package saltyim

import (
	"bytes"
	"context"
	"fmt"
	"os"
	"time"

	"git.mills.io/prologic/msgbus"
	"git.mills.io/prologic/msgbus/client"
	"github.com/keys-pub/keys"
	log "github.com/sirupsen/logrus"

	"go.mills.io/salty"
)

const (
	defaultRunCmdTimeout = time.Second * 3
)

func handleMessage(key *keys.EdX25519Key, prehook, posthook string, msgs chan string) msgbus.HandlerFunc {
	return func(msg *msgbus.Message) error {
		if prehook != "" {
			out, err := RunCmd(defaultRunCmdTimeout, prehook, bytes.NewBuffer(msg.Payload))
			if err != nil {
				log.WithError(err).Debugf("error running pre-hook %s", prehook)
			}
			log.Debugf("pre-hook: %q", out)
		}

		data, _, err := salty.Decrypt(key, msg.Payload)
		if err != nil {
			fmt.Fprintf(os.Stderr, "error decrypting message")
			return err
		}

		msgs <- string(data)

		if posthook != "" {
			out, err := RunCmd(defaultRunCmdTimeout, posthook, bytes.NewBuffer(data))
			if err != nil {
				log.WithError(err).Debugf("error running post-hook %s", posthook)
			}
			log.Debugf("post-hook: %q", out)
		}

		return nil
	}
}

// Read ...
func Read(ctx context.Context, key *keys.EdX25519Key, endpoint, prehook, posthook string) chan string {
	uri, inbox := SplitInbox(endpoint)
	client := client.NewClient(uri, nil)

	msgs := make(chan string)
	s := client.Subscribe(inbox, handleMessage(key, prehook, posthook, msgs))
	s.Start()

	log.Infof("Connected to %s/%s", uri, inbox)

	go func() {
		<-ctx.Done()
		s.Stop()
		close(msgs)
	}()

	return msgs
}