package client

import (
	"context"

	"github.com/mitchellh/mapstructure"
	"github.com/pkg/errors"
)

func OnMessage[T any](ctx context.Context, client *Client, mType string) (chan T, error) {
	ch := make(chan T)

	rawChan, err := client.On(ctx, mType)
	if err != nil {
		return nil, errors.WithStack(err)
	}

	go func() {
		defer close(ch)

		for {
			select {
			case <-ctx.Done():
				return

			case rawMsg := <-rawChan:
				var msg T
				if err := mapstructure.Decode(rawMsg, &msg); err != nil {
					panic(errors.WithStack(err))
				}

				ch <- msg
			}
		}
	}()

	return ch, nil
}

// Broadcast is a broadcasted message containing module realtime informations.
type Broadcast struct {
	Name    string `mapstructure:"name" json:"name"`
	Payload any    `mapstructure:"payload" json:"payload"`
}

// OnBroadcast listens for ReachView "broadcast" messages
func OnBroadcast(ctx context.Context, client *Client) (chan Broadcast, error) {
	ch, err := OnMessage[Broadcast](ctx, client, "broadcast")
	if err != nil {
		return nil, errors.WithStack(err)
	}

	return ch, nil
}