/* cmetar.c by TOYODA Eizi, 2014 - licensed GPLv3 */

#include <stdio.h>
#include <string.h>
#include <limits.h>
#include <ctype.h>
#include "cdetac.h"

  long
inhg_to_hpa(long val)
{
  if (val == LONG_MIN) { return val; }
  return (val * 2 + 1) * 6170 / 3644;
}

  int
ms_metar(struct message_t *ms,
  enum TokenType tt, const char *token,
  enum TokenType tt2, const char *token2)
{
  ms_default(ms, tt, token, tt2, token2);

  switch (tt) {
  case TTEQ:
    if (ms->ms_state == MSS_EQ) {
      fprintf(stdout, "# duplicated TTEQ\n");
    } else {
      /* unit conversion if necessary */;
    }
    ms->ms_state = MSS_EQ;
    goto endfunc;
  }

  /* state by position */
  switch (ms->ms_state) {

  case MSS_MetarMain:
    if (tt == TTMetarWW) {
      goto MetarWW;
    } else if (tt == TTMetarNH) {
      /* (FEW|SCT|BKN|OVC|\/\/\/)([0-9]{3}|\/\/\/)(CB|TCU|SC|CU|\/\/\/)? */
      char buf[3 + 1];
      long n;
      strncpy(buf, token + 3, 3);
      buf[3] = '\0';
      n =
        *token == '/' ? LONG_MIN :
        *token == 'F' ? 2 :
	*token == 'S' ? 4 :
	*token == 'B' ? 6 : 8;
      ms_set(ms, "3Ns", buf, n);
      if (token[6] && (token[6] != '/')) {
	ms_set(ms, token + 6, buf, 1);
      }
    } else if (tt == TTMetarZ) {
      /* [0-9]{6}Z */
      ms_set(ms, "2Y", NULL, tac_atoi(token, 0, 2));
      ms_set(ms, "2G", NULL, tac_atoi(token, 2, 2));
      ms_set(ms, "2g", NULL, tac_atoi(token, 4, 2));
    } else if (tt == TTMetarSM) {
      /* M?(([12]\040)?[1-5]\/)?[1-9][0-9]*SM */
      const char *fr = token;
      char *sp = strchr(token, ' ');
      char *sl = strchr(token, '/');
      long base, frac, fact, val;
      if (*fr == 'M') { fr++; }
      base = sp ? atoi(fr) : 0;
      frac = sp ? atoi(sp + 1) : atoi(fr);
      fact = sl ? atoi(sl + 1) : 1;
      val = (base * fact) + frac;
      val = val * 4828 / (fact * 3);
      ms_set(ms, "4V", NULL, val);
    } else if (tt == TTMetarTTd) {
      /* M?[0-9\/][0-9\/]\/M?[0-9\/][0-9\/] */
      const char *tt, *td;
      int mtt, mtd;
      tt = token;
      if (*token == 'M') { tt++; }
      mtt = (*token == 'M') ? '1' : '0';
      td = strchr(token, '/');
      if (td) {
        td++;
	if (*td == 'M') { td++; }
      }
      mtd = (td && (td[-1] == 'M')) ? '1' : '0';
      ms_set(ms, "2T_", NULL, tac_atosi(tt, mtt, 0, 2));
      ms_set(ms, "2Td_", NULL, tac_atosi(td, mtd, 0, 2));
    } else if (tt == TTMetarR) {
      /* R[0123][0-9][LCR]?\/[PM]?[0-9\/]{4}[UDN]? */
      const char *v;
      char rwy[7 + 1];
      long vr;
      v = strchr(token, '/');
      StringCopy(rwy, token, v - token);
      v++;
      if ((*v == 'P') || (*v == 'M')) {
        ms_set(ms, "tVR", rwy, tac_atoi(v, 0, 4));
        v++;
      }
      ms_set(ms, "4VR", rwy, tac_atoi(v, 0, 4));
      ms_set(ms, "i", rwy, v[4]);
    } else if (tt == TTMetarKT) {
      /* [0123][0-9][0]P?[0-9]{2,3}(GP?[0-9]{2,3})?(KTS?|MPS) */
      const char *c = token;
      long ff, fm;
      int w;
      /* direction takes always 3 digits */
      ms_set(ms, "3d", NULL, tac_atoi(c, 0, 3));
      c += 3;
      /* ff may take 2 or 3 digits */
      if (*c == 'P') { c++; }
      w = isdigit(c[2]) ? 3 : 2;
      ff = tac_atoi(c, 0, w);
      c += w;
      /* if c points to 'G' that is follwed by fm that may take 2 or 3 */
      if (*c == 'G') {
	if (*c == 'P') { c++; }
	w = isdigit(c[3]) ? 3 : 2;
	fm = tac_atoi(c, 0, w);
	c += w;
      } else {
        fm = LONG_MIN;
      }
      if (*c == 'M') {
	  if (ff != LONG_MIN) { ff = ff * 10; }
	  if (fm != LONG_MIN) { fm = fm * 10; }
      } else {
        if (c[1] == 'M') { /* KMH */
	  if (ff != LONG_MIN) { ff = ff * 1000 / 360; }
	  if (fm != LONG_MIN) { fm = fm * 1000 / 360; }
	} else { /* KT or KTS */
	  ff = knot_to_mps(ff);
	  fm = knot_to_mps(fm);
	}
      }
      ms_set(ms, "2f", NULL, ff);
      ms_set(ms, "2m", NULL, fm);
    } else if (tt == TTMetarDVD) {
      /* [0123][0-9][0-9]V[0123][0-9][0-9] */
      ms_set(ms, "3dn", NULL, tac_atoi(token, 0, 3));
      ms_set(ms, "3dx", NULL, tac_atoi(token, 4, 3));
    } else if (tt == TTMetarQNH) {
      /* [QA][0-9]{4} */
      if (token[0] == 'Q') {
	long ph = tac_atoi(token, 1, 4);
	if (ph != LONG_MIN) { ph *= 10; }
	ms_set(ms, "4PH", NULL, ph);
      } else if (token[0] == 'A') {
	ms_set(ms, "4PH", NULL, inhg_to_hpa(tac_atoi(token, 1, 4)));
      } else {
        goto BadTokenMetarMain;
      }
    } else if (tt == TTMetarFix) {
      if (StringEq(token, "CAVOK")) {
	ms_set(ms, "CAVOK", NULL, 1);
	ms_set(ms, "4V", NULL, 9999L);
      } else if (StringEq(token, "RMK")) {
	ms->ms_state = MSS_MetarRmk;
      } else if (StringEq(token, "BECMG") || StringEq(token, "TEMPO")) {
	ms->ms_state = MSS_MetarTrend;
      } else if (StringEq(token, "COR")) {
	ms_set(ms, "/COR", NULL, 1);
      } else if (StringEq(token, "NSC")) {
	ms_set(ms, "NSC", NULL, 1);
      } else if (StringEq(token, "NCD")) {
	ms_set(ms, "NCD", NULL, 1);
      } else if (StringEq(token, "CLR")) {
	ms_set(ms, "CLR", NULL, 1);
      } else if (StringEq(token, "SKC")) {
	ms_set(ms, "SKC", NULL, 1);
      } else if (StringEq(token, "NOSIG")) {
	ms_set(ms, "NOSIG", NULL, 1);
      } else {
        goto BadTokenMetarMain;
      }
    } else if (tt == TTNIL) {
      /* bad to omit YYGGggZ */
      if (ms_get(ms, "2Y", "") == LONG_MIN) {
	ms_set(ms, "2Y", NULL, tac_atoi(ms->ms_cccc, 5, 2));
	ms_set(ms, "2G", NULL, tac_atoi(ms->ms_cccc, 7, 2));
	ms_set(ms, "2g", NULL, tac_atoi(ms->ms_cccc, 9, 2));
      }
      ms->ms_state = MSS_MetarRmk;
    } else if (tt == TTMetarVV) {
      /* VV[0-9\/]{3} */
      ms_set(ms, "3hs", NULL, tac_atoi(token, 2, 3));
    } else if (tt == TTMetarRVR) {
      ms_set(ms, "4V", token + 4, tac_atoi(token, 0, 4));
    } else if (StringEq(token, "AUTO")) {
      ms_set(ms, "AUTO", NULL, 1);
    } else if (string_match(token, "[A-Z][-A-Z0-9][A-Z0-9][A-Z0-9]")) {
      if (ms->ms_id[0] == '\0') {
	StringCopy(ms->ms_id, token, 4);
      } else {
        goto MetarWW;
      }
    } else if ((token[2] == '/')
    && string_match(token, "[0-9/][0-9/]/[0-9/][0-9/]")) {
      ms_set(ms, "2T_", NULL, tac_atoi(token, 0, 2));
      ms_set(ms, "2Td_", NULL, tac_atoi(token, 3, 2));

    } else if (string_match(token, "[A-Z][A-Z][A-Z][A-Z]")) {
MetarWW:
      if (string_match(token, "RE%")) {
	ms_set(ms, "2w_/RE", token + 2, 1);
      } else {
	ms_set(ms, "2w_", token, 1);
      }
    } else {
BadTokenMetarMain:
      if (ms->ms_state == MSS_MetarMain) {
	fprintf(stdout, "# unrecognised (%s) in MetarMain\n", token);
      }
    }
    break;

  case MSS_MetarRmk:
    if (tt == TTMetarRI) { /* RI([0-9]{3}|\+\+) */
      if (token[2] == '+') {
	ms_set(ms, "RI", NULL, 30L);
      } else {
	ms_set(ms, "RI", NULL, tac_atoi(token, 2, 3));
      }
    } else if ((tt == TTMetarQNH) && (token[0] == 'A')) {
      ms_set(ms, "4PH", NULL, inhg_to_hpa(tac_atoi(token, 1, 4)));
    } else if (tt == TTMetarSLP) {
      /* SLP[0-9]{3} */
      long p = tac_atoi(token, 3, 3);
      if (p >= 500) {
        p += 9000;
      } else if (p >= 0) {
        p += 10000;
      }
      ms_set(ms, "4P", NULL, p);
    } else if (tt == TTMetarTT) {
      /* T[01][0-9]{3}[01][0-9]{3} */
      ms_set(ms, "3T",  NULL, tac_atosi(token, token[1], 2, 3));
      ms_set(ms, "3Td", NULL, tac_atosi(token, token[5], 6, 3));
    } else if (tt == TTMetarCld) {
      /* [0-9](CU|SC|AS|AC|CI|CS|CB|TCU)[0-9]{3} */
      const char *p;
      char cld[4];
      p = token + 3;
      if (p[0] == 'U') { p++; }
      StringCopy(cld, token + 1, (p - token - 1));
      ms_set(ms, cld, p, 1);
      ms_set(ms, "N", p, tac_atoi(token, 0, 1));
    } else if (tt == TTMetarA) {
      ms_set(ms, token, NULL, 1);
    } else if (tt == TTMetarSD) {
      ms_set(ms, "SD", NULL, tac_atoi(token, 2, 3));
      ms_set(ms, "SDCHG", NULL, tac_atoi(token, 6, 3));
    }
    break;

  }

endfunc:
  return 0;
}