package event

import (
	"encoding/json"
	"fmt"
)

func Serialize(t string, v any) ([]byte, error) {
	var wrapper struct {
		Type    string `json:"type"`
		Payload any    `json:"payload"`
	}
	wrapper.Type = t
	wrapper.Payload = v
	return json.Marshal(wrapper)
}

func Parse(b []byte, typesToPointers map[string]any) (string, error) {
	var wrapper struct {
		Type    string          `json:"type"`
		Payload json.RawMessage `json:"payload"`
	}
	if err := json.Unmarshal(b, &wrapper); err != nil {
		return "", err
	}

	if ptr, ok := typesToPointers[wrapper.Type]; !ok {
		return "", fmt.Errorf("cannot parse unknown type %s", wrapper.Type)
	} else if err := json.Unmarshal(wrapper.Payload, ptr); err != nil {
		return "", fmt.Errorf("failed parsing type %s: %w", wrapper.Type, err)
	}

	return wrapper.Type, nil
}