/*
 * Copyright (c) 2011, Jim Hollinger
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *   * Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *   * Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *   * Neither the name of Jim Hollinger nor the names of its contributors
 *     may be used to endorse or promote products derived from this
 *     software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#if defined (WIN32)
#  include <conio.h>  // _getch()
#else
#  include <termios.h>
#  include <unistd.h>

  int _getch(void) {
    struct termios oldt, newt;
    tcgetattr( STDIN_FILENO, &oldt );
    newt = oldt;
    newt.c_lflag &= ~( ICANON | ECHO );
    tcsetattr( STDIN_FILENO, TCSANOW, &newt );
    int ch = getchar();
    tcsetattr( STDIN_FILENO, TCSANOW, &oldt );
    return ch;
  }
#endif

#include <curl/curl.h>

#define VERSION_STR  "V1.0"

// error handling macros
#define my_curl_easy_setopt(A, B, C) \
  if ((res = curl_easy_setopt((A), (B), (C))) != CURLE_OK) \
    fprintf(stderr, "curl_easy_setopt(%s, %s, %s) failed: %d\n", #A, #B, #C, res);

#define my_curl_easy_perform(A) \
  if ((res = curl_easy_perform((A))) != CURLE_OK) \
    fprintf(stderr, "curl_easy_perform(%s) failed: %d\n", #A, res);


// send RTSP OPTIONS request
void rtsp_options(CURL *curl, const char *uri) {
    CURLcode res = CURLE_OK;
    printf("\nRTSP: OPTIONS %s\n", uri);
    my_curl_easy_setopt(curl, CURLOPT_RTSP_STREAM_URI, uri);
    my_curl_easy_setopt(curl, CURLOPT_RTSP_REQUEST, CURL_RTSPREQ_OPTIONS);
    my_curl_easy_perform(curl);
}


// send RTSP DESCRIBE request and write sdp response to a file
void rtsp_describe(CURL *curl, const char *uri, const char *sdp_filename) {
    CURLcode res = CURLE_OK;
    printf("\nRTSP: DESCRIBE %s\n", uri);
    FILE *sdp_fp = fopen(sdp_filename, "wt");
    if (sdp_fp == NULL) {
        fprintf(stderr, "Could not open '%s' for writing\n", sdp_filename);
        sdp_fp = stdout;
    } else {
        printf("Writing SDP to '%s'\n", sdp_filename);
    }
    my_curl_easy_setopt(curl, CURLOPT_WRITEDATA, sdp_fp);
    my_curl_easy_setopt(curl, CURLOPT_RTSP_REQUEST, CURL_RTSPREQ_DESCRIBE);
    my_curl_easy_perform(curl);
    my_curl_easy_setopt(curl, CURLOPT_WRITEDATA, stdout);
    if (sdp_fp != stdout) {
        fclose(sdp_fp);
    }
}


// send RTSP SETUP request
void rtsp_setup(CURL *curl, const char *uri, const char *transport) {
    CURLcode res = CURLE_OK;
    printf("\nRTSP: SETUP %s\n", uri);
    printf("      TRANSPORT %s\n", transport);
    my_curl_easy_setopt(curl, CURLOPT_RTSP_STREAM_URI, uri);
    my_curl_easy_setopt(curl, CURLOPT_RTSP_TRANSPORT, transport);
    my_curl_easy_setopt(curl, CURLOPT_RTSP_REQUEST, CURL_RTSPREQ_SETUP);
    my_curl_easy_perform(curl);
}


// send RTSP PLAY request
void rtsp_play(CURL *curl, const char *uri, const char *range) {
    CURLcode res = CURLE_OK;
    printf("\nRTSP: PLAY %s\n", uri);
    my_curl_easy_setopt(curl, CURLOPT_RTSP_STREAM_URI, uri);
    my_curl_easy_setopt(curl, CURLOPT_RANGE, range);
    my_curl_easy_setopt(curl, CURLOPT_RTSP_REQUEST, CURL_RTSPREQ_PLAY);
    my_curl_easy_perform(curl);
}


// send RTSP TEARDOWN request
void rtsp_teardown(CURL *curl, const char *uri) {
    CURLcode res = CURLE_OK;
    printf("\nRTSP: TEARDOWN %s\n", uri);
    my_curl_easy_setopt(curl, CURLOPT_RTSP_REQUEST, CURL_RTSPREQ_TEARDOWN);
    my_curl_easy_perform(curl);
}


// convert url into an sdp filename
void get_sdp_filename(const char *url, char *sdp_filename) {
    strcpy(sdp_filename, "video.sdp");
    const char *s = strrchr(url, '/');
    if (s != NULL) {
        s++;
        if (s[0] != '\0') {
            sprintf(sdp_filename, "%s.sdp", s);
        }
    }
}


// scan sdp file for media control attribute
void get_media_control_attribute(const char *sdp_filename, char *control) {
    control[0] = '\0';
    int max_len = 256;
    char *s = new char[max_len];
    FILE *sdp_fp = fopen(sdp_filename, "rt");
    if (sdp_fp != NULL) {
        while (fgets(s, max_len - 2, sdp_fp) != NULL) {
            sscanf(s, " a = control: %s", control);
        }
        fclose(sdp_fp);
    }
    delete []s;
}


// main app
int main(int argc, char * const argv[]) {
    const char *transport = "RTP/AVP;unicast;client_port=1234-1235";  // UDP		
//    const char *transport = "RTP/AVP/TCP;unicast;client_port=1234-1235";  // TCP
    const char *range = "0.000-";
    int rc = EXIT_SUCCESS;

    printf("\nRTSP request %s\n", VERSION_STR);
    printf("    Project web site: http://code.google.com/p/rtsprequest/\n");
    printf("    Requires cURL V7.20 or greater\n\n");

    // check command line
    char *basename = NULL;
    if ((argc != 2) && (argc != 3)) {
        basename = strrchr(argv[0], '/');
        if (basename == NULL) {
            basename = strrchr(argv[0], '\\');
        }
        if (basename == NULL) {
            basename = argv[0];
        } else {
            basename++;
        }
        printf("Usage:   %s url [transport]\n", basename);
        printf("         url of video server\n");
        printf("         transport (optional) specifier for media stream protocol\n");
        printf("         default transport: %s\n", transport);
        printf("Example: %s rtsp://192.168.0.2/media/video1\n\n", basename);
        rc = EXIT_FAILURE;
    } else {
        const char *url = argv[1];
        char *uri = new char[strlen(url) + 32];
        char *sdp_filename = new char[strlen(url) + 32];
        char *control = new char[strlen(url) + 32];
        get_sdp_filename(url, sdp_filename);
        if (argc == 3) {
            transport = argv[2];
        }

        // initialize curl
        CURLcode res = CURLE_OK;
        res = curl_global_init(CURL_GLOBAL_ALL);
        if (res == CURLE_OK) {
            curl_version_info_data *data = curl_version_info(CURLVERSION_NOW);
            fprintf(stderr, "    cURL V%s loaded\n", data->version);

            // initialize this curl session
            CURL *curl = curl_easy_init();
            if (curl != NULL) {
                my_curl_easy_setopt(curl, CURLOPT_VERBOSE, 0L);
                my_curl_easy_setopt(curl, CURLOPT_NOPROGRESS, 1L);
                my_curl_easy_setopt(curl, CURLOPT_WRITEHEADER, stdout);
                my_curl_easy_setopt(curl, CURLOPT_URL, url);

                // request server options
                sprintf(uri, "%s", url);
                rtsp_options(curl, uri);

                // request session description and write response to sdp file
                rtsp_describe(curl, uri, sdp_filename);

                // get media control attribute from sdp file
                get_media_control_attribute(sdp_filename, control);

                // setup media stream
                sprintf(uri, "%s/%s", url, control);
                rtsp_setup(curl, uri, transport);

                // start playing media stream
                sprintf(uri, "%s/", url);
                rtsp_play(curl, uri, range);
                printf("Playing video, press any key to stop ...");
                _getch();
                printf("\n");

                // teardown session
                rtsp_teardown(curl, uri);

                // cleanup
                curl_easy_cleanup(curl);
                curl = NULL;
            } else {
                fprintf(stderr, "curl_easy_init() failed\n");
            }
            curl_global_cleanup();
        } else {
            fprintf(stderr, "curl_global_init(%s) failed\n", "CURL_GLOBAL_ALL", res);
        }
        delete []control;
        delete []sdp_filename;
        delete []uri;
    }

    return rc;
}