/* options.c - command line arguments processing
   $Id: options.c,v 0.2 1997/03/28 03:17:12 tjchol01 Exp $
   Authors: Andrew Trevorrow, Ian Dall, Geoffrey Tobin, Tomasz J. Cholewo
 */

#include "dvgt.h"
#include "screenio.h"
#include "options.h"
#include "defaults.h"

/* Variables Exported, via "options.h" */

/* X and Y resolutions, in dpi */
double xres, yres;

/* Magnification */
int mag;

/* The next four are in paper pixels, and calculated. */
int hoffset, voffset;
int paperwd, paperht;

String dummy_pk, dummy_tfm;
String vdu;

/* DVI file's name */
string DVIname;


typedef struct
  {
    units unit;
    char *name;
    double per_inch;
  }
Dan;				/* `Dimension and name' */

static
Dan dans[] =			/* `dimensions and names series' */
{
  {ic, "in", 1.0},
  {cm, "cm", 2.54},
  {mm, "mm", 25.4},
  {bp, "bp", 72.0},
  {pc, "pc", 72.27 / 12},
  {pt, "pt", 72.27},
  {sp, "sp", 72.27 * 65536},
  {px, "px", 300.0}		/* "px"'s per_inch value is not used, */
};				/* but Qume, Laserwriter, etc, are 300 dpi */

static
size_t ldans = sizeof (dans) / sizeof (Dan);	/* length of dans[] */

static int Inint PARAMS ((double f));

/*--------------------------------------------------------------------*/
/* Auxiliary routines */
/*--------------------------------------------------------------------*/

/* Copy at most n characters from ct to s; set s[n] = NUL character. */
/* This ASSUMES that s has memory >= n+1 characters. */

char *
strMcpy (char *s, const char *ct, size_t n)
{
  strncpy (s, ct, n);
  s[n] = '\0';
  return s;
}
/* strMcpy */

/*--------------------------------------------------------------------*/

/* Copy at most maxstring characters from ct to s; */
/* set s[maxstring] = NUL character. */

char *
stringcopy (String s, const char *ct)
{
  strncpy (s, ct, maxstring);
  s[maxstring] = '\0';
  return (char *) &s;
}
/* stringcopy */
/*--------------------------------------------------------------------*/
static int 
Inint (double f)
{
  return ((int) (f + 0.5));
}
/* Inint */
/*--------------------------------------------------------------------*/
static void 
ToCardinal (const char *option, const char *value, int *n)
{
  /* If value represents a positive integer, then return via n. */

  int check;
  double r;

  check = sscanf (value, "%lf", &r);
  *n = Inint (r);		/* round value to nearest integer */

  /* check can be 1 or EOF if ok! */
  if ((check == 1 || check == EOF) && *n > 0)
    return;

  FATAL2 ("Bad `%s' value: %s.  Specify a positive integer.", option, value);
}
/* ToCardinal */

/*--------------------------------------------------------------------*/

static void
ToRes (const char *option, const char *value, double *xr, double *yr)
{
  /* X and Y resolutions, specified in dots per inch. */

  int check;

  check = sscanf (value, "%lf,%lf", xr, yr);
  if (check == 2 && *xr > 0 && *yr > 0)
    {
      return;
    }
  else
    {
      check = sscanf (value, "%lf", xr);
      if (check == 1 && *xr > 0)
	{
	  *yr = *xr;
	  return;
	}
    }

  FATAL2 ("Bad `%s' value(s): %s.\n"
	  "Resolutions must be positive reals,\n"
	  "specified as `-r xres' or `-r xres,yres'\n"
	  "in dots per inch.", option, value);
}
/* ToRes */

/*--------------------------------------------------------------------*/

static units 
Name2Unit (const char *uname)
{
  units unit = ic;
  char Luname[3];		/* Lower case unit name */
  int j;

#define ToLower(x)  (isupper(x) ? tolower(x) : (x))

  Luname[0] = ToLower (uname[0]);
  Luname[1] = ToLower (uname[1]);
  Luname[2] = '\0';

  for (j = 0; j < ldans && strcmp (Luname, dans[j].name); j++);		/* Search for the name of the unit. */

  if (j < ldans)
    unit = dans[j].unit;
  else
    {
      MesgString ("Bad unit name `");
      MesgString (uname);
      MesgString ("'");
      MesgLine ();

      MesgString ("Last two letters should be one of  ");
      for (j = 0; j < ldans; j++)
	{
	  MesgString (" `");
	  MesgString (dans[j].name);
	  MesgString ("'");
	}
      MesgChar ('.');
      MesgLine ();

      MesgString ("Using inch.");
      MesgLine ();
      unit = ic;
    }
  return unit;
}
/* Name2Unit */

/*--------------------------------------------------------------------*/

static void
ToDimen (const char *option, const char *value, double *r, units *un)
{
  /* A valid dimension consists of an integer or real number followed
     by a two-letter unit:  see  dans[]  above.
     If value represents a valid dimension,
     return number part in r, and units part in un.
   */

  int check;
  String nun;			/* name of unit - ample space in a string for it */

  check = sscanf (value, "%lf%2s", r, nun);
  if (check == 2)
    {
      /* extract unit's code from its name */
      *un = Name2Unit (nun);
    }
  else if (check == 1)
    {
      MesgString ("No dimension given, using inch.");
      MesgLine ();
      *un = ic;
    }
  else
    {				/* check < 1 */
      FATAL2 ("Bad `%s' value: %s.\nSpecify a dimensioned quantity.",
	      option, value);
    }
}
/* ToDimen */

/*--------------------------------------------------------------------*/

static void
ToPosDimen (const char *option, const char *value, double *r, units *un)
{
  /* A valid +ve dimension consists of a positive integer or real number
     followed by a two-letter unit:  see  dans[]  above.
     If value represents a valid dimension,
     return numeric part in r, and units part in un.
   */

  ToDimen (option, value, r, un);

  if (*r <= 0)
    {
      FATAL2 ("Bad `%s' value: %s.\nSpecify a positive dimension.",
	      option, value);
    }
}
/* ToPosDimen */

/*--------------------------------------------------------------------*/

static int 
DimenPixels (double r, units u, double res)
{
  /* Return given dimension as nearest whole number of pixels, */
  /* given the appropriate (eg, X or Y direction's) resolution in dpi. */

  int Result;

  int i;

  if (u == px)
    Result = Inint (r);
  else
    {
      for (i = 0; i < ldans && u != dans[i].unit; i++);		/* search for unit */

      if (i < ldans)
	Result = Inint (r / dans[i].per_inch * res);
      else
	{
	  MesgString ("Unimplemented unit, treating as inch.");
	  MesgLine ();
	  Result = Inint (r * res);
	}
    }
  return Result;
}
/* DimenPixels */
/*--------------------------------------------------------------------*/
void 
WriteCardinal (char *name, int value)
{
  String outstring;

  sprintf (outstring, "%s= %d", name, value);
  MesgString (outstring);
  MesgLine ();
}
/* WriteCardinal */
/*--------------------------------------------------------------------*/

void 
WriteReal (char *name, double value)
{
  String outstring;

  sprintf (outstring, "%s= %f", name, value);
  MesgString (outstring);
  MesgLine ();
}

/* WriteReal */

/*--------------------------------------------------------------------*/

/* GT - TO BE FINISHED - Write... FUNCTIONS BELOW, TOO! */
/* Might be better to use a pair of arrays, or array of pairs */
/* That is, data-driven may be more flexible. */

void 
NameUnit (units un, String nun)
/* Interface:  un (I),  *nun (O). */
{
  int i;

  for (i = 0; i < ldans && un != dans[i].unit; i++);	/* Search for unit un. */

  if (i < ldans)
    stringcopy (nun, dans[i].name);
  else
    {
      MesgString ("Unknown unit!  Assuming inch.");
      MesgLine ();

      stringcopy (nun, "in");
    }
}
/* NameUnit */

/*--------------------------------------------------------------------*/

void 
WriteDimen (char *varname, double r, units un)
{
  String outstring, nun;

  NameUnit (un, nun);
  /* !! gt - this line is unsafe, as outstring may overflow! */
  sprintf (outstring, "%s= %f %s", varname, r, nun);
  MesgString (outstring);
  MesgLine ();
}

/* WriteDimen */

/*--------------------------------------------------------------------*/

void 
WriteName (char *varname, char *svalue)
{
  String outstring;

  sprintf (outstring, "%s= %s", varname, svalue);
  MesgString (outstring);
  MesgLine ();
}

/* WriteName */

/*--------------------------------------------------------------------*/

double 
Unit2Value (units unit)
{
  double per_inch = 1.0;	/* 1 unit per inch */
  int j;

  for (j = 0; (j < ldans) && (unit != dans[j].unit); j++);	/* Search for the unit. */

  if (j < ldans)
    per_inch = dans[j].per_inch;
  else
    {
      FATAL1 ("Bad unit, enumeration value = %d", unit);
    }
  return per_inch;
}
/* Unit2Value */

/*--------------------------------------------------------------------*/

int 
InitOptions (int argc, char **argv)
{
  /* Get DVI file, and any options, from the command line.
     If an option appears more than once, then we return the last value.

     Actually, proceed in three steps, in increasing priority:
     (1)  Initialise to default values, as set in "defaults.h".
     (2)  If the appropriate environment variable is set, use that.
     (3)  If the appropriate command line option is set, use that.
   */

  char *env;			/* environment variable */
  units def_unit = ic;		/* default unit is inch */
  units hoffu, voffu, xu, yu;
  double hoffr, voffr, xr, yr;
  boolean landscape;
  int c;


  /*
     (1)  DEFAULTS.
     initialize option values with defaults; note that the dv script can
     set up different defaults  [- quoth Andrew Trevorrow, I presume]
     - gt observes - no "dv" script provided with DVItoVDU version 3.0!
   */

  /* "dpi" means "dots per inch" */
  /* printer's X and Y resolutions in dpi */
  xres = (double) DEF_XRES;
  yres = (double) DEF_YRES;

  /* Page Offsets from Paper edges */
  hoffu = def_unit;
  voffu = def_unit;
  hoffr = 0.0;			/* no margin shifting, so 1" left and top margins */
  voffr = 0.0;

  mag = 0;			/* use DVI file's intrinsic magnification */

  /*
     (2)  ENVIRONMENT VARIABLES.
   */

  /* Resolution, in dots per inch */
  /* If DV_RES is set in the environment, then try to use that. */
  /* If two real values are in DV_RES, copy them to xres and yres. */
  /* If only one is in DV_RES, copy it to both xres and yres. */
  /* If none is, then ignore DV_RES. */

  if ((env = getenv ("DV_RES")) != (char *) NULL)
    ToRes (" -r", env, &xres, &yres);

#if 0
  if (!(env = getenv ("DV_TERM")))
    env = getenv ("TERM");
  stringcopy (vdu, !env ? "" : env);
#else
  stringcopy (vdu, "tek4010");
#endif

  /* Paper Width */
  ToPosDimen ("", !(env = getenv ("DV_PAPERWD")) ? DEF_PAPERWD : env,
	      &xr, &xu);

  /* Paper Height */
  ToPosDimen ("", !(env = getenv ("DV_PAPERHT")) ? DEF_PAPERHT : env,
	      &yr, &yu);

  /* fall-back PK font */
  stringcopy (dummy_pk, !(env = getenv ("DV_DUMMY_PK")) ? DEF_DUMMY_PK : env);
  /* fall-back TFM metric */
  stringcopy (dummy_tfm, !(env = getenv ("DV_DUMMY_TFM")) ? DEF_DUMMY_TFM : env);
  /* portrait or landscape page dimensions? */
  landscape = false;		/* portrait:  don't swap -x and -y values */

  /*
     (3)  COMMAND LINE OPTIONS.
   */

  while ((c = getopt (argc, argv, "H:V:d:e:k:lm:r:t:x:y:")) != -1)
    {
      switch (c)
	{
	case 0:		/* flags already processed */
	  break;

	case 'H':
	  ToDimen (" -H", optarg, &hoffr, &hoffu);
	  break;
	case 'V':
	  ToDimen (" -V", optarg, &voffr, &voffu);
	  break;
	case 'd':
	  stringcopy (dummy_pk, optarg);
	  break;
	case 'e':		/* gt - not very mnemonic, I know */
	  stringcopy (dummy_tfm, optarg);
	  break;
	case 'k':
	  kpathsea_debug |= atoi (optarg);
	  break;
	case 'l':
	  landscape = true;
	  break;
	case 'm':
	  ToCardinal (" -m", optarg, &mag);
	case 'r':
	  /* gt - resolutions should allow non-integer dpi */
	  /*    - this is because there are such output devices */
	  /*    - for example, metric printers.                 */
	  /* Get resolutions, specified in dots per inch */
	  ToRes (" -r", optarg, &xres, &yres);
	  break;
	case 'v':
	  stringcopy (vdu, optarg);
	  break;
	case 'x':
	  ToPosDimen (" -x", optarg, &xr, &xu);
	  break;
	case 'y':
	  ToPosDimen (" -y", optarg, &yr, &yu);
	  break;
	case '?':		/* error message in getopt */
	  FATAL ("Exiting");
	default:
	  FATAL ("Fatal error in getopt");
	}			/* switch */
    }

  argv += optind - 1;
  argc -= optind - 1;

  if (argc < 2)
    {
      return 0;
    }

  /* bad DVIname will be detected upon open in main module */
  DVIname = extend_filename (argv[1], "dvi");

  /* set h/voffset and paperwd/ht only after resolutions have been decided */
  hoffset = DimenPixels (hoffr, hoffu, xres);
  voffset = DimenPixels (voffr, voffu, yres);

  paperwd = DimenPixels (xr, xu, xres);
  paperht = DimenPixels (yr, yu, yres);

  if (landscape)
    {				/* swap paperwd and paperht */
      int temp = paperwd;
      paperwd = paperht;
      paperht = temp;
    }
  return 1;
}

/* InitOptions */

/* end options.c */