/* ------------------------------------------------------------------
 * Copyright (C) 2022 Matthias P. Braendli
 *
 * 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.
 * -------------------------------------------------------------------
 */
/*! \file VLCInput.h
 *
 * This input uses libvlc to get audio data. It is extremely useful, and allows
 * the encoder to use all inputs VLC supports.
 */

#pragma once

#include "config.h"

#if HAVE_VLC

#include <cstdio>
#include <string>
#include <sstream>
#include <vector>
#include <deque>
#include <thread>
#include <mutex>
#include <future>

#include <vlc/vlc.h>

#include "SampleQueue.h"
#include "common.h"
#include "InputInterface.h"
#include "utils.h"

/*! Common functionality for the direct libvlc input and the
 *  threaded libvlc input
 */

class VLCInput : public InputInterface
{
    public:
        VLCInput(const std::string& uri,
                 int rate,
                 unsigned channels,
                 unsigned verbosity,
                 std::string& cache,
                 std::vector<std::string>& additional_opts,
                 SampleQueue<uint8_t>& queue) :
            m_uri(uri),
            m_verbosity(verbosity),
            m_channels(channels),
            m_rate(rate),
            m_cache(cache),
            m_additional_opts(additional_opts),
            m_vlc(nullptr),
            m_mp(nullptr),
            m_fault(false),
            m_running(false),
            m_samplequeue(queue) {}

        VLCInput(const VLCInput& other) = delete;
        VLCInput& operator=(const VLCInput& other) = delete;
        virtual ~VLCInput();

        /*! Initialise VLC and start playing, and start
         *  the libVLC thread that fills m_samplequeue */
        virtual void prepare() override;

        virtual bool read_source(size_t num_bytes) override;

        /*! Write the last received ICY-Text to the
         * file.
         */
        ICY_TEXT_t get_icy_text() const;

        //! Callbacks for VLC

        /*! Notification of VLC exit */
        void exit_cb(void);

        /*! Prepare a buffer for VLC */
        void preRender_cb(
                uint8_t** pp_pcm_buffer,
                size_t size);

        /*! Notification from VLC that the buffer is now filled.
         *  VLC also tells us how many channels and how many
         *  samples
         */
        void postRender_cb(unsigned int channels, size_t size);

        int getRate() { return m_rate; }

        virtual bool fault_detected(void) const override { return m_fault; };
    private:
        /*! Stop the player and release resources
         */
        void cleanup(void);

        /*! Fill exactly length bytes into buf. Blocking.
         *
         * \return number of bytes written into buf, or
         * -1 in case of error
         */
        ssize_t m_read(uint8_t* buf, size_t length);

        /*! Buffer used in the callback functions for VLC */
        std::vector<float> m_current_buf;

        std::mutex m_queue_mutex;

        /*! Buffer containing all available samples from VLC */
        std::deque<float> m_queue;

        std::string m_uri;
        unsigned m_verbosity;
        unsigned m_channels;
        int m_rate;

        //! Whether to enable network caching in VLC or not
        std::string m_cache;

        //! Given as-is to libvlc, useful for additional arguments
        std::vector<std::string> m_additional_opts;

        /*! VLC can give us the ICY-Text from an Icecast stream,
         * which we optionally write into a text file for ODR-PadEnc
         */
        mutable std::mutex m_nowplaying_mutex;
        ICY_TEXT_t m_nowplaying;

        // VLC pointers
        libvlc_instance_t     *m_vlc;
        libvlc_media_player_t *m_mp;

        // For the thread

        /* The thread running process takes samples from m_queue and writes
         * them into m_samplequeue. This decouples m_queue from m_samplequeue
         * which is directly used by odr-audioenc.cpp
         */
        void process();

        std::atomic<bool> m_fault;
        std::atomic<bool> m_running;
        std::thread m_thread;

        SampleQueue<uint8_t>& m_samplequeue;
};

#endif // HAVE_VLC