package main

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

	"github.com/hibiken/asynq"
	"github.com/rs/zerolog/log"
	"gorm.io/gorm"

	"github.com/treytartt/honeydue-api/internal/config"
	"github.com/treytartt/honeydue-api/internal/database"
	"github.com/treytartt/honeydue-api/internal/i18n"
	"github.com/treytartt/honeydue-api/internal/monitoring"
	"github.com/treytartt/honeydue-api/internal/push"
	"github.com/treytartt/honeydue-api/internal/router"
	"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/pkg/utils"
)

func main() {
	// Load configuration
	cfg, err := config.Load()
	if err != nil {
		fmt.Printf("Failed to load configuration: %v\n", err)
		os.Exit(1)
	}

	// Initialize basic logger first (will be enhanced after Redis connects)
	utils.InitLogger(cfg.Server.Debug)

	// Initialize i18n
	if err := i18n.Init(); err != nil {
		log.Warn().Err(err).Msg("Failed to initialize i18n - using English only")
	} else {
		log.Info().Strs("languages", i18n.SupportedLanguages).Msg("i18n initialized")
	}

	log.Info().
		Bool("debug", cfg.Server.Debug).
		Int("port", cfg.Server.Port).
		Str("db_host", cfg.Database.Host).
		Int("db_port", cfg.Database.Port).
		Str("db_name", cfg.Database.Database).
		Str("db_user", cfg.Database.User).
		Str("redis_url", config.MaskURLCredentials(cfg.Redis.URL)).
		Msg("Starting HoneyDue API server")

	// Initialize OpenTelemetry tracing — exports to obs.88oakapps.com
	// (Jaeger via OTLP/HTTP) when OBS_TRACES_URL is set; otherwise installs
	// a no-op tracer so call sites can use otel.Tracer() unconditionally.
	// 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-api",
		Environment: deploymentEnvironment(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("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("tracing shutdown error")
		}
	}()

	// Connect to database (retry with backoff)
	var db *gorm.DB
	var dbErr error
	for i := 0; i < 3; i++ {
		db, dbErr = database.Connect(&cfg.Database, cfg.Server.Debug)
		if dbErr == nil {
			break
		}
		log.Warn().Err(dbErr).Int("attempt", i+1).Msg("Failed to connect to database, retrying...")
		time.Sleep(time.Duration(i+1) * time.Second)
	}
	if dbErr != nil {
		log.Error().Err(dbErr).Msg("Failed to connect to database - API will start but database operations will fail")
	} else {
		defer database.Close()
		// Migrations are managed out-of-band by golang-migrate (see
		// cmd/migrate and deploy-k3s/manifests/migrate/job.yaml) so the api
		// no longer runs AutoMigrate at startup. Instead we verify the
		// schema is at the expected version and refuse to start if not —
		// this catches the "operator forgot to run migrate" footgun loudly,
		// at boot, instead of with mysterious runtime errors.
		if err := database.RequireSchemaApplied(); err != nil {
			log.Fatal().Err(err).Msg("Schema precondition failed — run `kubectl -n honeydue create job --from=cronjob/honeydue-migrate` (or `make migrate-up` locally) and retry")
		}
	}

	// Connect to Redis (optional - don't fail if unavailable)
	var cache *services.CacheService
	cache, err = services.NewCacheService(&cfg.Redis)
	if err != nil {
		log.Warn().Err(err).Msg("Failed to connect to Redis - caching disabled")
		cache = nil
	} else {
		defer cache.Close()
		if database.SeedInitialDataApplied {
			if err := cache.InvalidateSeededData(context.Background()); err != nil {
				log.Warn().Err(err).Msg("Failed to invalidate seeded data cache after initial seed")
			} else {
				log.Info().Msg("Invalidated seeded_data cache after initial seed migration")
			}
		}
	}

	// Initialize monitoring service (if Redis is available)
	var monitoringService *monitoring.Service
	if cache != nil {
		monitoringService = monitoring.NewService(monitoring.Config{
			Process:     "api",
			RedisClient: cache.Client(),
			DB:          db, // Pass database for enable_monitoring setting sync
		})

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

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

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

	// Initialize email service
	var emailService *services.EmailService
	log.Info().
		Str("email_host", cfg.Email.Host).
		Str("email_user", cfg.Email.User).
		Str("email_from", cfg.Email.From).
		Int("email_port", cfg.Email.Port).
		Msg("Email config loaded")
	if cfg.Email.Host != "" && cfg.Email.User != "" {
		emailService = services.NewEmailService(&cfg.Email, cfg.Features.EmailEnabled)
		log.Info().
			Str("host", cfg.Email.Host).
			Msg("Email service initialized")
	} else {
		log.Warn().
			Str("host", cfg.Email.Host).
			Str("user", cfg.Email.User).
			Msg("Email service not configured - emails will not be sent")
	}

	// Initialize storage service for file uploads (local filesystem or S3-compatible)
	var storageService *services.StorageService
	if cfg.Storage.UploadDir != "" || cfg.Storage.IsS3() {
		storageService, err = services.NewStorageService(&cfg.Storage)
		if err != nil {
			log.Warn().Err(err).Msg("Failed to initialize storage service - uploads disabled")
		} else {
			// Initialize file encryption at rest if configured
			if cfg.Storage.EncryptionKey != "" {
				encSvc, encErr := services.NewEncryptionService(cfg.Storage.EncryptionKey)
				if encErr != nil {
					log.Error().Err(encErr).Msg("Failed to initialize encryption service - files will NOT be encrypted")
				} else {
					storageService.SetEncryptionService(encSvc)
					log.Info().Msg("File encryption at rest enabled")
				}
			}
		}
	}

	// Initialize PDF service for report generation
	pdfService := services.NewPDFService()
	log.Info().Msg("PDF service initialized")

	// Initialize push notification 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 Asynq enqueuer (api-side). Used by services that move
	// long-running work off the request path (currently: task-completion
	// notification fan-out). Same Redis as cmd/worker — file-mounted password
	// applied separately because cfg.Redis.URL does not embed it (audit HIGH-1).
	var taskEnqueuer *worker.TaskClient
	if redisOpt, parseErr := asynq.ParseRedisURI(cfg.Redis.URL); parseErr != nil {
		log.Warn().Err(parseErr).Msg("Failed to parse Redis URL for Asynq enqueuer — completion notifications will run inline")
	} else if clientOpt, ok := redisOpt.(asynq.RedisClientOpt); ok {
		if cfg.Redis.Password != "" {
			clientOpt.Password = cfg.Redis.Password
		}
		taskEnqueuer = worker.NewTaskClient(clientOpt)
		defer func() {
			if cerr := taskEnqueuer.Close(); cerr != nil {
				log.Warn().Err(cerr).Msg("Failed to close Asynq enqueuer on shutdown")
			}
		}()
		log.Info().Msg("Asynq enqueuer initialized")
	} else {
		log.Warn().Msg("Redis opt is not RedisClientOpt — Asynq enqueuer skipped; completion notifications will run inline")
	}

	// Setup router with dependencies (includes admin panel at /admin)
	deps := &router.Dependencies{
		DB:                db,
		Cache:             cache,
		Config:            cfg,
		EmailService:      emailService,
		PDFService:        pdfService,
		PushClient:        pushClient,
		StorageService:    storageService,
		MonitoringService: monitoringService,
	}
	// Only assign the enqueuer when we actually constructed one. Assigning a
	// nil *worker.TaskClient directly would create a typed-nil interface that
	// fails the `if deps.TaskEnqueuer != nil` check in router.SetupRouter.
	if taskEnqueuer != nil {
		deps.TaskEnqueuer = taskEnqueuer
	}
	e := router.SetupRouter(deps)

	// Create HTTP server
	srv := &http.Server{
		Addr:         fmt.Sprintf(":%d", cfg.Server.Port),
		Handler:      e,
		ReadTimeout:  30 * time.Second,
		WriteTimeout: 30 * time.Second,
		IdleTimeout:  60 * time.Second,
	}

	// Start server in goroutine
	go func() {
		log.Info().
			Str("addr", srv.Addr).
			Msg("HTTP server listening")

		if err := srv.ListenAndServe(); err != nil && err != http.ErrServerClosed {
			log.Fatal().Err(err).Msg("Failed to start HTTP server")
		}
	}()

	// Wait for interrupt signal for graceful shutdown
	quit := make(chan os.Signal, 1)
	signal.Notify(quit, syscall.SIGINT, syscall.SIGTERM)
	<-quit

	log.Info().Msg("Shutting down server...")

	// Graceful shutdown with timeout
	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
	defer cancel()

	if err := srv.Shutdown(ctx); err != nil {
		log.Fatal().Err(err).Msg("Server forced to shutdown")
	}

	log.Info().Msg("Server exited")
}

// deploymentEnvironment turns the boolean Debug flag into the conventional
// environment label spans get tagged with.
func deploymentEnvironment(debug bool) string {
	if env := os.Getenv("DEPLOYMENT_ENVIRONMENT"); env != "" {
		return env
	}
	if debug {
		return "dev"
	}
	return "prod"
}