namespace IfLoc.Sim;

// Reference constants for the frozen IF-LOC v1.0 contract.
// Source of truth: meta/contracts/ble-device-interface.md. Keep the two in lockstep;
// enum values and message-type ids are append-only once frozen.

/// <summary>Wire message-type ids (frame header byte 1).</summary>
public enum MessageType : byte
{
    Telemetry       = 0x01,
    CaptureTrigger  = 0x02,
    CaptureResult   = 0x03,
    Alert           = 0x04,
    Ack             = 0x05,

    CmdRequestSnapshot   = 0x10,
    CmdSetFrequency      = 0x11,
    CmdSetMode           = 0x12,
    CmdSetTelemetryRate  = 0x13,
    CmdTimeSync          = 0x14,
    CmdSetUtility        = 0x15,

    OtaBegin  = 0x20,
    OtaData   = 0x21,
    OtaEnd    = 0x22,

    UsageLogRequest = 0x30,
    UsageLogRecord  = 0x31,
    UsageLogEnd     = 0x32,

    ClaimChallenge  = 0x40,
    ClaimAssertion  = 0x41,
    ClaimCertReq    = 0x42,
    ClaimCert       = 0x43,
}

/// <summary>§4.1 locateMode.</summary>
public enum LocateMode : byte
{
    Single = 0, Twin = 1, Null = 2, Sweep = 3, TwinSweep = 4, Omni = 5, TwinOmni = 6,
    NotAvailable = 0xFF,
}

/// <summary>§4.2 signalType.</summary>
public enum SignalType : byte
{
    Active = 0, LineDropActive = 1, Power = 2, GroupedPower = 3, Cathodic = 4,
    Sonde = 5, Radio = 6, FaultFind = 7, NotAvailable = 0xFF,
}

/// <summary>§4.4 utilityType (APWA-aligned).</summary>
public enum UtilityType : byte
{
    None = 0, Gas = 1, Power = 2, Communications = 3, Water = 4, Sewer = 5, Fiber = 6,
    Other = 7, NotAvailable = 0xFF,
}

/// <summary>§4.3 warningFlags bitfield.</summary>
[Flags]
public enum WarningFlags : ushort
{
    None           = 0,
    Shallow        = 1 << 0,
    Overload       = 1 << 1,
    SwingTilt      = 1 << 2,
    DepthInvalid   = 1 << 3,
    CurrentInvalid = 1 << 4,
    OutOfRange     = 1 << 5,
    DistortionHigh = 1 << 6,
    LowBattery     = 1 << 7,
}

/// <summary>§4.5 statusFlags bitfield.</summary>
[Flags]
public enum StatusFlags : byte
{
    None          = 0,
    Locating      = 1 << 0,
    MenuActive    = 1 << 1,
    TimeSynced    = 1 << 2,
    DepthModeAuto = 1 << 3,
}

/// <summary>§5.1 triggerType.</summary>
public enum TriggerType : byte
{
    ButtonSingle = 0, ButtonHold = 1, OffsetRequest = 2, AppInitiated = 3,
}

/// <summary>§5.2 outcome — the deterministic capture outcome (SRS-LOG-7).</summary>
public enum CaptureOutcome : byte
{
    Stored = 0, StoredFlagged = 1, Rejected = 2,
}

/// <summary>§5.4 reasonCode / gateStatus.</summary>
public enum ReasonCode : byte
{
    Ok = 0,
    FixTypeTooLow = 1,
    HrmsExceeded = 2,
    VrmsExceeded = 3,
    CorrectionAgeExceeded = 4,
    NoActiveTicket = 5,
    ImuCalibrationInvalid = 6,
    HeadingConfidenceLow = 7,
    BufferFull = 8,
    NoPosition = 9,
    WaiverRequired = 10,
    Other = 255,
}

/// <summary>§5.2 fixType (GGA-quality mapping; 3 reserved).</summary>
public enum FixType : byte
{
    NoFix = 0, Autonomous = 1, Dgps = 2, RtkFixed = 4, RtkFloat = 5,
}

/// <summary>Frozen wire constants and sentinels.</summary>
public static class IfLoc
{
    public const byte FrameVersion = 0x01;

    // Fixed frame lengths (Appendix A).
    public const int HeaderLen = 4;
    public const int TelemetryFrameLen = 32;
    public const int TelemetryPayloadLen = 28;   // offsets 4..31
    public const int CaptureTriggerFrameLen = 36;
    public const int CaptureResultFrameLen = 52;

    // Sentinels (§1).
    public const short DepthNoValue = unchecked((short)0x8000);
    public const ushort CurrentInvalid = 0xFFFF;
    public const uint FrequencyNa = 0xFFFFFFFF;
    public const short GuidanceNa = unchecked((short)0x8000);
    public const int PositionNoValue = unchecked((int)0x80000000);
    public const ushort RmsUnknown = 0xFFFF;

    // GATT (§2) — recommended UUIDs the App builds against.
    public const string BaseUuidFormat = "A9E1{0:X4}-1B4C-4F9A-9B7E-2D6F0C3A5E11";
    public static string LocateServiceUuid   => string.Format(BaseUuidFormat, 0x0001);
    public static string ProtocolInfoUuid    => string.Format(BaseUuidFormat, 0x0002);
    public static string TelemetryUuid       => string.Format(BaseUuidFormat, 0x0003);
    public static string EventUuid           => string.Format(BaseUuidFormat, 0x0004);
    public static string CommandUuid         => string.Format(BaseUuidFormat, 0x0005);
    public static string CaptureResultUuid   => string.Format(BaseUuidFormat, 0x0006);
    public static string LinkStateUuid       => string.Format(BaseUuidFormat, 0x0007);
    public static string BulkOtaUuid         => string.Format(BaseUuidFormat, 0x0008);
    public static string ClaimUuid           => string.Format(BaseUuidFormat, 0x0009);
}