//go:build js && wasm

package hp_ipn

import (
	"errors"
	"syscall/js"
)

// Represents the options needed to initialize the TsWasmNet module.
type TsWasmNetOptions struct {
	// Tailscale control URL, e.g., "https://controlplane.tailscale.com"
	ControlURL string

	// Pre-authentication key for the Tailnet
	PreAuthKey string

	// Optional hostname, autogenerated if not provided.
	Hostname string
}

// Parses the provided JS object to validate and extract the TsWasmNetOptions.
func ParseTsWasmNetOptions(obj js.Value) (*TsWasmNetOptions, error) {
	if obj.IsUndefined() || obj.IsNull() {
		return nil, errors.New("TsWasmNetOptions cannot be undefined or null")
	}

	cUrl := safeString("ControlURL", obj)
	preAuthKey := safeString("PreAuthKey", obj)
	hostname := safeString("Hostname", obj)

	if cUrl == "" || preAuthKey == "" || hostname == "" {
		return nil, errors.New("missing required fields in TsWasmNetOptions")
	}

	return &TsWasmNetOptions{
		ControlURL: cUrl,
		PreAuthKey: preAuthKey,
		Hostname:   hostname,
	}, nil
}

// Retrieves a string value from a JS object safely.
func safeString(key string, obj js.Value) string {
	if obj.IsUndefined() || obj.IsNull() {
		return ""
	}

	val := obj.Get(key)
	if val.IsUndefined() || val.IsNull() {
		return ""
	}

	return val.String()
}