/**
 * @file PacketStreamSender.c
 * @author Ambroz Bizjak <ambrop7@gmail.com>
 * 
 * @section LICENSE
 * 
 * This file is part of BadVPN.
 * 
 * BadVPN is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2
 * as published by the Free Software Foundation.
 * 
 * BadVPN 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.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include <stdlib.h>

#include <misc/debug.h>

#include <flow/PacketStreamSender.h>

static void send_data (PacketStreamSender *s)
{
    ASSERT(s->in_len >= 0)
    
    if (s->in_used < s->in_len) {
        // send more data
        StreamPassInterface_Sender_Send(s->output, s->in + s->in_used, s->in_len - s->in_used);
    } else {
        // finish input packet
        s->in_len = -1;
        PacketPassInterface_Done(&s->input);
    }
}

static void input_handler_send (PacketStreamSender *s, uint8_t *data, int data_len)
{
    ASSERT(s->in_len == -1)
    ASSERT(data_len >= 0)
    DebugObject_Access(&s->d_obj);
    
    // set input packet
    s->in_len = data_len;
    s->in = data;
    s->in_used = 0;
    
    // send
    send_data(s);
}

static void output_handler_done (PacketStreamSender *s, int data_len)
{
    ASSERT(s->in_len >= 0)
    ASSERT(data_len > 0)
    ASSERT(data_len <= s->in_len - s->in_used)
    DebugObject_Access(&s->d_obj);
    
    // update number of bytes sent
    s->in_used += data_len;
    
    // send
    send_data(s);
}

void PacketStreamSender_Init (PacketStreamSender *s, StreamPassInterface *output, int mtu, BPendingGroup *pg)
{
    ASSERT(mtu >= 0)
    
    // init arguments
    s->output = output;
    
    // init input
    PacketPassInterface_Init(&s->input, mtu, (PacketPassInterface_handler_send)input_handler_send, s, pg);
    
    // init output
    StreamPassInterface_Sender_Init(s->output, (StreamPassInterface_handler_done)output_handler_done, s);
    
    // have no input packet
    s->in_len = -1;
    
    DebugObject_Init(&s->d_obj);
}

void PacketStreamSender_Free (PacketStreamSender *s)
{
    DebugObject_Free(&s->d_obj);
    
    // free input
    PacketPassInterface_Free(&s->input);
}

PacketPassInterface * PacketStreamSender_GetInput (PacketStreamSender *s)
{
    DebugObject_Access(&s->d_obj);
    
    return &s->input;
}