/*
 * Copyright (c) 1993-1994 by Xerox Corporation.  All rights reserved.
 *
 * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
 * OR IMPLIED.  ANY USE IS AT YOUR OWN RISK.
 *
 * Permission is hereby granted to use or copy this program
 * for any purpose,  provided the above notices are retained on all copies.
 * Permission to modify the code and to distribute modified code is granted,
 * provided the above notices are retained, and a notice that the code was
 * modified is included with the above copyright notice.
 */
/* An sprintf implementation that understands cords.  This is probably  */
/* not terribly portable.  It assumes an ANSI stdarg.h.  It further     */
/* assumes that I can make copies of va_list variables, and read        */
/* arguments repeatedly by applying va_arg to the copies.  This         */
/* could be avoided at some performance cost.                           */
/* We also assume that unsigned and signed integers of various kinds    */
/* have the same sizes, and can be cast back and forth.                 */
/* We assume that void * and char * have the same size.                 */
/* All this cruft is needed because we want to rely on the underlying   */
/* sprintf implementation whenever possible.                            */

#include "cord.h"
#include "ec.h"
#include <stdio.h>
#include <stdarg.h>
#include <string.h>
#include "gc.h"

#define CONV_SPEC_LEN 50        /* Maximum length of a single   */
                                /* conversion specification.    */
#define CONV_RESULT_LEN 50      /* Maximum length of any        */
                                /* conversion with default      */
                                /* width and prec.              */


static int ec_len(CORD_ec x)
{
    return(CORD_len(x[0].ec_cord) + (x[0].ec_bufptr - x[0].ec_buf));
}

/* Possible nonumeric precision values. */
# define NONE -1
# define VARIABLE -2
/* Copy the conversion specification from CORD_pos into the buffer buf  */
/* Return negative on error.                                            */
/* Source initially points one past the leading %.                      */
/* It is left pointing at the conversion type.                          */
/* Assign field width and precision to *width and *prec.                */
/* If width or prec is *, VARIABLE is assigned.                         */
/* Set *left to 1 if left adjustment flag is present.                   */
/* Set *long_arg to 1 if long flag ('l' or 'L') is present, or to       */
/* -1 if 'h' is present.                                                */
static int extract_conv_spec(CORD_pos source, char *buf,
                             int * width, int *prec, int *left, int * long_arg)
{
    register int result = 0;
    register int current_number = 0;
    register int saw_period = 0;
    register int saw_number = 0;
    register int chars_so_far = 0;
    register char current;

    *width = NONE;
    buf[chars_so_far++] = '%';
    while(CORD_pos_valid(source)) {
        if (chars_so_far >= CONV_SPEC_LEN) return(-1);
        current = CORD_pos_fetch(source);
        buf[chars_so_far++] = current;
        switch(current) {
          case '*':
            saw_number = 1;
            current_number = VARIABLE;
            break;
          case '0':
            if (!saw_number) {
                /* Zero fill flag; ignore */
                break;
            } /* otherwise fall through: */
          case '1':
          case '2':
          case '3':
          case '4':
          case '5':
          case '6':
          case '7':
          case '8':
          case '9':
            saw_number = 1;
            current_number *= 10;
            current_number += current - '0';
            break;
          case '.':
            saw_period = 1;
            if(saw_number) {
                *width = current_number;
                saw_number = 0;
            }
            current_number = 0;
            break;
          case 'l':
          case 'L':
            *long_arg = 1;
            current_number = 0;
            break;
          case 'h':
            *long_arg = -1;
            current_number = 0;
            break;
          case ' ':
          case '+':
          case '#':
            current_number = 0;
            break;
          case '-':
            *left = 1;
            current_number = 0;
            break;
          case 'd':
          case 'i':
          case 'o':
          case 'u':
          case 'x':
          case 'X':
          case 'f':
          case 'e':
          case 'E':
          case 'g':
          case 'G':
          case 'c':
          case 'C':
          case 's':
          case 'S':
          case 'p':
          case 'n':
          case 'r':
            goto done;
          default:
            return(-1);
        }
        CORD_next(source);
    }
    return(-1);
  done:
    if (saw_number) {
        if (saw_period) {
            *prec = current_number;
        } else {
            *prec = NONE;
            *width = current_number;
        }
    } else {
        *prec = NONE;
    }
    buf[chars_so_far] = '\0';
    return(result);
}

int CORD_vsprintf(CORD * out, CORD format, va_list args)
{
    CORD_ec result;
    register int count;
    register char current;
    CORD_pos pos;
    char conv_spec[CONV_SPEC_LEN + 1];

    CORD_ec_init(result);
    for (CORD_set_pos(pos, format, 0); CORD_pos_valid(pos); CORD_next(pos)) {
        current = CORD_pos_fetch(pos);
        if (current == '%') {
            CORD_next(pos);
            if (!CORD_pos_valid(pos)) return(-1);
            current = CORD_pos_fetch(pos);
            if (current == '%') {
                CORD_ec_append(result, current);
            } else {
                int width, prec;
                int left_adj = 0;
                int long_arg = 0;
                CORD arg;
                size_t len;

                if (extract_conv_spec(pos, conv_spec,
                                      &width, &prec,
                                      &left_adj, &long_arg) < 0) {
                    return(-1);
                }
                current = CORD_pos_fetch(pos);
                switch(current) {
                    case 'n':
                        /* Assign length to next arg */
                        if (long_arg == 0) {
                            int * pos_ptr;
                            pos_ptr = va_arg(args, int *);
                            *pos_ptr = ec_len(result);
                        } else if (long_arg > 0) {
                            long * pos_ptr;
                            pos_ptr = va_arg(args, long *);
                            *pos_ptr = ec_len(result);
                        } else {
                            short * pos_ptr;
                            pos_ptr = va_arg(args, short *);
                            *pos_ptr = ec_len(result);
                        }
                        goto done;
                    case 'r':
                        /* Append cord and any padding  */
                        if (width == VARIABLE) width = va_arg(args, int);
                        if (prec == VARIABLE) prec = va_arg(args, int);
                        arg = va_arg(args, CORD);
                        len = CORD_len(arg);
                        if (prec != NONE && len > (size_t)prec) {
                          if (prec < 0) return(-1);
                          arg = CORD_substr(arg, 0, prec);
                          len = prec;
                        }
                        if (width != NONE && len < (size_t)width) {
                          char * blanks = GC_MALLOC_ATOMIC(width-len+1);

                          memset(blanks, ' ', width-len);
                          blanks[width-len] = '\0';
                          if (left_adj) {
                            arg = CORD_cat(arg, blanks);
                          } else {
                            arg = CORD_cat(blanks, arg);
                          }
                        }
                        CORD_ec_append_cord(result, arg);
                        goto done;
                    case 'c':
                        if (width == NONE && prec == NONE) {
                            register char c;

                            c = (char)va_arg(args, int);
                            CORD_ec_append(result, c);
                            goto done;
                        }
                        break;
                    case 's':
                        if (width == NONE && prec == NONE) {
                            char * str = va_arg(args, char *);
                            register char c;

                            while ((c = *str++)) {
                                CORD_ec_append(result, c);
                            }
                            goto done;
                        }
                        break;
                    default:
                        break;
                }
                /* Use standard sprintf to perform conversion */
                {
                    register char * buf;
                    va_list vsprintf_args;
                    int max_size = 0;
                    int res;
#                   ifdef __va_copy
                      __va_copy(vsprintf_args, args);
#                   else
#                     if defined(__GNUC__) && !defined(__DJGPP__) /* and probably in other cases */
                        va_copy(vsprintf_args, args);
#                     else
                        vsprintf_args = args;
#                     endif
#                   endif
                    if (width == VARIABLE) width = va_arg(args, int);
                    if (prec == VARIABLE) prec = va_arg(args, int);
                    if (width != NONE) max_size = width;
                    if (prec != NONE && prec > max_size) max_size = prec;
                    max_size += CONV_RESULT_LEN;
                    if (max_size >= CORD_BUFSZ) {
                        buf = GC_MALLOC_ATOMIC(max_size + 1);
                    } else {
                        if (CORD_BUFSZ - (result[0].ec_bufptr-result[0].ec_buf)
                            < max_size) {
                            CORD_ec_flush_buf(result);
                        }
                        buf = result[0].ec_bufptr;
                    }
                    switch(current) {
                        case 'd':
                        case 'i':
                        case 'o':
                        case 'u':
                        case 'x':
                        case 'X':
                        case 'c':
                            if (long_arg <= 0) {
                              (void) va_arg(args, int);
                            } else if (long_arg > 0) {
                              (void) va_arg(args, long);
                            }
                            break;
                        case 's':
                        case 'p':
                            (void) va_arg(args, char *);
                            break;
                        case 'f':
                        case 'e':
                        case 'E':
                        case 'g':
                        case 'G':
                            (void) va_arg(args, double);
                            break;
                        default:
                            return(-1);
                    }
                    res = vsprintf(buf, conv_spec, vsprintf_args);
                    len = (size_t)res;
                    if ((char *)(GC_word)res == buf) {
                        /* old style vsprintf */
                        len = strlen(buf);
                    } else if (res < 0) {
                        return(-1);
                    }
                    if (buf != result[0].ec_bufptr) {
                        register char c;

                        while ((c = *buf++)) {
                            CORD_ec_append(result, c);
                        }
                    } else {
                        result[0].ec_bufptr = buf + len;
                    }
                }
              done:;
            }
        } else {
            CORD_ec_append(result, current);
        }
    }
    count = ec_len(result);
    *out = CORD_balance(CORD_ec_to_cord(result));
    return(count);
}

int CORD_sprintf(CORD * out, CORD format, ...)
{
    va_list args;
    int result;

    va_start(args, format);
    result = CORD_vsprintf(out, format, args);
    va_end(args);
    return(result);
}

int CORD_fprintf(FILE * f, CORD format, ...)
{
    va_list args;
    int result;
    CORD out;

    va_start(args, format);
    result = CORD_vsprintf(&out, format, args);
    va_end(args);
    if (result > 0) CORD_put(out, f);
    return(result);
}

int CORD_vfprintf(FILE * f, CORD format, va_list args)
{
    int result;
    CORD out;

    result = CORD_vsprintf(&out, format, args);
    if (result > 0) CORD_put(out, f);
    return(result);
}

int CORD_printf(CORD format, ...)
{
    va_list args;
    int result;
    CORD out;

    va_start(args, format);
    result = CORD_vsprintf(&out, format, args);
    va_end(args);
    if (result > 0) CORD_put(out, stdout);
    return(result);
}

int CORD_vprintf(CORD format, va_list args)
{
    int result;
    CORD out;

    result = CORD_vsprintf(&out, format, args);
    if (result > 0) CORD_put(out, stdout);
    return(result);
}
