namespace HC_APTBS.Services
{
    /// <summary>
    /// Phases of the Dashboard "Connect &amp; Auto Test" orchestration.
    /// Drives the inline snackbar label and the orchestrator's internal branching.
    /// </summary>
    public enum AutoTestState
    {
        /// <summary>No auto-test sequence is active.</summary>
        Idle = 0,

        /// <summary>Pre-flight gate before any hardware action (e.g. operator confirmation).</summary>
        Preflight,

        /// <summary>Opening the K-Line session over FTDI.</summary>
        ConnectingKLine,

        /// <summary>Reading pump identification/DFI/serial over K-Line.</summary>
        ReadingPump,

        /// <summary>Running the immobilizer unlock (Ford VP44 Types 1 and 2).</summary>
        Unlocking,

        /// <summary>Energising the electronic relay and starting CAN senders.</summary>
        TurningOnBench,

        /// <summary>Energising the oil-pump relay.</summary>
        StartingOilPump,

        /// <summary>Kicking off <c>RunTestsAsync</c>.</summary>
        StartingTest,

        /// <summary>Test sequence executing; phase/sample updates from BenchService.</summary>
        Running,

        /// <summary>Sequence finished successfully.</summary>
        Completed,

        /// <summary>Sequence aborted; <see cref="AutoTestFailureReason"/> carries the cause.</summary>
        Aborted,
    }

    /// <summary>
    /// Reason an auto-test sequence aborted, for snackbar messaging and logging.
    /// </summary>
    public enum AutoTestFailureReason
    {
        /// <summary>No failure (default).</summary>
        None = 0,

        /// <summary>Operator cancelled from the snackbar or dismissed the pre-flight dialog.</summary>
        UserCancelled,

        /// <summary>CanExecute gate failed after click (alarm appeared between render and execute).</summary>
        PreflightDenied,

        /// <summary>FTDI port not found or <see cref="IKwpService.ConnectAsync"/> threw.</summary>
        KLineConnectFailed,

        /// <summary>K-Line session dropped to Failed state mid-sequence.</summary>
        KLineLost,

        /// <summary>Pump identification read failed (exception or result=0).</summary>
        ReadFailed,

        /// <summary>K-Line read completed but the pump ID is not in <c>pumps.xml</c>.</summary>
        PumpNotRecognized,

        /// <summary>Unlock sequence failed or verification returned locked.</summary>
        UnlockFailed,

        /// <summary>Bench CAN liveness dropped mid-sequence.</summary>
        BenchCanLost,

        /// <summary>Pump ECU CAN liveness dropped mid-sequence.</summary>
        PumpCanLost,

        /// <summary>A critical alarm bit transitioned to active during the sequence.</summary>
        AlarmTriggered,

        /// <summary>Operator has not enabled AutoTestSkipsOilPumpConfirm and the auto flow cannot proceed.</summary>
        OilPumpNotConfirmed,

        /// <summary>BenchService.RunTestsAsync signalled <c>interrupted=true</c>.</summary>
        TestInterrupted,

        /// <summary>BenchService.RunTestsAsync completed with <c>success=false</c>.</summary>
        TestFailed,

        /// <summary>Unexpected exception not covered by the categories above.</summary>
        Unexpected,
    }

    /// <summary>Extension helpers for <see cref="AutoTestState"/>.</summary>
    public static class AutoTestStateExtensions
    {
        /// <summary>
        /// True for all intermediate phases (not Idle / Completed / Aborted).
        /// Used by MainViewModel.CanAutoTest to block re-entry and to pick the button's
        /// "Cancel" variant.
        /// </summary>
        public static bool IsRunning(this AutoTestState state) =>
            state != AutoTestState.Idle &&
            state != AutoTestState.Completed &&
            state != AutoTestState.Aborted;

        /// <summary>
        /// True once the bench has been energised, i.e. after a failure the auto-flow
        /// must request an emergency stop (not just disconnect).
        /// </summary>
        public static bool IsPastBenchOn(this AutoTestState state) =>
            state == AutoTestState.TurningOnBench ||
            state == AutoTestState.StartingOilPump ||
            state == AutoTestState.StartingTest ||
            state == AutoTestState.Running;
    }
}