LehrerApp/LehrerApp.Sync/Models/SyncModels.cs

using LiteDB;

namespace LehrerApp.Sync.Models;

// ── Events ────────────────────────────────────────────────────────────────────

/// <summary>Desktop-Event: Payload ist AES-256-GCM verschlüsselt.</summary>
public class SyncEvent
{
    // LiteDB erkennt nur eine Property namens "Id" automatisch als Primärschlüssel.
    // Ohne [BsonId] würde ein eigener, von EventId unabhängiger _id vergeben, wodurch
    // EventQueue.Acknowledge()/_queue.Delete(EventId) niemals etwas löschen würde.
    [BsonId]
    public Guid EventId { get; init; } = Guid.NewGuid();
    public string DeviceId { get; init; } = "";
    public DeviceType DeviceType { get; init; }
    public DateTime Timestamp { get; init; } = DateTime.UtcNow;
    public long SequenceNr { get; init; }
    public string EntityType { get; init; } = "";
    public string EntityId { get; init; } = "";
    public string Operation { get; init; } = "";
    /// <summary>Verschlüsselt (Desktop) oder Klartext (Companion/WebApp).</summary>
    public string Payload { get; init; } = "";
}

/// <summary>WebApp/Companion-Event: Payload ist Klartext-JSON.</summary>
public class PlainSyncEvent
{
    public Guid EventId { get; init; } = Guid.NewGuid();
    public string DeviceId { get; init; } = "";
    public DeviceType DeviceType { get; init; } = DeviceType.Companion;
    public DateTime Timestamp { get; init; } = DateTime.UtcNow;
    public string EntityType { get; init; } = "";
    public string EntityId { get; init; } = "";
    public string Operation { get; init; } = "";
    public string Payload { get; init; } = "";
}

// ── Sync API Responses ────────────────────────────────────────────────────────

public class PushResponse
{
    public bool Success { get; init; }
    public long ServerSequenceNr { get; init; }
    public List<Guid> ConflictingEventIds { get; init; } = [];
}
public class PullResponse
{
    public List<SyncEvent> Events { get; init; } = [];
    public long ServerSequenceNr { get; init; }
}
public class PlainPushResponse
{
    public bool Success { get; init; }
    public long ServerSequenceNr { get; init; }
    public List<Guid> RejectedEventIds { get; init; } = [];
}

// ── Snapshot Modelle ──────────────────────────────────────────────────────────

/// <summary>
/// Upload-Request für Device-Pairing.
/// EncryptedPayload: LiteDB verschlüsselt mit Sync-Key.
/// EncryptedSyncKey: Sync-Key verschlüsselt mit PBKDF2(Code).
/// → Empfänger braucht nur den Code um beides zu entschlüsseln.
/// </summary>
public class SnapshotUploadRequest
{
    public string EncryptedPayload { get; init; } = "";
    public string EncryptedSyncKey { get; init; } = "";
    public DeviceType DeviceType { get; init; }
}
public class SnapshotUploadResponse
{
    /// <summary>Format: WORT-ZZ-WORT, z.B. "TIGER-42-BLAU". 24h gültig, einmalig.</summary>
    public string Code { get; init; } = "";
    public DateTime ExpiresAt { get; init; }
}
public class SnapshotDownloadResponse
{
    public string EncryptedPayload { get; init; } = "";
    public string EncryptedSyncKey { get; init; } = "";
    public DateTime CreatedAt { get; init; }
    public DeviceType SourceDeviceType { get; init; }
}

// ── Status ────────────────────────────────────────────────────────────────────

public class SyncStatus
{
    public SyncState State { get; set; } = SyncState.Idle;
    public DateTime? LastSyncAt { get; set; }
    public int PendingEvents { get; set; }
    public int ConflictCount { get; set; }
    public string? ErrorMessage { get; set; }
}

// ── Enums ─────────────────────────────────────────────────────────────────────

public enum DeviceType { Desktop, Companion }
public enum SyncState  { Idle, Syncing, Error, Offline }