feat: Introduce route to change group permission

docs/sharing.md

@@ -1246,6 +1246,8 @@ This route is used to add the read-only flag on a recipient of a sharing.
 
 **Note**: 0 is not accepted for `index`, as it is the sharer him-self.
 
+It returns 400 if the member belongs to any non-revoked group.
+
 ##### Request
 
 ```http
@@ -1300,6 +1302,8 @@ This route is used to remove the read-only flag on a recipient of a sharing.
 
 **Note**: 0 is not accepted for `index`, as it is the sharer him-self.
 
+It returns 400 if the member belongs to any non-revoked group.
+
 ##### Request
 
 ```http
@@ -1313,6 +1317,60 @@ Host: alice.example.net
 HTTP/1.1 204 No Content
 ```
 
+### POST /sharings/:sharing-id/groups/:group-index/readonly
+
+Downgrade all the members of a group to read-only.
+
+- The owner can always call this route.
+- A non-owner can call it only if:
+  - they are a member of the target group,
+  - the group is currently read-write,
+  - the sharing is not an OrgDrive.
+- The change is propagated to recipients via the standard credentials
+  exchange.
+
+#### Request
+
+```http
+POST /sharings/ce8835a061d0ef68947afe69a0046722/groups/0/readonly HTTP/1.1
+Host: alice.example.net
+```
+
+#### Response
+
+```http
+HTTP/1.1 204 No Content
+```
+
+It returns 400 `group_read_only_conflict` if:
+
+- a member of the group also belongs to another group whose read-only state
+  differs from the target, or
+- a member of the group was added individually (`only_in_groups: false`) and
+  their individual `read_only` flag conflicts with the target state.
+
+### DELETE /sharings/:sharing-id/groups/:group-index/readonly
+
+Upgrade all the members of a group to read-write.
+
+- Only the owner can call this route.
+
+It returns 400 `group_read_only_conflict` under the same conditions as
+`POST /sharings/:sharing-id/groups/:group-index/readonly`.
+
+#### Request
+
+```http
+DELETE /sharings/ce8835a061d0ef68947afe69a0046722/groups/0/readonly HTTP/1.1
+Host: alice.example.net
+```
+
+#### Response
+
+```http
+HTTP/1.1 204 No Content
+```
+
 ### DELETE /sharings/:sharing-id/recipients/self/readonly
 
 This is an internal route for the stack. It's used to inform the recipient's

model/sharing/error.go

@@ -79,4 +79,7 @@ var (
 	ErrFileInTrash = errors.New("Cannot share trashed file")
 	// ErrSystemFolder is used when trying to share a system folder
 	ErrSystemFolder = errors.New("Cannot share system folder")
+	// ErrGroupReadOnlyConflict is used when changing a group's read-only flag
+	// would conflict with another group's state for a member belonging to both.
+	ErrGroupReadOnlyConflict = errors.New("Cannot change group read-only flag: a member also belongs to another group with a conflicting read-only state")
 )

model/sharing/group_readonly.go

@@ -0,0 +1,215 @@
+package sharing
+
+import (
+	"fmt"
+	"net/http"
+	"strings"
+
+	"github.com/cozy/cozy-stack/client/request"
+	"github.com/cozy/cozy-stack/model/instance"
+	"github.com/cozy/cozy-stack/pkg/couchdb"
+	multierror "github.com/hashicorp/go-multierror"
+	"github.com/labstack/echo/v4"
+)
+
+func (s *Sharing) CheckMemberGroupReadOnlyConsistency(memberIndex int) error {
+	for _, gidx := range s.Members[memberIndex].Groups {
+		if gidx < 0 || gidx >= len(s.Groups) {
+			continue
+		}
+		if s.Groups[gidx].Revoked {
+			continue
+		}
+		return ErrGroupReadOnlyConflict
+	}
+	return nil
+}
+
+func (s *Sharing) checkGroupReadOnlyChangeConsistency(groupIndex int, targetReadOnly bool) error {
+	for _, m := range s.Members {
+		inGroup := false
+		for _, idx := range m.Groups {
+			if idx == groupIndex {
+				inGroup = true
+				break
+			}
+		}
+		if !inGroup {
+			continue
+		}
+		for _, otherIdx := range m.Groups {
+			if otherIdx == groupIndex {
+				continue
+			}
+			if otherIdx < 0 || otherIdx >= len(s.Groups) {
+				continue
+			}
+			if s.Groups[otherIdx].Revoked {
+				continue
+			}
+			if s.Groups[otherIdx].ReadOnly != targetReadOnly {
+				return ErrGroupReadOnlyConflict
+			}
+		}
+	}
+	return nil
+}
+
+func (s *Sharing) checkGroupMembersIndividualConsistency(groupIndex int, targetReadOnly bool) error {
+	for _, m := range s.Members {
+		inGroup := false
+		for _, idx := range m.Groups {
+			if idx == groupIndex {
+				inGroup = true
+				break
+			}
+		}
+		if !inGroup {
+			continue
+		}
+		if !m.OnlyInGroups && m.ReadOnly != targetReadOnly {
+			return ErrGroupReadOnlyConflict
+		}
+	}
+	return nil
+}
+
+func (s *Sharing) AddReadOnlyFlagToGroup(inst *instance.Instance, groupIndex int) error {
+	if !s.Owner {
+		return ErrInvalidSharing
+	}
+	if groupIndex < 0 || groupIndex >= len(s.Groups) {
+		return ErrInvalidSharing
+	}
+	if s.Groups[groupIndex].Revoked {
+		return ErrInvalidSharing
+	}
+	if s.Groups[groupIndex].ReadOnly {
+		return nil
+	}
+	if err := s.checkGroupReadOnlyChangeConsistency(groupIndex, true); err != nil {
+		return err
+	}
+	if err := s.checkGroupMembersIndividualConsistency(groupIndex, true); err != nil {
+		return err
+	}
+	var errm error
+	for i, m := range s.Members {
+		if i == 0 {
+			continue
+		}
+		inGroup := false
+		for _, idx := range m.Groups {
+			if idx == groupIndex {
+				inGroup = true
+				break
+			}
+		}
+		if !inGroup {
+			continue
+		}
+		if s.Members[i].ReadOnly {
+			continue
+		}
+		if err := s.AddReadOnlyFlag(inst, i); err != nil {
+			errm = multierror.Append(errm, err)
+		}
+	}
+	if errm == nil {
+		s.Groups[groupIndex].ReadOnly = true
+		if err := couchdb.UpdateDoc(inst, s); err != nil {
+			errm = err
+		}
+	}
+	return errm
+}
+
+func (s *Sharing) RemoveReadOnlyFlagFromGroup(inst *instance.Instance, groupIndex int) error {
+	if !s.Owner {
+		return ErrInvalidSharing
+	}
+	if groupIndex < 0 || groupIndex >= len(s.Groups) {
+		return ErrInvalidSharing
+	}
+	if s.Groups[groupIndex].Revoked {
+		return ErrInvalidSharing
+	}
+	if !s.Groups[groupIndex].ReadOnly {
+		return nil
+	}
+	if err := s.checkGroupReadOnlyChangeConsistency(groupIndex, false); err != nil {
+		return err
+	}
+	if err := s.checkGroupMembersIndividualConsistency(groupIndex, false); err != nil {
+		return err
+	}
+	var errm error
+	for i, m := range s.Members {
+		if i == 0 {
+			continue
+		}
+		inGroup := false
+		for _, idx := range m.Groups {
+			if idx == groupIndex {
+				inGroup = true
+				break
+			}
+		}
+		if !inGroup {
+			continue
+		}
+		if !s.Members[i].ReadOnly {
+			continue
+		}
+		if err := s.RemoveReadOnlyFlag(inst, i); err != nil {
+			errm = multierror.Append(errm, err)
+		}
+	}
+	if errm == nil {
+		s.Groups[groupIndex].ReadOnly = false
+		if err := couchdb.UpdateDoc(inst, s); err != nil {
+			errm = err
+		}
+	}
+	return errm
+}
+
+func (s *Sharing) DelegateAddReadOnlyFlagToGroup(inst *instance.Instance, groupIndex int) error {
+	if len(s.Credentials) != 1 {
+		return ErrInvalidSharing
+	}
+	m := &s.Members[0]
+	u, ok := m.InstanceURL()
+	if !ok {
+		return ErrInvalidSharing
+	}
+	c := &s.Credentials[0]
+	if c.AccessToken == nil {
+		return ErrInvalidSharing
+	}
+	opts := &request.Options{
+		Method: http.MethodPost,
+		Scheme: u.Scheme,
+		Domain: u.Host,
+		Path:   fmt.Sprintf("/sharings/%s/groups/%d/readonly", s.SID, groupIndex),
+		Headers: request.Headers{
+			echo.HeaderAuthorization: "Bearer " + c.AccessToken.AccessToken,
+		},
+		ParseError: ParseRequestError,
+	}
+	res, err := request.Req(opts)
+	if res != nil && res.StatusCode/100 == 4 {
+		res, err = RefreshToken(inst, res, err, s, m, c, opts, nil)
+	}
+	if err != nil {
+		if res != nil && res.StatusCode == http.StatusBadRequest {
+			if reqErr, ok := err.(*request.Error); ok && strings.Contains(reqErr.Detail, ErrGroupReadOnlyConflict.Error()) {
+				return ErrGroupReadOnlyConflict
+			}
+			return ErrInvalidURL
+		}
+		return err
+	}
+	res.Body.Close()
+	return nil
+}