Last Owner should edit admins, and not leave when is last (#4372)

ElementX/Sources/Services/Room/RoomRole.swift

@@ -0,0 +1,129 @@
+//
+// Copyright 2025 New Vector Ltd.
+//
+// SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
+// Please see LICENSE files in the repository root for full details.
+//
+
+import MatrixRustSDK
+
+enum RoomRole: Comparable {
+    /// Default role PL 0...49
+    case user
+    /// Able to perform room moderation actions PL 50...99
+    case moderator
+    /// Able to edit room settings and perform any action aside from room upgrading PL 100...149
+    case administrator
+    /// Same power of an admin, but they can also upgrade the room, PL 150 onwards
+    case owner
+    /// Creator of the room, PL infinite
+    case creator
+}
+
+extension RoomRole {
+    init(powerLevel: RoomPowerLevel) {
+        do {
+            let role = try suggestedRoleForPowerLevel(powerLevel: powerLevel.rustPowerLevel)
+            self.init(role, powerLevel: powerLevel)
+        } catch {
+            MXLog.error("Failled to get suggested role for power level \(powerLevel): \(error)")
+            self = .user
+        }
+    }
+    
+    init(_ role: RoomMemberRole, powerLevel: RoomPowerLevel) {
+        switch role {
+        case .creator:
+            self = .creator
+        case .administrator:
+            switch powerLevel {
+            case .value(let value):
+                self = value >= 150 ? .owner : .administrator
+            default:
+                fatalError("Impossible")
+            }
+        case .moderator:
+            self = .moderator
+        case .user:
+            self = .user
+        }
+    }
+        
+    var isAdminOrHigher: Bool {
+        switch self {
+        case .administrator, .creator, .owner:
+            return true
+        case .moderator, .user:
+            return false
+        }
+    }
+    
+    var isOwner: Bool {
+        switch self {
+        case .creator, .owner:
+            return true
+        case .administrator, .moderator, .user:
+            return false
+        }
+    }
+}
+
+extension RoomRole {
+    init(powerLevelValue: Int64) {
+        // Also this is not great, and should be handled by a `suggestedRoleForPowerLevelValue` function from the SDK
+        guard powerLevelValue < 150 else {
+            self = .owner
+            return
+        }
+        
+        do {
+            switch try suggestedRoleForPowerLevel(powerLevel: .value(value: powerLevelValue)) {
+            case .administrator:
+                self = .administrator
+            case .creator:
+                fatalError("Impossible")
+            case .moderator:
+                self = .moderator
+            case .user:
+                self = .user
+            }
+        } catch {
+            MXLog.error("Falied to convert power level value to role: \(error)")
+            self = .user
+        }
+    }
+    
+    var rustRole: RoomMemberRole {
+        switch self {
+        case .creator:
+            .creator
+        case .administrator, .owner:
+            .administrator
+        case .moderator:
+            .moderator
+        case .user:
+            .user
+        }
+    }
+    
+    /// To be used when setting the power level of a user to get the suggested equivalent power level value for that specific role
+    /// NOTE: Do not use for comparison, use the true power level instead.
+    var powerLevelValue: Int64 {
+        guard self != .owner else {
+            // Would be better if the SDK would return this, maybe a `suggestedPowerLevelValueForRole` function would solve the problem
+            return 150
+        }
+        
+        do {
+            switch try suggestedPowerLevelForRole(role: rustRole) {
+            case .infinite:
+                fatalError("Impossible")
+            case .value(let value):
+                return value
+            }
+        } catch {
+            MXLog.error("Falied to convert role to power level value: \(error)")
+            return 0
+        }
+    }
+}