using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Routing;
using StellaOps.Auth.ServerIntegration.Tenancy;
using StellaOps.Platform.WebService.Constants;
using StellaOps.Platform.WebService.Contracts;
using StellaOps.Platform.WebService.Services;
using StellaOps.Telemetry.Federation.Bundles;
using StellaOps.Telemetry.Federation.Consent;
using StellaOps.Telemetry.Federation.Intelligence;
using StellaOps.Telemetry.Federation.Privacy;

namespace StellaOps.Platform.WebService.Endpoints;

public static class FederationTelemetryEndpoints
{
    // In-memory bundle store for MVP; production would use persistent store
    private static readonly List<FederatedBundle> _bundles = new();
    private static readonly object _bundleLock = new();

    public static IEndpointRouteBuilder MapFederationTelemetryEndpoints(this IEndpointRouteBuilder app)
    {
        var group = app.MapGroup("/api/v1/telemetry/federation")
            .WithTags("Federated Telemetry")
            .RequireAuthorization(PlatformPolicies.FederationRead)
            .RequireTenant();

        // GET /consent — get consent state
        group.MapGet("/consent", async Task<IResult>(
            HttpContext context,
            PlatformRequestContextResolver resolver,
            IConsentManager consentManager,
            CancellationToken ct) =>
        {
            if (!TryResolveContext(context, resolver, out var requestContext, out var failure))
                return failure!;

            var state = await consentManager.GetConsentStateAsync(requestContext!.TenantId, ct).ConfigureAwait(false);

            return Results.Ok(new FederationConsentStateResponse(
                state.Granted, state.GrantedBy, state.GrantedAt, state.ExpiresAt, state.DsseDigest));
        })
        .WithName("GetFederationConsent")
        .WithSummary("Get federation consent state for current tenant")
        .RequireAuthorization(PlatformPolicies.FederationRead);

        // POST /consent/grant — grant consent
        group.MapPost("/consent/grant", async Task<IResult>(
            HttpContext context,
            PlatformRequestContextResolver resolver,
            IConsentManager consentManager,
            FederationGrantConsentRequest request,
            CancellationToken ct) =>
        {
            if (!TryResolveContext(context, resolver, out var requestContext, out var failure))
                return failure!;

            TimeSpan? ttl = request.TtlHours.HasValue
                ? TimeSpan.FromHours(request.TtlHours.Value)
                : null;

            var proof = await consentManager.GrantConsentAsync(
                requestContext!.TenantId, request.GrantedBy, ttl, ct).ConfigureAwait(false);

            return Results.Ok(new FederationConsentProofResponse(
                proof.TenantId, proof.GrantedBy, proof.GrantedAt, proof.ExpiresAt, proof.DsseDigest));
        })
        .WithName("GrantFederationConsent")
        .WithSummary("Grant federation telemetry consent")
        .RequireAuthorization(PlatformPolicies.FederationManage);

        // POST /consent/revoke — revoke consent
        group.MapPost("/consent/revoke", async Task<IResult>(
            HttpContext context,
            PlatformRequestContextResolver resolver,
            IConsentManager consentManager,
            FederationRevokeConsentRequest request,
            CancellationToken ct) =>
        {
            if (!TryResolveContext(context, resolver, out var requestContext, out var failure))
                return failure!;

            await consentManager.RevokeConsentAsync(requestContext!.TenantId, request.RevokedBy, ct).ConfigureAwait(false);

            return Results.Ok(new { revoked = true });
        })
        .WithName("RevokeFederationConsent")
        .WithSummary("Revoke federation telemetry consent")
        .RequireAuthorization(PlatformPolicies.FederationManage);

        // GET /status — federation status
        group.MapGet("/status", async Task<IResult>(
            HttpContext context,
            PlatformRequestContextResolver resolver,
            IConsentManager consentManager,
            IPrivacyBudgetTracker budgetTracker,
            Microsoft.Extensions.Options.IOptions<Telemetry.Federation.FederatedTelemetryOptions> fedOptions,
            CancellationToken ct) =>
        {
            if (!TryResolveContext(context, resolver, out var requestContext, out var failure))
                return failure!;

            var consent = await consentManager.GetConsentStateAsync(requestContext!.TenantId, ct).ConfigureAwait(false);
            var snapshot = budgetTracker.GetSnapshot();

            int bundleCount;
            lock (_bundleLock) { bundleCount = _bundles.Count; }

            return Results.Ok(new FederationStatusResponse(
                Enabled: !fedOptions.Value.SealedModeEnabled,
                SealedMode: fedOptions.Value.SealedModeEnabled,
                SiteId: fedOptions.Value.SiteId,
                ConsentGranted: consent.Granted,
                EpsilonRemaining: snapshot.Remaining,
                EpsilonTotal: snapshot.Total,
                BudgetExhausted: snapshot.Exhausted,
                NextBudgetReset: snapshot.NextReset,
                BundleCount: bundleCount));
        })
        .WithName("GetFederationStatus")
        .WithSummary("Get federation telemetry status")
        .RequireAuthorization(PlatformPolicies.FederationRead);

        // GET /bundles — list bundles
        group.MapGet("/bundles", Task<IResult>(
            HttpContext context,
            PlatformRequestContextResolver resolver) =>
        {
            if (!TryResolveContext(context, resolver, out _, out var failure))
                return Task.FromResult(failure!);

            List<FederationBundleSummary> summaries;
            lock (_bundleLock)
            {
                summaries = _bundles.Select(b => new FederationBundleSummary(
                    b.Id, b.SourceSiteId,
                    b.Aggregation.Buckets.Count,
                    b.Aggregation.SuppressedBuckets,
                    b.Aggregation.EpsilonSpent,
                    Verified: true,
                    b.CreatedAt)).ToList();
            }

            return Task.FromResult(Results.Ok(summaries));
        })
        .WithName("ListFederationBundles")
        .WithSummary("List federation telemetry bundles")
        .RequireAuthorization(PlatformPolicies.FederationRead);

        // GET /bundles/{id} — bundle detail
        group.MapGet("/bundles/{id:guid}", async Task<IResult>(
            HttpContext context,
            PlatformRequestContextResolver resolver,
            IFederatedTelemetryBundleBuilder bundleBuilder,
            Guid id,
            CancellationToken ct) =>
        {
            if (!TryResolveContext(context, resolver, out _, out var failure))
                return failure!;

            FederatedBundle? bundle;
            lock (_bundleLock) { bundle = _bundles.FirstOrDefault(b => b.Id == id); }

            if (bundle is null)
                return Results.NotFound(new { error = "bundle_not_found", id });

            var verified = await bundleBuilder.VerifyAsync(bundle, ct).ConfigureAwait(false);

            return Results.Ok(new FederationBundleDetailResponse(
                bundle.Id, bundle.SourceSiteId,
                bundle.Aggregation.TotalFacts,
                bundle.Aggregation.Buckets.Count,
                bundle.Aggregation.SuppressedBuckets,
                bundle.Aggregation.EpsilonSpent,
                bundle.ConsentDsseDigest,
                bundle.BundleDsseDigest,
                verified,
                bundle.Aggregation.AggregatedAt,
                bundle.CreatedAt,
                bundle.Aggregation.Buckets.Select(b => new FederationBucketDetail(
                    b.CveId, b.ObservationCount, b.ArtifactCount, b.NoisyCount, b.Suppressed)).ToList()));
        })
        .WithName("GetFederationBundle")
        .WithSummary("Get federation telemetry bundle detail")
        .RequireAuthorization(PlatformPolicies.FederationRead);

        // GET /intelligence — exploit corpus
        group.MapGet("/intelligence", async Task<IResult>(
            HttpContext context,
            PlatformRequestContextResolver resolver,
            IExploitIntelligenceMerger intelligenceMerger,
            CancellationToken ct) =>
        {
            if (!TryResolveContext(context, resolver, out _, out var failure))
                return failure!;

            var corpus = await intelligenceMerger.GetCorpusAsync(ct).ConfigureAwait(false);

            return Results.Ok(new FederationIntelligenceResponse(
                corpus.Entries.Select(e => new FederationIntelligenceEntry(
                    e.CveId, e.SourceSiteId, e.ObservationCount, e.NoisyCount, e.ArtifactCount, e.ObservedAt)).ToList(),
                corpus.TotalEntries,
                corpus.UniqueCves,
                corpus.ContributingSites,
                corpus.LastUpdated));
        })
        .WithName("GetFederationIntelligence")
        .WithSummary("Get shared exploit intelligence corpus")
        .RequireAuthorization(PlatformPolicies.FederationRead);

        // GET /privacy-budget — budget snapshot
        group.MapGet("/privacy-budget", Task<IResult>(
            HttpContext context,
            PlatformRequestContextResolver resolver,
            IPrivacyBudgetTracker budgetTracker) =>
        {
            if (!TryResolveContext(context, resolver, out _, out var failure))
                return Task.FromResult(failure!);

            var snapshot = budgetTracker.GetSnapshot();

            return Task.FromResult(Results.Ok(new FederationPrivacyBudgetResponse(
                snapshot.Remaining, snapshot.Total, snapshot.Exhausted,
                snapshot.PeriodStart, snapshot.NextReset,
                snapshot.QueriesThisPeriod, snapshot.SuppressedThisPeriod)));
        })
        .WithName("GetFederationPrivacyBudget")
        .WithSummary("Get privacy budget snapshot")
        .RequireAuthorization(PlatformPolicies.FederationRead);

        // POST /trigger — trigger aggregation
        group.MapPost("/trigger", Task<IResult>(
            HttpContext context,
            PlatformRequestContextResolver resolver,
            IPrivacyBudgetTracker budgetTracker) =>
        {
            if (!TryResolveContext(context, resolver, out _, out var failure))
                return Task.FromResult(failure!);

            if (budgetTracker.IsBudgetExhausted)
            {
                return Task.FromResult(Results.Ok(new FederationTriggerResponse(
                    Triggered: false,
                    Reason: "Privacy budget exhausted")));
            }

            // Placeholder: actual implementation would trigger sync service
            return Task.FromResult(Results.Ok(new FederationTriggerResponse(
                Triggered: true,
                Reason: null)));
        })
        .WithName("TriggerFederationAggregation")
        .WithSummary("Trigger manual federation aggregation cycle")
        .RequireAuthorization(PlatformPolicies.FederationManage);

        return app;
    }

    private static bool TryResolveContext(
        HttpContext context,
        PlatformRequestContextResolver resolver,
        out PlatformRequestContext? requestContext,
        out IResult? failure)
    {
        if (resolver.TryResolve(context, out requestContext, out var error))
        {
            failure = null;
            return true;
        }

        failure = Results.BadRequest(new { error = error ?? "tenant_missing" });
        return false;
    }
}