using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using FrameworkDAL.CustomCode.SIP;
using GB5Shared.DTO.Framework.Login;
using GB5Shared.GEF;
using GB5Shared.SIP;
using GB5Shared.Telemetry;
using Microsoft.Extensions.Logging;

namespace FrameworkBLL.SIP
{
    // ============================================================
    // SIPSignalService — GB5Framework implementation of GB5Shared.SIP.ISIPSignalService.
    //
    // v1 ingests signals via direct EmitSignalAsync calls from producing modules (e.g.
    // SalesMind's InteractionRecord save path); generalizing to a Dapr event-subscriber that
    // ingests any module's EventLogPublish output without each producer needing a direct SIP
    // reference is a near-term follow-up, not yet built in this slice.
    //
    // GEF must never be called from here — one-way dependency: GEF may read SIP's output, SIP
    // never calls GEF (canvas §8.2). This class has no reference to IGEFEngine and must not gain
    // one.
    // ============================================================
    public class SIPSignalService : ISIPSignalService
    {
        private readonly ISIPPatternEntryDAL     _Dal;
        private readonly ILogger<SIPSignalService> _Logger;

        public SIPSignalService(ISIPPatternEntryDAL dal, ILogger<SIPSignalService> logger)
        {
            _Dal    = dal;
            _Logger = logger;
        }

        public async Task EmitSignalAsync(
            SignalDTO signal, string domain, string entityCode, int entityId,
            LoginDTO login, CancellationToken ct)
        {
            GB5Trace.Step("sip-emit-signal", new { domain, entityCode, entityId, signal.SignalType });

            try
            {
                var entry = new PatternEntryDTO
                {
                    Domain     = domain,
                    EntityCode = entityCode,
                    EntityId   = entityId,
                    SignalType = signal.SignalType,
                    Detail     = signal.Detail,
                    Strength   = signal.Strength,
                    // ISIPSignalService.EmitSignalAsync's contract does not accept a separate actor
                    // parameter (SignalDTO carries none either) — ActorId is the authenticated
                    // caller (login.UserId); ActorRole is left null since no clean role-name string
                    // is available at this layer without additional plumbing (login.RoleId is an
                    // ID, not a display name). Revisit if a consumer needs it populated.
                    ActorRole  = null,
                    ActorId    = login.UserId,
                    DetectedOn = signal.DetectedOn == default ? DateTime.UtcNow : signal.DetectedOn
                };

                // Immutable append — NOT routed through ExecuteSaveAsync: this is a ledger row, not
                // a primary business entity (no workflow/WIP gate applies, and the row IS itself
                // the audit record) — a plain DAL insert is the correct, simpler choice per
                // CLAUDE.md's carve-out for non-entity operations.
                await _Dal.InsertPatternEntry(entry, login, ct).ConfigureAwait(false);
            }
            catch (Exception ex)
            {
                GB5Trace.MarkFailed("sip-emit-signal-failed", ex);
                _Logger.LogError(ex,
                    "SIPSignalService.EmitSignalAsync failed for domain {Domain} entity {EntityCode}/{EntityId}",
                    domain, entityCode, entityId);
                throw;
            }
        }

        public async Task<IReadOnlyList<PatternSummaryDTO>> GetPatternSummaryAsync(
            string domain, string entityCode, int entityId, LoginDTO login, CancellationToken ct)
        {
            var rows = (await _Dal.GetPatternSummary(domain, entityCode, entityId, login, ct)
                                   .ConfigureAwait(false)).ToList();

            // v1 hardcoded recurrence rule: 3+ occurrences of the same SignalType clustered within
            // a 30-day span. TODO: make both the threshold and window configurable per
            // domain/signal type once a real tenant needs a different rule.
            const int recurringThresholdCount = 3;
            var       recurringWindow         = TimeSpan.FromDays(30);

            foreach (var row in rows)
            {
                row.IsRecurring = row.OccurrenceCount >= recurringThresholdCount
                                   && (row.LastSeen - row.FirstSeen) <= recurringWindow;
            }

            return rows;
        }
    }
}