/* XMRig
 * Copyright (c) 2014-2019 heapwolf    <https://github.com/heapwolf>
 * Copyright (c) 2018-2021 SChernykh   <https://github.com/SChernykh>
 * Copyright (c) 2016-2021 XMRig       <https://github.com/xmrig>, <support@xmrig.com>
 *
 *   This program is free software: you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation, either version 3 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program. If not, see <http://www.gnu.org/licenses/>.
 */


#include "base/net/http/HttpClient.h"
#include "3rdparty/llhttp/llhttp.h"
#include "base/io/log/Log.h"
#include "base/kernel/Platform.h"
#include "base/net/dns/Dns.h"
#include "base/net/dns/DnsRecords.h"
#include "base/net/tools/NetBuffer.h"
#include "base/tools/Timer.h"


#include <sstream>
#include <uv.h>


namespace xmrig {


static const char *kCRLF = "\r\n";


} // namespace xmrig


xmrig::HttpClient::HttpClient(const char *tag, FetchRequest &&req, const std::weak_ptr<IHttpListener> &listener) :
    HttpContext(HTTP_RESPONSE, listener),
    m_tag(tag),
    m_req(std::move(req))
{
    method  = m_req.method;
    url     = std::move(m_req.path);
    body    = std::move(m_req.body);
    headers = std::move(m_req.headers);

    if (m_req.timeout) {
        m_timer = std::make_shared<Timer>(this, m_req.timeout, 0);
    }
}


bool xmrig::HttpClient::connect()
{
    m_dns = Dns::resolve(m_req.host, this);

    return true;
}


void xmrig::HttpClient::onResolved(const DnsRecords &records, int status, const char *error)
{
    this->status = status;
    m_dns.reset();

    if (status < 0 && records.isEmpty()) {
        if (!isQuiet()) {
            LOG_ERR("%s " RED("DNS error: ") RED_BOLD("\"%s\""), tag(), error);
        }

        return;
    }

    auto req  = new uv_connect_t;
    req->data = this;

    uv_tcp_connect(req, m_tcp, records.get().addr(port()), onConnect);
}


void xmrig::HttpClient::onTimer(const Timer *)
{
    close(UV_ETIMEDOUT);
}


void xmrig::HttpClient::handshake()
{
    headers.insert({ "Host",       host() });
    headers.insert({ "Connection", "close" });
    headers.insert({ "User-Agent", Platform::userAgent().data() });

    if (!body.empty()) {
        headers.insert({ "Content-Length", std::to_string(body.size()) });
    }

    std::stringstream ss;
    ss << llhttp_method_name(static_cast<llhttp_method>(method)) << " " << url << " HTTP/1.1" << kCRLF;

    for (auto &header : headers) {
        ss << header.first << ": " << header.second << kCRLF;
    }

    ss << kCRLF;

    headers.clear();

    body.insert(0, ss.str());
    write(std::move(body), false);
}


void xmrig::HttpClient::read(const char *data, size_t size)
{
    if (parse(data, size) < size) {
        close(UV_EPROTO);
    }
}


void xmrig::HttpClient::onConnect(uv_connect_t *req, int status)
{
    auto client = static_cast<HttpClient *>(req->data);
    delete req;

    if (!client) {
        return;
    }

    if (status < 0) {
        if (status == UV_ECANCELED) {
            status = UV_ETIMEDOUT;
        }

        if (!client->isQuiet()) {
            LOG_ERR("%s " RED("connect error: ") RED_BOLD("\"%s\""), client->tag(), uv_strerror(status));
        }

        return client->close(status);
    }

    uv_read_start(client->stream(), NetBuffer::onAlloc,
        [](uv_stream_t *tcp, ssize_t nread, const uv_buf_t *buf)
        {
            auto client = static_cast<HttpClient*>(tcp->data);

            if (nread >= 0) {
                client->read(buf->base, static_cast<size_t>(nread));
            } else {
                if (!client->isQuiet() && nread != UV_EOF) {
                    LOG_ERR("%s " RED("read error: ") RED_BOLD("\"%s\""), client->tag(), uv_strerror(static_cast<int>(nread)));
                }

                client->close(static_cast<int>(nread));
            }

            NetBuffer::release(buf);
        });

    client->handshake();
}