// Package config loads engine settings from the environment, replacing the
// hard-coded values in the original config.js / HTTPServer.js.
package config

import (
	"net"
	"os"
	"strconv"
	"time"
)

// Config holds all runtime settings.
type Config struct {
	Host string // bind address, e.g. "0.0.0.0"
	Port int    // listen port, default 7707

	PublicDir string // static assets directory (default "./public")
	ScriptDir string // built SDK directory (default "./script")

	ReadHeaderTimeout time.Duration // HTTP read-header timeout
	ShutdownTimeout   time.Duration // grace period for in-flight work on shutdown

	TermOutput bool // verbose terminal logging (the old `termoutput` flag)
}

// Load reads configuration from the environment, applying defaults that match the
// original server. Recognised variables:
//
//	MWSE_HOST, MWSE_PORT, MWSE_PUBLIC_DIR, MWSE_SCRIPT_DIR,
//	MWSE_SHUTDOWN_TIMEOUT (seconds), MWSE_TERM_OUTPUT (1/true)
func Load() Config {
	return Config{
		Host:              env("MWSE_HOST", "0.0.0.0"),
		Port:              envInt("MWSE_PORT", 7707),
		PublicDir:         env("MWSE_PUBLIC_DIR", "./public"),
		ScriptDir:         env("MWSE_SCRIPT_DIR", "./script"),
		ReadHeaderTimeout: 10 * time.Second,
		ShutdownTimeout:   time.Duration(envInt("MWSE_SHUTDOWN_TIMEOUT", 10)) * time.Second,
		TermOutput:        envBool("MWSE_TERM_OUTPUT", false),
	}
}

// Addr returns the host:port string for net/http.
func (c Config) Addr() string {
	return net.JoinHostPort(c.Host, strconv.Itoa(c.Port))
}

func env(key, def string) string {
	if v, ok := os.LookupEnv(key); ok && v != "" {
		return v
	}
	return def
}

func envInt(key string, def int) int {
	if v, ok := os.LookupEnv(key); ok {
		if n, err := strconv.Atoi(v); err == nil {
			return n
		}
	}
	return def
}

func envBool(key string, def bool) bool {
	if v, ok := os.LookupEnv(key); ok {
		if b, err := strconv.ParseBool(v); err == nil {
			return b
		}
	}
	return def
}