// Command runner is the homelab worker binary.
//
// It polls PocketBase for pending scrape and audio tasks, executes them, and
// writes results back. It connects directly to PocketBase and MinIO using
// admin credentials loaded from environment variables.
//
// Usage:
//
//	runner          # start polling loop (blocks until SIGINT/SIGTERM)
package main

import (
	"context"
	"fmt"
	"io"
	"log/slog"
	"os"
	"os/signal"
	"runtime"
	"syscall"
	"time"

	"github.com/getsentry/sentry-go"
	"github.com/libnovel/backend/internal/asynqqueue"
	"github.com/libnovel/backend/internal/browser"
	"github.com/libnovel/backend/internal/config"
	"github.com/libnovel/backend/internal/kokoro"
	"github.com/libnovel/backend/internal/libretranslate"
	"github.com/libnovel/backend/internal/meili"
	"github.com/libnovel/backend/internal/novelfire"
	"github.com/libnovel/backend/internal/otelsetup"
	"github.com/libnovel/backend/internal/pockettts"
	"github.com/libnovel/backend/internal/runner"
	"github.com/libnovel/backend/internal/storage"
	"github.com/libnovel/backend/internal/taskqueue"
)

// version and commit are set at build time via -ldflags.
var (
	version = "dev"
	commit  = "unknown"
)

func main() {
	if err := run(); err != nil {
		fmt.Fprintf(os.Stderr, "runner: fatal: %v\n", err)
		os.Exit(1)
	}
}

func run() error {
	cfg := config.Load()

	// ── Sentry / GlitchTip error tracking ────────────────────────────────────
	if dsn := os.Getenv("GLITCHTIP_DSN"); dsn != "" {
		if err := sentry.Init(sentry.ClientOptions{
			Dsn:              dsn,
			Release:          version + "@" + commit,
			TracesSampleRate: 0.1,
		}); err != nil {
			fmt.Fprintf(os.Stderr, "runner: sentry init warning: %v\n", err)
		} else {
			defer sentry.Flush(2 * time.Second)
		}
	}

	// ── Logger ──────────────────────────────────────────────────────────────
	log := buildLogger(cfg.LogLevel)
	log.Info("runner starting",
		"version", version,
		"commit", commit,
		"worker_id", cfg.Runner.WorkerID,
	)

	// ── Context: cancel on SIGINT / SIGTERM ─────────────────────────────────
	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
	defer stop()

	// ── OpenTelemetry tracing + logs ─────────────────────────────────────────
	otelShutdown, otelLog, err := otelsetup.Init(ctx, version)
	if err != nil {
		return fmt.Errorf("init otel: %w", err)
	}
	if otelShutdown != nil {
		defer otelShutdown()
		// Switch to the OTel-bridged logger so all structured log lines are
		// forwarded to Loki with trace IDs attached.
		log = otelLog
		log.Info("otel tracing + logs enabled", "endpoint", os.Getenv("OTEL_EXPORTER_OTLP_ENDPOINT"))
	}

	// ── Storage ─────────────────────────────────────────────────────────────
	store, err := storage.NewStore(ctx, cfg, log)
	if err != nil {
		return fmt.Errorf("init storage: %w", err)
	}

	// ── Browser / Scraper ───────────────────────────────────────────────────
	workers := cfg.Runner.Workers
	if workers <= 0 {
		workers = runtime.NumCPU()
	}
	timeout := cfg.Runner.Timeout
	if timeout <= 0 {
		timeout = 90 * time.Second
	}

	browserClient := browser.NewDirectClient(browser.Config{
		MaxConcurrent: workers,
		Timeout:       timeout,
	})
	novel := novelfire.New(browserClient, log)

	// ── Kokoro ──────────────────────────────────────────────────────────────
	var kokoroClient kokoro.Client
	if cfg.Kokoro.URL != "" {
		kokoroClient = kokoro.New(cfg.Kokoro.URL)
		log.Info("kokoro TTS enabled", "url", cfg.Kokoro.URL)
	} else {
		log.Warn("KOKORO_URL not set — kokoro voice tasks will fail")
		kokoroClient = &noopKokoro{}
	}

	// ── pocket-tts ──────────────────────────────────────────────────────────
	var pocketTTSClient pockettts.Client
	if cfg.PocketTTS.URL != "" {
		pocketTTSClient = pockettts.New(cfg.PocketTTS.URL)
		log.Info("pocket-tts enabled", "url", cfg.PocketTTS.URL)
	} else {
		log.Warn("POCKET_TTS_URL not set — pocket-tts voice tasks will fail")
	}

	// ── LibreTranslate ──────────────────────────────────────────────────────
	ltClient := libretranslate.New(cfg.LibreTranslate.URL, cfg.LibreTranslate.APIKey)
	if ltClient != nil {
		log.Info("libretranslate enabled", "url", cfg.LibreTranslate.URL)
	} else {
		log.Info("LIBRETRANSLATE_URL not set — machine translation disabled")
	}

	// ── Meilisearch ─────────────────────────────────────────────────────────
	var searchIndex meili.Client
	if cfg.Meilisearch.URL != "" {
		if err := meili.Configure(cfg.Meilisearch.URL, cfg.Meilisearch.APIKey); err != nil {
			log.Warn("meilisearch configure failed — search indexing disabled", "err", err)
			searchIndex = meili.NoopClient{}
		} else {
			searchIndex = meili.New(cfg.Meilisearch.URL, cfg.Meilisearch.APIKey)
			log.Info("meilisearch enabled", "url", cfg.Meilisearch.URL)
		}
	} else {
		log.Info("MEILI_URL not set — search indexing disabled")
		searchIndex = meili.NoopClient{}
	}

	// ── Runner ──────────────────────────────────────────────────────────────
	rCfg := runner.Config{
		WorkerID:                    cfg.Runner.WorkerID,
		PollInterval:                cfg.Runner.PollInterval,
		MaxConcurrentScrape:         cfg.Runner.MaxConcurrentScrape,
		MaxConcurrentAudio:          cfg.Runner.MaxConcurrentAudio,
		MaxConcurrentTranslation:    cfg.Runner.MaxConcurrentTranslation,
		OrchestratorWorkers:         workers,
		MetricsAddr:                 cfg.Runner.MetricsAddr,
		CatalogueRefreshInterval:    cfg.Runner.CatalogueRefreshInterval,
		CatalogueRequestDelay:       cfg.Runner.CatalogueRequestDelay,
		SkipInitialCatalogueRefresh: cfg.Runner.SkipInitialCatalogueRefresh,
		RedisAddr:                   cfg.Redis.Addr,
		RedisPassword:               cfg.Redis.Password,
	}

	// In Asynq mode the Consumer is a thin wrapper: claim/heartbeat/reap are
	// no-ops, but FinishAudioTask / FinishScrapeTask / FailTask write back to
	// PocketBase as before.
	var consumer taskqueue.Consumer = store
	if cfg.Redis.Addr != "" {
		log.Info("runner: asynq mode — using Redis for task dispatch", "addr", cfg.Redis.Addr)
		consumer = asynqqueue.NewConsumer(store)
	} else {
		log.Info("runner: poll mode — using PocketBase for task dispatch")
	}

	deps := runner.Dependencies{
		Consumer:         consumer,
		BookWriter:       store,
		BookReader:       store,
		AudioStore:       store,
		CoverStore:       store,
		TranslationStore: store,
		SearchIndex:      searchIndex,
		Novel:            novel,
		Kokoro:           kokoroClient,
		PocketTTS:        pocketTTSClient,
		LibreTranslate:   ltClient,
		Log:              log,
	}
	r := runner.New(rCfg, deps)

	return r.Run(ctx)
}

// ── Helpers ───────────────────────────────────────────────────────────────────

func buildLogger(level string) *slog.Logger {
	var lvl slog.Level
	switch level {
	case "debug":
		lvl = slog.LevelDebug
	case "warn":
		lvl = slog.LevelWarn
	case "error":
		lvl = slog.LevelError
	default:
		lvl = slog.LevelInfo
	}
	return slog.New(slog.NewJSONHandler(os.Stdout, &slog.HandlerOptions{Level: lvl}))
}

// noopKokoro is a no-op implementation used when KOKORO_URL is not set.
type noopKokoro struct{}

func (n *noopKokoro) GenerateAudio(_ context.Context, _, _ string) ([]byte, error) {
	return nil, fmt.Errorf("kokoro not configured (KOKORO_URL is empty)")
}

func (n *noopKokoro) StreamAudioMP3(_ context.Context, _, _ string) (io.ReadCloser, error) {
	return nil, fmt.Errorf("kokoro not configured (KOKORO_URL is empty)")
}

func (n *noopKokoro) ListVoices(_ context.Context) ([]string, error) {
	return nil, nil
}