package main

import (
	"context"
	"net/http"
	"os"
	"os/signal"
	"syscall"
	"time"

	"github.com/hibiken/asynq"
	"github.com/redis/go-redis/v9"
	"github.com/rs/zerolog/log"
	"go.opentelemetry.io/otel/attribute"
	"go.opentelemetry.io/otel/codes"
	"go.opentelemetry.io/otel/trace"

	"github.com/treytartt/honeydue-api/internal/config"
	"github.com/treytartt/honeydue-api/internal/database"
	"github.com/treytartt/honeydue-api/internal/monitoring"
	"github.com/treytartt/honeydue-api/internal/prom"
	"github.com/treytartt/honeydue-api/internal/push"
	"github.com/treytartt/honeydue-api/internal/repositories"
	"github.com/treytartt/honeydue-api/internal/services"
	"github.com/treytartt/honeydue-api/internal/tracing"
	"github.com/treytartt/honeydue-api/internal/worker"
	"github.com/treytartt/honeydue-api/internal/worker/jobs"
	"github.com/treytartt/honeydue-api/pkg/utils"
)

const workerHealthAddr = ":6060"

func main() {
	// Initialize logger
	utils.InitLogger(true)

	// Load configuration
	cfg, err := config.Load()
	if err != nil {
		log.Fatal().Err(err).Msg("Failed to load configuration")
	}

	// Check worker kill switch
	if !cfg.Features.WorkerEnabled {
		log.Warn().Msg("Worker disabled by FEATURE_WORKER_ENABLED=false — exiting")
		os.Exit(0)
	}

	// Initialize OpenTelemetry tracing for the worker process. Same OTLP
	// destination as the api; service.name distinguishes them in Jaeger.
	// config.SecretValue (not os.Getenv) so file-mounted secrets resolve
	// after audit F8 removed these from the process environment.
	tracingShutdown, err := tracing.Init(context.Background(), tracing.Config{
		ServiceName: "honeydue-worker",
		Environment: workerDeploymentEnv(cfg.Server.Debug),
		EndpointURL: config.SecretValue("OBS_TRACES_URL"),
		BearerToken: config.SecretValue("OBS_INGEST_TOKEN"),
		SampleRatio: tracing.SampleRatioFromEnv(),
	})
	if err != nil {
		log.Error().Err(err).Msg("worker tracing init failed — continuing without traces")
	}
	defer func() {
		shutdownCtx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
		defer cancel()
		if err := tracingShutdown(shutdownCtx); err != nil {
			log.Warn().Err(err).Msg("worker tracing shutdown error")
		}
	}()
	asynqTracer := tracing.Tracer("honeydue/worker/asynq")

	// Initialize database
	db, err := database.Connect(&cfg.Database, cfg.Server.Debug)
	if err != nil {
		log.Fatal().Err(err).Msg("Failed to connect to database")
	}
	log.Info().Msg("Connected to database")

	// Get underlying *sql.DB for cleanup
	sqlDB, _ := db.DB()
	defer sqlDB.Close()

	// Initialize push client (APNs + FCM)
	var pushClient *push.Client
	pushClient, err = push.NewClient(&cfg.Push, cfg.Features.PushEnabled)
	if err != nil {
		log.Warn().Err(err).Msg("Failed to initialize push client - push notifications disabled")
	} else {
		log.Info().
			Bool("ios_enabled", pushClient.IsIOSEnabled()).
			Bool("android_enabled", pushClient.IsAndroidEnabled()).
			Msg("Push notification client initialized")
	}

	// Initialize email service (optional)
	var emailService *services.EmailService
	if cfg.Email.Host != "" {
		emailService = services.NewEmailService(&cfg.Email, cfg.Features.EmailEnabled)
		log.Info().Str("host", cfg.Email.Host).Msg("Email service initialized")
	}

	// Initialize notification service for actionable push notifications
	notificationRepo := repositories.NewNotificationRepository(db)
	notificationService := services.NewNotificationService(notificationRepo, pushClient)
	log.Info().Msg("Notification service initialized")

	// Parse Redis URL for Asynq
	redisOpt, err := asynq.ParseRedisURI(cfg.Redis.URL)
	if err != nil {
		log.Fatal().Err(err).Msg("Failed to parse Redis URL")
	}
	// Audit HIGH-1: the Redis password is a file-mounted secret (REDIS_PASSWORD),
	// not embedded in REDIS_URL — REDIS_URL travels in the honeydue-config
	// ConfigMap. Apply the password onto the parsed opt so the Asynq server,
	// inspector and monitoring client (all derived from redisOpt below)
	// authenticate against a requirepass-protected Redis.
	if cfg.Redis.Password != "" {
		if clientOpt, ok := redisOpt.(asynq.RedisClientOpt); ok {
			clientOpt.Password = cfg.Redis.Password
			redisOpt = clientOpt
		}
	}

	// Initialize monitoring service (if Redis is available)
	var monitoringService *monitoring.Service
	redisClientOpt, ok := redisOpt.(asynq.RedisClientOpt)
	if ok {
		redisClient := redis.NewClient(&redis.Options{
			Addr:     redisClientOpt.Addr,
			Password: redisClientOpt.Password,
			DB:       redisClientOpt.DB,
		})

		// Verify Redis connection
		if err := redisClient.Ping(context.Background()).Err(); err != nil {
			log.Warn().Err(err).Msg("Failed to connect to Redis for monitoring - monitoring disabled")
		} else {
			monitoringService = monitoring.NewService(monitoring.Config{
				Process:     "worker",
				RedisClient: redisClient,
				DB:          db, // Pass database for enable_monitoring setting sync
			})

			// Reinitialize logger with monitoring writer
			utils.InitLoggerWithWriter(cfg.Server.Debug, monitoringService.LogWriter())

			// Create Asynq inspector for queue statistics
			inspector := asynq.NewInspector(redisOpt)
			monitoringService.SetAsynqInspector(inspector)

			// Start stats collection
			monitoringService.Start()
			defer monitoringService.Stop()

			log.Info().
				Bool("log_capture_enabled", monitoringService.IsEnabled()).
				Msg("Monitoring service initialized")
		}
	}

	// Create Asynq server
	srv := asynq.NewServer(
		redisOpt,
		asynq.Config{
			Concurrency: 10,
			Queues: map[string]int{
				"critical": 6,
				"default":  3,
				"low":      1,
			},
			ErrorHandler: asynq.ErrorHandlerFunc(func(ctx context.Context, task *asynq.Task, err error) {
				log.Error().
					Err(err).
					Str("type", task.Type()).
					Bytes("payload", task.Payload()).
					Msg("Task processing failed")
			}),
		},
	)

	// Create job handler
	jobHandler := jobs.NewHandler(db, pushClient, emailService, notificationService, cfg)

	// Wire upload service for the pending_uploads cleanup cron AND share the
	// underlying storage service with the TaskService below so the worker can
	// load completion images for email embedding. Storage may be local-disk
	// (no S3 backend), in which case the upload service stays nil and the
	// cleanup handler no-ops. Cache is optional — the cleanup path doesn't
	// rate-limit and works fine with a nil cache.
	var sharedStorageService *services.StorageService
	if storageService, sErr := services.NewStorageService(&cfg.Storage); sErr == nil {
		sharedStorageService = storageService
		if s3 := storageService.S3Backend(); s3 != nil {
			pendingUploadRepo := repositories.NewPendingUploadRepository(db)
			uploadService := services.NewUploadService(pendingUploadRepo, s3, &cfg.Storage, nil)
			jobHandler.SetUploadService(uploadService)
		}
	} else {
		log.Warn().Err(sErr).Msg("Failed to initialize storage service for upload cleanup; cleanup cron will no-op")
	}

	// Wire a TaskService for the task-completed notification handler. The
	// worker re-creates this (vs. importing the api's wired instance) because
	// each binary owns its own dependency graph. The handler is fully nil-safe
	// — if any of the wired services are absent, the corresponding side of
	// notification delivery (push or email) is skipped.
	taskRepo := repositories.NewTaskRepository(db)
	residenceRepo := repositories.NewResidenceRepository(db)
	workerTaskService := services.NewTaskService(taskRepo, residenceRepo)
	if notificationService != nil {
		workerTaskService.SetNotificationService(notificationService)
	}
	if emailService != nil {
		workerTaskService.SetEmailService(emailService)
	}
	if sharedStorageService != nil {
		workerTaskService.SetStorageService(sharedStorageService)
	}
	jobHandler.SetTaskService(workerTaskService)

	// Create Asynq mux and register handlers
	mux := asynq.NewServeMux()

	// Tracing + metrics middleware: every job runs inside a span and emits
	// asynq_job_duration_seconds{task_type,result}.
	mux.Use(asynqTracingMiddleware(asynqTracer))

	mux.HandleFunc(jobs.TypeSmartReminder, jobHandler.HandleSmartReminder)
	mux.HandleFunc(jobs.TypeDailyDigest, jobHandler.HandleDailyDigest)
	mux.HandleFunc(jobs.TypeSendEmail, jobHandler.HandleSendEmail)
	mux.HandleFunc(jobs.TypeSendPush, jobHandler.HandleSendPush)
	mux.HandleFunc(jobs.TypeOnboardingEmails, jobHandler.HandleOnboardingEmails)
	mux.HandleFunc(jobs.TypeReminderLogCleanup, jobHandler.HandleReminderLogCleanup)
	mux.HandleFunc(jobs.TypeUploadCleanup, jobHandler.HandleUploadCleanup)
	mux.HandleFunc(worker.TypeTaskCompletedNotification, jobHandler.HandleTaskCompletedNotification)

	// Register email job handlers (welcome, verification, password reset, password changed)
	if emailService != nil {
		emailJobHandler := jobs.NewEmailJobHandler(emailService)
		emailJobHandler.RegisterHandlers(mux)
	}

	// Start scheduler for periodic tasks
	scheduler := asynq.NewScheduler(redisOpt, nil)

	// Schedule smart reminder notifications (runs every hour to support per-user custom times)
	// Replaces old task reminder and overdue reminder with frequency-aware system
	// Uses TaskReminderLog to prevent duplicate notifications
	if _, err := scheduler.Register("0 * * * *", asynq.NewTask(jobs.TypeSmartReminder, nil)); err != nil {
		log.Fatal().Err(err).Msg("Failed to register smart reminder job")
	}
	log.Info().Str("cron", "0 * * * *").Int("default_hour", cfg.Worker.TaskReminderHour).Msg("Registered smart reminder job (runs hourly for per-user times)")

	// Schedule daily digest (runs every hour to support per-user custom times)
	// The job handler filters users based on their preferred notification hour
	if _, err := scheduler.Register("0 * * * *", asynq.NewTask(jobs.TypeDailyDigest, nil)); err != nil {
		log.Fatal().Err(err).Msg("Failed to register daily digest job")
	}
	log.Info().Str("cron", "0 * * * *").Int("default_hour", cfg.Worker.DailyNotifHour).Msg("Registered daily digest job (runs hourly for per-user times)")

	// Schedule onboarding emails (runs daily at 10:00 AM UTC)
	// Sends emails to users who haven't created residences or tasks after registration
	if _, err := scheduler.Register("0 10 * * *", asynq.NewTask(jobs.TypeOnboardingEmails, nil)); err != nil {
		log.Fatal().Err(err).Msg("Failed to register onboarding emails job")
	}
	log.Info().Str("cron", "0 10 * * *").Msg("Registered onboarding emails job (runs daily at 10:00 AM UTC)")

	// Schedule reminder log cleanup (runs daily at 3:00 AM UTC)
	// Removes reminder logs older than 90 days to prevent table bloat
	if _, err := scheduler.Register("0 3 * * *", asynq.NewTask(jobs.TypeReminderLogCleanup, nil)); err != nil {
		log.Fatal().Err(err).Msg("Failed to register reminder log cleanup job")
	}
	log.Info().Str("cron", "0 3 * * *").Msg("Registered reminder log cleanup job (runs daily at 3:00 AM UTC)")

	// Schedule pending_uploads cleanup (hourly at :30 to avoid colliding with
	// the top-of-hour reminder + digest crons). Reaps unclaimed expired
	// upload sessions; the B2 bucket lifecycle (7 days on uploads/ prefix)
	// is the backstop if this worker is offline for an extended period.
	if _, err := scheduler.Register("30 * * * *", asynq.NewTask(jobs.TypeUploadCleanup, nil)); err != nil {
		log.Fatal().Err(err).Msg("Failed to register upload cleanup job")
	}
	log.Info().Str("cron", "30 * * * *").Msg("Registered pending_uploads cleanup job (runs hourly)")

	// Handle graceful shutdown
	quit := make(chan os.Signal, 1)
	signal.Notify(quit, syscall.SIGINT, syscall.SIGTERM)

	// Health server (for container healthchecks; not externally published)
	healthMux := http.NewServeMux()
	healthMux.HandleFunc("/health", func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "application/json")
		w.WriteHeader(http.StatusOK)
		_, _ = w.Write([]byte(`{"status":"ok"}`))
	})
	healthSrv := &http.Server{
		Addr:              workerHealthAddr,
		Handler:           healthMux,
		ReadHeaderTimeout: 5 * time.Second,
	}
	go func() {
		log.Info().Str("addr", workerHealthAddr).Msg("Health server listening")
		if err := healthSrv.ListenAndServe(); err != nil && err != http.ErrServerClosed {
			log.Warn().Err(err).Msg("Health server terminated")
		}
	}()

	// Start scheduler in goroutine
	go func() {
		if err := scheduler.Run(); err != nil {
			log.Fatal().Err(err).Msg("Failed to start scheduler")
		}
	}()

	// Start worker server in goroutine
	go func() {
		log.Info().Msg("Starting worker server...")
		if err := srv.Run(mux); err != nil {
			log.Fatal().Err(err).Msg("Failed to start worker server")
		}
	}()

	<-quit
	log.Info().Msg("Shutting down worker...")

	// Graceful shutdown
	shutdownCtx, shutdownCancel := context.WithTimeout(context.Background(), 5*time.Second)
	defer shutdownCancel()
	_ = healthSrv.Shutdown(shutdownCtx)
	srv.Shutdown()
	scheduler.Shutdown()

	log.Info().Msg("Worker stopped")
}

// asynqTracingMiddleware returns an asynq.MiddlewareFunc that opens a span
// per task execution and records asynq_job_duration_seconds. Span attrs
// include task type, queue, retry count, and the result outcome.
func asynqTracingMiddleware(tracer trace.Tracer) asynq.MiddlewareFunc {
	return func(next asynq.Handler) asynq.Handler {
		return asynq.HandlerFunc(func(ctx context.Context, t *asynq.Task) error {
			ctx, span := tracer.Start(ctx, "asynq.handle:"+t.Type(),
				trace.WithAttributes(
					attribute.String("asynq.task_type", t.Type()),
					attribute.Int("asynq.payload_bytes", len(t.Payload())),
				),
			)
			defer span.End()

			start := time.Now()
			err := next.ProcessTask(ctx, t)
			dur := time.Since(start)
			result := "ok"
			if err != nil {
				result = "error"
				span.SetStatus(codes.Error, err.Error())
				span.RecordError(err)
			}
			span.SetAttributes(attribute.String("asynq.result", result))
			prom.ObserveAsynqJob(t.Type(), result, dur)
			return err
		})
	}
}

// workerDeploymentEnv mirrors deploymentEnvironment in cmd/api/main.go.
func workerDeploymentEnv(debug bool) string {
	if env := os.Getenv("DEPLOYMENT_ENVIRONMENT"); env != "" {
		return env
	}
	if debug {
		return "dev"
	}
	return "prod"
}