/*  This file is part of FediBlock-backend.
 *  Copyright © 2020 tastytea <tastytea@tastytea.de>
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU Affero General Public License as published by
 *  the Free Software Foundation, version 3.
 *
 *  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 Affero General Public License for more details.
 *
 *  You should have received a copy of the GNU Affero General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "gitea.hpp"

#include "config.hpp"
#include "files.hpp"
#include "json.hpp"
#include "types.hpp"

#include <curl/curl.h>
#include <fmt/format.h>
#include <nlohmann/json.hpp>

#include <stdexcept>
#include <string>
#include <string_view>

namespace FediBlock::gitea
{

using fmt::format;
using std::runtime_error;
using std::string;
using std::string_view;
using std::to_string;

CURL *_connection;
string _curl_buffer_body;
uint64_t _last_pr_number{0};

void init()
{
    _connection = curl_easy_init();

    // NOLINTNEXTLINE(cppcoreguidelines-pro-type-vararg)
    CURLcode code{curl_easy_setopt(_connection, CURLOPT_FOLLOWLOCATION, 1L)};
    if (code != CURLE_OK)
    {
        throw runtime_error{"HTTP is not supported."};
    }
    // NOLINTNEXTLINE(cppcoreguidelines-pro-type-vararg)
    curl_easy_setopt(_connection, CURLOPT_MAXREDIRS, 5L);

    // Add extra headers.
    struct curl_slist *headers{nullptr};
    string authheader{"Authorization: token " + files::get_access_token()};
    headers = curl_slist_append(headers, authheader.c_str());
    headers = curl_slist_append(headers, "Accept: application/json");
    headers = curl_slist_append(headers, "Content-Type: application/json");
    // NOLINTNEXTLINE(cppcoreguidelines-pro-type-vararg)
    code = curl_easy_setopt(_connection, CURLOPT_HTTPHEADER, headers);
    if (code != CURLE_OK)
    {
        throw runtime_error{"Could not add headers"};
    }

    // NOLINTNEXTLINE(cppcoreguidelines-pro-type-vararg)
    curl_easy_setopt(_connection, CURLOPT_WRITEFUNCTION, writer_body);
}

void cleanup()
{
    curl_easy_cleanup(gitea::_connection);
}

size_t writer_body(char *data, size_t size, size_t nmemb)
{
    if (data == nullptr)
    {
        return 0;
    }

    _curl_buffer_body.append(data, size * nmemb);

    return size * nmemb;
}

string api_request(const http_method method, const string_view path,
                   const string_view body)
{
    CURLcode code{};
    string url{format("https://{:s}{:s}", config::forge_domain, path)};
    _curl_buffer_body.clear();

    switch (method)
    {
    case http_method::GET:
    {
        // NOLINTNEXTLINE(cppcoreguidelines-pro-type-vararg)
        curl_easy_setopt(_connection, CURLOPT_HTTPGET, 1L);
        url += body;

        break;
    }
    case http_method::POST:
    {
        // NOLINTNEXTLINE(cppcoreguidelines-pro-type-vararg)
        curl_easy_setopt(_connection, CURLOPT_POSTFIELDSIZE, body.size());
        // NOLINTNEXTLINE(cppcoreguidelines-pro-type-vararg)
        code = curl_easy_setopt(_connection, CURLOPT_POSTFIELDS, body.data());
        if (code != CURLE_OK)
        {
            throw runtime_error{"Couldn't set up data to send"};
        }
        break;
    }
    }

    // NOLINTNEXTLINE(cppcoreguidelines-pro-type-vararg)
    code = curl_easy_setopt(_connection, CURLOPT_URL, url.c_str());
    if (code != CURLE_OK)
    {
        throw runtime_error{format("Couldn't set URL: {:d}", code)};
    }

    code = curl_easy_perform(_connection);
    if (code != CURLE_OK)
    {
        throw runtime_error{format("libcurl error: {:d}", code)};
    }

    long http_status{0}; // NOLINT(google-runtime-int)
    // NOLINTNEXTLINE(cppcoreguidelines-pro-type-vararg)
    curl_easy_getinfo(_connection, CURLINFO_RESPONSE_CODE, &http_status);
    if (http_status < 200 || http_status >= 300)
    {
        throw runtime_error{format("HTTP error: {:d}", http_status)};
    }

    return _curl_buffer_body;
}

void pull_request(const string_view branch, const entry_type &entry)
{
    api_request(http_method::POST,
                format("/api/v1/repos/{:s}/{:s}/pulls", config::forge_org,
                       config::forge_repo_data),
                json::pull_request_body(branch, entry));
    ++_last_pr_number;
}

uint64_t get_last_pr_number()
{
    if (_last_pr_number == 0)
    {
        const auto answer{
            api_request(http_method::GET,
                        format("/api/v1/repos/{:s}/{:s}/pulls",
                               config::forge_org, config::forge_repo_data),
                        "?sort=newest&limit=1")};
        if (answer == "[]")
        {
            return 0;
        }
        const auto json{nlohmann::json::parse(answer)};
        _last_pr_number = json.front().front()["number"].get<uint64_t>();
    }

    return _last_pr_number;
}

} // namespace FediBlock::gitea