package sway

import (
	"context"
	"encoding/json"
	"os/exec"
)

func Subscribe(ctx context.Context, events ...EventType) (<-chan Event, error) {
	data, err := json.Marshal(events)
	if err != nil {
		return nil, err
	}

	cmd := exec.CommandContext(ctx, "swaymsg", "-t", "subscribe", "-m", string(data))

	stdout, err := cmd.StdoutPipe()
	if err != nil {
		return nil, err
	}

	out := make(chan Event, 10)

	go func() {
		defer cmd.Wait()
		dec := json.NewDecoder(stdout)
		var event Event
		for err := dec.Decode(&event); err == nil; err = dec.Decode(&event) {
			out <- event
		}
	}()

	if err := cmd.Start(); err != nil {
		return nil, err
	}

	return out, nil
}