import Foundation

final class SafeJsonParser {
    struct SafeBackupData: Codable {
        let info: Info
        struct Info: Codable {
            let version: Int
            let device: String?
        }

        var user: User?
        var contacts: [Contact]?
        var groups: [Group]?
        var settings: Settings?
        
        final class User: Codable {
            var privatekey: String
            // Temporary field for manual pairing of iOS and desktop multi device clients
            var temporaryDeviceGroupKeyTodoRemove: String?
            var nickname: String?
            var profilePic: String?
            var profilePicRelease: [String?]?
            var links: [Link]?
            
            init(privatekey: String) {
                self.privatekey = privatekey
            }
            
            struct Link: Codable {
                let type: String?
                var name: String? = ""
                let value: String?
            }
        }
        
        final class Contact: Codable {
            var identity: String?
            var publickey: String?
            var createdAt: UInt64? = 0
            var verification: Int? = 0
            var workVerified: Bool? = false
            var hidden: Bool? = false
            var firstname: String? = ""
            var lastname: String? = ""
            var nickname: String? = ""
            var typingIndicators: Int? = 0
            var readReceipts: Int? = 0
            var lastUpdate: UInt64?
            var `private`: Bool? = false
            
            init(identity: String, verification: Int) {
                self.identity = identity
                self.verification = verification
            }
        }
        
        struct Group: Codable {
            let id: String?
            let creator: String?
            let groupname: String?
            var createdAt: UInt64? = 0
            let members: [String]?
            let deleted: Bool?
            var lastUpdate: UInt64?
            var `private`: Bool? = false
        }
        
        final class Settings: Codable {
            var syncContacts = false
            var blockUnknown: Bool? = false
            var readReceipts: Bool? = true
            var sendTyping: Bool? = true
            var threemaCalls: Bool? = true
            var relayThreemaCalls: Bool? = false
            var blockedContacts: [String]?
            var syncExcludedIDs: [String]?
        }
    }
    
    struct SafeServerConfig: Codable {
        let maxBackupBytes: Int
        let retentionDays: Int
    }

    func getSafeBackupData() -> SafeBackupData {
        SafeBackupData(
            info: SafeBackupData.Info(version: 1, device: "ios"),
            user: nil,
            contacts: nil,
            groups: nil,
            settings: nil
        )
    }

    func getSafeBackupData(from: Data) throws -> SafeBackupData {
        let decoder = JSONDecoder()
        decoder.dataDecodingStrategy = .deferredToData
        decoder.keyDecodingStrategy = .useDefaultKeys
        return try decoder.decode(SafeBackupData.self, from: from)
    }
    
    func getJsonAsBytes(from: SafeBackupData) -> [UInt8]? {
        let encoder = JSONEncoder()
        if let data = try? encoder.encode(from) {
            return data.withUnsafeBytes {
                Array($0)
            }
        }
        return nil
    }
    
    func getJsonAsString(from: SafeBackupData) -> String? {
        let encoder = JSONEncoder()
        if let data = try? encoder.encode(from) {
            return String(data: data, encoding: .utf8)!
        }
        return nil
    }
    
    func getSafeServerConfig(from: Data) -> SafeServerConfig? {
        let decoder = JSONDecoder()
        return try? decoder.decode(SafeServerConfig.self, from: from)
    }
}