/* file.c -- implements file.h */

#include "file.h"

/*	file.c
 *
 *	The routines in this file handle the reading, writing
 *	and lookup of disk files.  All of details about the
 *	reading and writing of the disk are in "fileio.c".
 *
 *	modified by Petri Kutvonen
 */

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

#include "buffer.h"
#include "defines.h"
#include "display.h"
#include "estruct.h"
#include "execute.h"
#include "fileio.h"
#include "input.h"
#include "line.h"
#include "lock.h"
#include "mlout.h"
#include "util.h"
#include "utf8.h"
#include "window.h"

typedef enum {
	EOL_NONE,
	EOL_UNIX,
	EOL_DOS,
	EOL_MAC,
	EOL_MIXED
} eoltype ;

static const char *eolname[] = {
	"NONE",
	"UNIX",
	"DOS",
	"MAC",
	"MIXED"
} ;

static const char *codename[] = {
	"ASCII",
	"UTF-8",
	"EXTENDED",
	"MIXED"
} ;

boolean restflag = FALSE ;	/* restricted use?				*/


static int ifile( const char *fname) ;


boolean resterr( void) {
	mloutfmt( "%B(That command is RESTRICTED)") ;
	return FALSE ;
}

/*
 * Read a file into the current
 * buffer. This is really easy; all you do is
 * find the name of the file, and call the standard
 * "read a file into the current buffer" code.
 * Bound to "C-X C-R".
 */
int fileread( int f, int n) {
	int status ;
	char *fname ;

	if( restflag)		/* don't allow this command if restricted */
		return resterr() ;

	status = newmlarg( &fname, "Read file: ", sizeof( fname_t)) ;
	if( status == TRUE) {
		status = readin( fname, TRUE) ;
		free( fname) ;
	}

	return status ;
}

/*
 * Insert a file into the current
 * buffer. This is really easy; all you do is
 * find the name of the file, and call the standard
 * "insert a file into the current buffer" code.
 * Bound to "C-X C-I".
 */
int insfile( int f, int n) {
	int status ;
	char *fname ;

	if( restflag)		/* don't allow this command if restricted */
		return resterr() ;

	if( curbp->b_mode & MDVIEW) /* don't allow this command if	*/
		return rdonly() ;		/* we are in read only mode 	*/

	status = newmlarg( &fname, "Insert file: ", sizeof( fname_t)) ;
	if( status == TRUE) {
		status = ifile( fname) ;
		free( fname) ;
	}

	if( status != TRUE)
		return status ;

	return reposition( TRUE, -1) ;	/* Redraw with dot at bottom of window */
}

/*
 * Select a file for editing.
 * Look around to see if you can find the
 * fine in another buffer; if you can find it
 * just switch to the buffer. If you cannot find
 * the file, create a new buffer, read in the
 * text, and switch to the new buffer.
 * Bound to C-X C-F.
 */
int filefind( int f, int n) {
	char *fname ;	/* file user wishes to find */
	int status ;	/* status return */

	if( restflag)	/* don't allow this command if restricted */
		return resterr() ;

	status = newmlarg( &fname, "Find file: ", sizeof( fname_t)) ;
	if( status == TRUE) {
		status = getfile( fname, TRUE) ;
		free( fname) ;
	}

	return status ;
}

static void upd_mode( void) {
	struct window *wp ;

/* Update mode lines */
	for( wp = wheadp ; wp != NULL ; wp = wp->w_wndp)
		if( wp->w_bufp == curbp)
			wp->w_flag |= WFMODE ;
}

int viewfile( int f, int n) {	/* visit a file in VIEW mode */
	char *fname ;	/* file user wishes to find */
	int status ;	/* status return */

	if( restflag)		/* don't allow this command if restricted */
		return resterr() ;

	status = newmlarg( &fname, "View file: ", sizeof( fname_t)) ;
	if( status == TRUE) {
		status = getfile(fname, FALSE) ;
		free( fname) ;

		if( status == TRUE) {	/* if we succeed, put it in view mode */
			curwp->w_bufp->b_mode |= MDVIEW ;
			upd_mode() ;
		}
	}

	return status ;
}

/*
 * getfile()
 *
 * char fname[];	file name to find
 * boolean lockfl;		check the file for locks?
 */
int getfile( const char *fname, boolean lockfl) {
	struct buffer *bp;
	int s;
	bname_t bname ;  /* buffer name to put file */

/* Is the file in current buffer? */
	if( strcmp( curbp->b_fname, fname) == 0) {
		mloutstr( "(Current buffer)") ;
		return TRUE ;
	}

/* Is the file in any buffer? */
	for( bp = bheadp; bp != NULL; bp = bp->b_bufp) {
		if( (bp->b_flag & BFINVS) == 0
		&& strcmp( bp->b_fname, fname) == 0) {
			line_p	lp ;
			int i ;

			swbuffer( bp) ;

		/* Center dotted line in window */
			i = curwp->w_ntrows / 2 ;
			for( lp = curwp->w_dotp ; lback( lp) != curbp->b_linep ; lp = lback( lp))
				if( i-- == 0)
					break ;

			curwp->w_linep = lp ;

		/* Refresh window */
			curwp->w_flag |= WFMODE | WFHARD ;
			cknewwindow() ;
			mloutstr( "(Old buffer)") ;
			return TRUE ;
		}
	}

	makename(bname, fname); /* New buffer name. 	*/
	while ((bp = bfind(bname, FALSE, 0)) != NULL) {
		char *new_bname ;

		/* old buffer name conflict code */
		s = newmlarg( &new_bname, "Buffer name: ", sizeof( bname_t)) ;
		if( s == ABORT) /* ^G to just quit		*/
			return s ;
		else if (s == FALSE) {	 /* CR to clobber it	 */
			makename( bname, fname) ;
			break ;
		} else { /* TRUE */
			mystrscpy( bname, new_bname, sizeof bname) ;
			free( new_bname) ;
		}
	}

	if (bp == NULL && (bp = bfind(bname, TRUE, 0)) == NULL) {
		mloutstr( "Cannot create buffer") ;
		return FALSE;
	}
	if (--curbp->b_nwnd == 0) { /* Undisplay.			*/
		curbp->b_dotp = curwp->w_dotp;
		curbp->b_doto = curwp->w_doto;
		curbp->b_markp = curwp->w_markp;
		curbp->b_marko = curwp->w_marko;
	}
	curbp = bp; 	/* Switch to it.		*/
	curwp->w_bufp = bp;
	curbp->b_nwnd++;
	s = readin(fname, lockfl);	/* Read it in.			*/
	cknewwindow();
	return s;
}

/*
 * Read file "fname" into the current buffer, blowing away any text
 * found there.  Called by both the read and find commands.  Return
 * the final status of the read.  Also called by the mainline, to
 * read in a file specified on the command line as an argument.
 * The command bound to M-FNR is called after the buffer is set up
 * and before it is read.
 *
 * char fname[];	name of file to read
 * boolean lockfl;		check for file locks?
 */
int readin(const char *fname, boolean lockfl)
{
	struct window *wp;
	struct buffer *bp;
	int status ;
	fio_code s ;

	bp = curbp; 	/* Cheap.				*/
#if (FILOCK && BSD) || SVR4
	if( lockfl && lockchk( fname) == ABORT) {
#if PKCODE
		s = FIOFNF;
		strcpy(bp->b_fname, "");
		mloutstr( "(File in use)") ;
#else
		return ABORT;
#endif
	} else
#endif
  {
	if( (status = bclear( bp)) != TRUE)   /* Might be old.		  */
		return status ;

	bp->b_flag &= ~(BFINVS | BFCHG);
	if( fname != bp->b_fname)	/* Copy if source differs from destination */
		mystrscpy( bp->b_fname, fname, sizeof( fname_t)) ;

	/* let a user macro get hold of things...if he wants */
	execute(META | SPEC | 'R', FALSE, 1);

	s = ffropen( bp->b_fname) ; /* Always use the name associated to buffer */
	if( s == FIOFNF)	/* File not found.		*/
		mloutstr( "(New file)") ;
	else if( s == FIOSUC) {
		char *errmsg ;
		eoltype found_eol ;
		int nline = 0 ;

	/* read the file in */
		mloutstr( "(Reading file)") ;
		while ((s = ffgetline()) == FIOSUC) {
			line_p	lp ;

			if( nline >= 10000000 /* MAXNLINE Maximum # of lines from one file */
			||	(lp = lalloc( fpayload)) == NULL) {
				s = FIOMEM ;	/* Keep message on the	*/
				break ; 		/* display. 			*/
			}

			memcpy( lp->l_text, fline, fpayload) ;
			lp->l_fp = curbp->b_linep ; /* insert before end of buffer */
			lp->l_bp = lp->l_fp->l_bp ;
			lp->l_fp->l_bp = lp ;
			lp->l_bp->l_fp = lp ;
			nline += 1 ;
		}

		if( s == FIOERR)
			mloutstr( "File read error") ;

		switch( ftype) {
		case FTYPE_DOS:
			found_eol = EOL_DOS ;
			curbp->b_mode |= MDDOS ;
			break ;
		case FTYPE_UNIX:
			found_eol = EOL_UNIX ;
			break ;
		case FTYPE_MAC:
			found_eol = EOL_MAC ;
			break ;
		case FTYPE_NONE:
			found_eol = EOL_NONE ;
			break ;
		default:
			found_eol = EOL_MIXED ;
			curbp->b_mode |= MDVIEW ;	/* force view mode as we have lost
										** EOL information */
		}

		if( fcode == FCODE_UTF_8)
			curbp->b_mode |= MDUTF8 ;

		if( s == FIOERR) {
			errmsg = "I/O ERROR, " ;
			curbp->b_flag |= BFTRUNC ;
		} else if( s == FIOMEM) {
			errmsg = "OUT OF MEMORY, " ;
			curbp->b_flag |= BFTRUNC ;
		} else
			errmsg = "" ;

		mloutfmt( "(%sRead %d line%s, code/eol: %s/%s)",
			errmsg,
			nline,
			&"s"[ nline == 1],
			codename[ fcode & (FCODE_MASK - 1)],
			eolname[ found_eol]) ;
		ffclose() ; /* Ignore errors.		*/
	}
  }

	for (wp = wheadp; wp != NULL; wp = wp->w_wndp) {
		if (wp->w_bufp == curbp) {
			wp->w_linep = lforw(curbp->b_linep);
			wp->w_dotp = lforw(curbp->b_linep);
			wp->w_doto = 0;
			wp->w_markp = NULL;
			wp->w_marko = 0;
			wp->w_flag |= WFMODE | WFHARD;
		}
	}

	return (s == FIOERR || s == FIOFNF) ? FALSE : TRUE ;
}

/*
 * Take a file name, and from it
 * fabricate a buffer name. This routine knows
 * about the syntax of file names on the target system.
 * I suppose that this information could be put in
 * a better place than a line of code.
 */
void makename( bname_t bname, const char *fname)
{
	const char *cp1;
	char *cp2;

	cp1 = &fname[0];
	while (*cp1 != 0)
		++cp1;


	while (cp1 != &fname[0] && cp1[-1] != '/')
		--cp1;

	cp2 = &bname[0];
	while( *cp1 != 0 && *cp1 != ';') {
		unicode_t c ;
		int n ;

		n = utf8_to_unicode( cp1, 0, 4, &c) ;
		if( cp2 + n <= &bname[ sizeof( bname_t) - 2])	/* 1 digit buffer name conflict [0..9] + EOS */
			while( n--)
				*cp2++ = *cp1++ ;
		else
			break ;
	}

 	*cp2 = 0;
}

/*
 * make sure a buffer name is unique
 *
 * char *name;		name to check on
 */
void unqname(char *name)
{
	char *sp;

	/* check to see if it is in the buffer list */
	while (bfind(name, 0, FALSE) != NULL) {

		/* go to the end of the name */
		sp = name;
		while (*sp)
			++sp;
		if (sp == name || (*(sp - 1) < '0' || *(sp - 1) > '8')) {
			*sp++ = '0';
			*sp = 0;
		} else
			*(--sp) += 1;
	}
}

/*
 * Ask for a file name, and write the
 * contents of the current buffer to that file.
 * Update the remembered file name and clear the
 * buffer changed flag. This handling of file names
 * is different from the earlier versions, and
 * is more compatible with Gosling EMACS than
 * with ITS EMACS. Bound to "C-X C-W".
 */
int filewrite( int f, int n) {
	int status ;
	char *fname ;

	if( restflag)		/* don't allow this command if restricted */
		return resterr() ;

	status = newmlarg( &fname, "Write file: ", sizeof( fname_t)) ;
	if( status == TRUE) {
		if( strlen( fname) > sizeof( fname_t) - 1)
			status = FALSE ;
		else {
			status = writeout( fname) ;
			if( status == TRUE)
				strcpy( curbp->b_fname, fname) ;
		}

		free( fname) ;
	}

	return status ;
}

/*
 * Save the contents of the current
 * buffer in its associated file. Do nothing
 * if nothing has changed (this may be a bug, not a
 * feature). Error if there is no remembered file
 * name for the buffer. Bound to "C-X C-S". May
 * get called by "C-Z".
 */
int filesave( int f, int n) {
	if (curbp->b_mode & MDVIEW) /* don't allow this command if		*/
		return rdonly();	/* we are in read only mode 	*/
	if ((curbp->b_flag & BFCHG) == 0)	/* Return, no changes.	*/
		return TRUE;
	if (curbp->b_fname[0] == 0) {	/* Must have a name.	*/
		mloutstr( "No file name") ;
		return FALSE;
	}

	/* complain about truncated files */
	if ((curbp->b_flag & BFTRUNC) != 0) {
		if (mlyesno("Truncated file ... write it out") == FALSE) {
			mloutstr( "(Aborted)") ;
			return FALSE;
		}
	}

	return writeout( curbp->b_fname) ;
}

/*
 * This function performs the details of file
 * writing. Uses the file management routines in the
 * "fileio.c" package. The number of lines written is
 * displayed. Sadly, it looks inside a struct line; provide
 * a macro for this. Most of the grief is error
 * checking of some sort.
 */
int writeout( const char *fn) {
	fio_code	s ;

	s = ffwopen( fn) ;	/* Open writes message. */
	if( s != FIOSUC)
		mloutstr( "Cannot open file for writing") ;
	else {
		line_p lp ;
		fio_code s2 ;
		int nline = 0 ;

		mloutstr( "(Writing...)") ; /* tell us we are writing */
		for( lp = lforw( curbp->b_linep) ; lp != curbp->b_linep ; lp = lforw( lp)) {
			s = ffputline( lp->l_text, llength( lp), curbp->b_mode & MDDOS) ;
			if( s != FIOSUC)
				break ;

			nline += 1 ;
		}

		s2 = ffclose() ;
		if( s != FIOSUC)
			mloutstr( "Write I/O error") ;
		else if( s2 != FIOSUC)
			mloutstr( "Error closing file") ;
		else {	/* Successfull write and close. */
			mloutfmt( "(Wrote %d line%s)", nline, &"s"[ nline == 1]) ;
			curbp->b_flag &= ~BFCHG ;
			upd_mode() ;
			return TRUE ;
		}
	}

	return FALSE ;
}

/*
 * The command allows the user
 * to modify the file name associated with
 * the current buffer. It is like the "f" command
 * in UNIX "ed". The operation is simple; just zap
 * the name in the buffer structure, and mark the windows
 * as needing an update. You can type a blank line at the
 * prompt if you wish.
 */
int filename( int f, int n) {
	int status ;
	char *fname ;

	if( restflag)		/* don't allow this command if restricted */
		return resterr() ;

	status = newmlarg( &fname, "Name: ", sizeof( fname_t)) ;
	if( status == ABORT)
		return status ;
	else if( status == FALSE)
		curbp->b_fname[ 0] = '\0' ;
	else { /* TRUE */
		mystrscpy( curbp->b_fname, fname, sizeof( fname_t)) ;
		free( fname) ;
	}

	curbp->b_mode &= ~MDVIEW ;	 /* no longer read only mode */
	upd_mode() ;
	return TRUE ;
}

/*
 * Insert file "fname" into the current
 * buffer, Called by insert file command. Return the final
 * status of the read.
 */
static int ifile( const char *fname) {
	fio_code	s ;

	curbp->b_flag |= BFCHG ;	/* we have changed		*/
	curbp->b_flag &= ~BFINVS ;	/* and are not temporary */
	s = ffropen( fname) ;
	if( s == FIOFNF) {	/* File not found.		*/
		mloutstr( "(No such file)") ;
		return FALSE ;
	}

	if( s == FIOSUC) {	/* Hard file open.		*/
		int nline = 0 ; /* number of line read */
		char *errmsg ;

		mloutstr( "(Inserting file)") ;

	/* back up a line and save the mark here */
		curwp->w_dotp = lback(curwp->w_dotp);
		curwp->w_doto = 0;
		curwp->w_markp = curwp->w_dotp;
		curwp->w_marko = 0;

		while( (s = ffgetline()) == FIOSUC) {
			line_p lpp, lp, lpn ;

			if( (lp = lalloc( fpayload)) == NULL) {
				s = FIOMEM ;	/* Keep message on the	*/
				break ; 		/* display. 			*/
			}

			memcpy( lp->l_text, fline, fpayload) ;
			lp->l_bp = lpp = curwp->w_dotp ;	/* insert after dot line */
			lp->l_fp = lpn = lpp->l_fp ;		/* line after insert */

		/* re-link new line between lpp and lpn */
			lpn->l_bp = lp ;
			lpp->l_fp = lp ;

		/* and advance and write out the current line */
			curwp->w_dotp = lp ;
			nline += 1 ;
		}

		ffclose() ; /* Ignore errors.		*/
		curwp->w_markp = lforw(curwp->w_markp);
		if( s == FIOERR) {
			errmsg = "I/O ERROR, " ;
			curbp->b_flag |= BFTRUNC ;
		} else if( s == FIOMEM) {
			errmsg = "OUT OF MEMORY, " ;
			curbp->b_flag |= BFTRUNC;
		} else
			errmsg = "" ;

		mloutfmt( "(%sInserted %d line%s)",
			errmsg,
			nline,
			&"s"[ nline == 1]) ;
	}

/* advance to the next line and mark the window for changes */
	curwp->w_dotp = lforw(curwp->w_dotp);
	curwp->w_flag |= WFHARD | WFMODE;

/* copy window parameters back to the buffer structure */
	curbp->b_dotp = curwp->w_dotp;
	curbp->b_doto = curwp->w_doto;
	curbp->b_markp = curwp->w_markp;
	curbp->b_marko = curwp->w_marko;

	return (s == FIOERR) ? FALSE : TRUE ;
}