// Licensed to the Apache Software Foundation (ASF) under one

// or more contributor license agreements.  See the NOTICE file

// distributed with this work for additional information

// regarding copyright ownership.  The ASF licenses this file

// to you under the Apache License, Version 2.0 (the

// "License"); you may not use this file except in compliance

// with the License.  You may obtain a copy of the License at

//

//   http://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing,

// software distributed under the License is distributed on an

// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY

// KIND, either express or implied.  See the License for the

// specific language governing permissions and limitations

// under the License.

#include "http/http_channel.h"

#include <event2/buffer.h>

#include <event2/bufferevent.h>

#include <event2/http.h>

#include <algorithm>

#include <sstream>

#include <string>

#include <vector>

#include "common/logging.h"

#include "common/status.h"

#include "gutil/strings/split.h"

#include "gutil/strings/strip.h"

#include "http/http_headers.h"

#include "http/http_request.h"

#include "http/http_status.h"

#include "util/slice.h"

#include "util/zlib.h"

namespace doris {

// Send Unauthorized status with basic challenge

void HttpChannel::send_basic_challenge(HttpRequest* req, const std::string& realm) {

    static std::string s_prompt_str = "Please provide your userid and password\n";

    std::stringstream ss;

    ss << "Basic realm=\"" << realm << "\"";

    req->add_output_header(HttpHeaders::WWW_AUTHENTICATE, ss.str().c_str());

    send_reply(req, HttpStatus::UNAUTHORIZED, s_prompt_str);

}

void HttpChannel::send_error(HttpRequest* request, HttpStatus status) {

    evhttp_send_error(request->get_evhttp_request(), status, default_reason(status).c_str());

}

void HttpChannel::send_reply(HttpRequest* request, HttpStatus status) {

    evhttp_send_reply(request->get_evhttp_request(), status, default_reason(status).c_str(),

                      nullptr);

}

void HttpChannel::send_reply(HttpRequest* request, HttpStatus status, const std::string& content) {

    auto evb = evbuffer_new();

    std::string compressed_content;

    if (compress_content(request->header(HttpHeaders::ACCEPT_ENCODING), content,

                         &compressed_content)) {

        request->add_output_header(HttpHeaders::CONTENT_ENCODING, "gzip");

        evbuffer_add(evb, compressed_content.c_str(), compressed_content.size());

    } else {

        evbuffer_add(evb, content.c_str(), content.size());

    }

    evhttp_send_reply(request->get_evhttp_request(), status, default_reason(status).c_str(), evb);

    evbuffer_free(evb);

}

void HttpChannel::send_file(HttpRequest* request, int fd, size_t off, size_t size,

                            bufferevent_rate_limit_group* rate_limit_group) {

    auto evb = evbuffer_new();

    evbuffer_add_file(evb, fd, off, size);

    auto* evhttp_request = request->get_evhttp_request();

    if (rate_limit_group) {

        auto* evhttp_connection = evhttp_request_get_connection(evhttp_request);

        auto* buffer_event = evhttp_connection_get_bufferevent(evhttp_connection);

        bufferevent_add_to_rate_limit_group(buffer_event, rate_limit_group);

    }

    evhttp_send_reply(evhttp_request, HttpStatus::OK, default_reason(HttpStatus::OK).c_str(), evb);

    evbuffer_free(evb);

}

bool HttpChannel::compress_content(const std::string& accept_encoding, const std::string& input,

                                   std::string* output) {

    // Don't bother compressing empty content.

    if (input.empty()) {

        return false;

    }

    // Check if gzip compression is accepted by the caller. If so, compress the

    // content and replace the prerendered output.

    bool is_compressed = false;

    std::vector<string> encodings = strings::Split(accept_encoding, ",");

    for (string& encoding : encodings) {

        StripWhiteSpace(&encoding);

        if (encoding == "gzip") {

            std::ostringstream oss;

            Status s = zlib::CompressLevel(Slice(input), 1, &oss);

            if (s.ok()) {

                *output = oss.str();

                is_compressed = true;

            } else {

                LOG(WARNING) << "Could not compress output: " << s.to_string();

            }

            break;

        }

    }

    return is_compressed;

}

} // namespace doris