// Command exploredns-receiver stores usage webhooks posted by the
// ExploreDNS API server in MySQL or SQLite.
//
// Configuration (environment):
//
//	RECEIVER_ADDR            listen address (default ":8080")
//	RECEIVER_MYSQL_DSN       go-sql-driver DSN; when set, events go to MySQL
//	RECEIVER_SQLITE_PATH     SQLite fallback path (default "data/exploredns-receiver.db")
//	RECEIVER_INGEST_TOKEN    bearer token required on POST /webhook (open when unset)
//	RECEIVER_ADMIN_USER      basic-auth username for /admin (default "admin")
//	RECEIVER_ADMIN_PASSWORD  basic-auth password for /admin (required)
package main

import (
	"fmt"
	"log"
	"os"
	"os/signal"
	"syscall"
	"time"

	"gitea.hansenits.com.au/hits/ExploreDNS/internal/receiver/server"
	"gitea.hansenits.com.au/hits/ExploreDNS/internal/receiver/store"
)

// version is stamped at build time via -ldflags "-X main.version=...".
var version = "dev"

func main() {
	addr := envOr("RECEIVER_ADDR", ":8080")

	adminPass := os.Getenv("RECEIVER_ADMIN_PASSWORD")
	if adminPass == "" {
		fmt.Fprintln(os.Stderr, "Error: RECEIVER_ADMIN_PASSWORD is not set; refusing to start with an unprotected admin interface")
		os.Exit(1)
	}

	var (
		st      *store.Store
		backend string
		err     error
	)
	if dsn := os.Getenv("RECEIVER_MYSQL_DSN"); dsn != "" {
		st, err = store.OpenMySQL(dsn)
		backend = "mysql " + store.RedactMySQLDSN(dsn)
	} else {
		path := envOr("RECEIVER_SQLITE_PATH", "data/exploredns-receiver.db")
		st, err = store.OpenSQLite(path)
		backend = "sqlite " + path
	}
	if err != nil {
		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
		os.Exit(1)
	}

	srv := server.New(addr, st)
	srv.SetVersion(version)
	srv.SetIngestToken(os.Getenv("RECEIVER_INGEST_TOKEN"))
	srv.SetAdminAuth(envOr("RECEIVER_ADMIN_USER", "admin"), adminPass)
	if err := srv.Start(); err != nil {
		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
		os.Exit(1)
	}

	log.Printf("ExploreDNS receiver %s listening on %s, storing to %s", version, srv.Addr(), backend)

	quit := make(chan os.Signal, 1)
	signal.Notify(quit, syscall.SIGINT, syscall.SIGTERM)
	<-quit

	log.Println("Shutting down...")
	if err := srv.Shutdown(15 * time.Second); err != nil {
		log.Printf("Shutdown error: %v", err)
	}
	if err := st.Close(); err != nil {
		log.Printf("Close store error: %v", err)
	}
}

// envOr returns the environment variable name, or def when unset or empty.
func envOr(name, def string) string {
	if v := os.Getenv(name); v != "" {
		return v
	}
	return def
}