/*
  * MMS protocol over HTTP
  * Copyright (c) 2010 Zhentan Feng <spyfeng at gmail dot com>
  *
  * 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
  */
 
 /*
  * Reference
  * Windows Media HTTP Streaming Protocol.
  * http://msdn.microsoft.com/en-us/library/cc251059(PROT.10).aspx
  */
 
 #include <string.h>
 #include "libavutil/intreadwrite.h"
 #include "libavutil/avstring.h"

 #include "libavutil/opt.h"

 #include "internal.h"

 #include "mms.h"
 #include "asf.h"
 #include "http.h"

 #include "url.h"

 
 #define CHUNK_HEADER_LENGTH 4   // 2bytes chunk type and 2bytes chunk length.
 #define EXT_HEADER_LENGTH   8   // 4bytes sequence, 2bytes useless and 2bytes chunk length.
 
 // see Ref 2.2.1.8
 #define USERAGENT  "User-Agent: NSPlayer/4.1.0.3856\r\n"
 // see Ref 2.2.1.4.33
 // the guid value can be changed to any valid value.
 #define CLIENTGUID "Pragma: xClientGUID={c77e7400-738a-11d2-9add-0020af0a3278}\r\n"
 
 // see Ref 2.2.3 for packet type define:
 // chunk type contains 2 fields: Frame and PacketID.
 // Frame is 0x24 or 0xA4(rarely), different PacketID indicates different packet type.
 typedef enum {
     CHUNK_TYPE_DATA          = 0x4424,
     CHUNK_TYPE_ASF_HEADER    = 0x4824,
     CHUNK_TYPE_END           = 0x4524,
     CHUNK_TYPE_STREAM_CHANGE = 0x4324,
 } ChunkType;
 
 typedef struct {
     MMSContext mms;

     uint8_t location[1024];

     int request_seq;  ///< request packet sequence
     int chunk_seq;    ///< data packet sequence
 } MMSHContext;
 
 static int mmsh_close(URLContext *h)
 {
     MMSHContext *mmsh = (MMSHContext *)h->priv_data;
     MMSContext *mms   = &mmsh->mms;
     if (mms->mms_hd)

         ffurl_close(mms->mms_hd);

     av_free(mms->streams);
     av_free(mms->asf_header);
     return 0;
 }
 
 static ChunkType get_chunk_header(MMSHContext *mmsh, int *len)
 {
     MMSContext *mms = &mmsh->mms;
     uint8_t chunk_header[CHUNK_HEADER_LENGTH];
     uint8_t ext_header[EXT_HEADER_LENGTH];
     ChunkType chunk_type;
     int chunk_len, res, ext_header_len;
 

     res = ffurl_read_complete(mms->mms_hd, chunk_header, CHUNK_HEADER_LENGTH);

     if (res != CHUNK_HEADER_LENGTH) {
         av_log(NULL, AV_LOG_ERROR, "Read data packet header failed!\n");
         return AVERROR(EIO);
     }
     chunk_type = AV_RL16(chunk_header);
     chunk_len  = AV_RL16(chunk_header + 2);
 
     switch (chunk_type) {
     case CHUNK_TYPE_END:
     case CHUNK_TYPE_STREAM_CHANGE:
         ext_header_len = 4;
         break;
     case CHUNK_TYPE_ASF_HEADER:
     case CHUNK_TYPE_DATA:
         ext_header_len = 8;
         break;
     default:
         av_log(NULL, AV_LOG_ERROR, "Strange chunk type %d\n", chunk_type);
         return AVERROR_INVALIDDATA;
     }
 

     res = ffurl_read_complete(mms->mms_hd, ext_header, ext_header_len);

     if (res != ext_header_len) {
         av_log(NULL, AV_LOG_ERROR, "Read ext header failed!\n");
         return AVERROR(EIO);
     }
     *len = chunk_len - ext_header_len;
     if (chunk_type == CHUNK_TYPE_END || chunk_type == CHUNK_TYPE_DATA)
         mmsh->chunk_seq = AV_RL32(ext_header);
     return chunk_type;
 }
 
 static int read_data_packet(MMSHContext *mmsh, const int len)
 {
     MMSContext *mms   = &mmsh->mms;
     int res;
     if (len > sizeof(mms->in_buffer)) {
         av_log(NULL, AV_LOG_ERROR,

                "Data packet length %d exceeds the in_buffer size %zu\n",

                len, sizeof(mms->in_buffer));
         return AVERROR(EIO);
     }

     res = ffurl_read_complete(mms->mms_hd, mms->in_buffer, len);

     av_dlog(NULL, "Data packet len = %d\n", len);

     if (res != len) {
         av_log(NULL, AV_LOG_ERROR, "Read data packet failed!\n");
         return AVERROR(EIO);
     }
     if (len > mms->asf_packet_len) {
         av_log(NULL, AV_LOG_ERROR,
                "Chunk length %d exceed packet length %d\n",len, mms->asf_packet_len);
         return AVERROR_INVALIDDATA;
     } else {
         memset(mms->in_buffer + len, 0, mms->asf_packet_len - len); // padding
     }
     mms->read_in_ptr      = mms->in_buffer;
     mms->remaining_in_len = mms->asf_packet_len;
     return 0;
 }
 
 static int get_http_header_data(MMSHContext *mmsh)
 {
     MMSContext *mms = &mmsh->mms;
     int res, len;
     ChunkType chunk_type;
 
     for (;;) {
         len = 0;

         res = chunk_type = get_chunk_header(mmsh, &len);
         if (res < 0) {
             return res;

         } else if (chunk_type == CHUNK_TYPE_ASF_HEADER){
             // get asf header and stored it
             if (!mms->header_parsed) {
                 if (mms->asf_header) {
                     if (len != mms->asf_header_size) {
                         mms->asf_header_size = len;

                         av_dlog(NULL, "Header len changed from %d to %d\n",

                                 mms->asf_header_size, len);
                         av_freep(&mms->asf_header);
                     }
                 }
                 mms->asf_header = av_mallocz(len);
                 if (!mms->asf_header) {
                     return AVERROR(ENOMEM);
                 }
                 mms->asf_header_size = len;
             }
             if (len > mms->asf_header_size) {
                 av_log(NULL, AV_LOG_ERROR,
                        "Asf header packet len = %d exceed the asf header buf size %d\n",
                        len, mms->asf_header_size);
                 return AVERROR(EIO);
             }

             res = ffurl_read_complete(mms->mms_hd, mms->asf_header, len);

             if (res != len) {
                 av_log(NULL, AV_LOG_ERROR,
                        "Recv asf header data len %d != expected len %d\n", res, len);
                 return AVERROR(EIO);
             }
             mms->asf_header_size = len;
             if (!mms->header_parsed) {
                 res = ff_mms_asf_header_parser(mms);
                 mms->header_parsed = 1;
                 return res;
             }
         } else if (chunk_type == CHUNK_TYPE_DATA) {
             // read data packet and do padding
             return read_data_packet(mmsh, len);
         } else {
             if (len) {
                 if (len > sizeof(mms->in_buffer)) {
                     av_log(NULL, AV_LOG_ERROR,

                            "Other packet len = %d exceed the in_buffer size %zu\n",

                            len, sizeof(mms->in_buffer));
                     return AVERROR(EIO);
                 }

                 res = ffurl_read_complete(mms->mms_hd, mms->in_buffer, len);

                 if (res != len) {
                     av_log(NULL, AV_LOG_ERROR, "Read other chunk type data failed!\n");
                     return AVERROR(EIO);
                 } else {

                     av_dlog(NULL, "Skip chunk type %d \n", chunk_type);

                     continue;
                 }
             }
         }
     }
 }
 

 static int mmsh_open_internal(URLContext *h, const char *uri, int flags, int timestamp, int64_t pos)

 {
     int i, port, err;

     char httpname[256], path[256], host[128];

     char *stream_selection = NULL;

     char headers[1024];

     MMSHContext *mmsh = h->priv_data;

     MMSContext *mms;
 
     mmsh->request_seq = h->is_streamed = 1;
     mms = &mmsh->mms;

     av_strlcpy(mmsh->location, uri, sizeof(mmsh->location));

 
     av_url_split(NULL, 0, NULL, 0,

         host, sizeof(host), &port, path, sizeof(path), mmsh->location);

     if (port<0)
         port = 80; // default mmsh protocol port

     ff_url_join(httpname, sizeof(httpname), "http", NULL, host, port, "%s", path);

     if (ffurl_alloc(&mms->mms_hd, httpname, AVIO_FLAG_READ,
                     &h->interrupt_callback) < 0) {

         return AVERROR(EIO);
     }
 
     snprintf(headers, sizeof(headers),
              "Accept: */*\r\n"
              USERAGENT
              "Host: %s:%d\r\n"
              "Pragma: no-cache,rate=1.000000,stream-time=0,"
              "stream-offset=0:0,request-context=%u,max-duration=0\r\n"
              CLIENTGUID

              "Connection: Close\r\n",

              host, port, mmsh->request_seq++);

     av_opt_set(mms->mms_hd->priv_data, "headers", headers, 0);

     err = ffurl_connect(mms->mms_hd, NULL);

     if (err) {
         goto fail;
     }
     err = get_http_header_data(mmsh);
     if (err) {
         av_log(NULL, AV_LOG_ERROR, "Get http header data failed!\n");
         goto fail;
     }
 
     // close the socket and then reopen it for sending the second play request.

     ffurl_close(mms->mms_hd);

     memset(headers, 0, sizeof(headers));

     if ((err = ffurl_alloc(&mms->mms_hd, httpname, AVIO_FLAG_READ,
                            &h->interrupt_callback)) < 0) {
         goto fail;

     }
     stream_selection = av_mallocz(mms->stream_num * 19 + 1);
     if (!stream_selection)
         return AVERROR(ENOMEM);
     for (i = 0; i < mms->stream_num; i++) {
         char tmp[20];
         err = snprintf(tmp, sizeof(tmp), "ffff:%d:0 ", mms->streams[i].id);
         if (err < 0)
             goto fail;
         av_strlcat(stream_selection, tmp, mms->stream_num * 19 + 1);
     }
     // send play request
     err = snprintf(headers, sizeof(headers),
                    "Accept: */*\r\n"
                    USERAGENT
                    "Host: %s:%d\r\n"
                    "Pragma: no-cache,rate=1.000000,request-context=%u\r\n"
                    "Pragma: xPlayStrm=1\r\n"
                    CLIENTGUID
                    "Pragma: stream-switch-count=%d\r\n"
                    "Pragma: stream-switch-entry=%s\r\n"

                    "Pragma: no-cache,rate=1.000000,stream-time=%u"

                    "Connection: Close\r\n",

                    host, port, mmsh->request_seq++, mms->stream_num, stream_selection, timestamp);

     av_freep(&stream_selection);
     if (err < 0) {
         av_log(NULL, AV_LOG_ERROR, "Build play request failed!\n");
         goto fail;
     }

     av_dlog(NULL, "out_buffer is %s", headers);

     av_opt_set(mms->mms_hd->priv_data, "headers", headers, 0);

     err = ffurl_connect(mms->mms_hd, NULL);

     if (err) {
           goto fail;
     }
 
     err = get_http_header_data(mmsh);
     if (err) {
         av_log(NULL, AV_LOG_ERROR, "Get http header data failed!\n");
         goto fail;
     }
 

     av_dlog(NULL, "Connection successfully open\n");

     return 0;
 fail:
     av_freep(&stream_selection);
     mmsh_close(h);

     av_dlog(NULL, "Connection failed with error %d\n", err);

     return err;
 }
 

 static int mmsh_open(URLContext *h, const char *uri, int flags)
 {

     return mmsh_open_internal(h, uri, flags, 0, 0);

 }
 

 static int handle_chunk_type(MMSHContext *mmsh)
 {
     MMSContext *mms = &mmsh->mms;
     int res, len = 0;
     ChunkType chunk_type;
     chunk_type = get_chunk_header(mmsh, &len);
 
     switch (chunk_type) {
     case CHUNK_TYPE_END:
         mmsh->chunk_seq = 0;
         av_log(NULL, AV_LOG_ERROR, "Stream ended!\n");
         return AVERROR(EIO);
     case CHUNK_TYPE_STREAM_CHANGE:
         mms->header_parsed = 0;
         if (res = get_http_header_data(mmsh)) {
             av_log(NULL, AV_LOG_ERROR,"Stream changed! Failed to get new header!\n");
             return res;
         }
         break;
     case CHUNK_TYPE_DATA:
         return read_data_packet(mmsh, len);
     default:
         av_log(NULL, AV_LOG_ERROR, "Recv other type packet %d\n", chunk_type);
         return AVERROR_INVALIDDATA;
     }
     return 0;
 }
 
 static int mmsh_read(URLContext *h, uint8_t *buf, int size)
 {
     int res = 0;
     MMSHContext *mmsh = h->priv_data;
     MMSContext *mms   = &mmsh->mms;
     do {
         if (mms->asf_header_read_size < mms->asf_header_size) {
             // copy asf header into buffer
             res = ff_mms_read_header(mms, buf, size);
         } else {
             if (!mms->remaining_in_len && (res = handle_chunk_type(mmsh)))
                 return res;
             res = ff_mms_read_data(mms, buf, size);
         }
     } while (!res);
     return res;
 }
 

 static int64_t mmsh_read_seek(URLContext *h, int stream_index,
                         int64_t timestamp, int flags)
 {
     MMSHContext *mmsh = h->priv_data;
     MMSContext *mms   = &mmsh->mms;
     int ret;
 

     ret= mmsh_open_internal(h, mmsh->location, 0, FFMAX(timestamp, 0), 0);
 

     if(ret>=0){
         if (mms->mms_hd)
             ffurl_close(mms->mms_hd);
         av_freep(&mms->streams);
         av_freep(&mms->asf_header);
         av_free(mmsh);

         mmsh = h->priv_data;
         mms   = &mmsh->mms;
         mms->asf_header_read_size= mms->asf_header_size;

     }else
         h->priv_data= mmsh;
     return ret;
 }
 

 static int64_t mmsh_seek(URLContext *h, int64_t pos, int whence)
 {
     MMSHContext *mmsh = h->priv_data;
     MMSContext *mms   = &mmsh->mms;
 
     if(pos == 0 && whence == SEEK_CUR)
         return mms->asf_header_read_size + mms->remaining_in_len + mmsh->chunk_seq * mms->asf_packet_len;
     return AVERROR(ENOSYS);
 }
 

 URLProtocol ff_mmsh_protocol = {

     .name           = "mmsh",
     .url_open       = mmsh_open,
     .url_read       = mmsh_read,

     .url_seek       = mmsh_seek,

     .url_close      = mmsh_close,

     .url_read_seek  = mmsh_read_seek,

     .priv_data_size = sizeof(MMSHContext),

     .flags          = URL_PROTOCOL_FLAG_NETWORK,

 };