package libgm

import (
	"crypto/sha256"
	"encoding/base64"

	"go.mau.fi/mautrix-gmessages/libgm/pblite"

	"go.mau.fi/mautrix-gmessages/libgm/gmproto"
)

func (r *RPC) deduplicateHash(hash [32]byte) bool {
	const recentUpdatesLen = len(r.recentUpdates)
	for i := r.recentUpdatesPtr + recentUpdatesLen - 1; i >= r.recentUpdatesPtr; i-- {
		if r.recentUpdates[i%recentUpdatesLen] == hash {
			return true
		}
	}
	r.recentUpdates[r.recentUpdatesPtr] = hash
	r.recentUpdatesPtr = (r.recentUpdatesPtr + 1) % recentUpdatesLen
	return false
}

func (r *RPC) logContent(res *pblite.Response) {
	if r.client.Logger.Trace().Enabled() && res.Data.Decrypted != nil {
		r.client.Logger.Trace().
			Str("proto_name", string(res.Data.Decrypted.ProtoReflect().Descriptor().FullName())).
			Str("data", base64.StdEncoding.EncodeToString(res.Data.RawDecrypted)).
			Msg("Got event")
	}
}

func (r *RPC) deduplicateUpdate(response *pblite.Response) bool {
	if response.Data.RawDecrypted != nil {
		contentHash := sha256.Sum256(response.Data.RawDecrypted)
		if r.deduplicateHash(contentHash) {
			r.client.Logger.Trace().Hex("data_hash", contentHash[:]).Msg("Ignoring duplicate update")
			return true
		}
		r.logContent(response)
	}
	return false
}

func (r *RPC) HandleRPCMsg(msg *gmproto.InternalMessage) {
	response, decodeErr := pblite.DecryptInternalMessage(msg, r.client.AuthData.RequestCrypto)
	if decodeErr != nil {
		r.client.Logger.Error().Err(decodeErr).Msg("rpc decrypt msg err")
		return
	}
	if response == nil {
		r.client.Logger.Error().Msg("nil response in rpc handler")
		return
	}

	r.client.sessionHandler.queueMessageAck(response.ResponseID)
	if r.client.sessionHandler.receiveResponse(response) {
		return
	}
	switch response.BugleRoute {
	case gmproto.BugleRoute_PairEvent:
		go r.client.handlePairingEvent(response)
	case gmproto.BugleRoute_DataEvent:
		if r.skipCount > 0 {
			r.skipCount--
			r.client.Logger.Debug().
				Any("action", response.Data.Action).
				Int("remaining_skip_count", r.skipCount).
				Msg("Skipped DataEvent")
			if response.Data.Decrypted != nil {
				r.client.Logger.Trace().
					Str("proto_name", string(response.Data.Decrypted.ProtoReflect().Descriptor().FullName())).
					Str("data", base64.StdEncoding.EncodeToString(response.Data.RawDecrypted)).
					Msg("Skipped event data")
			}
			return
		}
		r.client.handleUpdatesEvent(response)
	default:
		r.client.Logger.Debug().Any("res", response).Msg("Got unknown bugle route")
	}
}