/* Copyright (c) 1999, 2000 Carlo Wood.  All rights reserved.
 * Copyright (c) 1994 Joseph Arceneaux.  All rights reserved.
 * Copyright (c) 1992 Free Software Foundation, Inc.  All rights reserved.
 *
 * Copyright (c) 1985 Sun Microsystems, Inc. Copyright (c) 1980 The Regents
 * of the University of California. Copyright (c) 1976 Board of Trustees of
 * the University of Illinois. All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that
 * the above copyright notice and this paragraph are duplicated in all such
 * forms and that any documentation, advertising materials, and other
 * materials related to such distribution and use acknowledge that the
 * software was developed by the University of California, Berkeley, the
 * University of Illinois, Urbana, and Sun Microsystems, Inc.  The name of
 * either University or Sun Microsystems may not be used to endorse or
 * promote products derived from this software without specific prior written
 * permission. THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES
 * OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 *
 * HISTORY
 * 2002-01-17 D.Ingamells Add a final newline if not present in file.
 */

#include "sys.h"

#include <ctype.h>
#include <stdlib.h>
#if defined (HAVE_UNISTD_H)
   #include <unistd.h>
#endif
#include <string.h>

#ifdef VMS
   #include <file.h>
   #include <types.h>
   #include <stat.h>
#else /* not VMS */
   #include <sys/types.h>
   #include <sys/stat.h>
   /* POSIX says that <fcntl.h> should exist.  Some systems might need to use
    * <sys/fcntl.h> or <sys/file.h> instead.  */
   #include <fcntl.h>
   #if defined (_WIN32) && !defined (__CYGWIN__)
      #include <io.h>
   #endif
#endif /* not VMS */

#include "indent.h"
#include "io.h"
#include "globs.h"
#include "output.h"

RCSTAG_CC ("$Id: io.c,v 1.50 2002/08/04 17:08:41 david Exp $");

/* number of levels a label is placed to left of code */
#define LABEL_OFFSET 2

/******************************************************************************/
/* Stuff that needs to be shared with the rest of indent. Documented in
 * indent.h.
 */

char          * in_prog_pos    = NULL;  /* used in output.c        io.c indent.c */
char          * buf_ptr        = NULL;  /* used in output.c lexi.c io.c indent.c comments.c */
char          * buf_end        = NULL;  /* used in output.c lexi.c io.c indent.c comments.c */
BOOLEAN         had_eof        = false; /* used in output.c        io.c          comments.c parse.c */
char          * cur_line       = NULL;  /* used in output.c        io.c */

/******************************************************************************/

char * skip_horiz_space(const char * p)
{
    while ((*p == ' ') || (*p == TAB))
    {
        p++;
    }

    return (char *)p;
}

/******************************************************************************/

void skip_buffered_space(void)
{
    while ((*buf_ptr == ' ') ||
           (*buf_ptr == TAB))
    {
        buf_ptr++;
        
        if (buf_ptr >= buf_end)
        {
            fill_buffer ();
        }
    }
}

/******************************************************************************/

static BOOLEAN is_comment_start(const char * p)
{
    BOOLEAN ret;
    
    if ((*p == '/') && ((*(p + 1) == '*') ||
                        (*(p + 1) == '/')))
    {
        ret = true;
    }
    else
    {
        ret = false;
    }
    
    return ret;
}

/******************************************************************************/

int count_columns (
    int column,
    char *bp,
    int stop_char)
{
    while (*bp != stop_char && *bp != NULL_CHAR)
    {
        switch (*bp++)
        {
        case EOL:
        case '\f':           /* form feed */
            column = 1;
            break;
        case TAB:
            column += settings.tabsize - (column - 1) % settings.tabsize;
            break;
        case 010:           /* backspace */
            --column;
            break;
#ifdef COLOR_DEBUG
        case '\e':          /* ANSI color */
            while (*bp++ != 'm')
            {
            }
                
            break;
#endif
        default:
            ++column;
            break;
        }
    }

    return column;
}


#ifdef VMS
/******************************************************************************/
/* Folks say VMS requires its own read routine.  Then again, some folks
 * say it doesn't.  Different folks have also sent me conflicting versions
 * of this function.  Who's right?
 *
 * Anyway, this version was sent by address@hidden and modified
 * slightly by me. */

static int vms_read (
    int    file_desc,
    char * buffer,
    int    nbytes)
{
    char * bufp;
    int    nread;
    int    nleft;

    bufp = buffer;
    nread = 0;
    nleft = nbytes;

    nread = read (file_desc, bufp, nleft);
    
    while (nread > 0)
    {
        bufp += nread;
        nleft -= nread;
        if (nleft < 0)
        {
            fatal (_("Internal buffering error"), 0);
        }
        
        nread = read (file_desc, bufp, nleft);
    }

    return nbytes - nleft;
}
#endif /* VMS */

/******************************************************************************/
/* Return the column we are at in the input line. */

int current_column (void)
{
    char *p;
    int column;

    /* Use save_com.size here instead of save_com.end, because save_com is
     * already emptied at this point. */
  
    if ((buf_ptr >= save_com.ptr) && (buf_ptr <= save_com.ptr + save_com.len))
    {
        p = save_com.ptr;
        column = save_com.start_column;
    }
    else
    {
        p = cur_line;
        column = 1;
    }

    while (p < buf_ptr)
    {
        switch (*p)
        {
            case EOL:
            case 014:           /* form feed */
                column = 1;
                break;

            case TAB:
                column += settings.tabsize - (column - 1) % settings.tabsize;
                break;

            case '\b':          /* backspace */
                column--;
                break;

            default:
                column++;
                break;
        }

        p++;
    }

    return column;
}

/******************************************************************************/
/* Return the column in which we should place the code in s_code. */

int compute_code_target (
    int paren_targ)
{
    int target_col;

    if (buf_break_used)
    {
        return prev_target_col_break;
    }

    if (parser_state_tos->procname[0] &&
        (s_code_corresponds_to == parser_state_tos->procname))
    {
        target_col = 1;
        
        if (!parser_state_tos->paren_level)
        {
            return target_col;
        }
    }
    else
    {
        target_col = parser_state_tos->ind_level + 1;
    }

    if (!parser_state_tos->paren_level)
    {
        if (parser_state_tos->ind_stmt)
        {
            target_col += settings.continuation_indent;
        }
        
        return target_col;
    }

    if (!settings.lineup_to_parens)
    {
        return target_col + settings.continuation_indent +
                (settings.paren_indent * (parser_state_tos->paren_level - 1));
    }

    return paren_targ;
}

/******************************************************************************/
int compute_label_target (void)
{
    /* maybe there should be some option to tell indent where to put public:,
     * private: etc. ? */
    
    if (*s_lab == '#')
    {
        return 1;
    }
    
    if (parser_state_tos->pcase)
    {
        return parser_state_tos->cstk[parser_state_tos->tos] + 1;
    }
    
    if (settings.c_plus_plus && parser_state_tos->in_decl)
    {
        /* FIXME: does this belong here at all? */
        return 1;
    }
    else if (settings.label_offset)
    {
        return settings.label_offset;
    } 
    else
    {
        return parser_state_tos->ind_level - LABEL_OFFSET + 1;
    }
}

/******************************************************************************/
/* VMS defines it's own read routine, `vms_read' */
#ifndef INDENT_SYS_READ
#define INDENT_SYS_READ read
#endif

/* Read file FILENAME into a `fileptr' structure, and return a pointer to
   that structure. */

file_buffer_ty * read_file (
    char        * filename,
    struct stat * file_stats)
{
    static file_buffer_ty fileptr;
    
    /*
     * size is required to be unsigned for MSDOS,
     * in order to read files larger than 32767
     * bytes in a 16-bit world...
     */
  
    unsigned int size;

    int          namelen = strlen(filename);
    int          fd      = open(filename, O_RDONLY, 0777);

    if (fd < 0)
    {
        fatal (_("Can't open input file %s"), filename);
    }

    if (fstat(fd, file_stats) < 0)
    {
        fatal (_("Can't stat input file %s"), filename);
    }

    if (file_stats->st_size == 0)
    {
        ERROR (_("Warning: Zero-length file %s"), filename, 0);
    }

#if !defined(__DJGPP__)
    if (sizeof (int) == 2)      /* Old MSDOS */
    {
        if ((file_stats->st_size < 0) || (file_stats->st_size > (0xffff - 1)))
        {
            fatal (_("File %s is too big to read"), filename);
        }
    }
    else
#endif
    {
        if (file_stats->st_size < 0)
        {
            fatal (_("System problem reading file %s"), filename);
        }
    }

    fileptr.size = file_stats->st_size;
    
    if (fileptr.data != 0)
    {
        fileptr.data = (char *) xrealloc (fileptr.data,
                                          (unsigned) file_stats->st_size + 2); /* add 1 for '\0' and 1 for
                                                                                * potential final added
                                                                                * newline. */
    }
    else
    {
        fileptr.data = (char *) xmalloc ((unsigned) file_stats->st_size + 2); /* add 1 for '\0' and 1 for
                                                                               * potential final added
                                                                               * newline. */
    }

    size = INDENT_SYS_READ (fd, fileptr.data, fileptr.size);
    
    if (size == (unsigned int) -1)
    {
        fatal (_("Error reading input file %s"), filename);
    }
    
    if (close (fd) < 0)
    {
        fatal (_("Error closeing input file %s"), filename);
    }
    

    /* Apparently, the DOS stores files using CR-LF for newlines, but
     * then the DOS `read' changes them into '\n'.  Thus, the size of the
     * file on disc is larger than what is read into memory.  Thanks, Bill. */
    
    if (size < fileptr.size)
    {
        fileptr.size = size;
    }

    if (fileptr.name != NULL)
    {
        fileptr.name = (char *) xrealloc (fileptr.name, (unsigned) namelen + 1);
    }
    else
    {
        fileptr.name = (char *) xmalloc (namelen + 1);
    }
    
    (void)strncpy(fileptr.name, filename, namelen);
    fileptr.name[namelen] = EOS;

    if (fileptr.data[fileptr.size - 1] != EOL)
    {
        fileptr.data[fileptr.size] = EOL;
        fileptr.size++;
    }
    
    fileptr.data[fileptr.size] = EOS;

    return &fileptr;
}

/* This should come from stdio.h and be some system-optimal number */
#ifndef BUFSIZ
#define BUFSIZ 1024
#endif

/******************************************************************************/
/* Suck the standard input into a file_buffer structure, and
   return a pointer to that structure. */

file_buffer_ty * read_stdin (void)
{
    static file_buffer_ty stdinptr;

    unsigned int          size = 15 * BUFSIZ;
    int                   ch;
    char                * p = NULL;

    if (stdinptr.data != 0)
    {
        free (stdinptr.data);
    }

    stdinptr.data = (char *) xmalloc (size + 1);
    stdinptr.size = 0;
    
    p = stdinptr.data;
    
    do
    {
        while (stdinptr.size < size)
        {
            ch = getc (stdin);
            
            if (ch == EOF)
            {
                break;
            }

            *p++ = ch;
            stdinptr.size++;
        }

        if (ch != EOF)
        {
            size += (2 * BUFSIZ);
            stdinptr.data = xrealloc (stdinptr.data, (unsigned) size);
            p = stdinptr.data + stdinptr.size;
        }
    } while (ch != EOF);

    stdinptr.name = "Standard Input";

    stdinptr.data[stdinptr.size] = EOS;

    return &stdinptr;
}

/******************************************************************************/
/* Advance `buf_ptr' so that it points to the next line of input.
 *
 * If the next input line contains an indent control comment turning
 * off formatting (a comment, C or C++, beginning with *INDENT-OFF*),
 * disable indenting by calling inhibit_indenting() which will cause
 * `dump_line ()' to simply print out all input lines without formatting
 * until it finds a corresponding comment containing *INDENT-0N* which
 * re-enables formatting.
 *
 * Note that if this is a C comment we do not look for the closing
 * delimiter.  Note also that older version of this program also
 * skipped lines containing *INDENT** which represented errors
 * generated by indent in some previous formatting.  This version does
 * not recognize such lines. */

void fill_buffer (void)
{
    char    * p = NULL;
    BOOLEAN   finished_a_line = false;

    /* indent() may be saving the text between "if (...)" and the following
     * statement.  To do so, it uses another buffer (`save_com').  Switch
     * back to the previous buffer here. */
    
    if (bp_save != 0)
    {
        buf_ptr = bp_save;
        buf_end = be_save;
        bp_save = be_save = 0;

        /* only return if there is really something in this buffer */
        
        if (buf_ptr < buf_end)
        {
            return;
        }
    }

    if (*in_prog_pos == EOS)
    {
        cur_line = buf_ptr = in_prog_pos;
        had_eof = true;
        return;
    }

    /* Here if we know there are chars to read.  The file is
     * NULL-terminated, so we can always look one character ahead
     * safely. */
    
    p = cur_line = in_prog_pos;
    finished_a_line = false;
    
    do
    {
        p = skip_horiz_space(p);

        /* If we are looking at the beginning of a comment, see
         * if it turns off formatting with off-on directives. */
        
        if (is_comment_start(p))
        {
            p += 2;
            
            p = skip_horiz_space(p);
            
            /* Skip all lines between the indent off and on directives. */
            
            if (strncmp (p, "*INDENT-OFF*", 12) == 0)
            {
                inhibit_indenting(true);
            }
        }

        while ((*p != EOS) && *p != EOL)
        {
            p++;
        }

        /* Here for newline -- finish up unless formatting is off */
        
        if (*p == EOL)
        {
            finished_a_line = true;
            in_prog_pos = p + 1;
        }
        
        /* Here for embedded NULLs */
        
        else if ((unsigned int) (p - current_input->data) < current_input->size)
        {
            WARNING (_("Warning: File %s contains NULL-characters\n"), current_input->name, 0);
            p++;
        }
        
        /* Here for EOF with no terminating newline char. */
        else
        {
            in_prog_pos = p;
            finished_a_line = true;
        }
    } while (!finished_a_line);

    buf_ptr = cur_line;
    buf_end = in_prog_pos;
    
    if (buf_break && ((buf_break->offset >= e_code - s_code) || (buf_break->offset <= 0)))
    {
        clear_buf_break_list ();
    }
}