// End-to-end probe: publish visits through the real agent path.
//
// SIM controls the similarity of the second visit to the first, which is what
// exercises the reinforcement branch: identical vectors teach the gallery
// nothing and must be refused, a genuinely different view of the same person
// must be kept.
package main

import (
	"context"
	"encoding/json"
	"fmt"
	"log"
	"math"
	"math/rand"
	"os"
	"strconv"
	"time"

	"github.com/loyaly/behavision-agent/pkg/mqtt"
	"github.com/loyaly/behavision-agent/pkg/spool"
)

func unit(seed int64) []float32 {
	rng := rand.New(rand.NewSource(seed))
	v := make([]float32, 512)
	var n float64
	for i := range v {
		v[i] = float32(rng.NormFloat64())
		n += float64(v[i]) * float64(v[i])
	}
	n = math.Sqrt(n)
	for i := range v {
		v[i] /= float32(n)
	}
	return v
}

// atSimilarity builds a unit vector exactly `target` from base.
func atSimilarity(base []float32, target float64, seed int64) []float32 {
	other := unit(seed)
	var dot float64
	for i := range base {
		dot += float64(base[i]) * float64(other[i])
	}
	var n float64
	for i := range other {
		other[i] -= float32(dot) * base[i]
		n += float64(other[i]) * float64(other[i])
	}
	n = math.Sqrt(n)
	out := make([]float32, len(base))
	k := math.Sqrt(1 - target*target)
	for i := range base {
		out[i] = float32(target)*base[i] + float32(k)*(other[i]/float32(n))
	}
	return out
}

func main() {
	broker, user := os.Getenv("BROKER"), os.Getenv("MQTT_USER")
	logger := log.New(os.Stdout, "  ", 0)

	q, err := spool.Open(os.Getenv("SPOOL_DIR"), 100)
	if err != nil {
		log.Fatal(err)
	}

	sim, _ := strconv.ParseFloat(os.Getenv("SIM"), 64)
	emb := unit(42)
	if sim > 0 {
		emb = atSimilarity(unit(42), sim, 7)
	}
	quality, _ := strconv.ParseFloat(os.Getenv("QUALITY"), 64)
	if quality == 0 {
		quality = 0.74
	}

	visit := map[string]any{
		"event_id":    os.Getenv("EVENT_ID"),
		"occurred_at": time.Now().UTC().Format(time.RFC3339Nano),
		"camera_id":   "entrance",
		"is_new":      sim == 0,
		"quality":     quality,
		"model":       "w600k_r50.onnx",
		"embedding":   emb,
		"attributes":  map[string]any{"gender": "Male", "age": 34},
	}
	if err := q.Append(fmt.Sprintf("bv/%s/visit", user), visit); err != nil {
		log.Fatal(err)
	}

	client, err := mqtt.NewClient(mqtt.ClientOptions{
		BrokerURL: broker, ClientID: "e2e-probe-" + os.Getenv("EVENT_ID"),
		Username: user, Password: os.Getenv("MQTT_PASS"),
		CAFile: os.Getenv("CA_FILE"), Log: logger,
	})
	if err != nil {
		log.Fatalf("connect: %v", err)
	}
	defer client.Close()

	ctx, cancel := context.WithTimeout(context.Background(), 20*time.Second)
	defer cancel()
	go (&mqtt.Pump{Queue: q, Publisher: client, Log: logger}).Run(ctx)

	deadline := time.Now().Add(15 * time.Second)
	for time.Now().Before(deadline) {
		if q.Len() == 0 {
			b, _ := json.Marshal(map[string]any{"sim": sim, "quality": quality})
			logger.Printf("published %s", b)
			return
		}
		time.Sleep(200 * time.Millisecond)
	}
	log.Fatalf("spool did not drain: %d left", q.Len())
}