#include <stdio.h>
#include <string.h>
#include "util/I2PEndian.h"
#include <fstream>
#include <boost/lexical_cast.hpp>
#include <cryptopp/sha.h>
#include <cryptopp/dsa.h>
#include "crypto/CryptoConst.h"
#include "util/base64.h"
#include "util/Timestamp.h"
#include "util/Log.h"
#include "RouterInfo.h"
#include "RouterContext.h"


namespace i2p
{
namespace data
{       
    RouterInfo::RouterInfo (const std::string& fullPath):
        m_FullPath (fullPath), m_IsUpdated (false), m_IsUnreachable (false), 
        m_SupportedTransports (0), m_Caps (0)
    {
        m_Buffer = new uint8_t[MAX_RI_BUFFER_SIZE];
        ReadFromFile ();
    }   

    RouterInfo::RouterInfo (const uint8_t * buf, int len):
        m_IsUpdated (true), m_IsUnreachable (false), m_SupportedTransports (0), m_Caps (0)
    {
        m_Buffer = new uint8_t[MAX_RI_BUFFER_SIZE];
        memcpy (m_Buffer, buf, len);
        m_BufferLen = len;
        ReadFromBuffer (true);
    }   

    RouterInfo::~RouterInfo ()
    {
        delete[] m_Buffer;
    }   
        
    void RouterInfo::Update (const uint8_t * buf, int len)
    {
        if (!m_Buffer)  
            m_Buffer = new uint8_t[MAX_RI_BUFFER_SIZE];
        m_IsUpdated = true;
        m_IsUnreachable = false;
        m_SupportedTransports = 0;
        m_Caps = 0;
        m_Addresses.clear ();
        m_Properties.clear ();
        memcpy (m_Buffer, buf, len);
        m_BufferLen = len;
        ReadFromBuffer (true);
        // don't delete buffer until saved to file
    }   
        
    void RouterInfo::SetRouterIdentity (const IdentityEx& identity)
    {   
        m_RouterIdentity = identity;
        m_Timestamp = i2p::util::GetMillisecondsSinceEpoch ();
    }
    
    bool RouterInfo::LoadFile ()
    {
        std::ifstream s(m_FullPath.c_str (), std::ifstream::binary);
        if (s.is_open ())   
        {   
            s.seekg (0,std::ios::end);
            m_BufferLen = s.tellg ();
            if (m_BufferLen < 40)
            {
                LogPrint(eLogError, "File", m_FullPath, " is malformed");
                return false;
            }
            s.seekg(0, std::ios::beg);
            if (!m_Buffer)
                m_Buffer = new uint8_t[MAX_RI_BUFFER_SIZE];
            s.read((char *)m_Buffer, m_BufferLen);
        }   
        else
        {
            LogPrint (eLogError, "Can't open file ", m_FullPath);
            return false;       
        }
        return true;
    }   

    void RouterInfo::ReadFromFile ()
    {
        if (LoadFile ())
            ReadFromBuffer (false); 
    }   

    void RouterInfo::ReadFromBuffer (bool verifySignature)
    {
        size_t identityLen = m_RouterIdentity.FromBuffer (m_Buffer, m_BufferLen);
        std::stringstream str (std::string ((char *)m_Buffer + identityLen, m_BufferLen - identityLen));
        ReadFromStream (str);
        if (verifySignature)
        {   
            // verify signature
            int l = m_BufferLen - m_RouterIdentity.GetSignatureLen ();
            if (!m_RouterIdentity.Verify ((uint8_t *)m_Buffer, l, (uint8_t *)m_Buffer + l))
            {   
                LogPrint (eLogError, "signature verification failed");  
                m_IsUnreachable = true;
            }
            m_RouterIdentity.DropVerifier ();
        }   
    }   
    
    void RouterInfo::ReadFromStream (std::istream& s)
    {
        s.read ((char *)&m_Timestamp, sizeof (m_Timestamp));
        m_Timestamp = be64toh (m_Timestamp);
        // read addresses
        uint8_t numAddresses;
        s.read ((char *)&numAddresses, sizeof (numAddresses));
        bool introducers = false;
        for (int i = 0; i < numAddresses; i++)
        {
            bool isValidAddress = true;
            Address address;
            s.read ((char *)&address.cost, sizeof (address.cost));
            s.read ((char *)&address.date, sizeof (address.date));
            char transportStyle[5];
            ReadString (transportStyle, s);
            if (!strcmp (transportStyle, "NTCP"))
                address.transportStyle = eTransportNTCP;
            else if (!strcmp (transportStyle, "SSU"))
                address.transportStyle = eTransportSSU;
            else
                address.transportStyle = eTransportUnknown;
            address.port = 0;
            address.mtu = 0;
            uint16_t size, r = 0;
            s.read ((char *)&size, sizeof (size));
            size = be16toh (size);
            while (r < size)
            {
                char key[500], value[500];
                r += ReadString (key, s);
                s.seekg (1, std::ios_base::cur); r++; // =
                r += ReadString (value, s); 
                s.seekg (1, std::ios_base::cur); r++; // ;
                if (!strcmp (key, "host"))
                {   
                    boost::system::error_code ecode;
                    address.host = boost::asio::ip::address::from_string (value, ecode);
                    if (ecode)
                    {   
                        if (address.transportStyle == eTransportNTCP)
                        {
                            m_SupportedTransports |= eNTCPV4; // TODO:
                            address.addressString = value;
                        }
                        else
                        {   
                            // TODO: resolve address for SSU
                            LogPrint (eLogWarning, "Unexpected SSU address ", value);
                            isValidAddress = false;
                        }   
                    }   
                    else
                    {
                        // add supported protocol
                        if (address.host.is_v4 ())
                            m_SupportedTransports |= (address.transportStyle == eTransportNTCP) ? eNTCPV4 : eSSUV4; 
                        else
                            m_SupportedTransports |= (address.transportStyle == eTransportNTCP) ? eNTCPV6 : eSSUV6;
                    }   
                }   
                else if (!strcmp (key, "port"))
                    address.port = boost::lexical_cast<int>(value);
                else if (!strcmp (key, "mtu"))
                    address.mtu = boost::lexical_cast<int>(value);
                else if (!strcmp (key, "key"))
                    i2p::util::Base64ToByteStream (value, strlen (value), address.key, 32);
                else if (!strcmp (key, "caps"))
                    ExtractCaps (value);
                else if (key[0] == 'i')
                {   
                    // introducers
                    introducers = true;
                    size_t l = strlen(key);     
                    unsigned char index = key[l-1] - '0'; // TODO:
                    key[l-1] = 0;
                    if (index >= address.introducers.size ())
                        address.introducers.resize (index + 1); 
                    Introducer& introducer = address.introducers.at (index);
                    if (!strcmp (key, "ihost"))
                    {
                        boost::system::error_code ecode;
                        introducer.iHost = boost::asio::ip::address::from_string (value, ecode);
                    }   
                    else if (!strcmp (key, "iport"))
                        introducer.iPort = boost::lexical_cast<int>(value);
                    else if (!strcmp (key, "itag"))
                        introducer.iTag = boost::lexical_cast<uint32_t>(value);
                    else if (!strcmp (key, "ikey"))
                        i2p::util::Base64ToByteStream (value, strlen (value), introducer.iKey, 32);
                }
            }   
            if (isValidAddress)
                m_Addresses.push_back(address);
        }   
        // read peers
        uint8_t numPeers;
        s.read ((char *)&numPeers, sizeof (numPeers));
        s.seekg (numPeers*32, std::ios_base::cur); // TODO: read peers
        // read properties
        uint16_t size, r = 0;
        s.read ((char *)&size, sizeof (size));
        size = be16toh (size);
        while (r < size)
        {
#ifdef _WIN32           
            char key[500], value[500];
            // TODO: investigate why properties get read as one long string under Windows
            // length should not be more than 44
#else
            char key[50], value[50];
#endif          
            r += ReadString (key, s);
            s.seekg (1, std::ios_base::cur); r++; // =
            r += ReadString (value, s); 
            s.seekg (1, std::ios_base::cur); r++; // ;
            m_Properties[key] = value;
            
            // extract caps 
            if (!strcmp (key, "caps"))
                ExtractCaps (value);
        }       

        if (!m_SupportedTransports || !m_Addresses.size() || (UsesIntroducer () && !introducers))
            SetUnreachable (true);
    }   

    void RouterInfo::ExtractCaps (const char * value)
    {
        const char * cap = value;
        while (*cap)
        {
            switch (*cap)
            {
                case CAPS_FLAG_FLOODFILL:
                    m_Caps |= Caps::eFloodfill;
                break;
                case CAPS_FLAG_HIGH_BANDWIDTH1:
                case CAPS_FLAG_HIGH_BANDWIDTH2:
                case CAPS_FLAG_HIGH_BANDWIDTH3:
                    m_Caps |= Caps::eHighBandwidth;
                break;
                case CAPS_FLAG_HIDDEN:
                    m_Caps |= Caps::eHidden;
                break;  
                case CAPS_FLAG_REACHABLE:
                    m_Caps |= Caps::eReachable;
                break;
                case CAPS_FLAG_UNREACHABLE:
                    m_Caps |= Caps::eUnreachable;
                break;  
                case CAPS_FLAG_SSU_TESTING:
                    m_Caps |= Caps::eSSUTesting;
                break;  
                case CAPS_FLAG_SSU_INTRODUCER:
                    m_Caps |= Caps::eSSUIntroducer;
                break;  
                default: ;
            }   
            cap++;
        }
    }

    void RouterInfo::UpdateCapsProperty ()
    {   
        std::string caps;
        if (m_Caps & eFloodfill) 
        {
            caps += CAPS_FLAG_HIGH_BANDWIDTH3; // highest bandwidth
            caps += CAPS_FLAG_FLOODFILL; // floodfill  
        }   
        else
            caps += (m_Caps & eHighBandwidth) ? CAPS_FLAG_HIGH_BANDWIDTH3 : CAPS_FLAG_LOW_BANDWIDTH2; // bandwidth      
        if (m_Caps & eHidden) caps += CAPS_FLAG_HIDDEN; // hidden
        if (m_Caps & eReachable) caps += CAPS_FLAG_REACHABLE; // reachable
        if (m_Caps & eUnreachable) caps += CAPS_FLAG_UNREACHABLE; // unreachable

        SetProperty ("caps", caps);
    }
        
    void RouterInfo::WriteToStream (std::ostream& s)
    {
        uint64_t ts = htobe64 (m_Timestamp);
        s.write ((char *)&ts, sizeof (ts));

        // addresses
        uint8_t numAddresses = m_Addresses.size ();
        s.write ((char *)&numAddresses, sizeof (numAddresses));
        for (auto& address : m_Addresses)
        {
            s.write ((char *)&address.cost, sizeof (address.cost));
            s.write ((char *)&address.date, sizeof (address.date));
            std::stringstream properties;
            if (address.transportStyle == eTransportNTCP)
                WriteString ("NTCP", s);
            else if (address.transportStyle == eTransportSSU)
            {   
                WriteString ("SSU", s);
                // caps
                WriteString ("caps", properties);
                properties << '=';
                std::string caps;
                if (IsPeerTesting ()) caps += CAPS_FLAG_SSU_TESTING;
                if (IsIntroducer ()) caps += CAPS_FLAG_SSU_INTRODUCER;
                WriteString (caps, properties);
                properties << ';';
            }   
            else
                WriteString ("", s);

            WriteString ("host", properties);
            properties << '=';
            WriteString (address.host.to_string (), properties);
            properties << ';';
            if (address.transportStyle == eTransportSSU)
            {
                // write introducers if any
                if (address.introducers.size () > 0)
                {   
                    int i = 0;
                    for (auto introducer: address.introducers)
                    {
                        WriteString ("ihost" + boost::lexical_cast<std::string>(i), properties);
                        properties << '=';
                        WriteString (introducer.iHost.to_string (), properties);
                        properties << ';';
                        i++;
                    }   
                    i = 0;
                    for (auto introducer: address.introducers)
                    {
                        WriteString ("ikey" + boost::lexical_cast<std::string>(i), properties);
                        properties << '=';
                        char value[64];
                        size_t l = i2p::util::ByteStreamToBase64 (introducer.iKey, 32, value, 64);
                        value[l] = 0;
                        WriteString (value, properties);
                        properties << ';';
                        i++;
                    }   
                    i = 0;
                    for (auto introducer: address.introducers)
                    {
                        WriteString ("iport" + boost::lexical_cast<std::string>(i), properties);
                        properties << '=';
                        WriteString (boost::lexical_cast<std::string>(introducer.iPort), properties);
                        properties << ';';
                        i++;
                    }   
                    i = 0;
                    for (auto introducer: address.introducers)
                    {
                        WriteString ("itag" + boost::lexical_cast<std::string>(i), properties);
                        properties << '=';
                        WriteString (boost::lexical_cast<std::string>(introducer.iTag), properties);
                        properties << ';';
                        i++;
                    }   
                }   
                // write intro key
                WriteString ("key", properties);
                properties << '=';
                char value[64];
                size_t l = i2p::util::ByteStreamToBase64 (address.key, 32, value, 64);
                value[l] = 0;
                WriteString (value, properties);
                properties << ';';
                // write mtu
                if (address.mtu)
                {
                    WriteString ("mtu", properties);
                    properties << '=';
                    WriteString (boost::lexical_cast<std::string>(address.mtu), properties);
                    properties << ';';
                }   
            }   
            WriteString ("port", properties);
            properties << '=';
            WriteString (boost::lexical_cast<std::string>(address.port), properties);
            properties << ';';
            
            uint16_t size = htobe16 (properties.str ().size ());
            s.write ((char *)&size, sizeof (size));
            s.write (properties.str ().c_str (), properties.str ().size ());
        }   

        // peers
        uint8_t numPeers = 0;
        s.write ((char *)&numPeers, sizeof (numPeers));

        // properties
        std::stringstream properties;
        for (auto& p : m_Properties)
        {
            WriteString (p.first, properties);
            properties << '=';
            WriteString (p.second, properties);
            properties << ';';
        }   
        uint16_t size = htobe16 (properties.str ().size ());
        s.write ((char *)&size, sizeof (size));
        s.write (properties.str ().c_str (), properties.str ().size ());
    }   

    const uint8_t * RouterInfo::LoadBuffer ()
    {
        if (!m_Buffer)
        {
            if (LoadFile ())
                LogPrint ("Buffer for ", GetIdentHashAbbreviation (), " loaded from file");
        } 
        return m_Buffer; 
    }

    void RouterInfo::CreateBuffer (const PrivateKeys& privateKeys)
    {
        m_Timestamp = i2p::util::GetMillisecondsSinceEpoch (); // refresh timestamp
        std::stringstream s;
        uint8_t ident[1024];
        auto identLen = privateKeys.GetPublic ().ToBuffer (ident, 1024);
        s.write ((char *)ident, identLen);          
        WriteToStream (s);
        m_BufferLen = s.str ().size ();
        if (!m_Buffer)
            m_Buffer = new uint8_t[MAX_RI_BUFFER_SIZE];
        memcpy (m_Buffer, s.str ().c_str (), m_BufferLen);
        // signature
        privateKeys.Sign ((uint8_t *)m_Buffer, m_BufferLen, (uint8_t *)m_Buffer + m_BufferLen);
        m_BufferLen += privateKeys.GetPublic ().GetSignatureLen ();
    }   

    void RouterInfo::SaveToFile (const std::string& fullPath)
    {
        m_FullPath = fullPath;
        if (m_Buffer)
        {   
            std::ofstream f (fullPath, std::ofstream::binary | std::ofstream::out);
            if (f.is_open ())
                f.write ((char *)m_Buffer, m_BufferLen);
            else
                LogPrint(eLogError, "Can't save RouterInfo to ", fullPath);
        }
        else
            LogPrint (eLogError, "Can't save RouterInfo m_Buffer==NULL");
    }
    
    size_t RouterInfo::ReadString (char * str, std::istream& s)
    {
        uint8_t len;
        s.read ((char *)&len, 1);
        s.read (str, len);
        str[len] = 0;
        return len+1;
    }   

    void RouterInfo::WriteString (const std::string& str, std::ostream& s)
    {
        uint8_t len = str.size ();
        s.write ((char *)&len, 1);
        s.write (str.c_str (), len);
    }   

    void RouterInfo::AddNTCPAddress (const char * host, int port)
    {
        Address addr;
        addr.host = boost::asio::ip::address::from_string (host);
        addr.port = port;
        addr.transportStyle = eTransportNTCP;
        addr.cost = 2;
        addr.date = 0;
        addr.mtu = 0;
        m_Addresses.push_back(addr);    
        m_SupportedTransports |= addr.host.is_v6 () ? eNTCPV6 : eNTCPV4;
    }   

    void RouterInfo::AddSSUAddress (const char * host, int port, const uint8_t * key, int mtu)
    {
        Address addr;
        addr.host = boost::asio::ip::address::from_string (host);
        addr.port = port;
        addr.transportStyle = eTransportSSU;
        addr.cost = 10; // NTCP should have priority over SSU
        addr.date = 0;
        addr.mtu = mtu; 
        memcpy (addr.key, key, 32);
        m_Addresses.push_back(addr);    
        m_SupportedTransports |= addr.host.is_v6 () ? eNTCPV6 : eSSUV4;
        m_Caps |= eSSUTesting; 
        m_Caps |= eSSUIntroducer; 
    }   

    bool RouterInfo::AddIntroducer (const Address * address, uint32_t tag)
    {
        for (auto& addr : m_Addresses)
        {
            if (addr.transportStyle == eTransportSSU && addr.host.is_v4 ())
            {   
                for (auto intro: addr.introducers)
                    if (intro.iTag == tag) return false; // already presented
                Introducer x;
                x.iHost = address->host;
                x.iPort = address->port;
                x.iTag = tag;
                memcpy (x.iKey, address->key, 32); // TODO: replace to Tag<32>
                addr.introducers.push_back (x);
                return true;
            }   
        }   
        return false;
    }   

    bool RouterInfo::RemoveIntroducer (const boost::asio::ip::udp::endpoint& e)
    {       
        for (auto& addr : m_Addresses)
        {
            if (addr.transportStyle == eTransportSSU && addr.host.is_v4 ())
            {   
                for (std::vector<Introducer>::iterator it = addr.introducers.begin (); it != addr.introducers.end (); it++)
                    if ( boost::asio::ip::udp::endpoint (it->iHost, it->iPort) == e) 
                    {
                        addr.introducers.erase (it);
                        return true;
                    }   
            }   
        }   
        return false;
    }

    void RouterInfo::SetCaps (uint8_t caps)
    {
        m_Caps = caps;
        UpdateCapsProperty ();
    }
        
    void RouterInfo::SetCaps (const char * caps)
    {
        SetProperty ("caps", caps);
        m_Caps = 0;
        ExtractCaps (caps);
    }   
        
    void RouterInfo::SetProperty (const std::string& key, const std::string& value)
    {
        m_Properties[key] = value;
    }   

    void RouterInfo::DeleteProperty (const std::string& key)
    {
        m_Properties.erase (key);
    }

    bool RouterInfo::IsFloodfill () const
    {
        return m_Caps & Caps::eFloodfill;
    }   

    bool RouterInfo::IsNTCP (bool v4only) const
    {
        if (v4only)
            return m_SupportedTransports & eNTCPV4;
        else
            return m_SupportedTransports & (eNTCPV4 | eNTCPV6);
    }       

    bool RouterInfo::IsSSU (bool v4only) const
    {
        if (v4only)
            return m_SupportedTransports & eSSUV4;
        else
            return m_SupportedTransports & (eSSUV4 | eSSUV6);
    }

    bool RouterInfo::IsV6 () const
    {
        return m_SupportedTransports & (eNTCPV6 | eSSUV6);
    }

    void RouterInfo::EnableV6 ()
    {
        if (!IsV6 ())
            m_SupportedTransports |= eNTCPV6 | eSSUV6;
    }
        
    void RouterInfo::DisableV6 ()
    {       
        if (IsV6 ())
        {   
            // NTCP
            m_SupportedTransports &= ~eNTCPV6; 
            for (size_t i = 0; i < m_Addresses.size (); i++)
            {
                if (m_Addresses[i].transportStyle == i2p::data::RouterInfo::eTransportNTCP &&
                    m_Addresses[i].host.is_v6 ())
                {
                    m_Addresses.erase (m_Addresses.begin () + i);
                    break;
                }
            }   
            
            // SSU
            m_SupportedTransports &= ~eSSUV6; 
            for (size_t i = 0; i < m_Addresses.size (); i++)
            {
                if (m_Addresses[i].transportStyle == i2p::data::RouterInfo::eTransportSSU &&
                    m_Addresses[i].host.is_v6 ())
                {
                    m_Addresses.erase (m_Addresses.begin () + i);
                    break;
                }
            }   
        }   
    }
        
    bool RouterInfo::UsesIntroducer () const
    {
        return m_Caps & Caps::eUnreachable; // non-reachable
    }       
        
    const RouterInfo::Address * RouterInfo::GetNTCPAddress (bool v4only) const
    {
        return GetAddress (eTransportNTCP, v4only);
    }   

    const RouterInfo::Address * RouterInfo::GetSSUAddress (bool v4only) const 
    {
        return GetAddress (eTransportSSU, v4only);
    }   

    const RouterInfo::Address * RouterInfo::GetSSUV6Address () const 
    {
        return GetAddress (eTransportSSU, false, true);
    }   
        
    const RouterInfo::Address * RouterInfo::GetAddress (TransportStyle s, bool v4only, bool v6only) const
    {
        for (auto& address : m_Addresses)
        {
            if (address.transportStyle == s)
            {   
                if ((!v4only || address.host.is_v4 ()) && (!v6only || address.host.is_v6 ()))
                    return &address;
            }   
        }   
        return nullptr;
    }   

    std::shared_ptr<RouterProfile> RouterInfo::GetProfile () const 
    {
        if (!m_Profile)
            m_Profile = GetRouterProfile (GetIdentHash ());
        return m_Profile;
    }   
}
}