Go code updates

Former-commit-id: ac2160fe6ef9c41c7b180a8af967f3d44f126394 [formerly c99451b289742e4738812c3f4bcfdc63931f2e6a] [formerly 10bc4c44b68391f2be0ee965187caaaaa27ba8f0 [formerly 1a4242ca06]]
Former-commit-id: b3555e3ea88e695ee72a87cee4b226f3d0a1d48d [formerly 70e58315f9e2a3bb3e46d48b3280127aa49107c5]
Former-commit-id: d66ddf727e7924b95e2caf88f3c02de17a1f86cf

resource.go

@@ -0,0 +1,265 @@
+package filemanager
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+func resourceHandler(c *requestContext, w http.ResponseWriter, r *http.Request) (int, error) {
+	switch r.Method {
+	case http.MethodGet:
+		return resourceGetHandler(c, w, r)
+	case http.MethodDelete:
+		return resourceDeleteHandler(c, w, r)
+	case http.MethodPut:
+		// Before save command handler.
+		path := filepath.Join(string(c.us.FileSystem), r.URL.Path)
+		if err := c.fm.Runner("before_save", path); err != nil {
+			return http.StatusInternalServerError, err
+		}
+
+		code, err := resourcePostPutHandler(c, w, r)
+		if code != http.StatusOK {
+			return code, err
+		}
+
+		// After save command handler.
+		if err := c.fm.Runner("after_save", path); err != nil {
+			return http.StatusInternalServerError, err
+		}
+
+		return code, err
+	case http.MethodPatch:
+		return resourcePatchHandler(c, w, r)
+	case http.MethodPost:
+		return resourcePostPutHandler(c, w, r)
+	}
+
+	return http.StatusNotImplemented, nil
+}
+
+func resourceGetHandler(c *requestContext, w http.ResponseWriter, r *http.Request) (int, error) {
+	// Obtains the information of the directory/file.
+	f, err := getInfo(r.URL, c.fm, c.us)
+	if err != nil {
+		return errorToHTTP(err, false), err
+	}
+
+	// If it's a dir and the path doesn't end with a trailing slash,
+	// redirect the user.
+	if f.IsDir && !strings.HasSuffix(r.URL.Path, "/") {
+		r.URL.Path = r.URL.Path + "/"
+	}
+
+	// If it is a dir, go and serve the listing.
+	if f.IsDir {
+		c.fi = f
+		return listingHandler(c, w, r)
+	}
+
+	// Tries to get the file type.
+	if err = f.RetrieveFileType(true); err != nil {
+		return errorToHTTP(err, true), err
+	}
+
+	// If it can't be edited or the user isn't allowed to,
+	// serve it as a listing, with a preview of the file.
+	if !f.CanBeEdited() || !c.us.AllowEdit {
+		f.Kind = "preview"
+	} else {
+		// Otherwise, we just bring the editor in!
+		f.Kind = "editor"
+
+		err = f.getEditor()
+		if err != nil {
+			return http.StatusInternalServerError, err
+		}
+	}
+
+	return renderJSON(w, f)
+}
+
+func listingHandler(c *requestContext, w http.ResponseWriter, r *http.Request) (int, error) {
+	f := c.fi
+	f.Kind = "listing"
+
+	err := f.getListing(c, r)
+	if err != nil {
+		return errorToHTTP(err, true), err
+	}
+
+	listing := f.listing
+
+	cookieScope := c.fm.RootURL()
+	if cookieScope == "" {
+		cookieScope = "/"
+	}
+
+	// Copy the query values into the Listing struct
+	listing.Sort, listing.Order, err = handleSortOrder(w, r, cookieScope)
+	if err != nil {
+		return http.StatusBadRequest, err
+	}
+
+	listing.ApplySort()
+	listing.Display = displayMode(w, r, cookieScope)
+
+	return renderJSON(w, f)
+}
+
+func resourceDeleteHandler(c *requestContext, w http.ResponseWriter, r *http.Request) (int, error) {
+	// Prevent the removal of the root directory.
+	if r.URL.Path == "/" {
+		return http.StatusForbidden, nil
+	}
+
+	// Remove the file or folder.
+	err := c.us.FileSystem.RemoveAll(context.TODO(), r.URL.Path)
+	if err != nil {
+		return errorToHTTP(err, true), err
+	}
+
+	return http.StatusOK, nil
+}
+
+func resourcePostPutHandler(c *requestContext, w http.ResponseWriter, r *http.Request) (int, error) {
+	// Checks if the current request is for a directory and not a file.
+	if strings.HasSuffix(r.URL.Path, "/") {
+		// If the method is PUT, we return 405 Method not Allowed, because
+		// POST should be used instead.
+		if r.Method == http.MethodPut {
+			return http.StatusMethodNotAllowed, nil
+		}
+
+		// Otherwise we try to create the directory.
+		err := c.us.FileSystem.Mkdir(context.TODO(), r.URL.Path, 0666)
+		return errorToHTTP(err, false), err
+	}
+
+	// If using POST method, we are trying to create a new file so it is not
+	// desirable to override an already existent file. Thus, we check
+	// if the file already exists. If so, we just return a 409 Conflict.
+	if r.Method == http.MethodPost {
+		if _, err := c.us.FileSystem.Stat(context.TODO(), r.URL.Path); err == nil {
+			return http.StatusConflict, errors.New("There is already a file on that path")
+		}
+	}
+
+	// Create/Open the file.
+	f, err := c.us.FileSystem.OpenFile(context.TODO(), r.URL.Path, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0666)
+	defer f.Close()
+
+	if err != nil {
+		return errorToHTTP(err, false), err
+	}
+
+	// Copies the new content for the file.
+	_, err = io.Copy(f, r.Body)
+	if err != nil {
+		return errorToHTTP(err, false), err
+	}
+
+	// Gets the info about the file.
+	fi, err := f.Stat()
+	if err != nil {
+		return errorToHTTP(err, false), err
+	}
+
+	// Writes the ETag Header.
+	etag := fmt.Sprintf(`"%x%x"`, fi.ModTime().UnixNano(), fi.Size())
+	w.Header().Set("ETag", etag)
+	return http.StatusOK, nil
+}
+
+func resourcePatchHandler(c *requestContext, w http.ResponseWriter, r *http.Request) (int, error) {
+	dst := r.Header.Get("Destination")
+	dst, err := url.QueryUnescape(dst)
+	if err != nil {
+		return errorToHTTP(err, true), err
+	}
+
+	src := r.URL.Path
+
+	if dst == "/" || src == "/" {
+		return http.StatusForbidden, nil
+	}
+
+	err = c.us.FileSystem.Rename(context.TODO(), src, dst)
+	return errorToHTTP(err, true), err
+}
+
+// displayMode obtaisn the display mode from URL, or from the
+// cookie.
+func displayMode(w http.ResponseWriter, r *http.Request, scope string) string {
+	displayMode := r.URL.Query().Get("display")
+
+	if displayMode == "" {
+		if displayCookie, err := r.Cookie("display"); err == nil {
+			displayMode = displayCookie.Value
+		}
+	}
+
+	if displayMode == "" || (displayMode != "mosaic" && displayMode != "list") {
+		displayMode = "mosaic"
+	}
+
+	http.SetCookie(w, &http.Cookie{
+		Name:   "display",
+		Value:  displayMode,
+		MaxAge: 31536000,
+		Path:   scope,
+		Secure: r.TLS != nil,
+	})
+
+	return displayMode
+}
+
+// handleSortOrder gets and stores for a Listing the 'sort' and 'order',
+// and reads 'limit' if given. The latter is 0 if not given. Sets cookies.
+func handleSortOrder(w http.ResponseWriter, r *http.Request, scope string) (sort string, order string, err error) {
+	sort = r.URL.Query().Get("sort")
+	order = r.URL.Query().Get("order")
+
+	// If the query 'sort' or 'order' is empty, use defaults or any values
+	// previously saved in Cookies.
+	switch sort {
+	case "":
+		sort = "name"
+		if sortCookie, sortErr := r.Cookie("sort"); sortErr == nil {
+			sort = sortCookie.Value
+		}
+	case "name", "size":
+		http.SetCookie(w, &http.Cookie{
+			Name:   "sort",
+			Value:  sort,
+			MaxAge: 31536000,
+			Path:   scope,
+			Secure: r.TLS != nil,
+		})
+	}
+
+	switch order {
+	case "":
+		order = "asc"
+		if orderCookie, orderErr := r.Cookie("order"); orderErr == nil {
+			order = orderCookie.Value
+		}
+	case "asc", "desc":
+		http.SetCookie(w, &http.Cookie{
+			Name:   "order",
+			Value:  order,
+			MaxAge: 31536000,
+			Path:   scope,
+			Secure: r.TLS != nil,
+		})
+	}
+
+	return
+}