#include "auth/auth_handler.hpp"
#include "network/tcp_socket.hpp"
#include "network/packet.hpp"
#include "core/logger.hpp"
#include <sstream>
#include <iomanip>

namespace wowee {
namespace auth {

AuthHandler::AuthHandler() {
    LOG_DEBUG("AuthHandler created");
}

AuthHandler::~AuthHandler() {
    disconnect();
}

bool AuthHandler::connect(const std::string& host, uint16_t port) {
    LOG_INFO("Connecting to auth server: ", host, ":", port);

    socket = std::make_unique<network::TCPSocket>();

    // Set up packet callback
    socket->setPacketCallback([this](const network::Packet& packet) {
        // Create a mutable copy for handling
        network::Packet mutablePacket = packet;
        handlePacket(mutablePacket);
    });

    if (!socket->connect(host, port)) {
        LOG_ERROR("Failed to connect to auth server");
        setState(AuthState::FAILED);
        return false;
    }

    setState(AuthState::CONNECTED);
    LOG_INFO("Connected to auth server");
    return true;
}

void AuthHandler::disconnect() {
    if (socket) {
        socket->disconnect();
        socket.reset();
    }
    setState(AuthState::DISCONNECTED);
    LOG_INFO("Disconnected from auth server");
}

bool AuthHandler::isConnected() const {
    return socket && socket->isConnected();
}

void AuthHandler::requestRealmList() {
    if (!isConnected()) {
        LOG_ERROR("Cannot request realm list: not connected to auth server");
        return;
    }

    if (state != AuthState::AUTHENTICATED) {
        LOG_ERROR("Cannot request realm list: not authenticated (state: ", (int)state, ")");
        return;
    }

    LOG_INFO("Requesting realm list");
    sendRealmListRequest();
}

void AuthHandler::authenticate(const std::string& user, const std::string& pass) {
    if (!isConnected()) {
        LOG_ERROR("Cannot authenticate: not connected to auth server");
        fail("Not connected");
        return;
    }

    if (state != AuthState::CONNECTED) {
        LOG_ERROR("Cannot authenticate: invalid state");
        fail("Invalid state");
        return;
    }

    LOG_INFO("Starting authentication for user: ", user);

    username = user;
    password = pass;

    // Initialize SRP
    srp = std::make_unique<SRP>();
    srp->initialize(username, password);

    // Send LOGON_CHALLENGE
    sendLogonChallenge();
}

void AuthHandler::sendLogonChallenge() {
    LOG_DEBUG("Sending LOGON_CHALLENGE");

    auto packet = LogonChallengePacket::build(username, clientInfo);
    socket->send(packet);

    setState(AuthState::CHALLENGE_SENT);
}

void AuthHandler::handleLogonChallengeResponse(network::Packet& packet) {
    LOG_DEBUG("Handling LOGON_CHALLENGE response");

    LogonChallengeResponse response;
    if (!LogonChallengeResponseParser::parse(packet, response)) {
        fail("Server sent an invalid response - it may use an incompatible protocol version");
        return;
    }

    if (!response.isSuccess()) {
        fail(std::string("LOGON_CHALLENGE failed: ") + getAuthResultString(response.result));
        return;
    }

    if (response.securityFlags != 0) {
        LOG_WARNING("Server sent security flags: 0x", std::hex, (int)response.securityFlags, std::dec);
        if (response.securityFlags & 0x01) LOG_WARNING("  PIN required (not supported)");
        if (response.securityFlags & 0x02) LOG_WARNING("  Matrix card required (not supported)");
        if (response.securityFlags & 0x04) LOG_WARNING("  Authenticator required (not supported)");
    }

    LOG_INFO("Challenge: N=", response.N.size(), "B g=", response.g.size(), "B salt=",
             response.salt.size(), "B secFlags=0x", std::hex, (int)response.securityFlags, std::dec);

    // Feed SRP with server challenge data
    srp->feed(response.B, response.g, response.N, response.salt);

    setState(AuthState::CHALLENGE_RECEIVED);

    // Send LOGON_PROOF immediately
    sendLogonProof();
}

void AuthHandler::sendLogonProof() {
    LOG_DEBUG("Sending LOGON_PROOF");

    auto A = srp->getA();
    auto M1 = srp->getM1();

    auto packet = LogonProofPacket::build(A, M1);
    socket->send(packet);

    setState(AuthState::PROOF_SENT);
}

void AuthHandler::handleLogonProofResponse(network::Packet& packet) {
    LOG_DEBUG("Handling LOGON_PROOF response");

    LogonProofResponse response;
    if (!LogonProofResponseParser::parse(packet, response)) {
        fail("Server sent an invalid login response - it may use an incompatible protocol");
        return;
    }

    if (!response.isSuccess()) {
        std::string reason = "Login failed: ";
        reason += getAuthResultString(static_cast<AuthResult>(response.status));
        fail(reason);
        return;
    }

    // Verify server proof
    if (!srp->verifyServerProof(response.M2)) {
        fail("Server identity verification failed - the server may be running an incompatible version");
        return;
    }

    // Authentication successful!
    sessionKey = srp->getSessionKey();
    setState(AuthState::AUTHENTICATED);

    LOG_INFO("========================================");
    LOG_INFO("   AUTHENTICATION SUCCESSFUL!");
    LOG_INFO("========================================");
    LOG_INFO("User: ", username);
    LOG_INFO("Session key size: ", sessionKey.size(), " bytes");

    if (onSuccess) {
        onSuccess(sessionKey);
    }
}

void AuthHandler::sendRealmListRequest() {
    LOG_DEBUG("Sending REALM_LIST request");

    auto packet = RealmListPacket::build();
    socket->send(packet);

    setState(AuthState::REALM_LIST_REQUESTED);
}

void AuthHandler::handleRealmListResponse(network::Packet& packet) {
    LOG_DEBUG("Handling REALM_LIST response");

    RealmListResponse response;
    if (!RealmListResponseParser::parse(packet, response)) {
        LOG_ERROR("Failed to parse REALM_LIST response");
        return;
    }

    realms = response.realms;
    setState(AuthState::REALM_LIST_RECEIVED);

    LOG_INFO("========================================");
    LOG_INFO("   REALM LIST RECEIVED!");
    LOG_INFO("========================================");
    LOG_INFO("Total realms: ", realms.size());

    for (size_t i = 0; i < realms.size(); ++i) {
        const auto& realm = realms[i];
        LOG_INFO("Realm ", (i + 1), ": ", realm.name);
        LOG_INFO("  Address: ", realm.address);
        LOG_INFO("  ID: ", (int)realm.id);
        LOG_INFO("  Population: ", realm.population);
        LOG_INFO("  Characters: ", (int)realm.characters);
        if (realm.hasVersionInfo()) {
            LOG_INFO("  Version: ", (int)realm.majorVersion, ".",
                     (int)realm.minorVersion, ".", (int)realm.patchVersion,
                     " (build ", realm.build, ")");
        }
    }

    if (onRealmList) {
        onRealmList(realms);
    }
}

void AuthHandler::handlePacket(network::Packet& packet) {
    if (packet.getSize() < 1) {
        LOG_WARNING("Received empty packet");
        return;
    }

    // Read opcode
    uint8_t opcodeValue = packet.readUInt8();
    // Note: packet now has read position advanced past opcode

    AuthOpcode opcode = static_cast<AuthOpcode>(opcodeValue);

    // Hex dump first bytes for diagnostics
    {
        const auto& raw = packet.getData();
        std::ostringstream hs;
        for (size_t i = 0; i < std::min<size_t>(raw.size(), 40); ++i)
            hs << std::hex << std::setfill('0') << std::setw(2) << (int)raw[i];
        if (raw.size() > 40) hs << "...";
        LOG_INFO("Auth pkt 0x", std::hex, (int)opcodeValue, std::dec,
                 " (", raw.size(), "B): ", hs.str());
    }

    switch (opcode) {
        case AuthOpcode::LOGON_CHALLENGE:
            if (state == AuthState::CHALLENGE_SENT) {
                handleLogonChallengeResponse(packet);
            } else {
                LOG_WARNING("Unexpected LOGON_CHALLENGE response in state: ", (int)state);
            }
            break;

        case AuthOpcode::LOGON_PROOF:
            if (state == AuthState::PROOF_SENT) {
                handleLogonProofResponse(packet);
            } else {
                LOG_WARNING("Unexpected LOGON_PROOF response in state: ", (int)state);
            }
            break;

        case AuthOpcode::REALM_LIST:
            if (state == AuthState::REALM_LIST_REQUESTED) {
                handleRealmListResponse(packet);
            } else {
                LOG_WARNING("Unexpected REALM_LIST response in state: ", (int)state);
            }
            break;

        default:
            LOG_WARNING("Unhandled auth opcode: 0x", std::hex, (int)opcodeValue, std::dec);
            break;
    }
}

void AuthHandler::update(float /*deltaTime*/) {
    if (!socket) {
        return;
    }

    // Update socket (processes incoming data and calls packet callback)
    socket->update();
}

void AuthHandler::setState(AuthState newState) {
    if (state != newState) {
        LOG_DEBUG("Auth state: ", (int)state, " -> ", (int)newState);
        state = newState;
    }
}

void AuthHandler::fail(const std::string& reason) {
    LOG_ERROR("Authentication failed: ", reason);
    setState(AuthState::FAILED);

    if (onFailure) {
        onFailure(reason);
    }
}

} // namespace auth
} // namespace wowee