/*
 *
 * NMEA library
 * URL: http://nmea.sourceforge.net
 * Author: Tim (xtimor@gmail.com)
 * Licence: http://www.gnu.org/licenses/lgpl.html
 * $Id: context.c 17 2008-03-11 11:56:11Z xtimor $
 *
 */
#include "nmea_parse.h"
#include "cp_logger.h"

#include <assert.h>
#include <stdarg.h>
#include <stdlib.h>
#include <stdio.h>
#include <ctype.h>
#include <string.h>
#include <limits.h>

#define NMEA_TOKS_COMPARE   (1)
#define NMEA_TOKS_PERCENT   (2)
#define NMEA_TOKS_WIDTH     (3)
#define NMEA_TOKS_TYPE      (4)

/**
 * \brief Convert string to number
 */
int nmea_atoi(const char *str, int str_sz, int radix)
{
    char *tmp_ptr;
    char buff[NMEA_CONVSTR_BUF];
    int res = 0;

    if(str_sz < NMEA_CONVSTR_BUF)
    {
        memcpy(&buff[0], str, str_sz);
        buff[str_sz] = '\0';
        res = strtol(&buff[0], &tmp_ptr, radix);
    }

    return res;
}

/**
 * \brief Convert string to fraction number
 */
double nmea_atof(const char *str, int str_sz)
{
    char *tmp_ptr;
    char buff[NMEA_CONVSTR_BUF];
    double res = 0;

    if(str_sz < NMEA_CONVSTR_BUF)
    {
        memcpy(&buff[0], str, str_sz);
        buff[str_sz] = '\0';
        res = strtod(&buff[0], &tmp_ptr);
    }

    return res;
}

/**
 * \brief Analyse string (specificate for NMEA sentences)
 */
int nmea_scanf(const char *buff, int buff_sz, const char *format, ...)
{
    const char *beg_tok;
    const char *end_buf = buff + buff_sz;

    va_list arg_ptr;
    int tok_type = NMEA_TOKS_COMPARE;
    int width = 0;
    const char *beg_fmt = 0;
    int snum = 0, unum = 0;

    int tok_count = 0;
    void *parg_target;

    va_start(arg_ptr, format);
    
    for(; *format && buff < end_buf; ++format)
    {
        switch(tok_type)
        {
        case NMEA_TOKS_COMPARE:
            if('%' == *format)
                tok_type = NMEA_TOKS_PERCENT;
            else if(*buff++ != *format)
                goto fail;
            break;
        case NMEA_TOKS_PERCENT:
            width = 0;
            beg_fmt = format;
            tok_type = NMEA_TOKS_WIDTH;
        case NMEA_TOKS_WIDTH:
            if(isdigit(*format))
                break;
            {
                tok_type = NMEA_TOKS_TYPE;
                if(format > beg_fmt)
                    width = nmea_atoi(beg_fmt, (int)(format - beg_fmt), 10);
            }
        case NMEA_TOKS_TYPE:
            beg_tok = buff;

            if(!width && ('c' == *format || 'C' == *format) && *buff != format[1])
                width = 1;

            if(width)
            {
                if(buff + width <= end_buf)
                    buff += width;
                else
                    goto fail;
            }
            else
            {
                if(!format[1] || (0 == (buff = (char *)memchr(buff, format[1], end_buf - buff))))
                    buff = end_buf;
            }

            if(buff > end_buf)
                goto fail;

            tok_type = NMEA_TOKS_COMPARE;
            tok_count++;

            parg_target = 0; width = (int)(buff - beg_tok);

            switch(*format)
            {
            case 'c':
            case 'C':
                parg_target = (void *)va_arg(arg_ptr, char *);
                if(width && 0 != (parg_target))
                    *((char *)parg_target) = *beg_tok;
                break;
            case 's':
            case 'S':
                parg_target = (void *)va_arg(arg_ptr, char *);
                if(width && 0 != (parg_target))
                {
                    memcpy(parg_target, beg_tok, width);
                    ((char *)parg_target)[width] = '\0';
                }
                break;
            case 'f':
            case 'g':
            case 'G':
            case 'e':
            case 'E':
                parg_target = (void *)va_arg(arg_ptr, double *);
                if(width && 0 != (parg_target))
                    *((double *)parg_target) = nmea_atof(beg_tok, width);
                break;
            };

            if(parg_target)
                break;
            if(0 == (parg_target = (void *)va_arg(arg_ptr, int *)))
                break;
            if(!width)
                break;

            switch(*format)
            {
            case 'd':
            case 'i':
                snum = nmea_atoi(beg_tok, width, 10);
                memcpy(parg_target, &snum, sizeof(int));
                break;
            case 'u':
                unum = nmea_atoi(beg_tok, width, 10);
                memcpy(parg_target, &unum, sizeof(unsigned int));
                break;
            case 'x':
            case 'X':
                unum = nmea_atoi(beg_tok, width, 16);
                memcpy(parg_target, &unum, sizeof(unsigned int));
                break;
            case 'o':
                unum = nmea_atoi(beg_tok, width, 8);
                memcpy(parg_target, &unum, sizeof(unsigned int));
                break;
            default:
                goto fail;
            };

            break;
        };
    }

fail:

    va_end(arg_ptr);

    return tok_count;
}

int nmea_parse_time(const char *buff, int buff_sz, nmeaTIME *res)
{
    int success = 0;

    switch(buff_sz)
    {
    case sizeof("hhmmss") - 1:
        success = (3 == nmea_scanf(buff, buff_sz,
            "%2d%2d%2d", &(res->hour), &(res->min), &(res->sec)
            ));
        break;
    case sizeof("hhmmss.s") - 1:
    case sizeof("hhmmss.ss") - 1:
    case sizeof("hhmmss.sss") - 1:
        success = (4 == nmea_scanf(buff, buff_sz,
            "%2d%2d%2d.%d", &(res->hour), &(res->min), &(res->sec), &(res->hsec)
            ));
        break;
    default:
        log_err("Parse of time error (format error)!\n");
        success = 0;
        break;
    }

    return (success?0:-1);        
}

/**
 * \brief Define packet type by header (nmeaPACKTYPE).
 * @param buff a constant character pointer of packet buffer.
 * @param buff_sz buffer size.
 * @return The defined packet type
 * @see nmeaPACKTYPE
 */
int nmea_pack_type(const char *buff, int buff_sz)
{
    static const char *pheads[] = {
        "GPGGA",
        "GPGSA",
        "GPGSV",
        "GPRMC",
        "GPVTG",
    };

    assert(buff);

    if(buff_sz < 5)
        return GPNON;
    else if(0 == memcmp(buff, pheads[0], 5))
        return GPGGA;
    else if(0 == memcmp(buff, pheads[1], 5))
        return GPGSA;
    else if(0 == memcmp(buff, pheads[2], 5))
        return GPGSV;
    else if(0 == memcmp(buff, pheads[3], 5))
        return GPRMC;
    else if(0 == memcmp(buff, pheads[4], 5))
        return GPVTG;

    return GPNON;
}

/**
 * \brief Get the first line in buffer and check control sum (CRC).
 * @param buff a constant character pointer of packets buffer.
 * @param buff_sz buffer size.
 * @param line pointer output for a line in the packet
 * @param line_len a integer pointer for return the line length (must be defined).
 * @return already read bytes to a line end from buff.
 */
int nmea_get_item_line(const char *buff, int buff_sz, char *line, int *line_len)
{
    static const int tail_sz = 3 /* *[CRC] */ + 2 /* \r\n */;
    char  *start, *star;
    int nread = 0;

    *line_len = -1;

    /* Data sample:
     * $GPGGA,081803.000,3029.9100,N,11423.2012,E,1,05,1.6,38.7,M,-13.7,M,,0000*4C
     * $GPGSA,A,3,18,24,21,22,15,,,,,,,,3.1,1.6,2.7*3A
     * $GPRMC,081803.000,A,3029.9100,N,11423.2012,E,1.14,126.38,210113,,,A*62  
     */
    start = strchr(buff, '$');
    if(!start)
    {
        /* Can not find the line start flag '$', means can not find an integrated line */
        return buff_sz;
    }

    star = strchr(start, '*');
    if(!star)
    {
        /* Can not find the line CRC start flag '*', means can not find an integrated line */
        return buff_sz;
    }

    *line_len = star - start + 1; /* include '*' */
    strncpy(line, start, *line_len);

    nread = (star-buff) + tail_sz ;

    return nread>buff_sz ? buff_sz : nread;
}

/**
 * \brief Find tail of packet ("\r\n") in buffer and check control sum (CRC).
 * @param buff a constant character pointer of packets buffer.
 * @param buff_sz buffer size.
 * @param res_crc a integer pointer for return CRC of packet (must be defined).
 * @return Number of bytes to packet tail.
 */
int nmea_find_tail(const char *buff, int buff_sz, int *res_crc)
{
    static const int tail_sz = 3 /* *[CRC] */ + 2 /* \r\n */;

    const char *end_buff = buff + buff_sz;
    int nread = 0;
    int crc = 0;

    assert(buff && res_crc);

    *res_crc = -1;

    for(;buff < end_buff; ++buff, ++nread)
    {
        if(('$' == *buff) && nread)
        {
            buff = 0;
            break;
        }
        else if('*' == *buff)
        {
            if(buff + tail_sz <= end_buff && '\r' == buff[3] && '\n' == buff[4])
            {
                *res_crc = nmea_atoi(buff + 1, 2, 16);
                nread = buff_sz - (int)(end_buff - (buff + tail_sz));
                if(*res_crc != crc)
                {
                    *res_crc = -1;
                    buff = 0;
                }
            }

            break;
        }
        else if(nread)
            crc ^= (int)*buff;
    }

    if(*res_crc < 0 && buff)
        nread = 0;

    return nread;
}

/**
 * \brief Parse GGA packet from buffer.
 * @param buff a constant character pointer of packet buffer.
 * @param buff_sz buffer size.
 * @param pack a pointer of packet which will filled by function.
 * @return 1 (true) - if parsed successfully or 0 (false) - if fail.
 */
int nmea_parse_GPGGA(const char *buff, int buff_sz, nmeaGPGGA *pack)
{
    char time_buff[NMEA_TIMEPARSE_BUF];

    assert(buff && pack);

    memset(pack, 0, sizeof(nmeaGPGGA));

    log_dbg("parse_GPGGA: %s\n", buff);

    if(14 != nmea_scanf(buff, buff_sz,
        "$GPGGA,%s,%f,%C,%f,%C,%d,%d,%f,%f,%C,%f,%C,%f,%d*",
        &(time_buff[0]),
        &(pack->lat), &(pack->ns), &(pack->lon), &(pack->ew),
        &(pack->sig), &(pack->satinuse), &(pack->HDOP), &(pack->elv), &(pack->elv_units),
        &(pack->diff), &(pack->diff_units), &(pack->dgps_age), &(pack->dgps_sid)))
    {
        log_err("GPGGA parse error!\n");
        return 0;
    }

    if(0 != nmea_parse_time(&time_buff[0], (int)strlen(&time_buff[0]), &(pack->utc)))
    {
        log_err("GPGGA time parse error!\n");
        return 0;
    }

    return 1;
}

/**
 * \brief Parse GSA packet from buffer.
 * @param buff a constant character pointer of packet buffer.
 * @param buff_sz buffer size.
 * @param pack a pointer of packet which will filled by function.
 * @return 1 (true) - if parsed successfully or 0 (false) - if fail.
 */
int nmea_parse_GPGSA(const char *buff, int buff_sz, nmeaGPGSA *pack)
{
    assert(buff && pack);

    memset(pack, 0, sizeof(nmeaGPGSA));

    log_dbg("parse_GPGSA: %s\n", buff);

    if(17 != nmea_scanf(buff, buff_sz,
        "$GPGSA,%C,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%f,%f,%f*",
        &(pack->fix_mode), &(pack->fix_type),
        &(pack->sat_prn[0]), &(pack->sat_prn[1]), &(pack->sat_prn[2]), &(pack->sat_prn[3]), &(pack->sat_prn[4]), &(pack->sat_prn[5]),
        &(pack->sat_prn[6]), &(pack->sat_prn[7]), &(pack->sat_prn[8]), &(pack->sat_prn[9]), &(pack->sat_prn[10]), &(pack->sat_prn[11]),
        &(pack->PDOP), &(pack->HDOP), &(pack->VDOP)))
    {
        log_err("GPGSA parse error!\n");
        return 0;
    }

    return 1;
}

/**
 * \brief Parse GSV packet from buffer.
 * @param buff a constant character pointer of packet buffer.
 * @param buff_sz buffer size.
 * @param pack a pointer of packet which will filled by function.
 * @return 1 (true) - if parsed successfully or 0 (false) - if fail.
 */
int nmea_parse_GPGSV(const char *buff, int buff_sz, nmeaGPGSV *pack)
{
    int nsen, nsat;

    assert(buff && pack);

    memset(pack, 0, sizeof(nmeaGPGSV));

    log_dbg("parse_GPGSV: %s\n", buff);

    nsen = nmea_scanf(buff, buff_sz,
        "$GPGSV,%d,%d,%d,"
        "%d,%d,%d,%d,"
        "%d,%d,%d,%d,"
        "%d,%d,%d,%d,"
        "%d,%d,%d,%d*",
        &(pack->pack_count), &(pack->pack_index), &(pack->sat_count),
        &(pack->sat_data[0].id), &(pack->sat_data[0].elv), &(pack->sat_data[0].azimuth), &(pack->sat_data[0].sig),
        &(pack->sat_data[1].id), &(pack->sat_data[1].elv), &(pack->sat_data[1].azimuth), &(pack->sat_data[1].sig),
        &(pack->sat_data[2].id), &(pack->sat_data[2].elv), &(pack->sat_data[2].azimuth), &(pack->sat_data[2].sig),
        &(pack->sat_data[3].id), &(pack->sat_data[3].elv), &(pack->sat_data[3].azimuth), &(pack->sat_data[3].sig));

    nsat = (pack->pack_index - 1) * NMEA_SATINPACK;
    nsat = (nsat + NMEA_SATINPACK > pack->sat_count)?pack->sat_count - nsat:NMEA_SATINPACK;
    nsat = nsat * 4 + 3 /* first three sentence`s */;

    if(nsen < nsat || nsen > (NMEA_SATINPACK * 4 + 3))
    {
        log_err("GPGSV parse error!\n");
        return 0;
    }

    return 1;
}

/**
 * \brief Parse RMC packet from buffer.
 * @param buff a constant character pointer of packet buffer.
 * @param buff_sz buffer size.
 * @param pack a pointer of packet which will filled by function.
 * @return 1 (true) - if parsed successfully or 0 (false) - if fail.
 */
int nmea_parse_GPRMC(const char *buff, int buff_sz, nmeaGPRMC *pack)
{
    int nsen;
    char time_buff[NMEA_TIMEPARSE_BUF];

    assert(buff && pack);

    memset(pack, 0, sizeof(nmeaGPRMC));

    log_dbg("parse_GPGRMC: %s\n", buff);

    nsen = nmea_scanf(buff, buff_sz,
        "$GPRMC,%s,%C,%f,%C,%f,%C,%f,%f,%2d%2d%2d,%f,%C,%C*",
        &(time_buff[0]),
        &(pack->status), &(pack->lat), &(pack->ns), &(pack->lon), &(pack->ew),
        &(pack->speed), &(pack->direction),
        &(pack->utc.day), &(pack->utc.mon), &(pack->utc.year),
        &(pack->declination), &(pack->declin_ew), &(pack->mode));

    if(nsen != 13 && nsen != 14)
    {
        log_err("GPRMC parse error!\n");
        return 0;
    }

    if(0 != nmea_parse_time(&time_buff[0], (int)strlen(&time_buff[0]), &(pack->utc)))
    {
        log_err("GPRMC time parse error!\n");
        return 0;
    }

    if(pack->utc.year < 90)
        pack->utc.year += 100;
    pack->utc.mon -= 1;

    return 1;
}

/**
 * \brief Parse VTG packet from buffer.
 * @param buff a constant character pointer of packet buffer.
 * @param buff_sz buffer size.
 * @param pack a pointer of packet which will filled by function.
 * @return 1 (true) - if parsed successfully or 0 (false) - if fail.
 */
int nmea_parse_GPVTG(const char *buff, int buff_sz, nmeaGPVTG *pack)
{
    assert(buff && pack);

    memset(pack, 0, sizeof(nmeaGPVTG));

    log_dbg("parse_GPVTG: %s\n", buff);

    if(8 != nmea_scanf(buff, buff_sz,
        "$GPVTG,%f,%C,%f,%C,%f,%C,%f,%C*",
        &(pack->dir), &(pack->dir_t),
        &(pack->dec), &(pack->dec_m),
        &(pack->spn), &(pack->spn_n),
        &(pack->spk), &(pack->spk_k)))
    {
        log_err("GPVTG parse error!\n");
        return 0;
    }

    if( pack->dir_t != 'T' ||
        pack->dec_m != 'M' ||
        pack->spn_n != 'N' ||
        pack->spk_k != 'K')
    {
        log_err("GPVTG parse error (format error)!\n");
        return 0;
    }

    return 1;
}

/**
 * \brief Fill nmeaINFO structure by GGA packet data.
 * @param pack a pointer of packet structure.
 * @param info a pointer of summary information structure.
 */
void nmea_GPGGA2info(nmeaGPGGA *pack, nmeaINFO *info)
{
    assert(pack && info);

    info->utc.hour = pack->utc.hour;
    info->utc.min = pack->utc.min;
    info->utc.sec = pack->utc.sec;
    info->utc.hsec = pack->utc.hsec;
    info->sig = pack->sig;
    info->HDOP = pack->HDOP;
    info->elv = pack->elv;
    info->lat = ((pack->ns == 'N')?pack->lat:-(pack->lat));
    info->lon = ((pack->ew == 'E')?pack->lon:-(pack->lon));
    info->smask |= GPGGA;
}

/**
 * \brief Fill nmeaINFO structure by GSA packet data.
 * @param pack a pointer of packet structure.
 * @param info a pointer of summary information structure.
 */
void nmea_GPGSA2info(nmeaGPGSA *pack, nmeaINFO *info)
{
    int i, j, nuse = 0;

    assert(pack && info);

    info->fix = pack->fix_type;
    info->PDOP = pack->PDOP;
    info->HDOP = pack->HDOP;
    info->VDOP = pack->VDOP;

    for(i = 0; i < NMEA_MAXSAT; ++i)
    {
        for(j = 0; j < info->satinfo.inview; ++j)
        {
            if(pack->sat_prn[i] && pack->sat_prn[i] == info->satinfo.sat[j].id)
            {
                info->satinfo.sat[j].in_use = 1;
                nuse++;
            }
        }
    }

    info->satinfo.inuse = nuse;
    info->smask |= GPGSA;
}

/**
 * \brief Fill nmeaINFO structure by GSV packet data.
 * @param pack a pointer of packet structure.
 * @param info a pointer of summary information structure.
 */
void nmea_GPGSV2info(nmeaGPGSV *pack, nmeaINFO *info)
{
    int isat, isi, nsat;

    assert(pack && info);

    if(pack->pack_index > pack->pack_count ||
        pack->pack_index * NMEA_SATINPACK > NMEA_MAXSAT)
        return;

    if(pack->pack_index < 1)
        pack->pack_index = 1;

    info->satinfo.inview = pack->sat_count;

    nsat = (pack->pack_index - 1) * NMEA_SATINPACK;
    nsat = (nsat + NMEA_SATINPACK > pack->sat_count)?pack->sat_count - nsat:NMEA_SATINPACK;

    for(isat = 0; isat < nsat; ++isat)
    {
        isi = (pack->pack_index - 1) * NMEA_SATINPACK + isat;
        info->satinfo.sat[isi].id = pack->sat_data[isat].id;
        info->satinfo.sat[isi].elv = pack->sat_data[isat].elv;
        info->satinfo.sat[isi].azimuth = pack->sat_data[isat].azimuth;
        info->satinfo.sat[isi].sig = pack->sat_data[isat].sig;
    }

    info->smask |= GPGSV;
}

/**
 * \brief Fill nmeaINFO structure by RMC packet data.
 * @param pack a pointer of packet structure.
 * @param info a pointer of summary information structure.
 */
void nmea_GPRMC2info(nmeaGPRMC *pack, nmeaINFO *info)
{
    assert(pack && info);

    if('A' == pack->status)
    {
        if(NMEA_SIG_BAD == info->sig)
            info->sig = NMEA_SIG_MID;
        if(NMEA_FIX_BAD == info->fix)
            info->fix = NMEA_FIX_2D;
    }
    else if('V' == pack->status)
    {
        info->sig = NMEA_SIG_BAD;
        info->fix = NMEA_FIX_BAD;
    }

    info->utc = pack->utc;
    info->lat = ((pack->ns == 'N')?pack->lat:-(pack->lat));
    info->lon = ((pack->ew == 'E')?pack->lon:-(pack->lon));
    info->speed = pack->speed * NMEA_TUD_KNOTS;
    info->direction = pack->direction;
    info->smask |= GPRMC;
}

/**
 * \brief Fill nmeaINFO structure by VTG packet data.
 * @param pack a pointer of packet structure.
 * @param info a pointer of summary information structure.
 */
void nmea_GPVTG2info(nmeaGPVTG *pack, nmeaINFO *info)
{
    assert(pack && info);

    info->direction = pack->dir;
    info->declination = pack->dec;
    info->speed = pack->spk;
    info->smask |= GPVTG;
}