//! # All the message identifiers used by RakNet.
//!
//! Message identifiers comprise the first byte of any message.
//!
//! This file is part of RakNet Copyright 2003 Kevin Jenkins.
//!
//! Usage of RakNet is subject to the appropriate license agreement.
//! Creative Commons Licensees are subject to the
//! license found at
//! <http://creativecommons.org/licenses/by-nc/2.5/>
//! Single application licensees are subject to the license found at
//! <http://www.jenkinssoftware.com/SingleApplicationLicense.html>
//! Custom license users are subject to the terms therein.
//! GPL license users are subject to the GNU General Public
//! License as published by the Free
//! Software Foundation; either version 2 of the License, or (at your
//! option) any later version.

use num_derive::{FromPrimitive, ToPrimitive};
use std::mem::size_of;

use crate::Error;

#[derive(Debug, FromPrimitive, ToPrimitive)]
#[repr(u8)]
pub enum ID {
    //
    // RESERVED TYPES - DO NOT CHANGE THESE
    // All types from RakPeer
    //
    /// These types are never returned to the user.
    /// Ping from a connected system.  Update timestamps (internal use only)
    InternalPing,
    /// Ping from an unconnected system.  Reply but do not update timestamps. (internal use only)
    Ping,
    /// Ping from an unconnected system.  Only reply if we have open connections. Do not update timestamps. (internal use only)
    PingOpenConnections,
    /// Pong from a connected system.  Update timestamps (internal use only)
    ConnectedPong,
    /// Asking for a new connection (internal use only)
    ConnectionRequest,
    /// Connecting to a secured server/peer (internal use only)
    SecuredConnectionResponse,
    /// Connecting to a secured server/peer (internal use only)
    SecuredConnectionConfirmation,
    /// Packet that tells us the packet contains an integer ID to name mapping for the remote system (internal use only)
    RPCMapping,
    /// A reliable packet to detect lost connections (internal use only)
    DetectLostConnection,
    /// Offline message so we know when to reset and start a new connection (internal use only)
    OpenConnectionRequest,
    /// Offline message response so we know when to reset and start a new connection (internal use only)
    OpenConnectionReply,
    /// Remote procedure call (internal use only)
    RPC,
    /// Remote procedure call reply, for RPCs that return data (internal use only)
    RPCReply,
    /// RakPeer - Same as ID_ADVERTISE_SYSTEM, but intended for internal use rather than being passed to the user. Second byte indicates type. Used currently for NAT punchthrough for receiver port advertisement. See ID_NAT_ADVERTISE_RECIPIENT_PORT
    OutOfBandInternal,

    //
    // USER TYPES - DO NOT CHANGE THESE
    //
    /// RakPeer - In a client/server environment, our connection request to the server has been accepted.
    ConnectionRequestAccepted,
    /// RakPeer - Sent to the player when a connection request cannot be completed due to inability to connect.
    ConnectionAttemptFailed,
    /// RakPeer - Sent a connect request to a system we are currently connected to.
    AlreadyConnected,
    /// RakPeer - A remote system has successfully connected.
    NewIncomingConnection,
    /// RakPeer - The system we attempted to connect to is not accepting new connections.
    NoFreeIncomingConnections,
    /// RakPeer - The system specified in Packet::systemAddress has disconnected from us.  For the client, this would mean the server has shutdown.
    DisconnectionNotification,
    /// RakPeer - Reliable packets cannot be delivered to the system specified in Packet::systemAddress.  The connection to that system has been closed.
    ConnectionLost,
    /// RakPeer - We preset an RSA public key which does not match what the system we connected to is using.
    RSAPublicKeyMismatch,
    /// RakPeer - We are banned from the system we attempted to connect to.
    ConnectionBanned,
    /// RakPeer - The remote system is using a password and has refused our connection because we did not set the correct password.
    InvalidPassword,
    /// RakPeer - A packet has been tampered with in transit.  The sender is contained in Packet::systemAddress.
    ModifiedPacket,
    /// RakPeer - The four bytes following this byte represent an unsigned int which is automatically modified by the difference in system times between the sender and the recipient. Requires that you call SetOccasionalPing.
    Timestamp,
    /// RakPeer - Pong from an unconnected system.  First byte is ID_PONG, second sizeof(RakNetTime) bytes is the ping, following bytes is system specific enumeration data.
    Pong,
    /// RakPeer - Inform a remote system of our IP/Port, plus some offline data
    AdvertiseSystem,
    /// ConnectionGraph plugin - In a client/server environment, a client other than ourselves has disconnected gracefully.  Packet::systemAddress is modified to reflect the systemAddress of this client.
    RemoteDisconnectNotification,
    /// ConnectionGraph plugin - In a client/server environment, a client other than ourselves has been forcefully dropped. Packet::systemAddress is modified to reflect the systemAddress of this client.
    RemoteConnectionLost,
    /// ConnectionGraph plugin - In a client/server environment, a client other than ourselves has connected.  Packet::systemAddress is modified to reflect the systemAddress of the client that is not connected directly to us. The packet encoding is SystemAddress 1, ConnectionGraphGroupID 1, SystemAddress 2, ConnectionGraphGroupID 2
    RemoteNewIncomingConnection,
    // RakPeer - Downloading a large message. Format is ID_DOWNLOAD_PROGRESS (MessageID), partCount (unsigned int), partTotal (unsigned int), partLength (unsigned int), first part data (length <= MAX_MTU_SIZE). See the three parameters partCount, partTotal and partLength in OnFileProgress in FileListTransferCBInterface.h
    DownloadProgress,

    /// FileListTransfer plugin - Setup data
    FileListTransferHeader,
    /// FileListTransfer plugin - A file
    FileListTransferFile,

    /// DirectoryDeltaTransfer plugin - Request from a remote system for a download of a directory
    DDTDownloadRequest,

    /// RakNetTransport plugin - Transport provider message, used for remote console
    TransportString,

    /// ReplicaManager plugin - Create an object
    ReplicaManagerConstruction,
    /// ReplicaManager plugin - Destroy an object
    ReplicaManagerDestruction,
    /// ReplicaManager plugin - Changed scope of an object
    ReplicaManagerScopeChange,
    /// ReplicaManager plugin - Serialized data of an object
    ReplicaManagerSerialize,
    /// ReplicaManager plugin - New connection, about to send all world objects
    ReplicaManagerDownloadStarted,
    /// ReplicaManager plugin - Finished downloading all serialized objects
    ReplicaManagerDownloadComplete,

    /// ConnectionGraph plugin - Request the connection graph from another system
    ConnectionGraphRequest,
    /// ConnectionGraph plugin - Reply to a connection graph download request
    ConnectionGraphReply,
    /// ConnectionGraph plugin - Update edges / nodes for a system with a connection graph
    ConnectionGraphUpdate,
    /// ConnectionGraph plugin - Add a new connection to a connection graph
    ConnectionGraphNewConnection,
    /// ConnectionGraph plugin - Remove a connection from a connection graph - connection was abruptly lost
    ConnectionGraphConnectionLost,
    /// ConnectionGraph plugin - Remove a connection from a connection graph - connection was gracefully lost
    ConnectionGraphDisconnectionNotification,

    /// Router plugin - route a message through another system
    RouteAndMulticast,

    /// RakVoice plugin - Open a communication channel
    RakVoiceOpenChannelRequest,
    /// RakVoice plugin - Communication channel accepted
    RakVoiceOpenChannelReply,
    /// RakVoice plugin - Close a communication channel
    RakVoiceCloseChannel,
    /// RakVoice plugin - Voice data
    RakVoiceData,

    /// Autopatcher plugin - Get a list of files that have changed since a certain date
    AutopatcherGetChangelistSinceDate,
    /// Autopatcher plugin - A list of files to create
    AutopatcherCreatingList,
    /// Autopatcher plugin - A list of files to delete
    AutopatcherDeletionList,
    /// Autopatcher plugin - A list of files to get patches for
    AutopatcherGetPatch,
    /// Autopatcher plugin - A list of patches for a list of files
    AutopatcherPatchList,
    /// Autopatcher plugin - Returned to the user: An error from the database repository for the autopatcher.
    AutopatcherRepositoryFatalError,
    /// Autopatcher plugin - Finished getting all files from the autopatcher
    AutopatcherFinishedInternal,
    AutopatcherFinished,
    /// Autopatcher plugin - Returned to the user: You must restart the application to finish patching.
    AutopatcherRestartApplication,

    /// NATPunchthrough plugin - Intermediary got a request to help punch through a nat
    NATPunchthroughRequest,
    /// NATPunchthrough plugin - Intermediary cannot complete the request because the target system is not connected
    NATTargetNotConnected,
    /// NATPunchthrough plugin - While attempting to connect, we lost the connection to the target system
    NATTargetConnectionLost,
    /// NATPunchthrough plugin - Internal message to connect at a certain time
    NATConnectAtTime,
    /// NATPunchthrough plugin - Internal message to send a message (to punch through the nat) at a certain time
    NATSendOfflineMessageAtTime,
    /// NATPunchthrough plugin - The facilitator is already attempting this connection
    NATInProgress,

    /// LightweightDatabase plugin - Query
    DatabaseQueryRequest,
    /// LightweightDatabase plugin - Update
    DatabaseUpdateRow,
    /// LightweightDatabase plugin - Remove
    DatabaseRemoveRow,
    /// LightweightDatabase plugin - A serialized table.  Bytes 1+ contain the table.  Pass to TableSerializer::DeserializeTable
    DatabaseQueryReply,
    /// LightweightDatabase plugin - Specified table not found
    DatabaseUnknownTable,
    /// LightweightDatabase plugin - Incorrect password
    DatabaseIncorrectPassword,

    /// ReadyEvent plugin - Set the ready state for a particular system
    ReadyEventSet,
    /// ReadyEvent plugin - Unset the ready state for a particular system
    ReadyEventUnset,
    /// All systems are in state ID_READY_EVENT_SET
    ReadyEventAllSet,
    /// ReadyEvent plugin - Request of ready event state - used for pulling data when newly connecting
    ReadyEventQuery,

    /// Lobby packets. Second byte indicates type.
    LobbyGeneral,

    /// Auto RPC procedure call
    AutoRPCCall,
    /// Auto RPC functionName to index mapping
    AutoRPCRemoteIndex,
    /// Auto RPC functionName to index mapping, lookup failed. Will try to auto recover
    AutoRPCUnknownRemoteIndex,

    /// Auto RPC error code
    /// See `AutoRPC.h` for codes, stored in `packet->data[1]`
    RPCRemoteError,
    // /// For the user to use.  Start your first enumeration at this value.
    // UserPacketEnum,
}

impl ID {
    pub fn of_packet(bytes: &[u8]) -> Result<u8, Error> {
        const TIMESTAMP: u8 = ID::Timestamp as u8;
        const INDEX_WITH_TIMESTAMP: usize = size_of::<u8>() + size_of::<u32>();
        let first_byte = bytes.first().copied().ok_or(Error::MissingID)?;
        match first_byte {
            TIMESTAMP => bytes
                .get(INDEX_WITH_TIMESTAMP)
                .copied()
                .ok_or(Error::MissingTimedID),
            first => Ok(first),
        }
    }
}