/*
  * Icecast protocol for FFmpeg
  * Copyright (c) 2014 Marvin Scholz
  *
  * 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 "libavutil/avstring.h"
 #include "libavutil/bprint.h"
 #include "libavutil/opt.h"
 
 #include "avformat.h"
 #include "network.h"
 
 
 typedef struct IcecastContext {
     const AVClass *class;
     URLContext *hd;
     int send_started;
     char *user;
     // Options
     char *content_type;
     char *description;
     char *genre;
     int legacy_icecast;
     char *name;
     char *pass;
     int public;
     char *url;
     char *user_agent;
 } IcecastContext;
 
 #define DEFAULT_ICE_USER "source"
 
 #define NOT_EMPTY(s) (s && s[0])
 
 #define OFFSET(x) offsetof(IcecastContext, x)
 #define E AV_OPT_FLAG_ENCODING_PARAM
 
 static const AVOption options[] = {

     { "ice_genre", "set stream genre", OFFSET(genre), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, E },
     { "ice_name", "set stream description", OFFSET(name), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, E },
     { "ice_description", "set stream description", OFFSET(description), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, E },
     { "ice_url", "set stream website", OFFSET(url), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, E },

     { "ice_public", "set if stream is public", OFFSET(public), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, E },

     { "user_agent", "override User-Agent header", OFFSET(user_agent), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, E },
     { "password", "set password", OFFSET(pass), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, E },
     { "content_type", "set content-type, MUST be set if not audio/mpeg", OFFSET(content_type), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, E },

     { "legacy_icecast", "use legacy SOURCE method, for Icecast < v2.4", OFFSET(legacy_icecast), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, E },

     { NULL }
 };
 
 
 static void cat_header(AVBPrint *bp, const char key[], const char value[])
 {
     if (NOT_EMPTY(value))
         av_bprintf(bp, "%s: %s\r\n", key, value);
 }
 

 static int icecast_close(URLContext *h)
 {
     IcecastContext *s = h->priv_data;
     if (s->hd)
         ffurl_close(s->hd);
     return 0;
 }
 

 static int icecast_open(URLContext *h, const char *uri, int flags)
 {
     IcecastContext *s = h->priv_data;
 
     // Dict to set options that we pass to the HTTP protocol
     AVDictionary *opt_dict = NULL;
 
     // URI part variables
     char h_url[1024], host[1024], auth[1024], path[1024];

     char *headers = NULL, *user = NULL;

     int port, ret;
     AVBPrint bp;
 

     if (flags & AVIO_FLAG_READ)
         return AVERROR(ENOSYS);
 

     av_bprint_init(&bp, 0, 1);
 
     // Build header strings
     cat_header(&bp, "Ice-Name", s->name);
     cat_header(&bp, "Ice-Description", s->description);
     cat_header(&bp, "Ice-URL", s->url);
     cat_header(&bp, "Ice-Genre", s->genre);
     cat_header(&bp, "Ice-Public", s->public ? "1" : "0");
     if (!av_bprint_is_complete(&bp)) {
         ret = AVERROR(ENOMEM);
         goto cleanup;
     }
     av_bprint_finalize(&bp, &headers);
 
     // Set options
     av_dict_set(&opt_dict, "method", s->legacy_icecast ? "SOURCE" : "PUT", 0);
     av_dict_set(&opt_dict, "auth_type", "basic", 0);
     av_dict_set(&opt_dict, "headers", headers, 0);

     av_dict_set(&opt_dict, "chunked_post", "0", 0);

     av_dict_set(&opt_dict, "send_expect_100", s->legacy_icecast ? "0" : "1", 0);

     if (NOT_EMPTY(s->content_type))
         av_dict_set(&opt_dict, "content_type", s->content_type, 0);

     else
         av_dict_set(&opt_dict, "content_type", "audio/mpeg", 0);

     if (NOT_EMPTY(s->user_agent))
         av_dict_set(&opt_dict, "user_agent", s->user_agent, 0);
 
     // Parse URI
     av_url_split(NULL, 0, auth, sizeof(auth), host, sizeof(host),
                  &port, path, sizeof(path), uri);
 
     // Check for auth data in URI
     if (auth[0]) {
         char *sep = strchr(auth, ':');
         if (sep) {
             *sep = 0;
             sep++;
             if (s->pass) {
                 av_free(s->pass);
                 av_log(h, AV_LOG_WARNING, "Overwriting -password <pass> with URI password!\n");
             }

             if (!(s->pass = av_strdup(sep))) {
                 ret = AVERROR(ENOMEM);
                 goto cleanup;
             }
         }
         if (!(user = av_strdup(auth))) {
             ret = AVERROR(ENOMEM);
             goto cleanup;

         }
     }
 
     // Build new authstring
     snprintf(auth, sizeof(auth),
              "%s:%s",
              user ? user : DEFAULT_ICE_USER,
              s->pass ? s->pass : "");
 
     // Check for mountpoint (path)
     if (!path[0] || strcmp(path, "/") == 0) {
         av_log(h, AV_LOG_ERROR, "No mountpoint (path) specified!\n");
         ret = AVERROR(EIO);
         goto cleanup;
     }
 
     // Build new URI for passing to http protocol
     ff_url_join(h_url, sizeof(h_url), "http", auth, host, port, "%s", path);
     // Finally open http proto handler

     ret = ffurl_open_whitelist(&s->hd, h_url, AVIO_FLAG_READ_WRITE, NULL,

                                &opt_dict, h->protocol_whitelist, h->protocol_blacklist, h);

 
 cleanup:
     av_freep(&user);
     av_freep(&headers);
     av_dict_free(&opt_dict);
 
     return ret;
 }
 
 static int icecast_write(URLContext *h, const uint8_t *buf, int size)
 {
     IcecastContext *s = h->priv_data;
     if (!s->send_started) {
         s->send_started = 1;
         if (!s->content_type && size >= 8) {
             static const uint8_t oggs[4] = { 0x4F, 0x67, 0x67, 0x53 };
             static const uint8_t webm[4] = { 0x1A, 0x45, 0xDF, 0xA3 };
             static const uint8_t opus[8] = { 0x4F, 0x70, 0x75, 0x73, 0x48, 0x65, 0x61, 0x64 };
             if (memcmp(buf, oggs, sizeof(oggs)) == 0) {

                 av_log(h, AV_LOG_WARNING, "Streaming Ogg but appropriate content type NOT set!\n");

                 av_log(h, AV_LOG_WARNING, "Set it with -content_type application/ogg\n");
             } else if (memcmp(buf, opus, sizeof(opus)) == 0) {

                 av_log(h, AV_LOG_WARNING, "Streaming Opus but appropriate content type NOT set!\n");

                 av_log(h, AV_LOG_WARNING, "Set it with -content_type audio/ogg\n");
             } else if (memcmp(buf, webm, sizeof(webm)) == 0) {

                 av_log(h, AV_LOG_WARNING, "Streaming WebM but appropriate content type NOT set!\n");

                 av_log(h, AV_LOG_WARNING, "Set it with -content_type video/webm\n");
             } else {
                 av_log(h, AV_LOG_WARNING, "It seems you are streaming an unsupported format.\n");
                 av_log(h, AV_LOG_WARNING, "It might work, but is not officially supported in Icecast!\n");
             }
         }
     }
     return ffurl_write(s->hd, buf, size);
 }
 
 static const AVClass icecast_context_class = {
     .class_name     = "icecast",
     .item_name      = av_default_item_name,
     .option         = options,
     .version        = LIBAVUTIL_VERSION_INT,
 };
 

 const URLProtocol ff_icecast_protocol = {

     .name            = "icecast",
     .url_open        = icecast_open,
     .url_write       = icecast_write,
     .url_close       = icecast_close,
     .priv_data_size  = sizeof(IcecastContext),
     .priv_data_class = &icecast_context_class,
     .flags           = URL_PROTOCOL_FLAG_NETWORK,
 };