/*
 * Copyright (C) 2022 by Claudio Cambra <claudio.cambra@nextcloud.com>
 *
 * This program 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 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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.
 */

import Foundation
import RealmSwift
import FileProvider

class NextcloudFilesDatabaseManager : NSObject {
    static let shared = {
        return NextcloudFilesDatabaseManager();
    }()

    let relativeDatabaseFolderPath: String = "Database/"
    let databaseFilename: String = "fileproviderextdatabase.realm"
    let relativeDatabaseFilePath: String
    var databasePath: URL?

    let schemaVersion: UInt64 = 100

    override init() {
        self.relativeDatabaseFilePath = self.relativeDatabaseFolderPath + self.databaseFilename

        guard let fileProviderDataDirUrl = pathForFileProviderExtData() else {
            super.init()
            return
        }

        self.databasePath = fileProviderDataDirUrl.appendingPathExtension(self.relativeDatabaseFilePath)

        // Disable file protection for directory DB
        // https://docs.mongodb.com/realm/sdk/ios/examples/configure-and-open-a-realm/#std-label-ios-open-a-local-realm
        let folderPath = fileProviderDataDirUrl.appendingPathComponent(self.relativeDatabaseFolderPath).path
        do {
            try FileManager.default.setAttributes([FileAttributeKey.protectionKey: FileProtectionType.completeUntilFirstUserAuthentication], ofItemAtPath: folderPath)
        } catch {
            print("Could not set permission level for File Provider database folder")
        }

        let config = Realm.Configuration(
            fileURL: self.databasePath,
            schemaVersion: self.schemaVersion,
            objectTypes: [NextcloudItemMetadataTable.self]
        )

        Realm.Configuration.defaultConfiguration = config

        do {
            let realm = try Realm()
            print("Successfully started Realm db for FileProviderExt")
        } catch let error as NSError {
            print("Error opening Realm db: %@", error.localizedDescription)
        }

        super.init()
    }

    private func ncDatabase() -> Realm {
        let realm = try! Realm()
        realm.refresh()
        return realm
    }

    func itemMetadataFromOcId(_ ocId: String) -> NextcloudItemMetadataTable? {
        return ncDatabase().objects(NextcloudItemMetadataTable.self).filter("ocId == %@", ocId).first
    }

    func itemMetadataFromFileProviderItemIdentifier(_ identifier: NSFileProviderItemIdentifier) -> NextcloudItemMetadataTable? {
        let ocId = identifier.rawValue
        return itemMetadataFromOcId(ocId)
    }

    func parentDirectoryMetadataForItem(_ itemMetadata: NextcloudItemMetadataTable) -> NextcloudDirectoryMetadataTable? {
        return ncDatabase().objects(NextcloudDirectoryMetadataTable.self).filter("account == %@ AND serverUrl == %@", itemMetadata.account, itemMetadata.serverUrl).first
    }

    func localFileMetadataFromOcId(_ ocId: String) -> NextcloudLocalFileMetadataTable? {
        return ncDatabase().objects(NextcloudLocalFileMetadataTable.self).filter("ocId == %@", ocId).first
    }
}