// 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/utils.h"

#include <fcntl.h>

#include <stdint.h>

#include <sys/stat.h>

#include <unistd.h>

#include <ostream>

#include <string>

#include <unordered_map>

#include <vector>

#include "common/config.h"

#include "common/logging.h"

#include "common/status.h"

#include "common/utils.h"

#include "http/http_channel.h"

#include "http/http_client.h"

#include "http/http_common.h"

#include "http/http_headers.h"

#include "http/http_method.h"

#include "http/http_request.h"

#include "http/http_status.h"

#include "io/fs/file_system.h"

#include "io/fs/local_file_system.h"

#include "olap/wal/wal_manager.h"

#include "runtime/exec_env.h"

#include "util/md5.h"

#include "util/path_util.h"

#include "util/security.h"

#include "util/url_coding.h"

namespace doris {

const uint32_t CHECK_SUPPORT_TIMEOUT = 3;

const uint32_t DOWNLOAD_FILE_MAX_RETRY = 3;

const uint32_t LIST_REMOTE_FILE_TIMEOUT = 15;

std::string encode_basic_auth(const std::string& user, const std::string& passwd) {

    std::string auth = user + ":" + passwd;

    std::string encoded_auth;

    base64_encode(auth, &encoded_auth);

    static std::string s_prefix = "Basic ";

    return s_prefix + encoded_auth;

}

bool parse_basic_auth(const HttpRequest& req, std::string* user, std::string* passwd) {

    const char k_basic[] = "Basic ";

    const auto& auth = req.header(HttpHeaders::AUTHORIZATION);

    if (auth.compare(0, sizeof(k_basic) - 1, k_basic, sizeof(k_basic) - 1) != 0) {

        return false;

    }

    std::string encoded_str = auth.substr(sizeof(k_basic) - 1);

    std::string decoded_auth;

    if (!base64_decode(encoded_str, &decoded_auth)) {

        return false;

    }

    auto pos = decoded_auth.find(':');

    if (pos == std::string::npos) {

        return false;

    }

    user->assign(decoded_auth.c_str(), pos);

    passwd->assign(decoded_auth.c_str() + pos + 1);

    return true;

}

bool parse_basic_auth(const HttpRequest& req, AuthInfo* auth) {

    const auto& token = req.header("token");

    const auto& auth_code = req.header(HTTP_AUTH_CODE);

    if (!token.empty()) {

        auth->token = token;

    } else if (!auth_code.empty()) {

        auth->auth_code = std::stoll(auth_code);

    } else {

        std::string full_user;

        if (!parse_basic_auth(req, &full_user, &auth->passwd)) {

            return false;

        }

        auto pos = full_user.find('@');

        if (pos != std::string::npos) {

            auth->user.assign(full_user.data(), pos);

            auth->cluster.assign(full_user.data() + pos + 1);

        } else {

            auth->user = full_user;

        }

    }

    // set user ip

    if (req.remote_host() != nullptr) {

        auth->user_ip.assign(req.remote_host());

    } else {

        auth->user_ip.assign("");

    }

    return true;

}

// Do a simple decision, only deal a few type

std::string get_content_type(const std::string& file_name) {

    std::string file_ext = path_util::file_extension(file_name);

    VLOG_TRACE << "file_name: " << file_name << "; file extension: [" << file_ext << "]";

    if (file_ext == std::string(".html") || file_ext == std::string(".htm")) {

        return "text/html; charset=utf-8";

    } else if (file_ext == std::string(".js")) {

        return "application/javascript; charset=utf-8";

    } else if (file_ext == std::string(".css")) {

        return "text/css; charset=utf-8";

    } else if (file_ext == std::string(".txt")) {

        return "text/plain; charset=utf-8";

    } else if (file_ext == std::string(".png")) {

        return "image/png";

    } else if (file_ext == std::string(".ico")) {

        return "image/x-icon";

    } else {

        return "text/plain; charset=utf-8";

    }

}

void do_file_response(const std::string& file_path, HttpRequest* req,

                      bufferevent_rate_limit_group* rate_limit_group, bool is_acquire_md5) {

    if (file_path.find("..") != std::string::npos) {

        LOG(WARNING) << "Not allowed to read relative path: " << file_path;

        HttpChannel::send_error(req, HttpStatus::FORBIDDEN);

        return;

    }

    // read file content and send response

    int fd = open(file_path.c_str(), O_RDONLY);

    if (fd < 0) {

        LOG(WARNING) << "Failed to open file: " << file_path;

        HttpChannel::send_error(req, HttpStatus::NOT_FOUND);

        return;

    }

    struct stat st;

    auto res = fstat(fd, &st);

    if (res < 0) {

        close(fd);

        LOG(WARNING) << "Failed to open file: " << file_path;

        HttpChannel::send_error(req, HttpStatus::NOT_FOUND);

        return;

    }

    int64_t file_size = st.st_size;

    // TODO(lingbin): process "IF_MODIFIED_SINCE" header

    // TODO(lingbin): process "RANGE" header

    const std::string& range_header = req->header(HttpHeaders::RANGE);

    if (!range_header.empty()) {

        // analyse range header

    }

    req->add_output_header(HttpHeaders::CONTENT_TYPE, get_content_type(file_path).c_str());

    if (is_acquire_md5) {

        Md5Digest md5;

        void* buf = mmap(nullptr, file_size, PROT_READ, MAP_SHARED, fd, 0);

        md5.update(buf, file_size);

        md5.digest();

        munmap(buf, file_size);

        req->add_output_header(HttpHeaders::CONTENT_MD5, md5.hex().c_str());

    }

    if (req->method() == HttpMethod::HEAD) {

        close(fd);

        req->add_output_header(HttpHeaders::CONTENT_LENGTH, std::to_string(file_size).c_str());

        HttpChannel::send_reply(req);

        return;

    }

    HttpChannel::send_file(req, fd, 0, file_size, rate_limit_group);

}

void do_dir_response(const std::string& dir_path, HttpRequest* req, bool is_acquire_filesize) {

    bool exists = true;

    std::vector<io::FileInfo> files;

    Status st = io::global_local_filesystem()->list(dir_path, true, &files, &exists);

    if (!st.ok()) {

        LOG(WARNING) << "Failed to scan dir. " << st;

        HttpChannel::send_error(req, HttpStatus::INTERNAL_SERVER_ERROR);

        return;

    }

    VLOG_DEBUG << "list dir: " << dir_path << ", file count: " << files.size();

    const std::string FILE_DELIMITER_IN_DIR_RESPONSE = "\n";

    std::stringstream result;

    for (auto& file : files) {

        result << file.file_name << FILE_DELIMITER_IN_DIR_RESPONSE;

        if (is_acquire_filesize) {

            result << file.file_size << FILE_DELIMITER_IN_DIR_RESPONSE;

        }

    }

    std::string result_str = result.str();

    HttpChannel::send_reply(req, result_str);

}

bool load_size_smaller_than_wal_limit(int64_t content_length) {

    // 1. req->header(HttpHeaders::CONTENT_LENGTH) will return streamload content length. If it is empty or equals to 0, it means this streamload

    // is a chunked streamload and we are not sure its size.

    // 2. if streamload content length is too large, like larger than 80% of the WAL constrain.

    //

    // This two cases, we are not certain that the Write-Ahead Logging (WAL) constraints allow for writing down

    // these blocks within the limited space. So we need to set group_commit = false to avoid dead lock.

    size_t max_available_size = ExecEnv::GetInstance()->wal_mgr()->get_max_available_size();

    return (content_length < 0.8 * max_available_size);

}

Status is_support_batch_download(const std::string& endpoint) {

    std::string url = fmt::format("http://{}/api/_tablet/_batch_download?check=true", endpoint);

    auto check_support_cb = [&url](HttpClient* client) {

        RETURN_IF_ERROR(client->init(url));

        client->set_timeout_ms(CHECK_SUPPORT_TIMEOUT * 1000);

        client->set_method(HttpMethod::HEAD);

        std::string response;

        return client->execute(&response);

    };

    return HttpClient::execute_with_retry(DOWNLOAD_FILE_MAX_RETRY, 1, check_support_cb);

}

Status list_remote_files_v2(const std::string& address, const std::string& token,

                            const std::string& remote_dir,

                            std::vector<std::pair<std::string, size_t>>* file_info_list) {

    std::string remote_url =

            fmt::format("http://{}/api/_tablet/_batch_download?token={}&dir={}&list=true", address,

                        token, remote_dir);

    std::string file_list_str;

    auto list_files_cb = [&](HttpClient* client) {

        file_list_str.clear();

        RETURN_IF_ERROR(client->init(remote_url, false));

        client->set_method(HttpMethod::GET);

        client->set_timeout_ms(LIST_REMOTE_FILE_TIMEOUT * 1000);

        return client->execute(&file_list_str);

    };

    Status status = HttpClient::execute_with_retry(DOWNLOAD_FILE_MAX_RETRY, 1, list_files_cb);

    if (!status.ok()) {

        LOG(WARNING) << "failed to list remote files from " << remote_url

                     << ", status: " << status.to_string() << ", response: " << file_list_str;

        return status;

    }

    std::vector<string> file_list = strings::Split(file_list_str, "\n", strings::SkipWhitespace());

    if (file_list.size() % 2 != 0) {

        return Status::InternalError("batch download files: invalid file list, size is not even");

    }

    VLOG_DEBUG << "list remote files from " << remote_url

               << ", file count: " << file_list.size() / 2;

    for (size_t i = 0; i < file_list.size(); i += 2) {

        uint64_t file_size = 0;

        try {

            file_size = std::stoull(file_list[i + 1]);

        } catch (std::exception&) {

            return Status::InternalError("batch download files: invalid file size format: " +

                                         file_list[i + 1]);

        }

        file_info_list->emplace_back(std::move(file_list[i]), file_size);

    }

    return Status::OK();

}

Status download_files_v2(const std::string& address, const std::string& token,

                         const std::string& remote_dir, const std::string& local_dir,

                         const std::vector<std::pair<std::string, size_t>>& file_info_list) {

    std::string remote_url = fmt::format("http://{}/api/_tablet/_batch_download?dir={}&token={}",

                                         address, remote_dir, token);

    size_t batch_file_size = 0;

    std::unordered_set<std::string> expected_files;

    std::stringstream ss;

    for (const auto& file_info : file_info_list) {

        ss << file_info.first << "\n";

        batch_file_size += file_info.second;

        expected_files.insert(file_info.first);

    }

    std::string payload = ss.str();

    uint64_t estimate_timeout = batch_file_size / config::download_low_speed_limit_kbps / 1024;

    if (estimate_timeout < config::download_low_speed_time) {

        estimate_timeout = config::download_low_speed_time;

    }

    LOG(INFO) << "begin to download files from " << remote_url << " to " << local_dir

              << ", file count: " << file_info_list.size() << ", total size: " << batch_file_size

              << ", timeout: " << estimate_timeout;

    auto callback = [&](HttpClient* client) -> Status {

        RETURN_IF_ERROR(client->init(remote_url, false));

        client->set_method(HttpMethod::POST);

        client->set_payload(payload);

        client->set_timeout_ms(estimate_timeout * 1000);

        RETURN_IF_ERROR(client->download_multi_files(local_dir, expected_files));

        for (auto&& [file_name, file_size] : file_info_list) {

            std::string local_file_path = local_dir + "/" + file_name;

            std::error_code ec;

            // Check file length

            uint64_t local_file_size = std::filesystem::file_size(local_file_path, ec);

            if (ec) {

                LOG(WARNING) << "download file error: " << ec.message();

                return Status::IOError("can't retrive file_size of {}, due to {}", local_file_path,

                                       ec.message());

            }

            if (local_file_size != file_size) {

                LOG(WARNING) << "download file length error"

                             << ", remote_path=" << mask_token(remote_url)

                             << ", file_name=" << file_name << ", file_size=" << file_size

                             << ", local_file_size=" << local_file_size;

                return Status::InternalError("downloaded file size is not equal");

            }

            RETURN_IF_ERROR(io::global_local_filesystem()->permission(

                    local_file_path, io::LocalFileSystem::PERMS_OWNER_RW));

        }

        return Status::OK();

    };

    return HttpClient::execute_with_retry(DOWNLOAD_FILE_MAX_RETRY, 1, callback);

}

} // namespace doris