using Microsoft.Extensions.Logging;
using ScadaLink.Commons.Entities.Audit;
using ScadaLink.Commons.Interfaces;
using ScadaLink.Commons.Interfaces.Services;
using ScadaLink.Commons.Messages.Integration;
using ScadaLink.Commons.Types;
using ScadaLink.Commons.Types.Enums;
namespace ScadaLink.AuditLog.Site.Telemetry;
///
/// Site-side dual emitter for cached-call lifecycle telemetry (Audit Log #23 /
/// M3). Sister to : where the M2 actor
/// drains audit-only events, this forwarder takes a combined
/// packet and fans it out to the two
/// site-local stores in a single call:
///
/// - The row is written via
/// (the site FallbackAuditWriter +
/// SqliteAuditWriter chain established in M2).
/// - The operational half
/// updates the site-local OperationTracking SQLite store via
/// , with the per-lifecycle method
/// (Enqueue / Attempt / Terminal) selected from the
/// audit row's .
///
///
///
///
/// Best-effort contract (alog.md §7): a thrown writer OR a thrown
/// tracking store must never propagate to the calling script. Both emission
/// halves are wrapped in independent try/catch blocks so a SQLite outage on
/// one side cannot starve the other — the failure is logged and the call
/// returns normally.
///
///
/// Wire push deferred to M6. M3 keeps this forwarder synchronous
/// against the local stores: there is no site→central gRPC channel yet, so
/// the RPC
/// is registered on the interface (Bundle E1) but the production binding
/// remains NoOpSiteStreamAuditClient. Once M6 wires a real client the
/// drain pattern from SiteAuditTelemetryActor can be reused — the
/// AuditEvent rows already live in SQLite tagged
/// , so a single drain loop sweeps
/// both M2 and M3 emissions.
///
///
public sealed class CachedCallTelemetryForwarder : ICachedCallTelemetryForwarder
{
private readonly IAuditWriter _auditWriter;
private readonly IOperationTrackingStore? _trackingStore;
private readonly ILogger _logger;
///
/// Construct the forwarder. is optional —
/// when null only the audit half of the packet is emitted, which matches
/// the M3 Bundle F composition-root contract on Central nodes: the
/// AuditLog DI surface registers the forwarder unconditionally (mirroring
/// the IAuditWriter chain) but the site-only tracking store has no central
/// registration. Production site nodes wire both — the central lazy
/// resolution is a no-op path kept symmetric with the M2 writer chain.
///
public CachedCallTelemetryForwarder(
IAuditWriter auditWriter,
IOperationTrackingStore? trackingStore,
ILogger logger)
{
_auditWriter = auditWriter ?? throw new ArgumentNullException(nameof(auditWriter));
_logger = logger ?? throw new ArgumentNullException(nameof(logger));
_trackingStore = trackingStore;
}
///
/// Fan out one combined-telemetry packet to the audit writer and the
/// tracking store. Returns once both halves have been attempted (success
/// OR logged failure). NEVER throws — exceptions are caught per-half and
/// logged at warning level so the calling script's outbound action is not
/// disturbed.
///
public async Task ForwardAsync(CachedCallTelemetry telemetry, CancellationToken ct = default)
{
ArgumentNullException.ThrowIfNull(telemetry);
// Independent try/catch — a thrown audit writer must not prevent the
// tracking-store update from running (and vice-versa). Both halves
// are best-effort.
await TryEmitAuditAsync(telemetry, ct).ConfigureAwait(false);
await TryEmitTrackingAsync(telemetry, ct).ConfigureAwait(false);
}
private async Task TryEmitAuditAsync(CachedCallTelemetry telemetry, CancellationToken ct)
{
try
{
await _auditWriter.WriteAsync(telemetry.Audit, ct).ConfigureAwait(false);
}
catch (Exception ex)
{
// alog.md §7 best-effort contract — log and swallow. The audit
// pipeline's own retry/recovery (RingBufferFallback in the
// FallbackAuditWriter) handles transient writer failures upstream;
// a throw bubbling up here means the writer's own swallow contract
// failed, which is itself best-effort-handled.
_logger.LogWarning(ex,
"CachedCallTelemetryForwarder: audit emission threw for EventId {EventId} (Kind {Kind}, Status {Status})",
telemetry.Audit.EventId, telemetry.Audit.Kind, telemetry.Audit.Status);
}
}
private async Task TryEmitTrackingAsync(CachedCallTelemetry telemetry, CancellationToken ct)
{
if (_trackingStore is null)
{
// No site-local tracking store wired — Central composition root or
// an integration-test host that skipped AddSiteRuntime. Emitting
// through the audit half is still meaningful; the tracking half
// is a no-op rather than an error.
return;
}
try
{
switch (telemetry.Audit.Kind)
{
case AuditKind.CachedSubmit:
// Enqueue — insert-if-not-exists with the operational
// channel as the kind discriminator. RetryCount is fixed
// at 0 by the tracking store's INSERT contract.
await _trackingStore.RecordEnqueueAsync(
telemetry.Operational.TrackedOperationId,
telemetry.Operational.Channel,
telemetry.Operational.Target,
telemetry.Audit.SourceInstanceId,
telemetry.Audit.SourceScript,
ct).ConfigureAwait(false);
break;
case AuditKind.ApiCallCached:
case AuditKind.DbWriteCached:
// Attempt — advance retry counter + last-error/HTTP-status.
// Terminal rows are guarded by the store's WHERE clause.
await _trackingStore.RecordAttemptAsync(
telemetry.Operational.TrackedOperationId,
telemetry.Operational.Status,
telemetry.Operational.RetryCount,
telemetry.Operational.LastError,
telemetry.Operational.HttpStatus,
ct).ConfigureAwait(false);
break;
case AuditKind.CachedResolve:
// Terminal — first-write-wins on the resolve flip.
await _trackingStore.RecordTerminalAsync(
telemetry.Operational.TrackedOperationId,
telemetry.Operational.Status,
telemetry.Operational.LastError,
telemetry.Operational.HttpStatus,
ct).ConfigureAwait(false);
break;
default:
// Defensive — only the four cached-lifecycle kinds are
// expected on this path. Anything else is logged so a
// mis-routed packet is visible but never crashes the
// forwarder.
_logger.LogWarning(
"CachedCallTelemetryForwarder: unexpected audit kind {Kind} on tracking emission for EventId {EventId}",
telemetry.Audit.Kind, telemetry.Audit.EventId);
break;
}
}
catch (Exception ex)
{
_logger.LogWarning(ex,
"CachedCallTelemetryForwarder: tracking-store emission threw for TrackedOperationId {Id} (Status {Status})",
telemetry.Operational.TrackedOperationId, telemetry.Operational.Status);
}
}
}