/***
  This file is part of PulseAudio.

  Copyright 2008 Colin Guthrie

  PulseAudio 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.

  PulseAudio 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 Lesser General Public License
  along with PulseAudio; if not, see <http://www.gnu.org/licenses/>.
***/

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <netinet/in.h>

#ifdef HAVE_SYS_FILIO_H
#include <sys/filio.h>
#endif

#include <pulse/xmalloc.h>

#include <pulsecore/core-error.h>
#include <pulsecore/core-util.h>
#include <pulsecore/log.h>
#include <pulsecore/macro.h>
#include <pulsecore/strbuf.h>
#include <pulsecore/ioline.h>
#include <pulsecore/arpa-inet.h>

#include "rtsp_client.h"

struct pa_rtsp_client {
    pa_mainloop_api *mainloop;
    char *hostname;
    uint16_t port;

    pa_socket_client *sc;
    pa_ioline *ioline;

    pa_rtsp_cb_t callback;

    void *userdata;
    const char *useragent;

    pa_rtsp_state state;
    uint8_t waiting;

    pa_headerlist* headers;
    char *last_header;
    pa_strbuf *header_buffer;
    pa_headerlist* response_headers;

    char *localip;
    char *url;
    uint16_t rtp_port;
    uint32_t cseq;
    char *session;
    char *transport;
};

pa_rtsp_client* pa_rtsp_client_new(pa_mainloop_api *mainloop, const char* hostname, uint16_t port, const char* useragent) {
    pa_rtsp_client *c;

    pa_assert(mainloop);
    pa_assert(hostname);
    pa_assert(port > 0);

    c = pa_xnew0(pa_rtsp_client, 1);
    c->mainloop = mainloop;
    c->hostname = pa_xstrdup(hostname);
    c->port = port;
    c->headers = pa_headerlist_new();

    if (useragent)
        c->useragent = useragent;
    else
        c->useragent = "PulseAudio RTSP Client";

    return c;
}

void pa_rtsp_client_free(pa_rtsp_client* c) {
    pa_assert(c);

    if (c->sc)
        pa_socket_client_unref(c->sc);

    pa_rtsp_disconnect(c);

    pa_xfree(c->hostname);
    pa_xfree(c->url);
    pa_xfree(c->localip);
    pa_xfree(c->session);
    pa_xfree(c->transport);
    pa_xfree(c->last_header);
    if (c->header_buffer)
        pa_strbuf_free(c->header_buffer);
    if (c->response_headers)
        pa_headerlist_free(c->response_headers);
    pa_headerlist_free(c->headers);

    pa_xfree(c);
}

static void headers_read(pa_rtsp_client *c) {
    char* token;
    char delimiters[] = ";";

    pa_assert(c);
    pa_assert(c->response_headers);
    pa_assert(c->callback);

    /* Deal with a SETUP response */
    if (STATE_SETUP == c->state) {
        const char* token_state = NULL;
        const char* pc = NULL;
        c->session = pa_xstrdup(pa_headerlist_gets(c->response_headers, "Session"));
        c->transport = pa_xstrdup(pa_headerlist_gets(c->response_headers, "Transport"));

        if (!c->session || !c->transport) {
            pa_log("Invalid SETUP response.");
            return;
        }

        /* Now parse out the server port component of the response. */
        while ((token = pa_split(c->transport, delimiters, &token_state))) {
            if ((pc = strchr(token, '='))) {
                if (0 == strncmp(token, "server_port", 11)) {
                    uint32_t p;

                    if (pa_atou(pc + 1, &p) < 0 || p <= 0 || p > 0xffff) {
                        pa_log("Invalid SETUP response (invalid server_port).");
                        pa_xfree(token);
                        return;
                    }

                    c->rtp_port = p;
                    pa_xfree(token);
                    break;
                }
            }
            pa_xfree(token);
        }
        if (0 == c->rtp_port) {
            /* Error no server_port in response */
            pa_log("Invalid SETUP response (no port number).");
            return;
        }
    }

    /* Call our callback */
    c->callback(c, c->state, c->response_headers, c->userdata);
}

static void line_callback(pa_ioline *line, const char *s, void *userdata) {
    char *delimpos;
    char *s2, *s2p;

    pa_rtsp_client *c = userdata;
    pa_assert(line);
    pa_assert(c);
    pa_assert(c->callback);

    if (!s) {
        /* Keep the ioline/iochannel open as they will be freed automatically */
        c->ioline = NULL;
        c->callback(c, STATE_DISCONNECTED, NULL, c->userdata);
        return;
    }

    s2 = pa_xstrdup(s);
    /* Trim trailing carriage returns */
    s2p = s2 + strlen(s2) - 1;
    while (s2p >= s2 && '\r' == *s2p) {
        *s2p = '\0';
        s2p -= 1;
    }
    if (c->waiting && pa_streq(s2, "RTSP/1.0 200 OK")) {
        c->waiting = 0;
        if (c->response_headers)
            pa_headerlist_free(c->response_headers);
        c->response_headers = pa_headerlist_new();
        goto exit;
    }
    if (c->waiting) {
        pa_log_warn("Unexpected response: %s", s2);
        goto exit;;
    }
    if (!strlen(s2)) {
        /* End of headers */
        /* We will have a header left from our looping iteration, so add it in :) */
        if (c->last_header) {
            char *tmp = pa_strbuf_tostring_free(c->header_buffer);
            /* This is not a continuation header so let's dump it into our proplist */
            pa_headerlist_puts(c->response_headers, c->last_header, tmp);
            pa_xfree(tmp);
            pa_xfree(c->last_header);
            c->last_header = NULL;
            c->header_buffer = NULL;
        }

        pa_log_debug("Full response received. Dispatching");
        headers_read(c);
        c->waiting = 1;
        goto exit;
    }

    /* Read and parse a header (we know it's not empty) */
    /* TODO: Move header reading into the headerlist. */

    /* If the first character is a space, it's a continuation header */
    if (c->last_header && ' ' == s2[0]) {
        pa_assert(c->header_buffer);

        /* Add this line to the buffer (sans the space. */
        pa_strbuf_puts(c->header_buffer, &(s2[1]));
        goto exit;
    }

    if (c->last_header) {
        char *tmp = pa_strbuf_tostring_free(c->header_buffer);
        /* This is not a continuation header so let's dump the full
          header/value into our proplist */
        pa_headerlist_puts(c->response_headers, c->last_header, tmp);
        pa_xfree(tmp);
        pa_xfree(c->last_header);
        c->last_header = NULL;
        c->header_buffer = NULL;
    }

    delimpos = strstr(s2, ":");
    if (!delimpos) {
        pa_log_warn("Unexpected response when expecting header: %s", s);
        goto exit;
    }

    pa_assert(!c->header_buffer);
    pa_assert(!c->last_header);

    c->header_buffer = pa_strbuf_new();
    if (strlen(delimpos) > 1) {
        /* Cut our line off so we can copy the header name out */
        *delimpos++ = '\0';

        /* Trim the front of any spaces */
        while (' ' == *delimpos)
            ++delimpos;

        pa_strbuf_puts(c->header_buffer, delimpos);
    } else {
        /* Cut our line off so we can copy the header name out */
        *delimpos = '\0';
    }

    /* Save the header name */
    c->last_header = pa_xstrdup(s2);
  exit:
    pa_xfree(s2);
}

static void on_connection(pa_socket_client *sc, pa_iochannel *io, void *userdata) {
    pa_rtsp_client *c = userdata;
    union {
        struct sockaddr sa;
        struct sockaddr_in in;
        struct sockaddr_in6 in6;
    } sa;
    socklen_t sa_len = sizeof(sa);

    pa_assert(sc);
    pa_assert(c);
    pa_assert(STATE_CONNECT == c->state);
    pa_assert(c->sc == sc);
    pa_socket_client_unref(c->sc);
    c->sc = NULL;

    if (!io) {
        pa_log("Connection failed: %s", pa_cstrerror(errno));
        return;
    }
    pa_assert(!c->ioline);

    c->ioline = pa_ioline_new(io);
    pa_ioline_set_callback(c->ioline, line_callback, c);

    /* Get the local IP address for use externally */
    if (0 == getsockname(pa_iochannel_get_recv_fd(io), &sa.sa, &sa_len)) {
        char buf[INET6_ADDRSTRLEN];
        const char *res = NULL;

        if (AF_INET == sa.sa.sa_family) {
            if ((res = inet_ntop(sa.sa.sa_family, &sa.in.sin_addr, buf, sizeof(buf)))) {
                c->localip = pa_xstrdup(res);
            }
        } else if (AF_INET6 == sa.sa.sa_family) {
            if ((res = inet_ntop(AF_INET6, &sa.in6.sin6_addr, buf, sizeof(buf)))) {
                c->localip = pa_sprintf_malloc("[%s]", res);
            }
        }
    }
    pa_log_debug("Established RTSP connection from local ip %s", c->localip);

    if (c->callback)
        c->callback(c, c->state, NULL, c->userdata);
}

int pa_rtsp_connect(pa_rtsp_client *c) {
    pa_assert(c);
    pa_assert(!c->sc);

    pa_xfree(c->session);
    c->session = NULL;

    pa_log_debug("Attempting to connect to server '%s:%d'", c->hostname, c->port);
    if (!(c->sc = pa_socket_client_new_string(c->mainloop, true, c->hostname, c->port))) {
        pa_log("failed to connect to server '%s:%d'", c->hostname, c->port);
        return -1;
    }

    pa_socket_client_set_callback(c->sc, on_connection, c);
    c->waiting = 1;
    c->state = STATE_CONNECT;
    return 0;
}

void pa_rtsp_set_callback(pa_rtsp_client *c, pa_rtsp_cb_t callback, void *userdata) {
    pa_assert(c);

    c->callback = callback;
    c->userdata = userdata;
}

void pa_rtsp_disconnect(pa_rtsp_client *c) {
    pa_assert(c);

    if (c->ioline)
        pa_ioline_close(c->ioline);
    c->ioline = NULL;
}

const char* pa_rtsp_localip(pa_rtsp_client* c) {
    pa_assert(c);

    return c->localip;
}

uint32_t pa_rtsp_serverport(pa_rtsp_client* c) {
    pa_assert(c);

    return c->rtp_port;
}

void pa_rtsp_set_url(pa_rtsp_client* c, const char* url) {
    pa_assert(c);

    c->url = pa_xstrdup(url);
}

void pa_rtsp_add_header(pa_rtsp_client *c, const char* key, const char* value) {
    pa_assert(c);
    pa_assert(key);
    pa_assert(value);

    pa_headerlist_puts(c->headers, key, value);
}

void pa_rtsp_remove_header(pa_rtsp_client *c, const char* key) {
    pa_assert(c);
    pa_assert(key);

    pa_headerlist_remove(c->headers, key);
}

static int rtsp_exec(pa_rtsp_client* c, const char* cmd,
                        const char* content_type, const char* content,
                        int expect_response,
                        pa_headerlist* headers) {
    pa_strbuf* buf;
    char* hdrs;

    pa_assert(c);
    pa_assert(c->url);
    pa_assert(cmd);
    pa_assert(c->ioline);

    pa_log_debug("Sending command: %s", cmd);

    buf = pa_strbuf_new();
    pa_strbuf_printf(buf, "%s %s RTSP/1.0\r\nCSeq: %d\r\n", cmd, c->url, ++c->cseq);
    if (c->session)
        pa_strbuf_printf(buf, "Session: %s\r\n", c->session);

    /* Add the headers */
    if (headers) {
        hdrs = pa_headerlist_to_string(headers);
        pa_strbuf_puts(buf, hdrs);
        pa_xfree(hdrs);
    }

    if (content_type && content) {
        pa_strbuf_printf(buf, "Content-Type: %s\r\nContent-Length: %d\r\n",
          content_type, (int)strlen(content));
    }

    pa_strbuf_printf(buf, "User-Agent: %s\r\n", c->useragent);

    if (c->headers) {
        hdrs = pa_headerlist_to_string(c->headers);
        pa_strbuf_puts(buf, hdrs);
        pa_xfree(hdrs);
    }

    pa_strbuf_puts(buf, "\r\n");

    if (content_type && content) {
        pa_strbuf_puts(buf, content);
    }

    /* Our packet is created... now we can send it :) */
    hdrs = pa_strbuf_tostring_free(buf);
    /*pa_log_debug("Submitting request:");
    pa_log_debug(hdrs);*/
    pa_ioline_puts(c->ioline, hdrs);
    pa_xfree(hdrs);

    return 0;
}

int pa_rtsp_announce(pa_rtsp_client *c, const char* sdp) {
    pa_assert(c);
    if (!sdp)
        return -1;

    c->state = STATE_ANNOUNCE;
    return rtsp_exec(c, "ANNOUNCE", "application/sdp", sdp, 1, NULL);
}

int pa_rtsp_setup(pa_rtsp_client* c) {
    pa_headerlist* headers;
    int rv;

    pa_assert(c);

    headers = pa_headerlist_new();
    pa_headerlist_puts(headers, "Transport", "RTP/AVP/TCP;unicast;interleaved=0-1;mode=record");

    c->state = STATE_SETUP;
    rv = rtsp_exec(c, "SETUP", NULL, NULL, 1, headers);
    pa_headerlist_free(headers);
    return rv;
}

int pa_rtsp_record(pa_rtsp_client* c, uint16_t* seq, uint32_t* rtptime) {
    pa_headerlist* headers;
    int rv;
    char *info;

    pa_assert(c);
    if (!c->session) {
        /* No session in progress */
        return -1;
    }

    /* Todo: Generate these values randomly as per spec */
    *seq = *rtptime = 0;

    headers = pa_headerlist_new();
    pa_headerlist_puts(headers, "Range", "npt=0-");
    info = pa_sprintf_malloc("seq=%u;rtptime=%u", *seq, *rtptime);
    pa_headerlist_puts(headers, "RTP-Info", info);
    pa_xfree(info);

    c->state = STATE_RECORD;
    rv = rtsp_exec(c, "RECORD", NULL, NULL, 1, headers);
    pa_headerlist_free(headers);
    return rv;
}

int pa_rtsp_teardown(pa_rtsp_client *c) {
    pa_assert(c);

    c->state = STATE_TEARDOWN;
    return rtsp_exec(c, "TEARDOWN", NULL, NULL, 0, NULL);
}

int pa_rtsp_setparameter(pa_rtsp_client *c, const char* param) {
    pa_assert(c);
    if (!param)
        return -1;

    c->state = STATE_SET_PARAMETER;
    return rtsp_exec(c, "SET_PARAMETER", "text/parameters", param, 1, NULL);
}

int pa_rtsp_flush(pa_rtsp_client *c, uint16_t seq, uint32_t rtptime) {
    pa_headerlist* headers;
    int rv;
    char *info;

    pa_assert(c);

    headers = pa_headerlist_new();
    info = pa_sprintf_malloc("seq=%u;rtptime=%u", seq, rtptime);
    pa_headerlist_puts(headers, "RTP-Info", info);
    pa_xfree(info);

    c->state = STATE_FLUSH;
    rv = rtsp_exec(c, "FLUSH", NULL, NULL, 1, headers);
    pa_headerlist_free(headers);
    return rv;
}
