#include "Lobby.hpp"

#include <algorithm>
#include <iomanip>
#include <sstream>

void Lobby::send(WS *ws, const std::string &type, json payload) {
    json msg = {{"type", type}, {"payload", std::move(payload)}};
    ws->send(msg.dump(), uWS::OpCode::TEXT);
}

void Lobby::sendError(WS *ws, const std::string &code, const std::string &message) {
    send(ws, "error", {{"code", code}, {"message", message}});
}

std::string Lobby::generateRoomId() {
    std::ostringstream oss;
    oss << "cactus-room-" << std::setw(2) << std::setfill('0') << next_room_id_++;
    return oss.str();
}

json Lobby::roomsSummary() const {
    json rooms = json::array();
    for (const auto &[id, room] : rooms_) {
        rooms.push_back({
            {"id", room.id},
            {"name", room.id},
            {"mode", room.mode},
            {"players", room.players.size()},
            {"max_players", kMaxPlayersPerRoom},
            {"state", room.state},
        });
    }
    return rooms;
}

json Lobby::roomPlayers(const Room &room) const {
    json players = json::array();
    for (size_t i = 0; i < room.players.size(); i++) {
        players.push_back({
            {"id", room.players[i].player_id},
            {"nickname", room.players[i].nickname},
            {"slot", i},
        });
    }
    return players;
}

void Lobby::broadcastRoomsToLobby() {
    json rooms = roomsSummary();
    for (WS *client : sockets_) {
        if (client->getUserData()->room_id.empty()) {
            send(client, "lobby.rooms", {{"rooms", rooms}});
        }
    }
}

void Lobby::broadcastRoomUpdated(const Room &room, WS *exclude) {
    json payload = {{"players", roomPlayers(room)}};
    for (const auto &p : room.players) {
        if (p.ws != exclude) {
            send(p.ws, "lobby.room_updated", payload);
        }
    }
}

void Lobby::onOpen(WS *ws) {
    sockets_.insert(ws);
}

void Lobby::onClose(WS *ws) {
    removePlayerFromRoom(ws);
    sockets_.erase(ws);
}

void Lobby::onMessage(WS *ws, std::string_view message) {
    json request;
    std::string type;
    try {
        request = json::parse(message);
        type = request.value("type", "");
    } catch (const std::exception &e) {
        sendError(ws, "bad_json", e.what());
        return;
    }

    json payload = request.value("payload", json::object());

    if (type == "hello") {
        handleHello(ws, payload);
    } else if (type == "lobby.list_rooms") {
        handleListRooms(ws);
    } else if (type == "lobby.create_room") {
        handleCreateRoom(ws, payload);
    } else if (type == "lobby.join_room") {
        handleJoinRoom(ws, payload);
    } else if (type == "lobby.leave_room") {
        handleLeaveRoom(ws);
    } else {
        sendError(ws, "unknown_type", "unknown message type: " + type);
    }
}

void Lobby::handleHello(WS *ws, const json &payload) {
    auto *data = ws->getUserData();
    if (data->player_id.empty()) {
        data->player_id = "player-" + std::to_string(next_player_id_++);
    }
    data->nickname = payload.value("nickname", "anon");
    send(ws, "hello.ack", {{"player_id", data->player_id}});
}

void Lobby::handleListRooms(WS *ws) {
    send(ws, "lobby.rooms", {{"rooms", roomsSummary()}});
}

void Lobby::handleCreateRoom(WS *ws, const json &payload) {
    auto *data = ws->getUserData();
    if (data->player_id.empty()) {
        sendError(ws, "not_authenticated", "send hello first");
        return;
    }
    if (!data->room_id.empty()) {
        sendError(ws, "already_in_room", "leave the current room first");
        return;
    }

    std::string mode = payload.value("mode", "");
    if (mode != "coop" && mode != "pvp") {
        sendError(ws, "invalid_mode", "mode must be \"coop\" or \"pvp\"");
        return;
    }

    Room room;
    room.id = generateRoomId();
    room.mode = mode;
    room.players.push_back({data->player_id, data->nickname, ws});

    data->room_id = room.id;
    std::string room_id = room.id;
    rooms_[room_id] = std::move(room);

    send(ws, "lobby.room_joined", {
        {"room_id", room_id},
        {"name", room_id},
        {"mode", mode},
        {"players", roomPlayers(rooms_[room_id])},
    });

    broadcastRoomsToLobby();
}

void Lobby::handleJoinRoom(WS *ws, const json &payload) {
    auto *data = ws->getUserData();
    if (data->player_id.empty()) {
        sendError(ws, "not_authenticated", "send hello first");
        return;
    }
    if (!data->room_id.empty()) {
        sendError(ws, "already_in_room", "leave the current room first");
        return;
    }

    std::string room_id = payload.value("room_id", "");
    auto it = rooms_.find(room_id);
    if (it == rooms_.end()) {
        sendError(ws, "room_not_found", "no such room: " + room_id);
        return;
    }

    Room &room = it->second;
    if (room.state != "waiting") {
        sendError(ws, "room_in_progress", "room is not accepting new players");
        return;
    }
    if (room.players.size() >= kMaxPlayersPerRoom) {
        sendError(ws, "room_full", "room is full");
        return;
    }

    room.players.push_back({data->player_id, data->nickname, ws});
    data->room_id = room_id;

    send(ws, "lobby.room_joined", {
        {"room_id", room_id},
        {"name", room_id},
        {"mode", room.mode},
        {"players", roomPlayers(room)},
    });

    broadcastRoomUpdated(room, ws);
    broadcastRoomsToLobby();
}

void Lobby::handleLeaveRoom(WS *ws) {
    if (ws->getUserData()->room_id.empty()) {
        sendError(ws, "not_in_room", "you are not in a room");
        return;
    }
    removePlayerFromRoom(ws);
    broadcastRoomsToLobby();
}

void Lobby::removePlayerFromRoom(WS *ws) {
    auto *data = ws->getUserData();
    if (data->room_id.empty()) {
        return;
    }

    auto it = rooms_.find(data->room_id);
    data->room_id.clear();
    if (it == rooms_.end()) {
        return;
    }

    Room &room = it->second;
    room.players.erase(
        std::remove_if(room.players.begin(), room.players.end(),
                        [ws](const RoomPlayer &p) { return p.ws == ws; }),
        room.players.end());

    if (room.players.empty()) {
        rooms_.erase(it);
    } else {
        broadcastRoomUpdated(room);
    }
}