//
//#include <mbgl/platform/platform.hpp>
//#include <mbgl/platform/request.hpp>
//#include <mbgl/util/uv_detail.hpp>
//#include <mbgl/util/std.hpp>
//
//#include <queue>
//#include <boost/lockfree/queue.hpp>
//
//#include <curl/curl.h>
//
//// This file contains code from http://curl.haxx.se/libcurl/c/multi-uv.html:
//
///***************************************************************************
// *                                  _   _ ____  _
// *  Project                     ___| | | |  _ \| |
// *                             / __| | | | |_) | |
// *                            | (__| |_| |  _ <| |___
// *                             \___|\___/|_| \_\_____|
// *
// * Copyright (C) 1998 - 2013, Daniel Stenberg, <daniel@haxx.se>, et al.
// *
// * This software is licensed as described in the file COPYING, which
// * you should have received as part of this distribution. The terms
// * are also available at http://curl.haxx.se/docs/copyright.html.
// *
// * You may opt to use, copy, modify, merge, publish, distribute and/or sell
// * copies of the Software, and permit persons to whom the Software is
// * furnished to do so, under the terms of the COPYING file.
// *
// * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
// * KIND, either express or implied.
// *
// ***************************************************************************/
//
///* Example application code using the multi socket interface to download
//   multiple files at once, but instead of using curl_multi_perform and
//   curl_multi_wait, which uses select(), we use libuv.
//   It supports epoll, kqueue, etc. on unixes and fast IO completion ports on
//   Windows, which means, it should be very fast on all platforms..
//
//   Written by Clemens Gruber, based on an outdated example from uvbook and
//   some tests from libuv.
//
//   Requires libuv and (of course) libcurl.
//
//   See http://nikhilm.github.com/uvbook/ for more information on libuv.
//*/
//
//namespace mbgl {
//namespace platform {
//namespace request {
//
//struct curl_context {
//    uv_poll_t poll_handle;
//    curl_socket_t sockfd;
//};
//
//// Handles the request thread + messaging to the thread.
//static uv_thread_t thread;
//static uv::once init_thread_once;
//static uv_loop_t *loop = nullptr;
//static uv_async_t async_add;
//static uv_async_t async_cancel;
//
//// Stores pointers (!) to shared_ptrs. We use shared_ptrs so that request objects don't get
//// auto-destructed while they're in progress. The TileData object retains a weak_ptr to this
//// request, so we have to use a shared_ptr here to ensure that this object stays alive.
//static boost::lockfree::queue<std::shared_ptr<mbgl::platform::Request> *> add_queue(8);
//static boost::lockfree::queue<std::shared_ptr<mbgl::platform::Request> *> cancel_queue(8);
//
//// Used as the CURL timer function to periodically check for socket updates.
//static uv_timer_t timeout;
//
//// CURL multi handle that we use to request multiple URLs at the same time, without having to block
//// and spawn threads.
//static CURLM *curl_multi = nullptr;
//
//// CURL share handles are used for sharing session state (e.g.)
//static uv::mutex curl_share_mutex;
//static CURLSH *curl_share = nullptr;
//
//// A queue that we use for storing resuable CURL easy handles to avoid creating and destroying them
//// all the time.
//static std::queue<CURL *> curl_handle_cache;
//
//
//class CURLRequest : public mbgl::platform::Request {
//public:
//    CURLRequest(const std::string &url,
//                std::function<void(mbgl::platform::Response *)> callback,
//                std::shared_ptr<uv::loop> loop)
//        : Request(url, callback, loop) {}
//
//    CURL *curl = nullptr;
//};
//
//
//// Implementation starts here.
//
//// Locks the CURL share handle
//void curl_share_lock(CURL *, curl_lock_data, curl_lock_access, void *) { curl_share_mutex.lock(); }
//
//// Unlocks the CURL share handle
//void curl_share_unlock(CURL *, curl_lock_data, void *) { curl_share_mutex.unlock(); }
//
//curl_context *create_curl_context(curl_socket_t sockfd) {
//    curl_context *context = new curl_context;
//    context->sockfd = sockfd;
//
//    uv_poll_init_socket(loop, &context->poll_handle, sockfd);
//    context->poll_handle.data = context;
//
//    return context;
//}
//
//void curl_close_cb(uv_handle_t *handle) {
//    curl_context *context = (curl_context *)handle->data;
//    free(context);
//}
//
//void destroy_curl_context(curl_context *context) {
//    uv_close((uv_handle_t *)&context->poll_handle, curl_close_cb);
//}
//
//void remove_curl_handle(CURL *handle) {
//    CURLMcode error = curl_multi_remove_handle(curl_multi, handle);
//    if (error != CURLM_OK) {
//        throw std::runtime_error(std::string("CURL multi error: ") + curl_multi_strerror(error));
//    }
//
//    curl_easy_reset(handle);
//    curl_handle_cache.push(handle);
//}
//
//void curl_perform(uv_poll_t *req, int /*status*/, int events) {
//    int running_handles;
//    int flags = 0;
//    curl_context *context;
//    CURLMsg *message;
//    int pending;
//
//    uv_timer_stop(&timeout);
//
//    if (events & UV_READABLE)
//        flags |= CURL_CSELECT_IN;
//    if (events & UV_WRITABLE)
//        flags |= CURL_CSELECT_OUT;
//
//    context = (curl_context *)req;
//
//    curl_multi_socket_action(curl_multi, context->sockfd, flags, &running_handles);
//
//    while ((message = curl_multi_info_read(curl_multi, &pending))) {
//        switch (message->msg) {
//        case CURLMSG_DONE: {
//            std::shared_ptr<Request> *req = nullptr;
//            curl_easy_getinfo(message->easy_handle, CURLINFO_PRIVATE, (char *)&req);
//
//            // Add human-readable error code
//            if (message->data.result != CURLE_OK) {
//                (*req)->res->error_message = curl_easy_strerror(message->data.result);
//                (*req)->res->code = -1;
//            } else {
//                curl_easy_getinfo(message->easy_handle, CURLINFO_RESPONSE_CODE, &(*req)->res->code);
//            }
//
//            // We're currently in the CURL request thread. We're going to schedule a uv_work request
//            // that executes the background function in a threadpool, and tell it to call the
//            // after callback back in the main uv loop.
//            (*req)->complete();
//
//            CURL *handle = message->easy_handle;
//            remove_curl_handle(handle);
//
//            // We're setting this to NULL because there might still be shared_ptrs around that could
//            // be cancelled.
//            ((CURLRequest *)req->get())->curl = nullptr;
//
//            // Delete the shared_ptr pointer we created earlier.
//            delete req;
//            break;
//        }
//
//        default:
//            // This should never happen, because there are no other message types.
//            throw std::runtime_error("CURLMSG returned unknown message type");
//        }
//    }
//}
//
//int handle_socket(CURL * /*easy*/, curl_socket_t s, int action, void * /*userp*/, void *socketp) {
//    curl_context *context = nullptr;
//
//    if (socketp) {
//        context = (curl_context *)socketp;
//    } else if (action != CURL_POLL_REMOVE) {
//        context = create_curl_context(s);
//    }
//
//    if (context) {
//        curl_multi_assign(curl_multi, s, (void *)context);
//        if (action == CURL_POLL_IN || action == CURL_POLL_INOUT) {
//            uv_poll_start(&context->poll_handle, UV_READABLE, curl_perform);
//        }
//        if (action == CURL_POLL_OUT || action == CURL_POLL_INOUT) {
//            uv_poll_start(&context->poll_handle, UV_WRITABLE, curl_perform);
//        }
//        if (action == CURL_POLL_REMOVE && socketp) {
//            uv_poll_stop(&context->poll_handle);
//            destroy_curl_context(context);
//            curl_multi_assign(curl_multi, s, NULL);
//        }
//    }
//
//    return 0;
//}
//
//void on_timeout(uv_timer_t * /*req*/) {
//    int running_handles;
//    CURLMcode error =
//        curl_multi_socket_action(curl_multi, CURL_SOCKET_TIMEOUT, 0, &running_handles);
//    if (error != CURLM_OK) {
//        throw std::runtime_error(std::string("CURL multi error: ") + curl_multi_strerror(error));
//    }
//}
//
//void start_timeout(CURLM * /*multi*/, long timeout_ms, void * /*userp*/) {
//    if (timeout_ms <= 0) {
//        on_timeout(&timeout);
//    } else {
//        uv_timer_start(&timeout, on_timeout, timeout_ms, 0);
//    }
//}
//
//// This function is the first function called in the request thread. It sets up the CURL share/multi
//// handles and runs the thread loop.
//void thread_init(void * /*ptr*/) {
//    uv_timer_init(loop, &timeout);
//
//    CURLSHcode share_error;
//    curl_share = curl_share_init();
//
//    share_error = curl_share_setopt(curl_share, CURLSHOPT_LOCKFUNC, curl_share_lock);
//    if (share_error != CURLSHE_OK) {
//        throw std::runtime_error(std::string("CURL share error: ") + curl_share_strerror(share_error));
//    }
//
//    share_error = curl_share_setopt(curl_share, CURLSHOPT_UNLOCKFUNC, curl_share_unlock);
//    if (share_error != CURLSHE_OK) {
//        throw std::runtime_error(std::string("CURL share error: ") + curl_share_strerror(share_error));
//    }
//
//    CURLMcode multi_error;
//    curl_multi = curl_multi_init();
//
//    multi_error = curl_multi_setopt(curl_multi, CURLMOPT_SOCKETFUNCTION, handle_socket);
//    if (multi_error != CURLM_OK) {
//        throw std::runtime_error(std::string("CURL multi error: ") + curl_multi_strerror(multi_error));
//    }
//    multi_error = curl_multi_setopt(curl_multi, CURLMOPT_TIMERFUNCTION, start_timeout);
//    if (multi_error != CURLM_OK) {
//        throw std::runtime_error(std::string("CURL multi error: ") + curl_multi_strerror(multi_error));
//
//    }
//
//    // Main event loop. This will not return until the request loop is terminated.
//    uv_run(loop, UV_RUN_DEFAULT);
//
//    curl_multi_cleanup(curl_multi);
//    curl_multi = nullptr;
//    curl_share_cleanup(curl_share);
//    curl_share = nullptr;
//
//    // Clean up all the CURL easy handles that we kept around for potential future reuse.
//    while (!curl_handle_cache.empty()) {
//        curl_easy_cleanup(curl_handle_cache.front());
//        curl_handle_cache.pop();
//    }
//}
//
//// This function is called when we have new data for a request. We just append it to the string
//// containing the previous data.
//size_t curl_write_cb(void *contents, size_t size, size_t nmemb, void *userp) {
//    ((std::string *)userp)->append((char *)contents, size * nmemb);
//    return size * nmemb;
//}
//
//// Compares the beginning of the (non-zero-terminated!) data buffer with the (zero-terminated!)
//// header string. If the data buffer contains the header string at the beginning, it returns
//// the length of the header string == begin of the value, otherwise it returns npos.
//// The comparison of the header is ASCII-case-insensitive.
//size_t header_matches(const char *header, const char *buffer, size_t length) {
//    const size_t header_length = strlen(header);
//    if (length < header_length) return std::string::npos;
//    size_t i = 0;
//    while (i < length && i < header_length && std::tolower(buffer[i]) == header[i]) {
//        i++;
//    }
//    return i == header_length ? i : std::string::npos;
//}
//
//size_t curl_header_cb(char *buffer, size_t size, size_t nmemb, void *userp) {
//    const size_t length = size * nmemb;
//
//    size_t begin = std::string::npos;
//    if ((begin = header_matches("last-modified: ", buffer, length)) != std::string::npos) {
//        const std::string value { buffer + begin, length - begin - 2 /* remove \r\n */ };
//        static_cast<Response *>(userp)->setLastModified(value.c_str());
//    } else if ((begin = header_matches("cache-control: ", buffer, length)) != std::string::npos) {
//        const std::string value { buffer + begin, length - begin - 2 /* remove \r\n */ };
//        static_cast<Response *>(userp)->setCacheControl(value.c_str());
//    }
//
//    return length;
//}
//
//// This callback is called in the request event loop (on the request thread).
//// It initializes newly queued up download requests and adds them to the CURL
//// multi handle.
//void async_add_cb(uv_async_t * /*async*/) {
//    std::shared_ptr<Request> *req = nullptr;
//    while (add_queue.pop(req)) {
//        // Make sure that we're not starting requests that have been cancelled
//        // already by async_cancel_cb.
//        if ((*req)->cancelled) {
//            delete req;
//            continue;
//        }
//
//        // Obtain a curl handle (and try to reuse existing handles before creating new ones).
//        CURL *handle = nullptr;
//        if (!curl_handle_cache.empty()) {
//            handle = curl_handle_cache.front();
//            curl_handle_cache.pop();
//        } else {
//            handle = curl_easy_init();
//        }
//
//        ((CURLRequest *)req->get())->curl = handle;
//
//        curl_easy_setopt(handle, CURLOPT_PRIVATE, req);
//        curl_easy_setopt(handle, CURLOPT_CAINFO, "ca-bundle.crt");
//        curl_easy_setopt(handle, CURLOPT_URL, (*req)->url.c_str());
//        curl_easy_setopt(handle, CURLOPT_WRITEFUNCTION, curl_write_cb);
//        curl_easy_setopt(handle, CURLOPT_WRITEDATA, &(*req)->res->body);
//        curl_easy_setopt(handle, CURLOPT_HEADERFUNCTION, curl_header_cb);
//        curl_easy_setopt(handle, CURLOPT_HEADERDATA, (*req)->res.get());
//        curl_easy_setopt(handle, CURLOPT_ACCEPT_ENCODING, "gzip, deflate");
//        curl_easy_setopt(handle, CURLOPT_SHARE, curl_share);
//        curl_multi_add_handle(curl_multi, handle);
//    }
//}
//
//void async_cancel_cb(uv_async_t * /*async*/) {
//    std::shared_ptr<Request> *req = nullptr;
//    while (cancel_queue.pop(req)) {
//        // It is possible that the request has not yet been started, but that it already has been
//        // added to the queue for scheduling new requests. In this case, the CURL handle is invalid
//        // and we manually mark the Request as cancelled.
//        CURL *handle = ((CURLRequest *)req->get())->curl;
//        if (handle && !(*req)->cancelled) {
//            remove_curl_handle(handle);
//            ((CURLRequest *)req->get())->curl = nullptr;
//        }
//        (*req)->cancelled = true;
//
//        delete req;
//        req = nullptr;
//    }
//}
//
//void thread_init_cb() {
//    curl_global_init(CURL_GLOBAL_ALL);
//
//    loop = uv_loop_new();
//    uv_async_init(loop, &async_add, async_add_cb);
//    uv_async_init(loop, &async_cancel, async_cancel_cb);
//    uv_thread_create(&thread, thread_init, nullptr);
//}
//} // end namespace request
//} // end namespace platform
//
//
//std::shared_ptr<platform::Request>
//platform::request_http(const std::string &url,
//                       std::function<void(Response *)> callback,
//                       std::shared_ptr<uv::loop> loop) {
//    using namespace request;
//    init_thread_once(thread_init_cb);
//    std::shared_ptr<CURLRequest> req = std::make_shared<CURLRequest>(url, callback, loop);
//
//    // Note that we are creating a new shared_ptr pointer(!) because the lockless queue can't store
//    // objects with nontrivial destructors. We have to make absolutely sure that we manually delete
//    // the shared_ptr when we pop it from the queue.
//    add_queue.push(new std::shared_ptr<Request>(req));
//    uv_async_send(&async_add);
//
//    return req;
//}
//
//// Cancels an HTTP request.
//void platform::cancel_request_http(const std::shared_ptr<Request> &req) {
//    if (req) {
//        using namespace request;
//
//        // Note that we are creating a new shared_ptr pointer(!) because the lockless queue can't
//        // store objects with nontrivial destructors. We have to make absolutely shure that we
//        // manually delete the shared_ptr when we pop it from the queue.
//        cancel_queue.push(new std::shared_ptr<Request>(req));
//        uv_async_send(&async_cancel);
//    }
//}
//} // end namespace mbgl