/*
 * Mimas conversion tools
 *
 * Copyright (C) 2010 Benjamin Moody
 *
 * This program is free software: you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 3 of the
 * License, or (at your option) any later version.
 *
 * 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, see <http://www.gnu.org/licenses/>.
 */

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

#include "mimas.h"
#include "pack.h"
#include "output.h"
#include "utils.h"

typedef struct _predef_symbol {
  char *name;
  unsigned int value;
} predef_symbol;

static int parse_line(const char *line, char **name, unsigned int *value)
{
  const char *p, *q, *r;
  char *e;

  p = line;
  while ((*p >= 'A' && *p <= 'Z')
	 || (*p >= 'a' && *p <= 'z')
	 || (*p >= '0' && *p <= '9')
	 || *p == '_')
    p++;

  if (p == line || (*line >= '0' && *line <= '9'))
    return 1;

  q = p;
  while (*q == ' ' || *q == '\t')
    q++;

  if (*q == '=')
    q++;
  else if (!strncasecmp(q, "equ", 3))
    q += 3;
  else if (!strncasecmp(q, ".equ", 4))
    q += 4;
  else
    return 1;

  while (*q == ' ' || *q == '\t')
    q++;

  r = q;
  while (*r && *r != ' ' && *r != '\t' && *r != '\n' && *r != '\r')
    r++;

  if (*q == '$') {
    *value = strtol(q + 1, &e, 16);
    q = e;
  }
  else if (*q == '%') {
    *value = strtol(q + 1, &e, 2);
    q = e;
  }
  else if (r != q && (r[-1] == 'h' || r[-1] == 'H')) {
    *value = strtol(q, &e, 16);
    q = e + 1;
  }
  else if (r != q && (r[-1] == 'b' || r[-1] == 'B')) {
    *value = strtol(q, &e, 2);
    q = e + 1;
  }
  else if (*q >= '0' && *q <= '9') {
    *value = strtol(q, &e, 10);
    q = e;
  }
  else
    return 1;

  if (q != r)
    return 1;

  while (*q == ' ' || *q == '\t')
    q++;
  if (*q != 0 && *q != '\n' && *q != '\r')
    return 1;

  *name = xstrndup(line, p - line);
  return 0;
}

static int map_char(char c)
{
  if (c == 0)
    return 0;
  else if (c == '_')
    return 1;
  else if (c >= 'a' && c <= 'z')
    return c - 'a' + 'A';
  else
    return c;
}

static int compare_syms(const void *a, const void *b)
{
  const predef_symbol *sa = a;
  const predef_symbol *sb = b;
  int i, ka, kb;

  for (i = 0; sa->name[i] || sb->name[i]; i++) {
    ka = map_char(sa->name[i]);
    kb = map_char(sb->name[i]);
    if (ka != kb)
      return (ka - kb);
  }

  return strcmp(sa->name, sb->name);
}

static const char usage[] = "Usage: %s [-o 8xv-file] [-n name] inc-file\n";

int main(int argc, char **argv)
{
  const char *infilename = NULL;
  char *outfilename = NULL;
  char *varname = NULL;
  FILE *inf, *outf;
  char *p, *line;
  int linenum = 0;
  char *name = NULL;
  unsigned int value;
  predef_symbol *symbols = NULL;
  int nsymbols = 0, nsymbols_a = 0;
  ti8x_file *f;
  ti8x_var_entry *v;
  unsigned int symstart, stringstart, conststart, impstart,
    sectstart, sectend;
  unsigned char buf[3];
  unsigned char *packed;
  int packedlen;
  int status = 0;
  int i;

  for (i = 1; i < argc; i++) {
    if (argv[i][0] == '-' && argv[i][1]) {
      if (argv[i][1] == 'o') {
	if (argv[i][2])
	  outfilename = xstrdup(&argv[i][2]);
	else if (++i < argc)
	  outfilename = xstrdup(argv[i]);
	else {
	  fprintf(stderr, "%s: -o: requires argument\n", argv[0]);
	  return 1;
	}
      }
      else if (argv[i][1] == 'n') {
	if (argv[i][2])
	  varname = xstrdup(&argv[i][2]);
	else if (++i < argc)
	  varname = xstrdup(argv[i]);
	else {
	  fprintf(stderr, "%s: -n: requires argument\n", argv[0]);
	  return 1;
	}
      }
      else {
	fprintf(stderr, "%s: unknown option %s\n", argv[0], argv[i]);
	fprintf(stderr, usage, argv[0]);
	return 1;
      }
    }
    else {
      infilename = argv[i];
    }
  }

  if (!infilename) {
    fprintf(stderr, usage, argv[0]);
    return 1;
  }

  if (!varname) {
    if (!strcmp(infilename, "-"))
      varname = xstrdup("OUT");
    else if ((p = strrchr(infilename, '/'))
	|| (p = strrchr(infilename, '\\')))
      varname = xstrdup(p + 1);
    else
      varname = xstrdup(infilename);

    if ((p = strrchr(varname, '.')))
      *p = 0;

    for (i = 0; varname[i]; i++)
      if (varname[i] >= 'a' && varname[i] <= 'z')
	varname[i] += 'A' - 'a';
  }

  if (!outfilename) {
    outfilename = xnew(char, strlen(varname) + 5);
    strcpy(outfilename, varname);
    strcat(outfilename, ".8xv");
  }

  if (!strcmp(infilename, "-")) {
    inf = stdin;
  }
  else {
    inf = fopen(infilename, "rt");
    if (!inf) {
      perror(infilename);
      return 2;
    }
  }

  while ((line = read_line(inf))) {
    linenum++;

    if ((p = strchr(line, ';')))
      *p = 0;

    if (*line == 0 || *line == '\n' || *line == '\r')
      continue;

    if (parse_line(line, &name, &value)) {
      fprintf(stderr, "%s:%d: syntax error\n", infilename, linenum);
      status = 3;
      continue;
    }

    if (nsymbols >= nsymbols_a) {
      nsymbols_a = nsymbols + 100;
      symbols = xrenew(predef_symbol, symbols, nsymbols_a);
    }

    symbols[nsymbols].name = name;
    symbols[nsymbols].value = value;
    nsymbols++;
  }

  if (inf != stdin)
    fclose(inf);

  if (!nsymbols) {
    fprintf(stderr, "input file empty\n");
    return 3;
  }

  if (!strcmp(outfilename, "-"))
    outf = stdout;
  else {
    outf = fopen(outfilename, "wb");
    if (!outf) {
      perror(outfilename);
      return 4;
    }
  }

  qsort(symbols, nsymbols, sizeof(predef_symbol), &compare_syms);

  f = ti8x_file_new(outfilename);
  v = ti8x_file_add_var(f, 0x15, varname, 1);

  ti8x_var_append_data(v, NULL, 2 + PROGHEADER_LENGTH);

  symstart = stringstart = v->length - 2;
  ti8x_var_append_data(v, NULL, 1);

  conststart = v->length - 2;

  /* sentinel */
  buf[0] = 1;
  buf[1] = 1;
  buf[2] = 0;
  ti8x_var_append_data(v, buf, 3);

  for (i = 0; i < nsymbols; i++) {
    pack_symbol_string(&packed, &packedlen, symbols[i].name);
    if (packedlen >= 3) {
      buf[0] = symbols[i].value;
      buf[1] = symbols[i].value >> 8;
      ti8x_var_append_data(v, buf, 2);
      ti8x_var_append_data(v, packed, packedlen);
    }
    else {
      fprintf(stderr, "symbol '%s' is too short\n", symbols[i].name);
    }
    xfree(packed);
  }

  impstart = sectstart = sectend = v->length - 2;

  memcpy(v->data + 2, "MimS\1", 5);
  v->data[2 + PROGHEADER_TYPE] = PROGTYPE_TI83P;
  v->data[2 + PROGHEADER_FLAGS] = PROGFLAG_LOCKED;
  v->data[2 + PROGHEADER_SYMBOL_START] = symstart;
  v->data[2 + PROGHEADER_SYMBOL_START + 1] = symstart >> 8;
  v->data[2 + PROGHEADER_SYMBOL_STRING_START] = stringstart;
  v->data[2 + PROGHEADER_SYMBOL_STRING_START + 1] = stringstart >> 8;
  v->data[2 + PROGHEADER_CONSTANT_START] = conststart;
  v->data[2 + PROGHEADER_CONSTANT_START + 1] = conststart >> 8;
  v->data[2 + PROGHEADER_IMPORT_START] = impstart;
  v->data[2 + PROGHEADER_IMPORT_START + 1] = impstart >> 8;
  v->data[2 + PROGHEADER_SECTION_TABLE_START] = sectstart;
  v->data[2 + PROGHEADER_SECTION_TABLE_START + 1] = sectstart >> 8;
  v->data[2 + PROGHEADER_SECTION_TABLE_END] = sectend;
  v->data[2 + PROGHEADER_SECTION_TABLE_END + 1] = sectend >> 8;

  v->data[0] = v->length - 2;
  v->data[1] = (v->length - 2) >> 8;

  if (ti8x_file_write(outf, f)) {
    if (outf != stdout)
      fclose(outf);
    return 4;
  }

  if (outf != stdout)
    fclose(outf);

  ti8x_file_free(f);
  xfree(outfilename);
  xfree(varname);
  for (i = 0; i < nsymbols; i++)
    xfree(symbols[i].name);
  xfree(symbols);

  return status;
}