using GB5Shared.DTO.Framework.Login;
using GB5Shared.GenerateAutoNumber;
using GB5Shared.Resource.Response;
using KmsBLL.Sync;
using KmsDAL.CustomCode.KmArtifact;
using KmsDAL.CustomCode.KmContent;
using KmsDAL.CustomCode.KmDiscovery;
using KmsDAL.DTO.KmArtifact;
using KmsDAL.DTO.KmContent;
using KmsDAL.DTO.KmDiscovery;
using Microsoft.Extensions.Logging;

namespace KmsBLL.KmDiscovery
{
    public class KmDiscoveryBLL : IKmDiscoveryBLL
    {
        private readonly IKmDiscoveryDAL _dal;
        private readonly IKmArtifactDAL _artifactDal;
        private readonly IKmContentDAL _contentDal;
        private readonly AutoNumber _autoNumber;
        private readonly IKmsAISyncClient _kmsAiSyncClient;
        private readonly ILogger<KmDiscoveryBLL> _logger;

        public KmDiscoveryBLL(IKmDiscoveryDAL dal, IKmArtifactDAL artifactDal,
            IKmContentDAL contentDal, AutoNumber autoNumber,
            IKmsAISyncClient kmsAiSyncClient, ILogger<KmDiscoveryBLL> logger)
        {
            _dal = dal;
            _artifactDal = artifactDal;
            _contentDal = contentDal;
            _autoNumber = autoNumber;
            _kmsAiSyncClient = kmsAiSyncClient;
            _logger = logger;
        }

        // Machine-to-machine calls (SaveCandidate/UpdateJobStatus, invoked directly by gbEAI's
        // kms_discovery_adapter.py) arrive via KmsApiKeyAuthMiddleware's placeholder LoginDTO
        // (ClientId = -1) — there's no HTTP session to inherit a real tenant from. Rebuilds a
        // real, DB-routable LoginDTO from the DTO's own TenantId field, matching the established
        // `new LoginDTO { ClientId = tenantId, UserId = -1 }` idiom already used by
        // EntitlementLoginFactory / FlsReminderJobHandler / ComplianceSL's AlertCheckSubscriber
        // for exactly this "no HTTP session, only a tenant id" situation.
        private static LoginDTO EffectiveLogin(LoginDTO login, int dtoTenantId)
            => login.ClientId > 0 ? login : new LoginDTO { ClientId = dtoTenantId, UserId = 0 };

        public async Task<string> TriggerExtractionJob(KmTriggerJobDTO trigger, LoginDTO login, CancellationToken ct)
        {
            if (string.IsNullOrWhiteSpace(trigger.SourceReference))
                throw new ArgumentException("SourceReference is required.");

            var autoNum = await _autoNumber.GetNumberAsync(1, "TKMJOB", login);
            var job = new KmExtractionJobDTO
            {
                JobId = autoNum.StartNumber,
                ConnectorId = trigger.ConnectorId <= 0 ? -1 : trigger.ConnectorId,
                SourceReference = trigger.SourceReference,
                TenantId = login.ClientId,
                CreatedById = login.UserId
            };

            await _dal.SaveKmJob(job, login, ct);

            // Domain association isn't part of KmTriggerJobDTO today — the pipeline runs
            // unassigned (domain_id = -1) until a candidate is reviewed and assigned a domain via
            // AcceptCandidate. Push failures don't roll back the local job row — GB5 stays
            // system-of-record even when gbEAI is unreachable; the failure surfaces in the
            // returned message so the caller knows to retry.
            var syncResult = await _kmsAiSyncClient.TriggerExtractionAsync(
                job.JobId, domainId: -1, trigger.SourceText, login, ct).ConfigureAwait(false);

            if (!syncResult.Success)
            {
                _logger.LogWarning(
                    "KmDiscoveryBLL | TriggerExtractionJob | gbEAI sync failed | JobId={JobId} | {Error}",
                    job.JobId, syncResult.Message);
                return $"{SuccessResponse.SaveSuccessMessage} {job.JobId}. " +
                       $"Sync to AI-Enterprise-v1.0 failed: {syncResult.Message} — retry from this screen.";
            }

            return $"{SuccessResponse.SaveSuccessMessage} {job.JobId}";
        }

        public async Task<string> GetExtractionJob(int jobId, LoginDTO login, CancellationToken ct)
            => await _dal.GetKmJob(jobId, login, ct);

        public async Task<string> GetExtractionJobs(int page, int pageSize, LoginDTO login, CancellationToken ct)
            => await _dal.GetKmJobs(page, pageSize, login, ct);

        public async Task<string> GetCandidatesPending(LoginDTO login, CancellationToken ct)
            => await _dal.GetKmCandidatesPending(login, ct);

        public async Task<string> AcceptCandidate(KmAcceptCandidateDTO dto, LoginDTO login, CancellationToken ct)
        {
            // Create artifact in Draft state from accepted candidate
            var autoNum = await _autoNumber.GetNumberAsync(2, "KMARTIFACT", login);
            int nextId = autoNum.StartNumber;

            var artifactDto = new KmArtifactDTO
            {
                ArtifactId = nextId++,
                DomainId = dto.DomainId,
                ArtifactCode = $"KN-{nextId:D6}",
                Title = dto.ModifiedTitle ?? "Pending Title",
                ArtifactType = 6,  // Document — reviewer should update
                SourceKind = 1,    // FileUpload as default
                ScopeLevel = 3,    // Tenant
                ScopeValue = login.ClientId.ToString(),
                VersionNumber = 1,
                ParentArtifactId = -1,
                OwnerUserId = login.UserId,
                ReviewerUserId = -1,
                ExtractionJobId = -1,
                TenantId = login.ClientId,
                CreatedById = login.UserId,
                ModifiedById = login.UserId,
                SortOrder = 9999
            };

            await _artifactDal.SaveKmArtifact(artifactDto, login, ct);

            // Save primary content
            var contentDto = new KmContentDTO
            {
                ContentId = nextId,
                ArtifactId = artifactDto.ArtifactId,
                Slno = 1,
                ContentBody = dto.ModifiedContent ?? string.Empty,
                ContentType = "Text",
                LanguageCode = "en",
                IsPrimary = 1,
                ChunkIndex = 0,
                ChunkTotal = 1
            };
            await _contentDal.SaveKmContent(contentDto, login, ct);

            // Update candidate with artifact reference
            dto.ArtifactId = artifactDto.ArtifactId;
            await _dal.AcceptCandidate(dto, login, ct);

            return $"{SuccessResponse.SaveSuccessMessage} — Artifact created in Draft: {artifactDto.ArtifactId}";
        }

        public async Task<string> RejectCandidate(KmRejectCandidateDTO dto, LoginDTO login, CancellationToken ct)
        {
            if (string.IsNullOrWhiteSpace(dto.RejectionReason))
                throw new ArgumentException("RejectionReason is required.");

            await _dal.RejectCandidate(dto, login, ct);
            return $"{SuccessResponse.UpdateSuccessMessage} — Candidate rejected.";
        }

        public async Task<string> SaveCandidate(KmCandidateDTO dto, LoginDTO login, CancellationToken ct)
        {
            // Called directly by gbEAI's kms_discovery_adapter.py (X-Api-Key, no browser
            // session) — dto.TenantId is already on the wire (gbEAI's own _post_candidate sends
            // it), trusted here instead of the placeholder login when there's no real session.
            var effectiveLogin = EffectiveLogin(login, dto.TenantId);

            var autoNum = await _autoNumber.GetNumberAsync(1, "TKMCANDIDATE", effectiveLogin);
            dto.CandidateId = autoNum.StartNumber;
            dto.TenantId = effectiveLogin.ClientId;
            await _dal.SaveKmCandidate(dto, effectiveLogin, ct);
            return $"{SuccessResponse.SaveSuccessMessage} {dto.CandidateId}";
        }

        public async Task<string> UpdateJobStatus(KmExtractionJobDTO dto, LoginDTO login, CancellationToken ct)
        {
            // Same M2M caller/rationale as SaveCandidate above.
            var effectiveLogin = EffectiveLogin(login, dto.TenantId);

            dto.TenantId = effectiveLogin.ClientId;
            dto.ModifiedById = effectiveLogin.UserId;
            await _dal.UpdateKmJobStatus(dto, effectiveLogin, ct);
            return SuccessResponse.UpdateSuccessMessage;
        }
    }
}