package main

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

	"finance-duck/internal/app"
	"finance-duck/internal/server"
	frontend "finance-duck/web"
)

func main() {
	if err := run(); err != nil {
		log.Print(err)
		os.Exit(1)
	}
}
func run() error {
	dir := flag.String("data", "./finance", "canonical finance directory")
	listen := flag.String("listen", "127.0.0.1:8080", "HTTP listen address; use a VPN address for remote access")
	publicURL := flag.String("public-url", "", "exact browser origin required for non-localhost access (e.g. https://finance.internal)")
	rebuild := flag.Bool("rebuild", false, "rebuild disposable DuckDB cache then exit")
	flag.Parse()
	host, _, err := net.SplitHostPort(*listen)
	if err != nil {
		return fmt.Errorf("listen: %w", err)
	}
	if (host == "" || host == "0.0.0.0" || host == "::") && *publicURL == "" {
		return fmt.Errorf("wildcard binding requires -public-url and VPN/firewall isolation; there is no login")
	}
	a, err := app.Open(*dir)
	if err != nil {
		return err
	}
	defer a.Close()
	ctx, cancel := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
	defer cancel()
	if *rebuild {
		s, e := a.Rebuild(ctx)
		if e != nil {
			return e
		}
		if s.Status.IndexError != "" {
			return fmt.Errorf("index: %s", s.Status.IndexError)
		}
		fmt.Println("DuckDB rebuilt from canonical plaintext")
		return nil
	}
	assets, err := frontend.Assets()
	if err != nil {
		return err
	}
	handler, err := server.New(a, assets, strings.TrimRight(*publicURL, "/"))
	if err != nil {
		return err
	}
	srv := &http.Server{Addr: *listen, Handler: handler, ReadHeaderTimeout: 10 * time.Second, IdleTimeout: 90 * time.Second, MaxHeaderBytes: 32 << 10, BaseContext: func(net.Listener) context.Context { return ctx }}
	ln, err := net.Listen("tcp", *listen)
	if err != nil {
		return err
	}
	schedulerDone := make(chan struct{})
	go func() { defer close(schedulerDone); a.RunScheduler(ctx) }()
	stopped := make(chan struct{})
	go func() {
		<-ctx.Done()
		shutdown, c := context.WithTimeout(context.Background(), 15*time.Second)
		defer c()
		srv.Shutdown(shutdown)
		close(stopped)
	}()
	log.Printf("Finance Duck listening on http://%s — no login; keep behind your VPN", *listen)
	err = srv.Serve(ln)
	cancel()
	<-stopped
	<-schedulerDone
	if err == http.ErrServerClosed {
		return nil
	}
	return err
}