package helpers

import (
	"errors"
	"fmt"
	"os"
	"path/filepath"
	"strconv"
	"strings"
	"time"

	"forge.redroom.link/yves/meowlib"
	"forge.redroom.link/yves/meowlib/client"
	"github.com/google/uuid"
	"google.golang.org/protobuf/proto"
)

func PackMessageForServer(packedMsg *meowlib.PackedUserMessage, srvuid string) ([]byte, string, error) {
	// Get the message server
	srv, err := client.GetConfig().GetIdentity().MessageServers.LoadServer(srvuid)
	if err != nil {
		return nil, "PackMessageForServer : LoadServer", err
	}
	// Fetch and persist the server public key if it was never stored
	// (servers added via invitation finalization only have a UserKp, no PublicKey)
	if srv.PublicKey == "" {
		srvdata, err := meowlib.HttpGetId(srv.Url)
		if err != nil {
			return nil, "PackMessageForServer : HttpGetId", err
		}
		srv.PublicKey = srvdata["publicKey"]
		client.GetConfig().GetIdentity().MessageServers.StoreServer(srv)
	}
	// Creating Server message for transporting the user message
	toServerMessage := srv.BuildToServerMessageFromUserMessage(packedMsg)
	data, err := srv.ProcessOutboundMessage(toServerMessage)
	if err != nil {
		return nil, "PackMessageForServer : ProcessOutboundMessage", err
	}
	return data, "", nil

}

func CreateStorePackUserMessageForServer(message string, srvuid string, peer_uid string, replyToUid string, filelist []string) ([]byte, string, error) {
	usermessage, _, _, errtxt, err := CreateAndStoreUserMessage(message, peer_uid, replyToUid, filelist)
	if err != nil {
		return nil, errtxt, err
	}
	return PackMessageForServer(usermessage, srvuid)
}

// CreateAndStoreUserMessage creates, signs, and stores an outbound message for
// peer_uid. It returns the packed (encrypted) form ready for server transport,
// the peer DB file UUID (dbFile), the SQLite row ID (dbId), an error context
// string, and any error.
func CreateAndStoreUserMessage(message string, peer_uid string, replyToUid string, filelist []string) (*meowlib.PackedUserMessage, string, int64, string, error) {
	peer := client.GetConfig().GetIdentity().Peers.GetFromUid(peer_uid)

	// Creating User message
	usermessage, err := peer.BuildSimpleUserMessage([]byte(message))
	if err != nil {
		return nil, "", 0, "PrepareServerMessage : BuildSimpleUserMessage", err
	}
	for _, file := range filelist {
		err = usermessage.AddFile(file, client.GetConfig().Chunksize)
		if err != nil {
			return nil, "", 0, "PrepareServerMessage : AddFile", err
		}
	}
	usermessage.Status.Sent = uint64(time.Now().UTC().Unix())
	usermessage.Status.ReplyToUuid = replyToUid

	// Store message
	err = peer.StoreMessage(usermessage, nil)
	if err != nil {
		return nil, "", 0, "messageBuildPostprocess : StoreMessage", err
	}

	dbFile := peer.LastMessage.Dbfile
	dbId := peer.LastMessage.Dbid

	// Prepare cyphered + packed user message
	packedMsg, err := peer.ProcessOutboundUserMessage(usermessage)
	if err != nil {
		return nil, "", 0, "messageBuildPostprocess : ProcessOutboundUserMessage", err
	}

	// Persist peer to save updated DR state (DrStateJson)
	if peer.DrRootKey != "" {
		if storeErr := client.GetConfig().GetIdentity().Peers.StorePeer(peer); storeErr != nil {
			logger.Warn().Err(storeErr).Str("peer", peer.Uid).Msg("messageBuildPostprocess: StorePeer (DR state)")
		}
	}

	return packedMsg, dbFile, dbId, "", nil
}

func BuildReceivedMessage(messageUid string, peer_uid string, received int64) (*meowlib.PackedUserMessage, string, error) {
	peer := client.GetConfig().GetIdentity().Peers.GetFromUid(peer_uid)
	// Creating User message
	usermessage, err := peer.BuildSimpleUserMessage(nil)
	if err != nil {
		return nil, "BuildReceivedMessage : BuildSimpleUserMessage", err
	}
	usermessage.Status.Uuid = messageUid
	usermessage.Status.Received = uint64(received)
	// Prepare cyphered + packed user message
	packedMsg, err := peer.ProcessOutboundUserMessage(usermessage)
	if err != nil {
		return nil, "BuildReceivedMessage : ProcessOutboundUserMessage", err
	}
	// Persist peer to save updated DR state (DrStateJson)
	if peer.DrRootKey != "" {
		client.GetConfig().GetIdentity().Peers.StorePeer(peer)
	}
	return packedMsg, "", nil
}

func BuildProcessedMessage(messageUid string, peer_uid string, processed int64) (*meowlib.PackedUserMessage, string, error) {
	peer := client.GetConfig().GetIdentity().Peers.GetFromUid(peer_uid)
	// Creating User message
	usermessage, err := peer.BuildSimpleUserMessage(nil)
	if err != nil {
		return nil, "BuildProcessedMessage : BuildSimpleUserMessage", err
	}
	usermessage.Status.Uuid = messageUid
	usermessage.Status.Processed = uint64(processed)
	// Prepare cyphered + packed user message
	packedMsg, err := peer.ProcessOutboundUserMessage(usermessage)
	if err != nil {
		return nil, "BuildProcessedMessage : ProcessOutboundUserMessage", err
	}
	// Persist peer to save updated DR state (DrStateJson)
	if peer.DrRootKey != "" {
		client.GetConfig().GetIdentity().Peers.StorePeer(peer)
	}
	return packedMsg, "", nil
}

func ReadAckMessageResponse() {
	//! update the status in message store
}

// MarkMessageProcessed stamps the stored message with a processed timestamp of
// now(), persists the updated record, and — if the peer has SendProcessingAck
// enabled and the message carries a UUID — enqueues a processed acknowledgment
// to the peer's contact pull servers.
func MarkMessageProcessed(peerUid string, dbFile string, dbId int64) error {
	password, _ := client.GetConfig().GetMemPass()
	processedAt := time.Now().UTC().Unix()

	dbm, err := client.GetDbMessage(dbFile, dbId, password)
	if err != nil {
		return fmt.Errorf("MarkMessageProcessed: GetDbMessage: %w", err)
	}
	if dbm.Status == nil {
		dbm.Status = &meowlib.ConversationStatus{}
	}
	dbm.Status.Processed = uint64(processedAt)
	if err := client.UpdateDbMessage(dbm, dbFile, dbId, password); err != nil {
		return fmt.Errorf("MarkMessageProcessed: UpdateDbMessage: %w", err)
	}

	peer := client.GetConfig().GetIdentity().Peers.GetFromUid(peerUid)
	if peer == nil || !peer.SendProcessingAck || dbm.Status.Uuid == "" {
		return nil
	}

	identity := client.GetConfig().GetIdentity()
	storagePath := filepath.Join(client.GetConfig().StoragePath, identity.Uuid)
	return sendProcessingAck(storagePath, peer, dbm.Status.Uuid, processedAt)
}

// sendProcessingAck builds a processing acknowledgment for messageUuid and
// enqueues it for sending to the peer's contact pull servers.
func sendProcessingAck(storagePath string, peer *client.Peer, messageUuid string, processedAt int64) error {
	packedMsg, _, err := BuildProcessedMessage(messageUuid, peer.Uid, processedAt)
	if err != nil {
		return fmt.Errorf("sendProcessingAck: BuildProcessedMessage: %w", err)
	}

	data, err := proto.Marshal(packedMsg)
	if err != nil {
		return fmt.Errorf("sendProcessingAck: proto.Marshal: %w", err)
	}

	outboxDir := filepath.Join(storagePath, "outbox")
	if err := os.MkdirAll(outboxDir, 0700); err != nil {
		return fmt.Errorf("sendProcessingAck: MkdirAll: %w", err)
	}

	outboxFile := filepath.Join(outboxDir, "ack_"+uuid.New().String())
	if err := os.WriteFile(outboxFile, data, 0600); err != nil {
		return fmt.Errorf("sendProcessingAck: WriteFile: %w", err)
	}

	var servers []client.Server
	for _, srvUid := range peer.ContactPullServers {
		srv, loadErr := client.GetConfig().GetIdentity().MessageServers.LoadServer(srvUid)
		if loadErr == nil && srv != nil {
			servers = append(servers, *srv)
		}
	}
	if len(servers) == 0 {
		os.Remove(outboxFile)
		return errors.New("sendProcessingAck: no contact servers found")
	}

	return client.PushSendJob(storagePath, &client.SendJob{
		Queue:   peer.Uid,
		File:    outboxFile,
		Servers: servers,
	})
}

// ProcessSentMessages scans every send queue under storagePath/queues/, updates
// the message storage entry with server delivery info for each sent job, then
// removes the job from the queue. Returns the number of messages updated.
//
// The message DB location is recovered from the job's File basename, which must
// follow the naming convention produced by CreateUserMessageAndSendJob:
//
//	outbox/{dbFile}_{dbId}
func ProcessSentMessages(storagePath string) int {
	password, _ := client.GetConfig().GetMemPass()
	queueDir := filepath.Join(storagePath, "queues")
	entries, err := os.ReadDir(queueDir)
	if err != nil {
		logger.Warn().Err(err).Str("dir", queueDir).Msg("ProcessSentMessages: ReadDir")
		return 0
	}

	updated := 0

	for _, entry := range entries {
		if entry.IsDir() {
			continue
		}
		queue := entry.Name()

		jobs, err := client.GetSentJobs(storagePath, queue)
		if err != nil {
			logger.Error().Err(err).Str("queue", queue).Msg("ProcessSentMessages: GetSentJobs")
			continue
		}

		for _, job := range jobs {
			if job.SuccessfulServer == nil || job.SentAt == nil {
				// No delivery info – discard the job so it doesn't block the queue
				if err := client.DeleteSendJob(storagePath, queue, job.ID); err != nil {
					logger.Error().Err(err).Int64("id", job.ID).Msg("ProcessSentMessages: DeleteSendJob (incomplete)")
				}
				continue
			}

			// Recover dbFile and dbId from the outbox filename: {dbFile}_{dbId}
			base := filepath.Base(job.File)
			sep := strings.LastIndex(base, "_")
			if sep <= 0 {
				logger.Error().Int64("id", job.ID).Str("file", job.File).
					Msg("ProcessSentMessages: cannot parse dbFile/dbId from job filename — use CreateUserMessageAndSendJob to build jobs")
				continue
			}
			dbFile := base[:sep]
			dbId, parseErr := strconv.ParseInt(base[sep+1:], 10, 64)
			if parseErr != nil || dbFile == "" || dbId == 0 {
				logger.Error().Int64("id", job.ID).Str("file", job.File).
					Msg("ProcessSentMessages: invalid dbFile/dbId in job filename")
				continue
			}

			serverUid := job.Servers[*job.SuccessfulServer].GetUid()
			receiveTime := uint64(job.SentAt.Unix())

			if err := client.SetMessageServerDelivery(dbFile, dbId, serverUid, receiveTime, password); err != nil {
				logger.Error().Err(err).Str("queue", queue).
					Str("dbFile", dbFile).Int64("dbId", dbId).
					Msg("ProcessSentMessages: SetMessageServerDelivery")
				continue
			}
			if err := client.DeleteSendJob(storagePath, queue, job.ID); err != nil {
				logger.Error().Err(err).Int64("id", job.ID).Msg("ProcessSentMessages: DeleteSendJob")
			}
			updated++
		}
	}
	return updated
}