// Package main is the CarrotAssistant backend entrypoint.
//
// It loads configuration, opens the database, bootstraps an initial admin
// account if none exists, and serves HTTP until interrupted.
package main

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

	"code.littlelan.cn/CarrotAssistant/backend/internal/config"
	"code.littlelan.cn/CarrotAssistant/backend/internal/security"
	"code.littlelan.cn/CarrotAssistant/backend/internal/server"
	"code.littlelan.cn/CarrotAssistant/backend/internal/store"
)

func main() {
	cfg, err := config.Load()
	if err != nil {
		log.Fatalf("load config: %v", err)
	}
	log.Printf("data dir: %s", cfg.DataDir)

	db, err := store.Open(cfg.DBPath)
	if err != nil {
		log.Fatalf("open db: %v", err)
	}

	crypto, err := security.NewCrypto(cfg.MasterKey)
	if err != nil {
		log.Fatalf("init crypto: %v", err)
	}

	// Bootstrap an admin account on first run so the console is reachable.
	// Production should set ADMIN_BOOTSTRAP_USER / ADMIN_BOOTSTRAP_PASSWORD.
	if cfg.AdminBootstrapUser != "" {
		if err := server.EnsureAdmin(db, cfg.AdminBootstrapUser, cfg.AdminBootstrapPassword); err != nil {
			log.Printf("ensure admin: %v", err)
		}
	}

	deps := server.Deps{
		DB:        db,
		Config:    cfg,
		Crypto:    crypto,
		SkillsDir: cfg.SkillsDir,
	}

	handler := server.New(deps)

	srv := &http.Server{
		Addr:              cfg.HTTPAddr,
		Handler:           handler,
		ReadHeaderTimeout: 10 * time.Second,
	}

	go func() {
		log.Printf("listening on %s", cfg.HTTPAddr)
		if err := srv.ListenAndServe(); err != nil && err != http.ErrServerClosed {
			log.Fatalf("server: %v", err)
		}
	}()

	// Graceful shutdown on SIGINT / SIGTERM.
	stop := make(chan os.Signal, 1)
	signal.Notify(stop, syscall.SIGINT, syscall.SIGTERM)
	<-stop
	log.Println("shutting down")

	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
	defer cancel()
	if err := srv.Shutdown(ctx); err != nil {
		fmt.Fprintf(os.Stderr, "shutdown: %v\n", err)
	}
}