package v2

import (
	"context"
	"net"
	"strconv"
	"strings"
	"sync"

	"forge.cadoles.com/cadoles/go-emlid/reach/client/protocol"
	"forge.cadoles.com/cadoles/go-emlid/reach/client/protocol/v2/api"
	"forge.cadoles.com/cadoles/go-emlid/reach/client/socketio"
	"github.com/pkg/errors"
)

type Operations struct {
	addr   string
	client *socketio.Client
	mutex  sync.RWMutex
}

// Alive implements protocol.Operations.
func (o *Operations) Alive(ctx context.Context) (bool, error) {
	o.mutex.RLock()
	defer o.mutex.RUnlock()

	return o.client.Alive(), nil
}

// Version implements protocol.Operations.
func (o *Operations) Version(ctx context.Context) (string, bool, error) {
	info, err := api.GetInfo(ctx, o.addr)
	if err != nil {
		return "", false, errors.WithStack(err)
	}

	updater, err := api.GetUpdater(ctx, o.addr)
	if err != nil {
		return "", false, errors.WithStack(err)
	}

	version := info.Reachview.Version
	stable := updater.Release.Channel == "stable"

	return version, stable, nil
}

// Close implements protocol.Operations.
func (o *Operations) Close(ctx context.Context) error {
	o.mutex.Lock()
	defer o.mutex.Unlock()

	if o.client == nil {
		return nil
	}

	o.client.Close()

	return nil
}

// Connect implements protocol.Operations.
func (o *Operations) Connect(ctx context.Context) error {
	o.mutex.Lock()
	defer o.mutex.Unlock()

	if o.client != nil {
		o.client.Close()
	}

	endpoint, err := o.getSocketIOEndpoint()
	if err != nil {
		return errors.WithStack(err)
	}

	client := socketio.NewClient(endpoint)

	if err := client.Connect(); err != nil {
		return errors.WithStack(err)
	}

	o.client = client

	return nil
}

func (o *Operations) getSocketIOEndpoint() (string, error) {
	host, rawPort, err := net.SplitHostPort(o.addr)
	if err != nil {
		var addrErr *net.AddrError
		if !errors.As(err, &addrErr) || !strings.Contains(addrErr.Error(), "missing port in address") {
			return "", errors.WithStack(err)
		}

		host = o.addr
	}

	port := int64(80)
	if rawPort != "" {
		port, err = strconv.ParseInt(rawPort, 10, 32)
		if err != nil {
			return "", errors.WithStack(err)
		}
	}

	endpoint := socketio.Endpoint(host, int(port), false)

	return endpoint, nil
}

// Emit implements protocol.Operations.
func (o *Operations) Emit(ctx context.Context, message any) error {
	o.mutex.RLock()
	defer o.mutex.RUnlock()

	if o.client == nil || !o.client.Alive() {
		return errors.WithStack(protocol.ErrClosed)
	}

	return nil
}

// On implements protocol.Operations.
func (o *Operations) On(ctx context.Context, event string) (chan any, error) {
	o.mutex.RLock()
	defer o.mutex.RUnlock()

	if o.client == nil || !o.client.Alive() {
		return nil, errors.WithStack(protocol.ErrClosed)
	}

	out := make(chan any)
	closer := new(sync.Once)

	handler := func(ch *socketio.Channel, data any) {
		select {
		case <-ctx.Done():
			closer.Do(func() {
				o.mutex.RLock()
				defer o.mutex.RUnlock()

				ch.Close()
				close(out)

				if o.client == nil {
					return
				}
			})

			return
		default:
			out <- data
		}
	}

	if err := o.client.On(event, handler); err != nil {
		return nil, errors.WithStack(err)
	}

	return out, nil

}

var _ protocol.Operations = &Operations{}