#pragma once
#include "network/websocket/WebSocketClient.h"
#include "trading/websocket/ZerodhaTickTypes.h"

#include <QObject>
#include <QSet>
#include <QString>
#include <QTimer>
#include <QVector>

namespace fincept::trading {

/// Zerodha KiteTicker WebSocket client.
///
/// Wraps WebSocketClient to handle Zerodha's binary tick protocol.
/// Manages subscriptions in batches of 200 tokens (Kite API limit).
///
/// Usage:
///   auto* ws = new ZerodhaWebSocket(api_key, access_token, this);
///   ws->subscribe({256265, 260105});  // instrument tokens
///   connect(ws, &ZerodhaWebSocket::tick_received, this, &MyWidget::on_tick);
///   ws->open();
///
/// Reconnect: exponential backoff via WebSocketClient; on reconnect all
/// subscribed tokens are re-sent automatically.
class ZerodhaWebSocket : public QObject {
    Q_OBJECT
  public:
    explicit ZerodhaWebSocket(const QString& api_key, const QString& access_token, QObject* parent = nullptr);

    /// Open the WebSocket connection.
    void open();

    /// Close the connection (does not clear subscription list).
    void close();

    bool is_connected() const;

    /// Add tokens to the subscription set and (re)subscribe if connected.
    /// Tokens stream in "quote" mode (44-byte: LTP/OHLC/volume) by default; the
    /// one token set via set_full_mode_token() streams in "full" mode (184-byte,
    /// 5-level depth) so the order book / depth table has data.
    void subscribe(const QVector<quint32>& tokens);

    /// Designate the single token that should stream in "full" mode (market depth).
    /// Typically the currently-selected symbol — the only one whose depth is shown.
    /// Pass 0 to put everything back on "quote". Re-sends mode immediately if
    /// connected (for both the previous and the new full-mode token).
    void set_full_mode_token(quint32 token);

    /// Remove tokens from the subscription set.
    void unsubscribe(const QVector<quint32>& tokens);

    /// Replace the full subscription set.
    void set_subscriptions(const QVector<quint32>& tokens);

    /// Clear all subscriptions.
    void clear_subscriptions();

  signals:
    void tick_received(const fincept::trading::ZerodhaTick& tick);
    void connected();
    void disconnected();
    void error_occurred(const QString& error);

  private slots:
    void on_connected();
    void on_binary_message(const QByteArray& data);
    void on_disconnected();

  private:
    void send_subscribe(const QVector<quint32>& tokens);
    void send_unsubscribe(const QVector<quint32>& tokens);
    void send_mode(const QVector<quint32>& tokens);
    // Send one "mode" message for a token batch (mode = "quote" or "full").
    void send_mode_batch(const char* mode, const QVector<quint32>& tokens);
    void resubscribe_all();

    // Binary packet parsing helpers
    ZerodhaTick parse_ltp_packet(const uchar* data) const;
    ZerodhaTick parse_quote_packet(const uchar* data) const;
    ZerodhaTick parse_full_packet(const uchar* data) const;

    static quint32 read_u32(const uchar* p);
    static qint32 read_i32(const uchar* p);
    static quint16 read_u16(const uchar* p);
    // Kite packs prices as int32 scaled per exchange segment (low byte of the
    // instrument token): CDS (3) → 1e7, BCD (6) → 1e4, everything else → 100
    // (paise). Convention per Zerodha's official KiteTicker clients.
    static double price_from_wire(qint32 raw, quint32 instrument_token);

    QString api_key_;
    QString access_token_;
    WebSocketClient* ws_;
    QSet<quint32> subscribed_tokens_;
    quint32 full_mode_token_ = 0; // streams in "full" mode (depth); 0 = none

    static constexpr int kBatchSize = 200;
    static constexpr const char* kWsUrl = "wss://ws.kite.trade";
};

} // namespace fincept::trading