ios-mail/Modules/InboxKeychain/Sources/KeychainSDKWrapper.swift

// Copyright (c) 2024 Proton Technologies AG
//
// This file is part of Proton Mail.
//
// Proton Mail is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Proton Mail is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Proton Mail. If not, see https://www.gnu.org/licenses/.

import Foundation
import InboxCore
import proton_app_uniffi

/**
 This is a wrapper to make the Keychain accessible from the SDK. Notice that even though the protocol does not
 mention the expected type of error to be thrown due to the Swift language limitations, we should
 use `OsKeyChainError`.
 */
public final class KeychainSDKWrapper: OsKeyChain, @unchecked Sendable {
    private let keychain: Keychain

    public init() {
        self.keychain = Keychain(service: Bundle.defaultIdentifier, accessGroup: AppGroup.mail)
    }

    public func store(kind: OsKeyChainEntryKind, key: String) throws {
        AppLogger.logTemporarily(message: "Storing \(kind) in Keychain", category: .rustLibrary)
        do {
            try keychain.setOrError(key, forKey: kind.key)
        } catch let error {
            throw osKeyChainError(error: error)
        }
    }

    public func delete(kind: OsKeyChainEntryKind) throws {
        AppLogger.logTemporarily(message: "Deleting \(kind) from Keychain", category: .rustLibrary)
        do {
            try keychain.removeOrError(forKey: kind.key)
        } catch let error {
            throw osKeyChainError(error: error)
        }
    }

    public func load(kind: OsKeyChainEntryKind) throws -> String? {
        AppLogger.logTemporarily(message: "Loading \(kind) from Keychain", category: .rustLibrary)
        do {
            return try keychain.stringOrError(forKey: kind.key)
        } catch let error {
            throw osKeyChainError(error: error)
        }
    }
}

// MARK: - Private

extension KeychainSDKWrapper {

    private func osKeyChainError(error: Error, function: String = #function) -> OsKeyChainError {
        AppLogger.log(message: "KeychainSDKWrapper \(function): \(String(describing: error))", isError: true)
        return OsKeyChainError.Os(String(describing: error))
    }
}

private extension OsKeyChainEntryKind {
    var key: String {
        switch self {
        case .encryptionKey: "mailApplicationKey"
        default: String(describing: self)
        }
    }
}