// 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"
	"log/slog"
	"os"
	"os/signal"
	"runtime"
	"syscall"
	"time"

	"github.com/libnovel/backend/internal/browser"
	"github.com/libnovel/backend/internal/config"
	"github.com/libnovel/backend/internal/kokoro"
	"github.com/libnovel/backend/internal/novelfire"
	"github.com/libnovel/backend/internal/runner"
	"github.com/libnovel/backend/internal/storage"
)

// 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()

	// ── 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()

	// ── 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,
		ProxyURL:      cfg.Runner.ProxyURL,
	})
	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 — audio tasks will fail")
		kokoroClient = &noopKokoro{}
	}

	// ── Runner ──────────────────────────────────────────────────────────────
	rCfg := runner.Config{
		WorkerID:            cfg.Runner.WorkerID,
		PollInterval:        cfg.Runner.PollInterval,
		MaxConcurrentScrape: cfg.Runner.MaxConcurrentScrape,
		MaxConcurrentAudio:  cfg.Runner.MaxConcurrentAudio,
		OrchestratorWorkers: workers,
	}
	deps := runner.Dependencies{
		Consumer:    store,
		BookWriter:  store,
		BookReader:  store,
		AudioStore:  store,
		BrowseStore: store,
		Novel:       novel,
		Kokoro:      kokoroClient,
		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) ListVoices(_ context.Context) ([]string, error) {
	return nil, nil
}