/*
 * SpanDSP - a series of DSP components for telephony
 *
 * fax_tester.c
 *
 * Written by Steve Underwood <steveu@coppice.org>
 *
 * Copyright (C) 2008 Steve Underwood
 *
 * All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2, as
 * published by the Free Software Foundation.
 *
 * This program 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 General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

/*! \file */

#if defined(HAVE_CONFIG_H)
#include "config.h"
#endif

#include <inttypes.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#if defined(HAVE_TGMATH_H)
#include <tgmath.h>
#endif
#if defined(HAVE_MATH_H)
#include <math.h>
#endif
#include "floating_fudge.h"
#include <assert.h>
#include <fcntl.h>
#include <time.h>
#include <unistd.h>

#if defined(HAVE_LIBXML_XMLMEMORY_H)
#include <libxml/xmlmemory.h>
#endif
#if defined(HAVE_LIBXML_PARSER_H)
#include <libxml/parser.h>
#endif
#if defined(HAVE_LIBXML_XINCLUDE_H)
#include <libxml/xinclude.h>
#endif

#define SPANDSP_EXPOSE_INTERNAL_STRUCTURES

#include "spandsp.h"

#include "fax_tester.h"

#define HDLC_FRAMING_OK_THRESHOLD       5

static void timer_update(faxtester_state_t *s, int len)
{
    s->timer += len;
    if (s->timer > s->timeout)
    {
        s->timeout = 0x7FFFFFFFFFFFFFFFLL;
        if (s->front_end_step_timeout_handler)
            s->front_end_step_timeout_handler(s, s->front_end_step_timeout_user_data);
    }
}
/*- End of function --------------------------------------------------------*/

static void front_end_step_complete(faxtester_state_t *s)
{
    if (s->front_end_step_complete_handler)
        s->front_end_step_complete_handler(s, s->front_end_step_complete_user_data);
}
/*- End of function --------------------------------------------------------*/

void faxtester_send_hdlc_flags(faxtester_state_t *s, int flags)
{
    hdlc_tx_flags(&s->modems.hdlc_tx, flags);
}
/*- End of function --------------------------------------------------------*/

void faxtester_send_hdlc_msg(faxtester_state_t *s, const uint8_t *msg, int len, int crc_ok)
{
    hdlc_tx_frame(&s->modems.hdlc_tx, msg, len);
    if (!crc_ok)
        hdlc_tx_corrupt_frame(&s->modems.hdlc_tx);
}
/*- End of function --------------------------------------------------------*/

static void hdlc_underflow_handler(void *user_data)
{
    faxtester_state_t *s;
    uint8_t buf[400];

    s = (faxtester_state_t *) user_data;

    if (s->image_buffer)
    {
        /* We are sending an ECM image */
        if (s->image_ptr < s->image_len)
        {
            buf[0] = 0xFF;
            buf[1] = 0x03;
            buf[2] = 0x06;
            buf[3] = s->image_ptr/s->ecm_frame_size;
            memcpy(buf + 4, &s->image_buffer[s->image_ptr], s->ecm_frame_size);
            hdlc_tx_frame(&s->modems.hdlc_tx, buf, 4 + s->ecm_frame_size);
            if (s->corrupt_crc >= 0  &&  s->corrupt_crc == s->image_ptr/s->ecm_frame_size)
                hdlc_tx_corrupt_frame(&s->modems.hdlc_tx);
            s->image_ptr += s->ecm_frame_size;
            return;
        }
        /* The actual image is over. We are sending the final RCP frames. */
        if (s->image_bit_ptr > 2)
        {
            s->image_bit_ptr--;
            buf[0] = 0xFF;
            buf[1] = 0x03;
            buf[2] = 0x86;
            hdlc_tx_frame(&s->modems.hdlc_tx, buf, 3);
            return;
        }
        /* All done. */
        s->image_buffer = NULL;
    }
    front_end_step_complete(s);
}
/*- End of function --------------------------------------------------------*/

static void modem_tx_status(void *user_data, int status)
{
    faxtester_state_t *s;

    s = (faxtester_state_t *) user_data;
    printf("Tx status is %s (%d)\n", signal_status_to_str(status), status);
    switch (status)
    {
    case SIG_STATUS_SHUTDOWN_COMPLETE:
        front_end_step_complete(s);
        break;
    }
}
/*- End of function --------------------------------------------------------*/

static void tone_detected(void *user_data, int tone, int level, int delay)
{
    faxtester_state_t *s;

    s = (faxtester_state_t *) user_data;
    span_log(&s->logging,
             SPAN_LOG_FLOW,
             "%s (%d) declared (%ddBm0)\n",
             modem_connect_tone_to_str(tone),
             tone,
             level);
    if (tone != MODEM_CONNECT_TONES_NONE)
    {
        s->tone_on_time = s->timer;
    }
    else
    {
        span_log(&s->logging,
                 SPAN_LOG_FLOW,
                 "Tone was on for %fs\n",
                 (float) (s->timer - s->tone_on_time)/SAMPLE_RATE + 0.55);
    }
    s->tone_state = tone;
    if (tone == MODEM_CONNECT_TONES_NONE)
        front_end_step_complete(s);
}
/*- End of function --------------------------------------------------------*/

static int non_ecm_get_bit(void *user_data)
{
    faxtester_state_t *s;
    int bit;

    s = (faxtester_state_t *) user_data;
    if (s->image_bit_ptr == 0)
    {
        if (s->image_ptr >= s->image_len)
        {
            s->image_buffer = NULL;
            return SIG_STATUS_END_OF_DATA;
        }
        s->image_bit_ptr = 8;
        s->image_ptr++;
    }
    s->image_bit_ptr--;
    bit = (s->image_buffer[s->image_ptr] >> (7 - s->image_bit_ptr)) & 0x01;
    //printf("Rx bit - %d\n", bit);
    return bit;
}
/*- End of function --------------------------------------------------------*/

void faxtester_set_non_ecm_image_buffer(faxtester_state_t *s, const uint8_t *buf, int len)
{
    s->image_ptr = 0;
    s->image_bit_ptr = 8;
    s->image_len = len;
    s->image_buffer = buf;
}
/*- End of function --------------------------------------------------------*/

void faxtester_set_ecm_image_buffer(faxtester_state_t *s, const uint8_t *buf, int len, int block, int frame_size, int crc_hit)
{
    int start;

    start = 256*frame_size*block;
    if (len > start + 256*frame_size)
        len = start + 256*frame_size;

    s->ecm_frame_size = frame_size;
    s->image_ptr = start;
    s->image_bit_ptr = 8;
    s->image_len = len;
    s->image_buffer = buf;
    s->corrupt_crc = crc_hit;
    /* Send the first frame */
    hdlc_underflow_handler(s);
}
/*- End of function --------------------------------------------------------*/

static void non_ecm_rx_status(void *user_data, int status)
{
    faxtester_state_t *s;

    s = (faxtester_state_t *) user_data;
    span_log(&s->logging, SPAN_LOG_FLOW, "Non-ECM carrier status is %s (%d)\n", signal_status_to_str(status), status);
    switch (status)
    {
    case SIG_STATUS_TRAINING_FAILED:
        s->modems.rx_trained = FALSE;
        break;
    case SIG_STATUS_TRAINING_SUCCEEDED:
        /* The modem is now trained */
        s->modems.rx_trained = TRUE;
        break;
    case SIG_STATUS_CARRIER_UP:
        s->modems.rx_signal_present = TRUE;
        break;
    case SIG_STATUS_CARRIER_DOWN:
        if (s->modems.rx_trained)
        {
            if (s->real_time_frame_handler)
                s->real_time_frame_handler(s, s->real_time_frame_user_data, TRUE, NULL, 0);
        }
        s->modems.rx_signal_present = FALSE;
        s->modems.rx_trained = FALSE;
        break;
    }
}
/*- End of function --------------------------------------------------------*/

static void non_ecm_put_bit(void *user_data, int bit)
{
    if (bit < 0)
    {
        non_ecm_rx_status(user_data, bit);
        return;
    }
}
/*- End of function --------------------------------------------------------*/

static void hdlc_rx_status(void *user_data, int status)
{
    faxtester_state_t *s;

    s = (faxtester_state_t *) user_data;
    span_log(&s->logging, SPAN_LOG_FLOW, "HDLC carrier status is %s (%d)\n", signal_status_to_str(status), status);
    switch (status)
    {
    case SIG_STATUS_TRAINING_FAILED:
        s->modems.rx_trained = FALSE;
        break;
    case SIG_STATUS_TRAINING_SUCCEEDED:
        /* The modem is now trained */
        s->modems.rx_trained = TRUE;
        break;
    case SIG_STATUS_CARRIER_UP:
        s->modems.rx_signal_present = TRUE;
        break;
    case SIG_STATUS_CARRIER_DOWN:
        s->modems.rx_signal_present = FALSE;
        s->modems.rx_trained = FALSE;
        break;
    }
}
/*- End of function --------------------------------------------------------*/

static void hdlc_accept(void *user_data, const uint8_t *msg, int len, int ok)
{
    faxtester_state_t *s;

    if (len < 0)
    {
        hdlc_rx_status(user_data, len);
        return;
    }
    s = (faxtester_state_t *) user_data;
    if (s->real_time_frame_handler)
        s->real_time_frame_handler(s, s->real_time_frame_user_data, TRUE, msg, len);
}
/*- End of function --------------------------------------------------------*/

int faxtester_rx(faxtester_state_t *s, int16_t *amp, int len)
{
    int i;

    for (i = 0;  i < len;  i++)
        amp[i] = dc_restore(&s->modems.dc_restore, amp[i]);
    if (s->modems.rx_handler)
        s->modems.rx_handler(s->modems.rx_user_data, amp, len);
    timer_update(s, len);
    if (s->wait_for_silence)
    {
        if (!s->modems.rx_signal_present)
        {
            s->wait_for_silence = FALSE;
            front_end_step_complete(s);
        }
    }
    return 0;
}
/*- End of function --------------------------------------------------------*/

int faxtester_tx(faxtester_state_t *s, int16_t *amp, int max_len)
{
    int len;

    len = 0;
    if (s->transmit)
    {
        while ((len += s->modems.tx_handler(s->modems.tx_user_data, amp + len, max_len - len)) < max_len)
        {
            /* Allow for a change of tx handler within a block */
            front_end_step_complete(s);
            if (!s->transmit)
            {
                if (s->modems.transmit_on_idle)
                {
                    /* Pad to the requested length with silence */
                    memset(amp + len, 0, (max_len - len)*sizeof(int16_t));
                    len = max_len;
                }
                break;
            }
        }
    }
    else
    {
        if (s->modems.transmit_on_idle)
        {
            /* Pad to the requested length with silence */
            memset(amp, 0, max_len*sizeof(int16_t));
            len = max_len;
        }
    }
    return len;
}
/*- End of function --------------------------------------------------------*/

void faxtest_set_rx_silence(faxtester_state_t *s)
{
    s->wait_for_silence = TRUE;
}
/*- End of function --------------------------------------------------------*/

void faxtester_set_rx_type(void *user_data, int type, int bit_rate, int short_train, int use_hdlc)
{
    faxtester_state_t *s;
    fax_modems_state_t *t;

    s = (faxtester_state_t *) user_data;
    t = &s->modems;
    span_log(&s->logging, SPAN_LOG_FLOW, "Set rx type %d\n", type);
    if (s->current_rx_type == type)
        return;
    s->current_rx_type = type;
    if (use_hdlc)
        hdlc_rx_init(&t->hdlc_rx, FALSE, FALSE, HDLC_FRAMING_OK_THRESHOLD, hdlc_accept, s);
    switch (type)
    {
    case T30_MODEM_CED:
        fax_modems_start_slow_modem(t, FAX_MODEM_CED_TONE_RX);
        s->tone_state = MODEM_CONNECT_TONES_NONE;
        break;
    case T30_MODEM_CNG:
        fax_modems_start_slow_modem(t, FAX_MODEM_CNG_TONE_RX);
        s->tone_state = MODEM_CONNECT_TONES_NONE;
        break;
    case T30_MODEM_V21:
        if (s->flush_handler)
            s->flush_handler(s, s->flush_user_data, 3);
        fax_modems_start_slow_modem(t, FAX_MODEM_V21_RX);
        break;
    case T30_MODEM_V27TER:
        fax_modems_start_fast_modem(t, FAX_MODEM_V27TER_RX, bit_rate, short_train, use_hdlc);
        break;
    case T30_MODEM_V29:
        fax_modems_start_fast_modem(t, FAX_MODEM_V29_RX, bit_rate, short_train, use_hdlc);
        break;
    case T30_MODEM_V17:
        fax_modems_start_fast_modem(t, FAX_MODEM_V17_RX, bit_rate, short_train, use_hdlc);
        break;
    case T30_MODEM_DONE:
        span_log(&s->logging, SPAN_LOG_FLOW, "FAX exchange complete\n");
    default:
        fax_modems_set_rx_handler(t, (span_rx_handler_t) &span_dummy_rx, s, NULL, s);
        break;
    }
}
/*- End of function --------------------------------------------------------*/

void faxtester_set_tx_type(void *user_data, int type, int bit_rate, int short_train, int use_hdlc)
{
    faxtester_state_t *s;
    get_bit_func_t get_bit_func;
    void *get_bit_user_data;
    fax_modems_state_t *t;
    int tone;

    s = (faxtester_state_t *) user_data;
    t = &s->modems;
    span_log(&s->logging, SPAN_LOG_FLOW, "Set tx type %d\n", type);
    if (s->current_tx_type == type)
        return;
    if (use_hdlc)
    {
        get_bit_func = (get_bit_func_t) hdlc_tx_get_bit;
        get_bit_user_data = (void *) &t->hdlc_tx;
    }
    else
    {
        get_bit_func = non_ecm_get_bit;
        get_bit_user_data = (void *) s;
    }
    switch (type)
    {
    case T30_MODEM_PAUSE:
        silence_gen_alter(&t->silence_gen, ms_to_samples(short_train));
        fax_modems_set_tx_handler(t, (span_tx_handler_t) &silence_gen, &t->silence_gen);
        s->transmit = TRUE;
        break;
    case T30_MODEM_CED:
    case T30_MODEM_CNG:
        tone = (type == T30_MODEM_CED)  ?  MODEM_CONNECT_TONES_FAX_CED  :  MODEM_CONNECT_TONES_FAX_CNG;
        fax_modems_start_slow_modem(t, tone);
        s->transmit = TRUE;
        break;
    case T30_MODEM_V21:
        fax_modems_start_slow_modem(t, FAX_MODEM_V21_TX);
        fsk_tx_set_modem_status_handler(&t->v21_tx, modem_tx_status, (void *) s);
        s->transmit = TRUE;
        break;
    case T30_MODEM_V27TER:
        fax_modems_set_get_bit(t, get_bit_func, get_bit_user_data);
        fax_modems_start_fast_modem(t, FAX_MODEM_V27TER_TX, bit_rate, short_train, use_hdlc);
        v27ter_tx_set_modem_status_handler(&t->fast_modems.v27ter_tx, modem_tx_status, (void *) s);
        /* For any fast modem, set 200ms of preamble flags */
        hdlc_tx_flags(&t->hdlc_tx, bit_rate/(8*5));
        s->transmit = TRUE;
        break;
    case T30_MODEM_V29:
        fax_modems_set_get_bit(t, get_bit_func, get_bit_user_data);
        fax_modems_start_fast_modem(t, FAX_MODEM_V29_TX, bit_rate, short_train, use_hdlc);
        v29_tx_set_modem_status_handler(&t->fast_modems.v29_tx, modem_tx_status, (void *) s);
        /* For any fast modem, set 200ms of preamble flags */
        hdlc_tx_flags(&t->hdlc_tx, bit_rate/(8*5));
        s->transmit = TRUE;
        break;
    case T30_MODEM_V17:
        fax_modems_set_get_bit(t, get_bit_func, get_bit_user_data);
        fax_modems_start_fast_modem(t, FAX_MODEM_V17_TX, bit_rate, short_train, use_hdlc);
        v17_tx_set_modem_status_handler(&t->fast_modems.v17_tx, modem_tx_status, (void *) s);
        /* For any fast modem, set 200ms of preamble flags */
        hdlc_tx_flags(&t->hdlc_tx, bit_rate/(8*5));
        s->transmit = TRUE;
        break;
    case T30_MODEM_DONE:
        span_log(&s->logging, SPAN_LOG_FLOW, "FAX exchange complete\n");
        /* Fall through */
    default:
        silence_gen_alter(&t->silence_gen, 0);
        fax_modems_set_tx_handler(t, (span_tx_handler_t) &silence_gen, &t->silence_gen);
        s->transmit = FALSE;
        break;
    }
    s->current_tx_type = type;
}
/*- End of function --------------------------------------------------------*/

void faxtester_set_timeout(faxtester_state_t *s, int timeout)
{
    if (timeout >= 0)
        s->timeout = s->timer + timeout*SAMPLE_RATE/1000;
    else
        s->timeout = 0x7FFFFFFFFFFFFFFFLL;
}
/*- End of function --------------------------------------------------------*/

void faxtester_set_transmit_on_idle(faxtester_state_t *s, int transmit_on_idle)
{
    s->modems.transmit_on_idle = transmit_on_idle;
}
/*- End of function --------------------------------------------------------*/

void faxtester_set_tep_mode(faxtester_state_t *s, int use_tep)
{
    fax_modems_set_tep_mode(&s->modems, use_tep);
}
/*- End of function --------------------------------------------------------*/

void faxtester_set_real_time_frame_handler(faxtester_state_t *s, faxtester_real_time_frame_handler_t handler, void *user_data)
{
    s->real_time_frame_handler = handler;
    s->real_time_frame_user_data = user_data;
}
/*- End of function --------------------------------------------------------*/

void faxtester_set_front_end_step_complete_handler(faxtester_state_t *s, faxtester_front_end_step_complete_handler_t handler, void *user_data)
{
    s->front_end_step_complete_handler = handler;
    s->front_end_step_complete_user_data = user_data;
}
/*- End of function --------------------------------------------------------*/

void faxtester_set_front_end_step_timeout_handler(faxtester_state_t *s, faxtester_front_end_step_complete_handler_t handler, void *user_data)
{
    s->front_end_step_timeout_handler = handler;
    s->front_end_step_timeout_user_data = user_data;
}
/*- End of function --------------------------------------------------------*/

faxtester_state_t *faxtester_init(faxtester_state_t *s, int calling_party)
{
    if (s == NULL)
    {
        if ((s = (faxtester_state_t *) malloc(sizeof(*s))) == NULL)
            return NULL;
    }

    memset(s, 0, sizeof(*s));
    span_log_init(&s->logging, SPAN_LOG_NONE, NULL);
    span_log_set_protocol(&s->logging, "TST");
    fax_modems_init(&s->modems,
                    FALSE,
                    NULL,
                    hdlc_underflow_handler,
                    non_ecm_put_bit,
                    t38_non_ecm_buffer_get_bit,
                    tone_detected,
                    s);
    fax_modems_set_tep_mode(&s->modems, FALSE);
    fax_modems_set_rx_active(&s->modems, TRUE);
    faxtester_set_timeout(s, -1);
    faxtester_set_tx_type(s, T30_MODEM_NONE, 0, FALSE, FALSE);

    return s;
}
/*- End of function --------------------------------------------------------*/

int faxtester_release(faxtester_state_t *s)
{
    return 0;
}
/*- End of function --------------------------------------------------------*/

int faxtester_free(faxtester_state_t *s)
{
    free(s);
    return 0;
}
/*- End of function --------------------------------------------------------*/

void faxtester_set_flush_handler(faxtester_state_t *s, faxtester_flush_handler_t handler, void *user_data)
{
    s->flush_handler = handler;
    s->flush_user_data = user_data;
}
/*- End of function --------------------------------------------------------*/
/*- End of file ------------------------------------------------------------*/