/*

 * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>

 *

 * SPDX-License-Identifier: BSD-2-Clause

 */

#pragma once

#include <AK/Badge.h>

#include <AK/ByteBuffer.h>

#include <AK/ByteString.h>

#include <AK/Function.h>

#include <AK/MemoryStream.h>

#include <AK/RefCounted.h>

#include <AK/WeakPtr.h>

#include <LibCore/Notifier.h>

#include <LibHTTP/HeaderMap.h>

#include <LibIPC/Forward.h>

namespace Protocol {

class RequestClient;

class Request : public RefCounted<Request> {

public:

    struct CertificateAndKey {

        ByteString certificate;

        ByteString key;

    };

    static NonnullRefPtr<Request> create_from_id(Badge<RequestClient>, RequestClient& client, i32 request_id)

    {

        return adopt_ref(*new Request(client, request_id));

    }

    int id() const { return m_request_id; }

    int fd() const { return m_fd; }

    bool stop();

    using BufferedRequestFinished = Function<void(bool success, u64 total_size, HTTP::HeaderMap const& response_headers, Optional<u32> response_code, ReadonlyBytes payload)>;

    // Configure the request such that the entirety of the response data is buffered. The callback receives that data and

    // the response headers all at once. Using this method is mutually exclusive with `set_unbuffered_data_received_callback`.

    void set_buffered_request_finished_callback(BufferedRequestFinished);

    using HeadersReceived = Function<void(HTTP::HeaderMap const& response_headers, Optional<u32> response_code)>;

    using DataReceived = Function<void(ReadonlyBytes data)>;

    using RequestFinished = Function<void(bool success, u64 total_size)>;

    // Configure the request such that the response data is provided unbuffered as it is received. Using this method is

    // mutually exclusive with `set_buffered_request_finished_callback`.

    void set_unbuffered_request_callbacks(HeadersReceived, DataReceived, RequestFinished);

    Function<void(Optional<u64> total_size, u64 downloaded_size)> on_progress;

    Function<CertificateAndKey()> on_certificate_requested;

    void did_finish(Badge<RequestClient>, bool success, u64 total_size);

    void did_progress(Badge<RequestClient>, Optional<u64> total_size, u64 downloaded_size);

    void did_receive_headers(Badge<RequestClient>, HTTP::HeaderMap const& response_headers, Optional<u32> response_code);

    void did_request_certificates(Badge<RequestClient>);

    RefPtr<Core::Notifier>& write_notifier(Badge<RequestClient>) { return m_write_notifier; }

    void set_request_fd(Badge<RequestClient>, int fd);

private:

    explicit Request(RequestClient&, i32 request_id);

    void set_up_internal_stream_data(DataReceived on_data_available);

    WeakPtr<RequestClient> m_client;

    int m_request_id { -1 };

    RefPtr<Core::Notifier> m_write_notifier;

    int m_fd { -1 };

    enum class Mode {

        Buffered,

        Unbuffered,

        Unknown,

    };

    Mode m_mode { Mode::Unknown };

    HeadersReceived on_headers_received;

    RequestFinished on_finish;

    struct InternalBufferedData {

        AllocatingMemoryStream payload_stream;

        HTTP::HeaderMap response_headers;

        Optional<u32> response_code;

    };

    struct InternalStreamData {

        InternalStreamData() { }

        OwnPtr<Stream> read_stream;

        RefPtr<Core::Notifier> read_notifier;

        bool success;

        u32 total_size { 0 };

        bool request_done { false };

        Function<void()> on_finish {};

        bool user_finish_called { false };

    };

    OwnPtr<InternalBufferedData> m_internal_buffered_data;

    OwnPtr<InternalStreamData> m_internal_stream_data;

};

}