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/* Copyright (C) 2017-2018 J.F.Dockes

 *   This program is free software; you can redistribute it and/or modify

 *   it under the terms of the GNU General Public License as published by

 *   the Free Software Foundation; either version 2 of the License, or

 *   (at your option) any later version.

 *

 *   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 General Public License for more details.

 *

 *   You should have received a copy of the GNU General Public License

 *   along with this program; if not, write to the

 *   Free Software Foundation, Inc.,

 *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

 */

#ifndef _MEDIAFETCH_H_INCLUDED_

#define _MEDIAFETCH_H_INCLUDED_

#include "bufxchange.h"

#include "abuffer.h"

//

// Wrapper for a network fetch

//

// The transfer is aborted when the object is deleted, with proper

// cleanup.

//

// The end of transfer is marked by pushing an empty buffer on the queue

//

// All methods are supposedly thread-safe

class NetFetch {

public:

    NetFetch() {}

    virtual ~NetFetch() {}

    virtual void setTimeout(int secs) = 0;

    /// Start the transfer to the output queue.

    virtual bool start(BufXChange<ABuffer*> *queue, uint64_t offset = 0) = 0;

    // Wait for headers. This allows, e.g. doing stuff depending on

    // content-type before proceeding with the actual data

    // transfer. May not work exactly the same depending on the

    // underlaying implementation.

    virtual bool waitForHeaders(int maxSecs = 0) = 0;

    // Retrieve header value (after a successful waitForHeaders).

    virtual bool headerValue(const std::string& nm, std::string& val) = 0;

    // Check if the fetch is done and retrieve the results if it

    // is. This does not wait, it returns false if the transfer is

    // still running.

    // The pointers can be set to zero if no value should be retrieved

    enum FetchStatus {FETCH_OK=0, FETCH_RETRYABLE, FETCH_FATAL};

    virtual bool fetchDone(FetchStatus *code, int *http_code) = 0;

    /// Reset after transfer done, for retrying for exemple.

    virtual void reset() = 0;

    // Callbacks

    // A function to create the first buffer (typically for prepending

    // a wav header to a raw pcm stream. If set this is called from

    // the first curl write callback, before processing the curl data,

    // so this happens at a point where the client may have had a look

    // at the headers).

    virtual void setBuf1GenCB(std::function<bool(std::string& buf,void*,int)>) {

    }

    // Called when the network transfer is done

    void setEOFetchCB(std::function<void(bool ok, u_int64_t count)>) {

    }

    // Called every time we get new data from the remote

    void setFetchBytesCB(std::function<void(u_int64_t count)>) {

    }

};

#endif /* _MEDIAFETCH_H_INCLUDED_ */