package main

import (
	"context"
	"fmt"
	"net/http"
	"net/http/httptest"
	"path/filepath"
	"strings"
	"testing"

	_ "modernc.org/sqlite"

	"github.com/tegwick/fluid-core/internal/contract"
	"github.com/tegwick/fluid-core/internal/evidence"
	"github.com/tegwick/fluid-core/internal/observation"
	"github.com/tegwick/fluid-core/internal/runtime"
)

// TestInsightLoopEndToEnd drives real traffic through the gateway and confirms
// the observation plane turns it into a pressure record.
//
// This is the Blueprint section 33 shape end to end: consumers repeatedly
// listing a collection to find one entry, observed at the gateway, redacted on
// ingest, and classified as inefficient usage without anyone naming it as such.
func TestInsightLoopEndToEnd(t *testing.T) {
	ctx := context.Background()
	dir := t.TempDir()

	store, err := evidence.OpenSQLite(ctx, filepath.Join(dir, "e.db"))
	if err != nil {
		t.Fatal(err)
	}
	defer store.Close()

	policy := observation.DefaultRedactionPolicy([]byte("a-stable-salt-for-this-test-only"))
	ingest, err := observation.NewIngest(store, "hall-publishing", policy)
	if err != nil {
		t.Fatal(err)
	}

	adapter := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		_, _ = w.Write([]byte(`[{"id":1},{"id":2}]`))
	}))
	defer adapter.Close()

	reg := runtime.NewRegistry("hall-publishing")
	d := contract.Revision{
		SchemaVersion: "0.1", ID: "R-1", Interface: "hall-publishing",
		State:    contract.RevisionStateStable,
		Contract: contract.RevisionContract{Type: contract.RevisionContractTypeOpenapi, Digest: contract.Digest("sha256:" + repeat("1", 64))},
		Runtime:  contract.RevisionRuntime{Upstream: adapter.URL},
		Intent:   contract.RevisionIntent{Version: "IEI-1"},
		Policy: contract.RevisionPolicy{
			Compatibility: contract.RevisionPolicyCompatibilityAdditive,
			SecurityCheck: contract.RevisionPolicySecurityCheckPassed,
		},
	}
	if err := reg.PutRevision(d); err != nil {
		t.Fatal(err)
	}
	if err := reg.PutPolicy(contract.RoutingPolicy{
		SchemaVersion: "0.1", Interface: "hall-publishing",
		Generation: 1, DefaultRevision: "R-1",
	}); err != nil {
		t.Fatal(err)
	}

	emitter := runtime.NewEmitter(ingest, runtime.EmitterOptions{Buffer: 4096, Workers: 2})
	gw, err := runtime.NewGateway(runtime.GatewayOptions{
		Interface: "hall-publishing",
		Registry:  reg,
		Resolver:  runtime.NewResolver(reg, false),
		Connector: runtime.NewConnector(),
		Emitter:   emitter,
		Cohorts:   observation.NewCohortEngine("coding-agents", policy),
		Response:  runtime.ResponsePolicy{FeedbackPath: "/v1/feedback"},
	})
	if err != nil {
		t.Fatal(err)
	}

	// Four independent consumers, each listing the collection four times per
	// task to find one entry: the Blueprint section 33 shape.
	for c := 0; c < 4; c++ {
		for chain := 0; chain < 3; chain++ {
			for i := 0; i < 4; i++ {
				req := httptest.NewRequest(http.MethodGet, "/v1/hall-entries", nil)
				req.Header.Set("X-FLUID-Consumer", fmt.Sprintf("agent-%d", c))
				req.Header.Set("X-FLUID-Correlation", fmt.Sprintf("c-%d-%d", c, chain))
				rec := httptest.NewRecorder()
				gw.ServeHTTP(rec, req)
				if rec.Code != http.StatusOK {
					t.Fatalf("request failed: %d", rec.Code)
				}
			}
		}
	}
	emitter.Close()

	events, err := store.Telemetry(ctx, evidence.TelemetryFilter{InterfaceID: "hall-publishing"})
	if err != nil {
		t.Fatal(err)
	}
	if len(events) != 48 {
		t.Fatalf("recorded %d telemetry events, want 48", len(events))
	}

	// The raw consumer header must never have reached the store.
	for _, ev := range events {
		if ev.ConsumerRef == "agent-0" {
			t.Fatal("a raw consumer identity reached the evidence store")
		}
	}

	classifier := observation.NewClassifier(
		observation.DefaultClassifierOptions(), observation.NewTopologyAnalyzer())
	findings := classifier.Classify(events)
	if len(findings) == 0 {
		t.Fatal("no pressure found in clearly inefficient traffic")
	}

	registry := observation.NewPressureRegistry(store, "hall-publishing")
	recorded, err := registry.RecordAll(ctx, findings)
	if err != nil {
		t.Fatal(err)
	}
	if len(recorded) == 0 {
		t.Fatal("no pressure recorded")
	}

	var inefficient *contract.FluidPressure
	for i := range recorded {
		if recorded[i].Class == contract.PressureClassSuccessfulButInefficientUsage {
			inefficient = &recorded[i]
		}
	}
	if inefficient == nil {
		t.Fatalf("inefficient usage not recorded; got %v", recorded)
	}
	if inefficient.Frequency == nil || *inefficient.Frequency.IndependentConsumers != 4 {
		t.Errorf("independent consumers not recorded correctly: %+v", inefficient.Frequency)
	}
	if len(inefficient.EvidenceRefs) == 0 {
		t.Error("pressure recorded with no evidence references")
	}

	t.Logf("pressure %s: %s (severity %.2f, confidence %.2f, %d consumers)",
		inefficient.ID, inefficient.Summary,
		float64(*inefficient.Severity), float64(*inefficient.Confidence),
		*inefficient.Frequency.IndependentConsumers)
}

func repeat(s string, n int) string { return strings.Repeat(s, n) }