package sign

import (
	"fmt"

	"github.com/dop251/goja"
	_ "embed"
)

//go:embed sign.js
var signJS []byte

//go:embed a_bogus.js
var abogusJS []byte

func GenerateSignature(wssURL string) (string, error) {
	vm := goja.New()
	vm.Set("console", goja.Null())
	if _, err := vm.RunString(string(signJS)); err != nil {
		return "", fmt.Errorf("run sign.js: %w", err)
	}
	fn := vm.Get("get_sign")
	if fn == nil || goja.IsUndefined(fn) {
		return "", fmt.Errorf("get_sign not found in sign.js")
	}
	result, err := fn.Export().(goja.Callable)(goja.Undefined(), vm.ToValue(wssURL))
	if err != nil {
		return "", fmt.Errorf("call get_sign: %w", err)
	}
	return result.Export().(string), nil
}

func GetABogus(urlParams map[string]string, userAgent string) (string, error) {
	vm := goja.New()
	if _, err := vm.RunString(string(abogusJS)); err != nil {
		return "", fmt.Errorf("run a_bogus.js: %w", err)
	}
	fn := vm.Get("get_ab")
	if fn == nil || goja.IsUndefined(fn) {
		return "", fmt.Errorf("get_ab not found in a_bogus.js")
	}
	dpf := ""
	for k, v := range urlParams {
		if dpf != "" {
			dpf += "&"
		}
		dpf += k + "=" + v
	}
	result, err := fn.Export().(goja.Callable)(goja.Undefined(), vm.ToValue(dpf), vm.ToValue(userAgent))
	if err != nil {
		return "", fmt.Errorf("call get_ab: %w", err)
	}
	return result.Export().(string), nil
}