#ifndef DB_MANAGER_H
#define DB_MANAGER_H

#include <sqlite3.h>
#include <QString>
#include <QList>
#include <QMap>
#include <QObject>
#include <cstdint>

struct ChannelRow {
    QString    channelId;
    QString    name;
    quint64    ownerNodeId = 0;
    bool       isDm = false;

    QByteArray x25519_pubkey;
    QByteArray x25519_privkey;
    QByteArray ed25519_pubkey;
    QByteArray ed25519_privkey;
    QByteArray signature;               // Ed25519 подпись всех полей записи privkey канала

    qint64     lastReadMsgId = 0;
    qint64     lastPosMsgId = 0;
    qint64     createdAt = 0;
};

struct MessageRow {
    qint64     id = 0;
    quint64    authorNodeId = 0;
    QString    contentType;
    QByteArray data;
    qint64     timestamp = 0;
    uint64_t   datahash = 0;
    QByteArray chainHash;
    QByteArray signature;
    bool       isOutgoing = false;
    bool       isRead = false;
};

struct AccountRow {
    quint64    nodeId = 0;
    QString    displayName;
    QString    avatarColor;
    QString    avatarLetter;
    bool       isContact = true;
};

struct NodeAddr {
    quint64    nodeId = 0;
    int        family = 0;
    int        protocol = 0;            // битмаска: 1=UDP, 2=TCP, 3=TCP+UDP
    QByteArray address;
    quint16    port = 0;
    int        rtt = 0;
    bool       isNat = false;
};

class DbManager : public QObject {
    Q_OBJECT
public:
    explicit DbManager(const QString& path, QObject* parent = nullptr);
    ~DbManager() override;

    bool    isOpen() const { return m_db != nullptr; }
    quint64 myNodeId() const { return m_myNodeId; }

    /* ── Каналы ── */
    QList<ChannelRow> getChannels() const;
    bool createChannel(const QString& chId, const QString& name,
                       quint64 ownerNodeId = 0,
                       const QByteArray& x25519pub = {}, const QByteArray& x25519priv = {},
                       const QByteArray& ed25519pub = {}, const QByteArray& ed25519priv = {});
    bool deleteChannel(const QString& chId);

    /* ── Сообщения (UI) ── */
    QList<MessageRow> getMessages(const QString& chId, int limit = 50) const;
    bool insertMessage(const QString& chId, quint64 nodeId,
                       const QString& contentType, const QByteArray& data,
                       qint64 timestamp, bool isOutgoing,
                       uint64_t* outDatahash, QByteArray* outChainHash);

    /* ── Участники канала ── */
    bool addPeer(const QString& chId, quint64 nodeId,
                 const QByteArray& joinSig, const QByteArray& creatorSig,
                 const QString& comment = {});
    bool removePeer(const QString& chId, quint64 nodeId);

    /* ── Узлы ── */
    bool upsertNode(quint64 nodeId, const QString& name,
                    const QByteArray& x25519pub, const QByteArray& ed25519pub);
    bool addNodeAddress(quint64 nodeId, int family, int protocol,
                        const QByteArray& addr, quint16 port, bool isNat);
    QByteArray loadNodeInfo(quint64 nodeId) const;
    QList<quint64> getOnlinePeers() const;
    QByteArray getNodeEdPub(quint64 nodeId) const;
    QList<NodeAddr> getOnlinePeerAddresses(quint64 excludeNodeId) const;

    /* ── Аккаунты ── */
    QList<AccountRow> getAccounts(bool contactsOnly = false) const;
    AccountRow getAccount(quint64 nodeId) const;

    /* ── UI state ── */
    QString getUiState(const QString& key) const;
    void    setUiState(const QString& key, const QString& value);

    /* ── Sync-операции (вызываются gui_bridge, в GUI-потоке) ── */
    QByteArray syncListChannels() const;
    QByteArray syncCount(const QString& chId) const;
    QByteArray syncChainHashAt(const QString& chId, uint32_t pos) const;
    QByteArray syncInsert(const QString& chId, const QByteArray& recData);
    QByteArray syncCursorOpen(const QString& chId);
    QByteArray syncCursorNext(uint32_t cursorId);
    void       syncCursorClose(uint32_t cursorId);
    QByteArray syncMarkSent(const QString& chId, quint64 ts, quint64 dh, quint64 myNodeId);
    QByteArray syncTtlDelete(const QString& chId, quint64 myNodeId, quint64 cutoffUs);
    QByteArray syncListPeers(const QString& chId) const;

    /* ── Уведомления из uasync ── */
    void onSyncMessageReceived(const QString& chId);
    void setNodeOnline(quint64 nodeId, bool online);
    void setUasyncInstance(void* ua) { m_ua = ua; }
    void* uasyncInstance() const { return m_ua; }

    /* ── seed ── */
    void seedStubData();

private:
    void initTables();
    sqlite3_stmt* prepareOrNull(const char* sql) const;
    static QString    colText(sqlite3_stmt* stmt, int col);
    static QByteArray colBlob(sqlite3_stmt* stmt, int col);

    QString msgTableName(const QString& chId) const;
    QString peersTableName(const QString& chId) const;
    static QString sanitizeTableName(const QString& chId);
    static uint64_t computeDatahash(const QByteArray& data);
    static QByteArray computeChainHash(const QByteArray& prevChain,
                                       qint64 timestamp, uint64_t datahash);
    QByteArray getLastChainHash(const QString& chId) const;

    sqlite3* m_db = nullptr;
    quint64  m_myNodeId = 0;
    void*    m_ua = nullptr;

    /* Кэш открытых курсоров для sync-операций */
    mutable QMap<uint32_t, sqlite3_stmt*> m_cursors;
    mutable uint32_t m_nextCursorId = 1;
};

#endif