/*
 * Copyright 2009-2017 Alibaba Cloud All rights reserved.
 * 
 * Licensed 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 "SignUtils.h"
#include "Utils.h"
#include <sstream>
#include <map>
#include <set>
#include <alibabacloud/oss/Const.h>
#include <alibabacloud/oss/Types.h>
#include <alibabacloud/oss/http/HttpType.h>

using namespace AlibabaCloud::OSS;

const static std::set<std::string> ParamtersToSign =
{
    "acl", "location", "bucketInfo", "stat", "referer", "cors", "website", "restore",
    "logging", "symlink", "qos", "uploadId", "uploads", "partNumber",
    "response-content-type", "response-content-language", "response-expires",
    "response-cache-control", "response-content-disposition", "response-content-encoding",
    "append", "position", "lifecycle", "delete", "live", "status", "comp", "vod",
    "startTime", "endTime", "x-oss-process", "security-token", "objectMeta",
    "callback", "callback-var", "tagging", "policy", "requestPayment", "x-oss-traffic-limit",
    "encryption", "qosInfo", "versioning", "versionId", "versions",
    "x-oss-request-payer", "sequential", "inventory", "inventoryId", "continuation-token"
};

SignUtils::SignUtils(const std::string &version):
    signVersion_(version),
    canonicalString_()
{
}

SignUtils::~SignUtils()
{
}

const std::string &SignUtils::CanonicalString() const
{
    return canonicalString_;
}

void SignUtils::build(const std::string &method, 
                      const std::string &resource, 
                      const std::string &date,
                      const HeaderCollection &headers,
                      const ParameterCollection &parameters)
{
    std::stringstream ss;

    /*Version 1*/
    // VERB + "\n" +
    // Content-MD5 + "\n"  +
    // Content-Type + "\n" 
    // Date + "\n"  +
    // CanonicalizedOSSHeaders +
    // CanonicalizedResource) +

    //common headers
    ss << method << "\n";
    if (headers.find(Http::CONTENT_MD5) != headers.end()) {
        ss << headers.at(Http::CONTENT_MD5);
    }
    ss << "\n";
    if (headers.find(Http::CONTENT_TYPE) != headers.end()) {
        ss << headers.at(Http::CONTENT_TYPE);
    }
    ss << "\n";
    //Date or EXPIRES
    ss << date << "\n";

    //CanonicalizedOSSHeaders, start with x-oss-
    for (const auto &header : headers) {
        std::string lower = Trim(ToLower(header.first.c_str()).c_str());
        if (lower.compare(0, 6, "x-oss-", 6) == 0) {
            std::string value = Trim(header.second.c_str());
            ss << lower << ":" << value << "\n";
        }
    }

    //CanonicalizedResource, the sub resouce in
    ss << resource;
    char separator = '?';
    for (auto const& param : parameters) {
        if (ParamtersToSign.find(param.first) == ParamtersToSign.end()) {
            continue;
        }

        ss << separator;
        ss << param.first;
        if (!param.second.empty()) {
            ss << "=" << param.second;
        }
        separator = '&';
    }

    canonicalString_ = ss.str();
}

void SignUtils::build(const std::string &expires,
    const std::string &resource,
    const ParameterCollection &parameters)
{
    std::stringstream ss;
    ss << expires << '\n';
    for(auto const& param : parameters)
    {
        ss << param.first << ":" << param.second << '\n';
    }
    ss << resource;
    canonicalString_ = ss.str();
}