// SPDX-License-Identifier: GPL-3.0-or-later
package webupdates

import (
	"fmt"

	gosocketio "github.com/graarh/golang-socketio"

	"git.blender.org/flamenco/internal/uuid"
	"git.blender.org/flamenco/pkg/api"
)

// Separate type aliases for room names and event types; it's otherwise too easy
// to confuse the two.
type (
	SocketIORoomName  string
	SocketIOEventType string
)

const (
	// Predefined SocketIO rooms. There will be others, but those will have a
	// dynamic name like `job-fa48930a-105c-4125-a7f7-0aa1651dcd57` and cannot be
	// listed here as constants. See `roomXXX()` functions for those.
	SocketIORoomChat    SocketIORoomName = "Chat"    // For chat messages.
	SocketIORoomJobs    SocketIORoomName = "Jobs"    // For job updates.
	SocketIORoomWorkers SocketIORoomName = "Workers" // For worker updates.
)

const (
	// Predefined SocketIO event types.
	SIOEventChatMessageRcv  SocketIOEventType = "/chat"         // clients send chat messages here
	SIOEventChatMessageSend SocketIOEventType = "/message"      // chat messages are broadcasted here
	SIOEventJobUpdate       SocketIOEventType = "/jobs"         // sends api.SocketIOJobUpdate
	SIOEventTaskUpdate      SocketIOEventType = "/task"         // sends api.SocketIOTaskUpdate
	SIOEventTaskLogUpdate   SocketIOEventType = "/tasklog"      // sends api.SocketIOTaskLogUpdate
	SIOEventWorkerUpdate    SocketIOEventType = "/workers"      // sends api.SocketIOWorkerUpdate
	SIOEventSubscription    SocketIOEventType = "/subscription" // clients send api.SocketIOSubscription
)

func (b *BiDirComms) BroadcastTo(room SocketIORoomName, eventType SocketIOEventType, payload interface{}) {
	b.sockserv.BroadcastTo(string(room), string(eventType), payload)
}

func (b *BiDirComms) registerRoomEventHandlers() {
	_ = b.sockserv.On(string(SIOEventSubscription), b.handleRoomSubscription)
}

func (b *BiDirComms) handleRoomSubscription(c *gosocketio.Channel, subs api.SocketIOSubscription) string {
	logger := sioLogger(c)
	logCtx := logger.With().
		Str("op", string(subs.Op)).
		Str("type", string(subs.Type))
	if subs.Uuid != nil {
		logCtx = logCtx.Str("uuid", string(*subs.Uuid))
	}
	logger = logCtx.Logger()

	if subs.Uuid != nil && !uuid.IsValid(*subs.Uuid) {
		logger.Warn().Msg("socketIO: invalid UUID, ignoring subscription request")
		return "invalid UUID, ignoring request"
	}

	var sioRoom SocketIORoomName
	switch subs.Type {
	case api.SocketIOSubscriptionTypeAllJobs:
		sioRoom = SocketIORoomJobs
	case api.SocketIOSubscriptionTypeAllWorkers:
		sioRoom = SocketIORoomWorkers
	case api.SocketIOSubscriptionTypeJob:
		if subs.Uuid == nil {
			logger.Warn().Msg("socketIO: trying to (un)subscribe to job without UUID")
			return "operation on job requires a UUID"
		}
		sioRoom = roomForJob(*subs.Uuid)
	case api.SocketIOSubscriptionTypeTasklog:
		if subs.Uuid == nil {
			logger.Warn().Msg("socketIO: trying to (un)subscribe to task without UUID")
			return "operation on task requires a UUID"
		}
		sioRoom = roomForTaskLog(*subs.Uuid)
	default:
		logger.Warn().Msg("socketIO: unknown subscription type, ignoring")
		return "unknown subscription type, ignoring request"
	}

	var err error
	switch subs.Op {
	case api.SocketIOSubscriptionOperationSubscribe:
		err = c.Join(string(sioRoom))
	case api.SocketIOSubscriptionOperationUnsubscribe:
		err = c.Leave(string(sioRoom))
	default:
		logger.Warn().Msg("socketIO: invalid subscription operation, ignoring")
		return "invalid subscription operation, ignoring request"
	}

	if err != nil {
		logger.Warn().Err(err).Msg("socketIO: performing subscription operation")
		return fmt.Sprintf("unable to perform subscription operation: %v", err)
	}

	logger.Debug().Msg("socketIO: subscription")
	return "ok"
}

// roomForJob will return the SocketIO room name for the given job. Clients in
// this room will receive info scoped to this job, so for example updates to all
// tasks of this job.
//
// Note that `api.SocketIOJobUpdate`s themselves are sent to all SocketIO clients, and
// not to this room.
func roomForJob(jobUUID string) SocketIORoomName {
	return SocketIORoomName("job-" + jobUUID)
}

// roomForTaskLog will return the SocketIO room name for receiving task logs of
// the the given task.
//
// Note that general task updates (`api.SIOEventTaskUpdate`) are sent to their
// job's room, and not to this room.
func roomForTaskLog(taskUUID string) SocketIORoomName {
	return SocketIORoomName("tasklog-" + taskUUID)
}