package reachview

import (
	"context"
	"sync"

	gosocketio "forge.cadoles.com/Pyxis/golang-socketio"
	"github.com/mitchellh/mapstructure"
	"github.com/pkg/errors"
)

const (
	eventBroadcast = "broadcast"
)

const (
	BroadcastRoverStatus   = "rover_status"
	BroadcastBaseStatus    = "base_status"
	BroadcastRTKStatus     = "rtk_status"
	BroadcastObservations  = "observations"
	BroadcastTimeMarks     = "time_marks"
	BroadcastBatteryStatus = "battery_status"
)

// Broadcast is a broadcasted message containing modules status informations.
type Broadcast struct {
	Name    string                 `mapstructure:"name"`
	Payload map[string]interface{} `mapstructure:"payload"`
}

// Broadcast listens for broadcast messages.
func (c *Client) Broadcast(ctx context.Context) (chan Broadcast, error) {
	out := make(chan Broadcast)

	closer := new(sync.Once)

	handler := func(_ *gosocketio.Channel, data interface{}) {
		res := Broadcast{}
		if err := mapstructure.WeakDecode(data, &res); err != nil {
			c.Logf("error while decoding broadcast message: %s", errors.WithStack(err))
		}
		select {
		case <-ctx.Done():
			closer.Do(func() {
				c.Off(eventBroadcast)
				close(out)
			})

			return
		default:
			out <- res
		}
	}

	if err := c.On(eventBroadcast, handler); err != nil {
		return nil, errors.WithStack(err)
	}

	return out, nil
}