package main

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

	hwlab "git.georgsen.dk/hwlab"
	"git.georgsen.dk/hwlab/internal/advisor"
	"git.georgsen.dk/hwlab/internal/ai"
	"git.georgsen.dk/hwlab/internal/api"
	"git.georgsen.dk/hwlab/internal/api/handlers"
	"git.georgsen.dk/hwlab/internal/config"
	"git.georgsen.dk/hwlab/internal/inventory"
	"git.georgsen.dk/hwlab/internal/netbox"
	"git.georgsen.dk/hwlab/internal/printer"
	"git.georgsen.dk/hwlab/internal/queue"
	"git.georgsen.dk/hwlab/internal/research"
	"git.georgsen.dk/hwlab/internal/store"
	"git.georgsen.dk/hwlab/internal/usb"
)

func main() {
	cfg, err := config.Load()
	if err != nil {
		log.Fatalf("config: %v", err)
	}

	staticFS, err := fs.Sub(hwlab.StaticFiles, "web/dist")
	if err != nil {
		log.Fatalf("embed: %v", err)
	}

	// Context for graceful shutdown
	ctx, stop := signal.NotifyContext(context.Background(), syscall.SIGINT, syscall.SIGTERM)
	defer stop()

	// NetBox client (required — fatal if misconfigured)
	nbClient, err := netbox.NewClient(cfg.NetBoxURL, cfg.NetBoxToken)
	if err != nil {
		log.Fatalf("netbox client: %v", err)
	}

	// AI tier clients and orchestrator
	tier1 := ai.NewTierClient(cfg.AI.Tier1)
	tier2 := ai.NewTierClient(cfg.AI.Tier2)
	orch := ai.NewOrchestrator(tier1, tier2, cfg.AI.ConfidenceThreshold)

	// Catalog updater
	catalogUpdater := inventory.NewCatalogUpdater(nbClient)

	// Start write-ahead queue worker (non-fatal if DragonFlyDB unavailable).
	// waqForHandler is typed as the interface so that a nil *WAQ is not wrapped in a non-nil interface.
	var waqForHandler handlers.IntakeWAQ
	waqInstance, waqErr := queue.NewWAQ(cfg.DragonflyURL)
	if waqErr != nil {
		log.Printf("WARNING: WAQ unavailable (%v) — NetBox operations will not be queued during downtime", waqErr)
	} else {
		nbHandler := queue.NewNetBoxOpHandler(nbClient)
		retryInterval := time.Duration(cfg.WAQRetryIntervalSeconds) * time.Second
		go waqInstance.RunWorker(ctx, nbHandler, cfg.WAQMaxAttempts, retryInterval)
		defer waqInstance.Close()
		waqForHandler = waqInstance
		log.Printf("WAQ worker started")
	}

	// USB Manager — polls for device connect/disconnect events.
	// Start with 2-second poll interval (production default).
	usbManager := usb.NewManager(2 * time.Second)
	go usbManager.Start(ctx)
	defer usbManager.Stop()

	// Printer driver — MockDriver until PRT Qutie hardware arrives (2026-04-13).
	// TODO(hardware): replace with printer.NewPrtQutieDriver(9600) after characterization.
	mockDriver := printer.NewMockDriver()
	if err := mockDriver.Connect(); err != nil {
		log.Printf("WARNING: mock printer connect: %v", err)
	}

	// Intake handler — waqForHandler and mockDriver may be nil; handler handles nil gracefully.
	intakeHandler := handlers.NewIntakeHandler(
		orch,
		nbClient,
		catalogUpdater,
		waqForHandler,
		cfg.NetBoxDefaultDeviceTypeID,
		cfg.NetBoxDefaultRoleID,
		cfg.NetBoxDefaultSiteID,
		cfg.AI.QuickAddEnabled,
		cfg.AI.QuickAddThreshold,
		mockDriver,
	)

	inventoryHandler := handlers.NewInventoryHandler(nbClient)
	labelHandler := handlers.NewLabelHandler(nbClient, mockDriver)
	usbEventsHandler := handlers.NewUSBEventsHandler(usbManager)
	testHandler := handlers.NewTestHandler(nbClient, mockDriver)

	// Store + advisor — non-fatal if DB unavailable (advisor degrades gracefully).
	var advisorHandler *advisor.AdvisorHandler
	dbDSN := os.Getenv("HWLAB_DATABASE_URL")
	if dbDSN != "" {
		s, storeErr := store.NewStore(ctx, dbDSN)
		if storeErr != nil {
			log.Printf("WARNING: store unavailable (%v) — advisor endpoints will be disabled", storeErr)
		} else {
			defer s.Close()
			if migErr := store.RunMigrations(ctx, s.Pool()); migErr != nil {
				log.Printf("WARNING: store migrations failed (%v) — advisor endpoints may misbehave", migErr)
			}
			ctxBuilder := advisor.NewInventoryContextBuilder(nbClient)
			advisorHandler = advisor.NewAdvisorHandler(s, ctxBuilder, cfg.AI)
			log.Printf("Advisor handler ready")
		}
	} else {
		log.Printf("HWLAB_DATABASE_URL not set — advisor endpoints disabled")
	}

	// Research agent — enriches needs_research items via SearXNG + Tier 2 LLM.
	searxngClient := research.NewSearXNGClient(cfg.SearXNGURL)
	researchAgent := research.NewAgent(nbClient, searxngClient, tier2, catalogUpdater)
	go researchAgent.Start(ctx, 10*time.Minute)
	researchHandler := handlers.NewResearchHandler(researchAgent)
	searchHandler := handlers.NewSearchHandler(nbClient, tier1)

	// Wire USB Manager events to cable tester driver when a RoleCableTester device connects.
	// Currently a no-op stub — wires the plumbing for Phase 5 hardware integration.
	go func() {
		for evt := range usbManager.Events() {
			if evt.Spec.Role == usb.RoleCableTester {
				log.Printf("cable tester connected: %s", evt.VIDPID)
				// TODO(hardware): construct tester driver for evt.VIDPID,
				// call driver.Connect(), then testHandler.AttachStream(driver.Stream())
				_ = testHandler
			}
		}
	}()

	router := api.NewRouter(staticFS, intakeHandler, inventoryHandler, labelHandler, usbEventsHandler, testHandler, advisorHandler, researchHandler, searchHandler)
	addr := fmt.Sprintf("%s:%d", cfg.Host, cfg.Port)
	log.Printf("HWLab starting on %s", addr)

	srv := &http.Server{Addr: addr, Handler: router}
	go func() {
		if err := srv.ListenAndServe(); err != nil && err != http.ErrServerClosed {
			log.Fatalf("server: %v", err)
		}
	}()

	// Wait for shutdown signal
	<-ctx.Done()
	log.Println("Shutting down...")
	shutdownCtx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
	defer cancel()
	if err := srv.Shutdown(shutdownCtx); err != nil {
		log.Printf("server shutdown: %v", err)
	}
	log.Println("Shutdown complete")
}