import Foundation

/// Key bundle for one device, used in X3DH
struct DeviceBundle {
    let deviceId: String
    let identityKey: Data      // Ed25519 public key (32 bytes)
    let spk: Data              // X25519 public key (32 bytes)
    let spkSignature: Data     // Ed25519 signature (64 bytes)
    let spkId: String
    let opk: Data?             // X25519 public key (32 bytes), optional
    let opkId: String?

    /// Parse from server response dictionary
    static func fromDict(_ dict: [String: Any]) throws -> DeviceBundle {
        guard let deviceId = dict["device_id"] as? String,
              let ikHex = dict["identity_key"] as? String,
              let ik = Data(hexString: ikHex),
              let spkHex = dict["spk"] as? String,
              let spk = Data(hexString: spkHex),
              let spkSigHex = dict["spk_signature"] as? String,
              let spkSig = Data(hexString: spkSigHex),
              let spkId = dict["spk_id"] as? String else {
            throw ChatError.invalidData("Invalid device bundle")
        }

        var opk: Data?
        var opkId: String?
        if let opkHex = dict["opk"] as? String, let opkData = Data(hexString: opkHex) {
            opk = opkData
            opkId = dict["opk_id"] as? String
        }

        return DeviceBundle(
            deviceId: deviceId,
            identityKey: ik,
            spk: spk,
            spkSignature: spkSig,
            spkId: spkId,
            opk: opk,
            opkId: opkId
        )
    }
}