/*
  * RTMP input format
  * Copyright (c) 2009 Kostya Shishkov
  *
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * FFmpeg 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
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 #include "libavcodec/bytestream.h"
 #include "libavutil/avstring.h"

 #include "libavutil/intfloat.h"

 #include "avformat.h"
 
 #include "rtmppkt.h"
 #include "flv.h"

 #include "url.h"

 
 void ff_amf_write_bool(uint8_t **dst, int val)
 {
     bytestream_put_byte(dst, AMF_DATA_TYPE_BOOL);
     bytestream_put_byte(dst, val);
 }
 
 void ff_amf_write_number(uint8_t **dst, double val)
 {
     bytestream_put_byte(dst, AMF_DATA_TYPE_NUMBER);

     bytestream_put_be64(dst, av_double2int(val));

 }
 
 void ff_amf_write_string(uint8_t **dst, const char *str)
 {
     bytestream_put_byte(dst, AMF_DATA_TYPE_STRING);
     bytestream_put_be16(dst, strlen(str));
     bytestream_put_buffer(dst, str, strlen(str));
 }
 

 void ff_amf_write_string2(uint8_t **dst, const char *str1, const char *str2)
 {
     int len1 = 0, len2 = 0;
     if (str1)
         len1 = strlen(str1);
     if (str2)
         len2 = strlen(str2);
     bytestream_put_byte(dst, AMF_DATA_TYPE_STRING);
     bytestream_put_be16(dst, len1 + len2);
     bytestream_put_buffer(dst, str1, len1);
     bytestream_put_buffer(dst, str2, len2);
 }
 

 void ff_amf_write_null(uint8_t **dst)
 {
     bytestream_put_byte(dst, AMF_DATA_TYPE_NULL);
 }
 
 void ff_amf_write_object_start(uint8_t **dst)
 {
     bytestream_put_byte(dst, AMF_DATA_TYPE_OBJECT);
 }
 
 void ff_amf_write_field_name(uint8_t **dst, const char *str)
 {
     bytestream_put_be16(dst, strlen(str));
     bytestream_put_buffer(dst, str, strlen(str));
 }
 
 void ff_amf_write_object_end(uint8_t **dst)
 {
     /* first two bytes are field name length = 0,
      * AMF object should end with it and end marker
      */
     bytestream_put_be24(dst, AMF_DATA_TYPE_OBJECT_END);
 }
 

 int ff_amf_read_bool(GetByteContext *bc, int *val)
 {
     if (bytestream2_get_byte(bc) != AMF_DATA_TYPE_BOOL)
         return AVERROR_INVALIDDATA;
     *val = bytestream2_get_byte(bc);
     return 0;
 }
 
 int ff_amf_read_number(GetByteContext *bc, double *val)
 {
     uint64_t read;
     if (bytestream2_get_byte(bc) != AMF_DATA_TYPE_NUMBER)
         return AVERROR_INVALIDDATA;
     read = bytestream2_get_be64(bc);
     *val = av_int2double(read);
     return 0;
 }
 
 int ff_amf_read_string(GetByteContext *bc, uint8_t *str,
                        int strsize, int *length)
 {
     int stringlen = 0;
     int readsize;
     if (bytestream2_get_byte(bc) != AMF_DATA_TYPE_STRING)
         return AVERROR_INVALIDDATA;
     stringlen = bytestream2_get_be16(bc);
     if (stringlen + 1 > strsize)
         return AVERROR(EINVAL);
     readsize = bytestream2_get_buffer(bc, str, stringlen);
     if (readsize != stringlen) {
         av_log(NULL, AV_LOG_WARNING,
                "Unable to read as many bytes as AMF string signaled\n");
     }
     str[readsize] = '\0';
     *length = FFMIN(stringlen, readsize);
     return 0;
 }
 
 int ff_amf_read_null(GetByteContext *bc)
 {
     if (bytestream2_get_byte(bc) != AMF_DATA_TYPE_NULL)
         return AVERROR_INVALIDDATA;
     return 0;
 }
 

 int ff_rtmp_packet_read(URLContext *h, RTMPPacket *p,
                         int chunk_size, RTMPPacket *prev_pkt)
 {

     uint8_t hdr;
 
     if (ffurl_read(h, &hdr, 1) != 1)
         return AVERROR(EIO);
 
     return ff_rtmp_packet_read_internal(h, p, chunk_size, prev_pkt, hdr);
 }
 
 int ff_rtmp_packet_read_internal(URLContext *h, RTMPPacket *p, int chunk_size,
                                  RTMPPacket *prev_pkt, uint8_t hdr)
 {
 
     uint8_t t, buf[16];

     int channel_id, timestamp, data_size, offset = 0;
     uint32_t extra = 0;

     enum RTMPPacketType type;

     int size = 0;

     int ret;

     size++;

     channel_id = hdr & 0x3F;
 

     if (channel_id < 2) { //special case for channel number >= 64
         buf[1] = 0;

         if (ffurl_read_complete(h, buf, channel_id + 1) != channel_id + 1)

             return AVERROR(EIO);

         size += channel_id + 1;

         channel_id = AV_RL16(buf) + 64;
     }

     data_size = prev_pkt[channel_id].data_size;
     type      = prev_pkt[channel_id].type;
     extra     = prev_pkt[channel_id].extra;
 
     hdr >>= 6;
     if (hdr == RTMP_PS_ONEBYTE) {

         timestamp = prev_pkt[channel_id].ts_delta;

     } else {

         if (ffurl_read_complete(h, buf, 3) != 3)

             return AVERROR(EIO);

         size += 3;

         timestamp = AV_RB24(buf);
         if (hdr != RTMP_PS_FOURBYTES) {

             if (ffurl_read_complete(h, buf, 3) != 3)

                 return AVERROR(EIO);

             size += 3;

             data_size = AV_RB24(buf);

             if (ffurl_read_complete(h, buf, 1) != 1)

                 return AVERROR(EIO);

             size++;

             type = buf[0];

             if (hdr == RTMP_PS_TWELVEBYTES) {

                 if (ffurl_read_complete(h, buf, 4) != 4)

                     return AVERROR(EIO);

                 size += 4;

                 extra = AV_RL32(buf);
             }
         }

         if (timestamp == 0xFFFFFF) {

             if (ffurl_read_complete(h, buf, 4) != 4)

                 return AVERROR(EIO);
             timestamp = AV_RB32(buf);
         }

     }

     if (hdr != RTMP_PS_TWELVEBYTES)
         timestamp += prev_pkt[channel_id].timestamp;
 

     if ((ret = ff_rtmp_packet_create(p, channel_id, type, timestamp,
                                      data_size)) < 0)
         return ret;

     p->extra = extra;
     // save history
     prev_pkt[channel_id].channel_id = channel_id;
     prev_pkt[channel_id].type       = type;
     prev_pkt[channel_id].data_size  = data_size;

     prev_pkt[channel_id].ts_delta   = timestamp - prev_pkt[channel_id].timestamp;

     prev_pkt[channel_id].timestamp  = timestamp;
     prev_pkt[channel_id].extra      = extra;
     while (data_size > 0) {
         int toread = FFMIN(data_size, chunk_size);

         if (ffurl_read_complete(h, p->data + offset, toread) != toread) {

             ff_rtmp_packet_destroy(p);
             return AVERROR(EIO);
         }
         data_size -= chunk_size;
         offset    += chunk_size;

         size      += chunk_size;

         if (data_size > 0) {

             if ((ret = ffurl_read_complete(h, &t, 1)) < 0) { // marker
                 ff_rtmp_packet_destroy(p);
                 return ret;
             }

             size++;

             if (t != (0xC0 + channel_id))
                 return -1;
         }
     }

     return size;

 }
 
 int ff_rtmp_packet_write(URLContext *h, RTMPPacket *pkt,
                          int chunk_size, RTMPPacket *prev_pkt)
 {
     uint8_t pkt_hdr[16], *p = pkt_hdr;
     int mode = RTMP_PS_TWELVEBYTES;
     int off = 0;

     int size = 0;

     int ret;

     pkt->ts_delta = pkt->timestamp - prev_pkt[pkt->channel_id].timestamp;

     //if channel_id = 0, this is first presentation of prev_pkt, send full hdr.
     if (prev_pkt[pkt->channel_id].channel_id &&
         pkt->extra == prev_pkt[pkt->channel_id].extra) {
         if (pkt->type == prev_pkt[pkt->channel_id].type &&
             pkt->data_size == prev_pkt[pkt->channel_id].data_size) {
             mode = RTMP_PS_FOURBYTES;
             if (pkt->ts_delta == prev_pkt[pkt->channel_id].ts_delta)
                 mode = RTMP_PS_ONEBYTE;
         } else {
             mode = RTMP_PS_EIGHTBYTES;
         }
     }
 

     if (pkt->channel_id < 64) {
         bytestream_put_byte(&p, pkt->channel_id | (mode << 6));
     } else if (pkt->channel_id < 64 + 256) {
         bytestream_put_byte(&p, 0               | (mode << 6));
         bytestream_put_byte(&p, pkt->channel_id - 64);
     } else {
         bytestream_put_byte(&p, 1               | (mode << 6));
         bytestream_put_le16(&p, pkt->channel_id - 64);
     }

     if (mode != RTMP_PS_ONEBYTE) {

         uint32_t timestamp = pkt->timestamp;
         if (mode != RTMP_PS_TWELVEBYTES)

             timestamp = pkt->ts_delta;

         bytestream_put_be24(&p, timestamp >= 0xFFFFFF ? 0xFFFFFF : timestamp);

         if (mode != RTMP_PS_FOURBYTES) {
             bytestream_put_be24(&p, pkt->data_size);
             bytestream_put_byte(&p, pkt->type);
             if (mode == RTMP_PS_TWELVEBYTES)
                 bytestream_put_le32(&p, pkt->extra);
         }

         if (timestamp >= 0xFFFFFF)
             bytestream_put_be32(&p, timestamp);

     }

     // save history
     prev_pkt[pkt->channel_id].channel_id = pkt->channel_id;
     prev_pkt[pkt->channel_id].type       = pkt->type;
     prev_pkt[pkt->channel_id].data_size  = pkt->data_size;
     prev_pkt[pkt->channel_id].timestamp  = pkt->timestamp;
     if (mode != RTMP_PS_TWELVEBYTES) {
         prev_pkt[pkt->channel_id].ts_delta   = pkt->ts_delta;
     } else {
         prev_pkt[pkt->channel_id].ts_delta   = pkt->timestamp;
     }
     prev_pkt[pkt->channel_id].extra      = pkt->extra;
 

     if ((ret = ffurl_write(h, pkt_hdr, p - pkt_hdr)) < 0)
         return ret;

     size = p - pkt_hdr + pkt->data_size;

     while (off < pkt->data_size) {
         int towrite = FFMIN(chunk_size, pkt->data_size - off);

         if ((ret = ffurl_write(h, pkt->data + off, towrite)) < 0)
             return ret;

         off += towrite;
         if (off < pkt->data_size) {
             uint8_t marker = 0xC0 | pkt->channel_id;

             if ((ret = ffurl_write(h, &marker, 1)) < 0)
                 return ret;

             size++;

         }
     }

     return size;

 }
 
 int ff_rtmp_packet_create(RTMPPacket *pkt, int channel_id, RTMPPacketType type,
                           int timestamp, int size)
 {

     if (size) {

         pkt->data = av_malloc(size);
         if (!pkt->data)
             return AVERROR(ENOMEM);

     }

     pkt->data_size  = size;
     pkt->channel_id = channel_id;
     pkt->type       = type;
     pkt->timestamp  = timestamp;
     pkt->extra      = 0;

     pkt->ts_delta   = 0;

 
     return 0;
 }
 
 void ff_rtmp_packet_destroy(RTMPPacket *pkt)
 {
     if (!pkt)
         return;
     av_freep(&pkt->data);
     pkt->data_size = 0;
 }
 
 int ff_amf_tag_size(const uint8_t *data, const uint8_t *data_end)
 {
     const uint8_t *base = data;
 
     if (data >= data_end)
         return -1;
     switch (*data++) {
     case AMF_DATA_TYPE_NUMBER:      return 9;
     case AMF_DATA_TYPE_BOOL:        return 2;
     case AMF_DATA_TYPE_STRING:      return 3 + AV_RB16(data);
     case AMF_DATA_TYPE_LONG_STRING: return 5 + AV_RB32(data);
     case AMF_DATA_TYPE_NULL:        return 1;
     case AMF_DATA_TYPE_ARRAY:
         data += 4;
     case AMF_DATA_TYPE_OBJECT:
         for (;;) {
             int size = bytestream_get_be16(&data);
             int t;
             if (!size) {
                 data++;
                 break;
             }

             if (size < 0 || size >= data_end - data)

                 return -1;
             data += size;
             t = ff_amf_tag_size(data, data_end);

             if (t < 0 || t >= data_end - data)

                 return -1;
             data += t;
         }
         return data - base;
     case AMF_DATA_TYPE_OBJECT_END:  return 1;
     default:                        return -1;
     }
 }
 
 int ff_amf_get_field_value(const uint8_t *data, const uint8_t *data_end,
                            const uint8_t *name, uint8_t *dst, int dst_size)
 {
     int namelen = strlen(name);
     int len;
 

     while (*data != AMF_DATA_TYPE_OBJECT && data < data_end) {
         len = ff_amf_tag_size(data, data_end);
         if (len < 0)
             len = data_end - data;
         data += len;
     }

     if (data_end - data < 3)
         return -1;

     data++;

     for (;;) {
         int size = bytestream_get_be16(&data);
         if (!size)
             break;

         if (size < 0 || size >= data_end - data)

             return -1;
         data += size;
         if (size == namelen && !memcmp(data-size, name, namelen)) {
             switch (*data++) {
             case AMF_DATA_TYPE_NUMBER:

                 snprintf(dst, dst_size, "%g", av_int2double(AV_RB64(data)));

                 break;
             case AMF_DATA_TYPE_BOOL:
                 snprintf(dst, dst_size, "%s", *data ? "true" : "false");
                 break;
             case AMF_DATA_TYPE_STRING:
                 len = bytestream_get_be16(&data);
                 av_strlcpy(dst, data, FFMIN(len+1, dst_size));
                 break;
             default:
                 return -1;
             }
             return 0;
         }
         len = ff_amf_tag_size(data, data_end);

         if (len < 0 || len >= data_end - data)

             return -1;
         data += len;
     }
     return -1;
 }

 
 static const char* rtmp_packet_type(int type)
 {
     switch (type) {
     case RTMP_PT_CHUNK_SIZE:     return "chunk size";
     case RTMP_PT_BYTES_READ:     return "bytes read";
     case RTMP_PT_PING:           return "ping";
     case RTMP_PT_SERVER_BW:      return "server bandwidth";
     case RTMP_PT_CLIENT_BW:      return "client bandwidth";
     case RTMP_PT_AUDIO:          return "audio packet";
     case RTMP_PT_VIDEO:          return "video packet";
     case RTMP_PT_FLEX_STREAM:    return "Flex shared stream";
     case RTMP_PT_FLEX_OBJECT:    return "Flex shared object";
     case RTMP_PT_FLEX_MESSAGE:   return "Flex shared message";
     case RTMP_PT_NOTIFY:         return "notification";
     case RTMP_PT_SHARED_OBJ:     return "shared object";
     case RTMP_PT_INVOKE:         return "invoke";
     case RTMP_PT_METADATA:       return "metadata";
     default:                     return "unknown";
     }
 }
 
 static void ff_amf_tag_contents(void *ctx, const uint8_t *data, const uint8_t *data_end)
 {

     unsigned int size;

     char buf[1024];
 
     if (data >= data_end)
         return;
     switch (*data++) {
     case AMF_DATA_TYPE_NUMBER:

         av_log(ctx, AV_LOG_DEBUG, " number %g\n", av_int2double(AV_RB64(data)));

         return;
     case AMF_DATA_TYPE_BOOL:
         av_log(ctx, AV_LOG_DEBUG, " bool %d\n", *data);
         return;
     case AMF_DATA_TYPE_STRING:
     case AMF_DATA_TYPE_LONG_STRING:
         if (data[-1] == AMF_DATA_TYPE_STRING) {
             size = bytestream_get_be16(&data);
         } else {

             size = bytestream_get_be32(&data);

         }

         size = FFMIN(size, sizeof(buf) - 1);

         memcpy(buf, data, size);
         buf[size] = 0;
         av_log(ctx, AV_LOG_DEBUG, " string '%s'\n", buf);
         return;
     case AMF_DATA_TYPE_NULL:
         av_log(ctx, AV_LOG_DEBUG, " NULL\n");
         return;
     case AMF_DATA_TYPE_ARRAY:
         data += 4;
     case AMF_DATA_TYPE_OBJECT:
         av_log(ctx, AV_LOG_DEBUG, " {\n");
         for (;;) {
             int t;

             size = bytestream_get_be16(&data);
             av_strlcpy(buf, data, FFMIN(sizeof(buf), size + 1));

             if (!size) {
                 av_log(ctx, AV_LOG_DEBUG, " }\n");
                 data++;
                 break;
             }

             if (size >= data_end - data)

                 return;
             data += size;
             av_log(ctx, AV_LOG_DEBUG, "  %s: ", buf);
             ff_amf_tag_contents(ctx, data, data_end);
             t = ff_amf_tag_size(data, data_end);

             if (t < 0 || t >= data_end - data)

                 return;
             data += t;
         }
         return;
     case AMF_DATA_TYPE_OBJECT_END:
         av_log(ctx, AV_LOG_DEBUG, " }\n");
         return;
     default:
         return;
     }
 }
 
 void ff_rtmp_packet_dump(void *ctx, RTMPPacket *p)
 {
     av_log(ctx, AV_LOG_DEBUG, "RTMP packet type '%s'(%d) for channel %d, timestamp %d, extra field %d size %d\n",
            rtmp_packet_type(p->type), p->type, p->channel_id, p->timestamp, p->extra, p->data_size);
     if (p->type == RTMP_PT_INVOKE || p->type == RTMP_PT_NOTIFY) {
         uint8_t *src = p->data, *src_end = p->data + p->data_size;
         while (src < src_end) {
             int sz;
             ff_amf_tag_contents(ctx, src, src_end);
             sz = ff_amf_tag_size(src, src_end);
             if (sz < 0)
                 break;
             src += sz;
         }
     } else if (p->type == RTMP_PT_SERVER_BW){
         av_log(ctx, AV_LOG_DEBUG, "Server BW = %d\n", AV_RB32(p->data));
     } else if (p->type == RTMP_PT_CLIENT_BW){
         av_log(ctx, AV_LOG_DEBUG, "Client BW = %d\n", AV_RB32(p->data));
     } else if (p->type != RTMP_PT_AUDIO && p->type != RTMP_PT_VIDEO && p->type != RTMP_PT_METADATA) {
         int i;
         for (i = 0; i < p->data_size; i++)
             av_log(ctx, AV_LOG_DEBUG, " %02X", p->data[i]);
         av_log(ctx, AV_LOG_DEBUG, "\n");
     }
 }