//
-// If there is no multi-part form in the request, this handler will call next.
-func newPasteHandlerMultipart(w http.ResponseWriter, r *http.Request, next http.HandlerFunc) {
-	reader, err := r.MultipartReader()
-	if err != nil {
-		next(w, r)
+	file, fileHeader, err := r.FormFile("file")
+	if err == nil {
+		newFileUploadPasteHandler(w, r, file, *fileHeader)
 		return
-	}
-
-	part, err := reader.NextPart()
-	if err != nil {
-		if err == io.EOF {
-			renderError(w, r, http.StatusBadRequest, "multipart form is empty\n")
-			return
-		}
-		panic(errors.Wrap(err, "multipart.Reader.NextPart"))
-	}
-	if part.FormName() != "file" {
-		msg := fmt.Sprintf("invalid multipart form name: %v", part.FormName())
+	} else if err == http.ErrMissingFile {
+		// Fallthrough
+	} else {
+		msg := fmt.Sprintf("could not parse form: %v\n", err)
 		renderError(w, r, http.StatusBadRequest, msg)
 		return
 	}
 
-	newFileUploadPasteHandler(w, r, *part)
+	shorten := r.FormValue("shorten")
+	if shorten != "" {
+		newRedirectPasteHandler(w, r, shorten)
+		return
 	}
 
-func newFileUploadPasteHandler(w http.ResponseWriter, r *http.Request, part multipart.Part) {
+	renderError(w, r, http.StatusBadRequest, "no 'file' and no 'shorten' fields given in form\n")
+}
+
+func newFileUploadPasteHandler(w http.ResponseWriter, r *http.Request, file multipart.File, header multipart.FileHeader) {
 	var fu *fileUpload
 	var paste *paste
 	if err := DB.Update(func(tx *bolt.Tx) error {
 		var err error
 		// Create the fileUpload in the database
-		fu, err = newFileUpload(tx, &part, part.FileName(), part.Header.Get("Content-Type"))
+		fu, err = newFileUpload(tx, file, header.Filename, header.Header.Get("Content-Type"))
 		if err != nil {
 			panic(errors.Wrap(err, "creating fileUpload"))
 		}
@@ -240,8 +227,7 @@ func newPasteHandlerURLEncoded(w http.ResponseWriter, r *http.Request, next http
 	newRedirectPasteHandler(w, r, shorten)
 }
 
-func newRedirectPasteHandler(w http.ResponseWriter, r *http.Request, shorten string) {
-	rawurl := r.PostForm.Get("shorten")
+func newRedirectPasteHandler(w http.ResponseWriter, r *http.Request, rawurl string) {
 	userURL, err := url.ParseRequestURI(rawurl)
 	if err != nil {
 		msg := fmt.Sprintf("invalid url (%v): %v", err, rawurl)
@@ -259,7 +245,6 @@ func newRedirectPasteHandler(w http.ResponseWriter, r *http.Request, shorten str
 
 	var paste *paste
 	if err := DB.Update(func(tx *bolt.Tx) error {
-		// Generate a new delete token for this paste
 		var err error
 		paste, err = shortenURL(tx, userURL)
 		return err
@@ -282,22 +267,35 @@ func deletePasteHandler(w http.ResponseWriter, r *http.Request) {
 	}
 
 	var errorCode int
+	var paste paste
 	if err := DB.Update(func(tx *bolt.Tx) error {
 		p, err := getPaste(tx, key)
 		if err != nil {
 			errorCode = http.StatusNotFound
 			return err
 		}
-		if subtle.ConstantTimeCompare([]byte(deleteToken), []byte(p.DeleteToken)) == 1 {
-			p.delete(tx)
+		if p.State == pasteStateDeleted {
+			errorCode = http.StatusGone
+			return errors.New("already deleted")
 		}
+		if subtle.ConstantTimeCompare([]byte(deleteToken), []byte(p.DeleteToken)) == 0 {
 			errorCode = http.StatusForbidden
 			return errors.New("invalid delete token")
+		}
+		if err := p.delete(tx); err != nil {
+			errorCode = http.StatusInternalServerError
+			return err
+		}
+		paste = *p
+		return nil
 	}); err != nil {
 		log.Printf("error: %v\n", err)
 		renderError(w, r, errorCode, fmt.Sprintf("error: %v\n", err))
 		return
 	}
+
+	data := map[string]interface{}{"Paste": paste}
+	render(w, r, "deletePasteSuccess", data)
 }
 
 // Add a new fileUpload redirect to the database

paste.go

@@ -7,6 +7,7 @@ import (
 	"strings"
 	"time"
 
+	"github.com/google/uuid"
 	"github.com/pkg/errors"
 	bolt "go.etcd.io/bbolt"
 )
@@ -44,6 +45,8 @@ func (t pasteType) String() string {
 		return "paste"
 	case pasteTypeRedirect:
 		return "redirect"
+	case pasteTypeFileUpload:
+		return "file"
 	default:
 		return "invalid"
 	}
@@ -94,12 +97,29 @@ func (p *paste) save(tx *bolt.Tx) error {
 }
 
 func (p *paste) delete(tx *bolt.Tx) error {
+	// Remove the (maybe) attached file
+	if p.Type == pasteTypeFileUpload {
+		fuID, err := uuid.FromBytes(p.Content)
+		if err != nil {
+			return errors.Wrap(err, "failed to parse uuid")
+		}
+		fu, err := getFileUpload(tx, fuID)
+		if err != nil {
+			return errors.Wrap(err, "failed to find file in database")
+		}
+		if err := fu.delete(tx); err != nil {
+			return errors.Wrap(err, "failed to remove file")
+		}
+	}
+
 	// Replace the old paste with a new empty paste
-	return (&paste{
-		Key:         p.Key,
-		State:       pasteStateDeleted,
-		DeleteToken: p.DeleteToken,
-	}).save(tx)
+	p.Type = pasteTypeUndef
+	p.State = pasteStateDeleted
+	p.Content = []byte{}
+	if err := p.save(tx); err != nil {
+		return errors.Wrap(err, "failed to delete paste in database")
+	}
+	return nil
 }
 
 // Get the URL from this paste.