/**
 * The MIT License (MIT)
 *
 * Copyright (c) 2013-2021 Winlin
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of
 * this software and associated documentation files (the "Software"), to deal in
 * the Software without restriction, including without limitation the rights to
 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
 * the Software, and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
 * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
 * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
 * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

#ifndef SRS_APP_CONN_HPP
#define SRS_APP_CONN_HPP

#include <srs_core.hpp>

#include <string>
#include <vector>
#include <map>

#include <openssl/ssl.h>

#include <srs_app_st.hpp>
#include <srs_protocol_kbps.hpp>
#include <srs_app_reload.hpp>
#include <srs_service_conn.hpp>

class SrsWallClock;

// Hooks for connection manager, to handle the event when disposing connections.
class ISrsDisposingHandler
{
public:
    ISrsDisposingHandler();
    virtual ~ISrsDisposingHandler();
public:
    // When before disposing resource, trigger when manager.remove(c), sync API.
    // @remark Recommend to unref c, after this, no other objects refs to c.
    virtual void on_before_dispose(ISrsResource* c) = 0;
    // When disposing resource, async API, c is freed after it.
    // @remark Recommend to stop any thread/timer of c, after this, fields of c is able
    // to be deleted in any order.
    virtual void on_disposing(ISrsResource* c) = 0;
};

// The item to identify the fast id object.
class SrsResourceFastIdItem
{
public:
    // If available, use the resource in item.
    bool available;
    // How many resource have the same fast-id, which contribute a collision.
    int nn_collisions;
    // The first fast-id of resources.
    uint64_t fast_id;
    // The first resource object.
    ISrsResource* impl;
public:
    SrsResourceFastIdItem() {
        available = false;
        nn_collisions = 0;
        fast_id = 0;
        impl = NULL;
    }
};

// The resource manager remove resource and delete it asynchronously.
class SrsResourceManager : public ISrsCoroutineHandler, public ISrsResourceManager
{
private:
    std::string label_;
    SrsContextId cid_;
    bool verbose_;
private:
    SrsCoroutine* trd;
    srs_cond_t cond;
    // Callback handlers.
    std::vector<ISrsDisposingHandler*> handlers_;
    // Unsubscribing handlers, skip it for notifying.
    std::vector<ISrsDisposingHandler*> unsubs_;
    // Whether we are removing resources.
    bool removing_;
    // The zombie connections, we will delete it asynchronously.
    std::vector<ISrsResource*> zombies_;
    std::vector<ISrsResource*>* p_disposing_;
private:
    // The connections without any id.
    std::vector<ISrsResource*> conns_;
    // The connections with resource id.
    std::map<std::string, ISrsResource*> conns_id_;
    // The connections with resource fast(int) id.
    std::map<uint64_t, ISrsResource*> conns_fast_id_;
    // The level-0 fast cache for fast id.
    int nn_level0_cache_;
    SrsResourceFastIdItem* conns_level0_cache_;
    // The connections with resource name.
    std::map<std::string, ISrsResource*> conns_name_;
public:
    SrsResourceManager(const std::string& label, bool verbose = false);
    virtual ~SrsResourceManager();
public:
    srs_error_t start();
    bool empty();
    size_t size();
// Interface ISrsCoroutineHandler
public:
    virtual srs_error_t cycle();
public:
    void add(ISrsResource* conn, bool* exists = NULL);
    void add_with_id(const std::string& id, ISrsResource* conn);
    void add_with_fast_id(uint64_t id, ISrsResource* conn);
    void add_with_name(const std::string& name, ISrsResource* conn);
    ISrsResource* at(int index);
    ISrsResource* find_by_id(std::string id);
    ISrsResource* find_by_fast_id(uint64_t id);
    ISrsResource* find_by_name(std::string name);
public:
    void subscribe(ISrsDisposingHandler* h);
    void unsubscribe(ISrsDisposingHandler* h);
// Interface ISrsResourceManager
public:
    virtual void remove(ISrsResource* c);
private:
    void do_remove(ISrsResource* c);
    void check_remove(ISrsResource* c, bool& in_zombie, bool& in_disposing);
    void clear();
    void do_clear();
    void dispose(ISrsResource* c);
};

// If a connection is able to be expired,
// user can use HTTP-API to kick-off it.
class ISrsExpire
{
public:
    ISrsExpire();
    virtual ~ISrsExpire();
public:
    // Set connection to expired to kick-off it.
    virtual void expire() = 0;
};

// Interface for connection that is startable.
class ISrsStartableConneciton : public ISrsConnection
    , public ISrsStartable, public ISrsKbpsDelta
{
public:
    ISrsStartableConneciton();
    virtual ~ISrsStartableConneciton();
};

// The basic connection of SRS, for TCP based protocols,
// all connections accept from listener must extends from this base class,
// server will add the connection to manager, and delete it when remove.
class SrsTcpConnection : public ISrsProtocolReadWriter
{
private:
    // The underlayer st fd handler.
    srs_netfd_t stfd;
    // The underlayer socket.
    SrsStSocket* skt;
public:
    SrsTcpConnection(srs_netfd_t c);
    virtual ~SrsTcpConnection();
public:
    virtual srs_error_t initialize();
public:
    // Set socket option TCP_NODELAY.
    virtual srs_error_t set_tcp_nodelay(bool v);
    // Set socket option SO_SNDBUF in srs_utime_t.
    virtual srs_error_t set_socket_buffer(srs_utime_t buffer_v);
// Interface ISrsProtocolReadWriter
public:
    virtual void set_recv_timeout(srs_utime_t tm);
    virtual srs_utime_t get_recv_timeout();
    virtual srs_error_t read_fully(void* buf, size_t size, ssize_t* nread);
    virtual int64_t get_recv_bytes();
    virtual int64_t get_send_bytes();
    virtual srs_error_t read(void* buf, size_t size, ssize_t* nread);
    virtual void set_send_timeout(srs_utime_t tm);
    virtual srs_utime_t get_send_timeout();
    virtual srs_error_t write(void* buf, size_t size, ssize_t* nwrite);
    virtual srs_error_t writev(const iovec *iov, int iov_size, ssize_t* nwrite);
};

// The SSL connection over TCP transport, in server mode.
class SrsSslConnection : public ISrsProtocolReadWriter
{
private:
    // The under-layer plaintext transport.
    ISrsProtocolReadWriter* transport;
private:
    SSL_CTX* ssl_ctx;
    SSL* ssl;
    BIO* bio_in;
    BIO* bio_out;
public:
    SrsSslConnection(ISrsProtocolReadWriter* c);
    virtual ~SrsSslConnection();
public:
    virtual srs_error_t handshake(std::string key_file, std::string crt_file);
// Interface ISrsProtocolReadWriter
public:
    virtual void set_recv_timeout(srs_utime_t tm);
    virtual srs_utime_t get_recv_timeout();
    virtual srs_error_t read_fully(void* buf, size_t size, ssize_t* nread);
    virtual int64_t get_recv_bytes();
    virtual int64_t get_send_bytes();
    virtual srs_error_t read(void* buf, size_t size, ssize_t* nread);
    virtual void set_send_timeout(srs_utime_t tm);
    virtual srs_utime_t get_send_timeout();
    virtual srs_error_t write(void* buf, size_t size, ssize_t* nwrite);
    virtual srs_error_t writev(const iovec *iov, int iov_size, ssize_t* nwrite);
};

#endif