// 
// Copyright 2023 New Vector Ltd
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//

import Foundation

/// Object responsible for calculating user and room trust level
@objc class EncryptionTrustLevel: NSObject {
    
    /// Calculate trust level for a single user given their cross-signing info
    @objc func userTrustLevel(
        crossSigning: MXCrossSigningInfo?,
        devicesTrust: MXTrustSummary
    ) -> UserEncryptionTrustLevel {
        
        // If we could cross-sign but we haven't, the user is simply not verified
        if let crossSigning, !crossSigning.isVerified {
            return .notVerified
        
        // If we cannot cross-sign the user (legacy behaviour) and have not signed
        // any devices manually, the user is not verified
        } else if crossSigning == nil && devicesTrust.trustedCount == 0 {
            return .notVerified
        }
        
        // In all other cases we check devices for trust level
        return devicesTrust.areAllTrusted ? .trusted : .warning
    }
    
    /// Calculate trust level for a room given trust level of users and their devices
    @objc func roomTrustLevel(summary: MXUsersTrustLevelSummary) -> RoomEncryptionTrustLevel {
        guard summary.usersTrust.totalCount > 0 && summary.usersTrust.areAllTrusted else {
            return .normal
        }
        return summary.devicesTrust.areAllTrusted ? .trusted : .warning
    }
}