package main

import (
	"context"
	"errors"
	"flag"
	"fmt"
	"io"
	"os"
	"os/signal"
	"strings"
	"syscall"

	"proxy-pool/internal/config"
	"proxy-pool/internal/controller/bootstrap"
	"proxy-pool/internal/platform/logging"
)

const (
	configEnvironment         = "PROXY_POOL_CONFIG"
	fingerprintKeyEnvironment = "PROXY_POOL_CONFIG_FINGERPRINT_KEY"
)

type environmentLookup func(string) string
type controllerRun func(context.Context, bootstrap.Options) error

func main() {
	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
	defer stop()
	os.Exit(execute(ctx, os.Args[1:], os.Getenv, bootstrap.Run, os.Stderr))
}

func execute(
	ctx context.Context,
	args []string,
	getenv environmentLookup,
	run controllerRun,
	stderr io.Writer,
) int {
	flags := flag.NewFlagSet("proxy-controller", flag.ContinueOnError)
	flags.SetOutput(stderr)
	configPath := flags.String("config", "", "configuration file path")
	if err := flags.Parse(args); err != nil {
		if errors.Is(err, flag.ErrHelp) {
			return 0
		}
		return 2
	}
	if flags.NArg() != 0 {
		_, _ = fmt.Fprintln(stderr, "proxy-controller: unexpected positional arguments")
		return 2
	}
	if *configPath == "" && getenv != nil {
		*configPath = getenv(configEnvironment)
	}
	if strings.TrimSpace(*configPath) != *configPath || *configPath == "" || ctx == nil || run == nil {
		_, _ = fmt.Fprintf(stderr, "proxy-controller: -config or %s is required\n", configEnvironment)
		return 2
	}

	var fingerprintKey []byte
	if getenv != nil {
		fingerprintKey = []byte(getenv(fingerprintKeyEnvironment))
	}
	err := run(ctx, bootstrap.Options{
		ConfigPath: *configPath, Resolver: config.OSResolver{}, FingerprintKey: fingerprintKey,
	})
	if err == nil || (errors.Is(err, context.Canceled) && ctx.Err() != nil) {
		return 0
	}
	logging.WriteProcessError(stderr, "proxy-controller", err)
	return 1
}