/*  Part of XPCE --- The SWI-Prolog GUI toolkit

    Author:        Jan Wielemaker and Anjo Anjewierden
    E-mail:        jan@swi.psy.uva.nl
    WWW:           http://www.swi.psy.uva.nl/projects/xpce/
    Copyright (c)  1985-2002, University of Amsterdam
    All rights reserved.

    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions
    are met:

    1. Redistributions of source code must retain the above copyright
       notice, this list of conditions and the following disclaimer.

    2. Redistributions in binary form must reproduce the above copyright
       notice, this list of conditions and the following disclaimer in
       the documentation and/or other materials provided with the
       distribution.

    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
    FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
    COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
    INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
    BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
    LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
    CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
    ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
    POSSIBILITY OF SUCH DAMAGE.
*/

#include <h/kernel.h>
#include <h/text.h>
#include <h/unix.h>

#define O_STATISTICS 0			/* statistics functions */

static int	unlink_fragment(Fragment);
static int	link_fragment(Fragment);
static status	normaliseFragment(Fragment f);

#define normalize_tb(tb, index) \
	(index < 0        ? 0 : \
         index > tb->size ? tb->size \
	   		  : index)


static status
initialiseFragment(Fragment f, TextBuffer tb, Int s, Int l, Name style)
{ assign(f, textbuffer, tb);
  assign(f, style, style);

  f->start      = valInt(s);
  f->length     = valInt(l);
  f->attributes = 0L;

  normaliseFragment(f);
  link_fragment(f);
  ChangedFragmentListTextBuffer(f->textbuffer);
  ChangedRegionTextBuffer(f->textbuffer,
			  toInt(f->start), toInt(f->start + f->length));

  succeed;
}

static status
unlinkFragment(Fragment f)
{ if ( notNil(f->textbuffer) )
  { unlink_fragment(f);
    ChangedFragmentListTextBuffer(f->textbuffer);
    ChangedRegionTextBuffer(f->textbuffer,
			    toInt(f->start), toInt(f->start + f->length));
    assign(f, textbuffer, NIL);
  }

  succeed;
}


static status
storeFragment(Fragment f, FileObj file)
{ if ( !storeSlotsObject(f, file) ||
       !storeWordFile(file, (Any) f->start) ||
       !storeWordFile(file, (Any) f->length) )
    fail;

  succeed;
}


static status
loadFragment(Fragment f, IOSTREAM *fd, ClassDef def)
{ TRY(loadSlotsObject(f, fd, def));
  if ( restoreVersion >= 10 )
  { f->start  = loadWord(fd);
    f->length = loadWord(fd);
  }

  succeed;
}


static status
convertOldSlotFragment(Fragment f, Name name, Any value)
{ if ( restoreVersion < 10 )
  { if ( name == NAME_start )
    { f->start = valInt(value);
      succeed;
    } else if ( name == NAME_length )
    { f->length = valInt(value);
      succeed;
    }
  }

  fail;
}


		/********************************
		*        LINK/UNLINK/PLACE      *
		*********************************/

/*  Unlink the fragment from the double linked chain in of fragments of the
    textbuffer.
*/

static int
unlink_fragment(Fragment f)
{ Fragment next = f->next;

  if ( notNil(f->next) )
  { assign(f->next, prev, f->prev);
    assign(f, next, NIL);
  } else
    assign(f->textbuffer, last_fragment, f->prev);

  if ( notNil(f->prev) )
  { assign(f->prev, next, next);
    assign(f, prev, NIL);
  } else
    assign(f->textbuffer, first_fragment, next);

  succeed;
}


/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Link a fragment in the double-linked fragment list.  Fragments are ordered
to their start-index to speedup repaint management.  If the start index is
equal, the largest fragment is first to ensure optimal `nesting'.
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

#if O_STATISTICS
static int mis;

static status
dumpMisFragment(Fragment f)
{ Cprintf("mis = %d\n", mis);

  succeed;
}

#endif

static int
link_fragment(Fragment f)
{ Fragment b;
  TextBuffer tb = f->textbuffer;

  if ( notNil(b = tb->first_fragment) )
  { if ( f->start > tb->last_fragment->start )
    { b = tb->last_fragment;		/* at the end  */
      assign(b, next, f);
      assign(f, prev, b);
      assign(tb, last_fragment, f);

      succeed;
    }

    if ( f->start < b->start )
    { assign(f, next, b);		/* at the start */
      assign(b, prev, f);
      assign(tb, first_fragment, f);

      succeed;
    }

    if ( (tb->last_fragment->start - f->start) < (f->start - b->start) )
    { b = tb->last_fragment;

      for( ; notNil(b); b = b->prev )
      { if ( b->start > f->start ||
	     (b->start == f->start && b->length < f->length) )
	{
#if O_STATISTICS
	  mis++;
#endif
	  continue;			/* f must be before b */
	}

	assign(f, next, b->next);
	assign(f, prev, b);
	if ( notNil(b->next) )
	{ assign(b, next, f);
	  assign(f->next, prev, f);
	} else
	{ assign(tb, last_fragment, f);
	  assign(b, next, f);
	}

	succeed;
      }

      b = tb->first_fragment;
      assign(f, next, b);		/* at the start */
      assign(b, prev, f);
      assign(tb, first_fragment, f);
    } else
    { for( ; notNil(b->next); b = b->next)
      { if ( b->next->start < f->start ||
	     (b->next->start == f->start && b->next->length > f->length) )
	{
#if O_STATISTICS
	  mis++;
#endif
	  continue;
	}

	assign(f, next, b->next);	/* somewere in the middle */
	assign(f, prev, b);
	assign(b, next, f);
	assign(f->next, prev, f);

	succeed;
      }

      assign(b, next, f);		/* at the end (should not happen) */
      assign(f, prev, b);
      assign(tb, last_fragment, f);
    }


    succeed;
  }

  assign(tb, first_fragment, f);	/* the only one */
  assign(tb, last_fragment, f);

  succeed;
}


static status
relink_fragment(Fragment f)
{ if ( (notNil(f->prev) && f->prev->start > f->start) ||
       (notNil(f->next) && f->next->start < f->start) )
  { addCodeReference(f);		/* should not drop out! */
    unlink_fragment(f);
    link_fragment(f);
    ChangedFragmentListTextBuffer(f->textbuffer);
    delCodeReference(f);
  }

  succeed;
}

		/********************************
		*         NORMALISATION         *
		*********************************/

static status
normaliseFragment(Fragment f)
{ TextBuffer tb = f->textbuffer;

  f->start = normalize_tb(tb, f->start);
  f->length = normalize_tb(tb, f->start + f->length) - f->start;

  succeed;
}

		 /*******************************
		 *	    ATTRIBUTES		*
		 *******************************/

static status
includeFragment(Fragment f, Name what, BoolObj val)
{ long mask;

  if ( what == NAME_start )
    mask = FRAG_INCLUDES_START;
  else if ( what == NAME_end )
    mask = FRAG_INCLUDES_END;
  else
    mask = FRAG_INCLUDES_START|FRAG_INCLUDES_END;

  if ( val == OFF )
    f->attributes &= ~mask;
  else
    f->attributes |= mask;

  succeed;
}


static status
doesIncludeFragment(Fragment f, Name what)
{ int rval;

  if ( what == NAME_start )
    rval = (f->attributes & FRAG_INCLUDES_START);
  else
    rval = (f->attributes & FRAG_INCLUDES_END);

  return rval ? SUCCEED : FAIL;
}


		/********************************
		*             METHODS           *
		*********************************/

#if 0					/* better? */
static status
setFragment(Fragment f, Int start, Int length)
{ if ( valInt(start) != f->start || valInt(length) != f->length )
  { int os = f->start;
    int ol = f->length;

    f->start  = valInt(start);
    f->length = valInt(length);
    normaliseFragment(f);
    ChangedRegionTextBuffer(f->textbuffer,
			    min(os, f->start),
			    max(os+ol, f->start + f->length));
  }

  succeed;
}
#endif

static status
startFragment(Fragment f, Int start, BoolObj moveend)
{ if ( valInt(start) != f->start )
  { int oldstart = f->start;
    int chend;

    f->start = valInt(start);

    if ( moveend == OFF )
    { f->length -= f->start - oldstart;
      chend = f->start;
    } else
      chend = f->start + f->length;

    normaliseFragment(f);
    relink_fragment(f);
    ChangedRegionTextBuffer(f->textbuffer, toInt(oldstart), toInt(chend));
  }

  succeed;
}


static status
lengthFragment(Fragment f, Int length)
{ if ( valInt(length) != f->length )
  { int oldl = f->length;

    f->length = valInt(length);
    normaliseFragment(f);
    ChangedRegionTextBuffer(f->textbuffer,
			    toInt(f->start + oldl),
			    toInt(f->start + f->length));
  }

  succeed;
}


static status
endFragment(Fragment f, Int end)
{ Int len = toInt(valInt(end) - f->start);

  return lengthFragment(f, len);
}


static Int
getStartFragment(Fragment f)
{ answer(toInt(f->start));
}


static Int
getLengthFragment(Fragment f)
{ answer(toInt(f->length));
}


static Int
getEndFragment(Fragment f)
{ answer(toInt(f->start + f->length));
}


static Fragment
getNextFragment(Fragment f, Code cond)
{ Fragment n = f->next;

  if ( notDefault(cond) )
  { while(notNil(n) && !forwardCodev(cond, 1, (Any *)&n))
      n = n->next;
  }

  if ( notNil(n) )
    answer(n);
  fail;
}


static Fragment
getPreviousFragment(Fragment f, Code cond)
{ Fragment n = f->prev;

  if ( notDefault(cond) )
  { while(notNil(n) && !forwardCodev(cond, 1, (Any *)&n))
      n = n->prev;
  }

  if ( notNil(n) )
    answer(n);
  fail;
}


static status
styleFragment(Fragment f, Name s)
{ if ( s != f->style )
  { assign(f, style, s);

    ChangedRegionTextBuffer(f->textbuffer,
			    toInt(f->start),
			    toInt(f->start + f->length));
  }

  succeed;
}


static status
overlapFragment(Fragment f, Any obj)
{
#define OVERLAPS(f, i) ( (i) >= f->start && (i) < f->start + f->length )

  if ( isInteger(obj) )
  { if ( OVERLAPS(f, valInt(obj)) )
      succeed;
  } else if ( instanceOfObject(obj, ClassFragment) )
  { Fragment f2 = obj;

    if ( max(f->start, f2->start) <
	 min(f->start + f->length, f2->start + f2->length) )
      succeed;
  } else /* if ( instanceOfObject(obj, ClassPoint) ) */
  { Point p = obj;
    int x = valInt(p->x);
    int y = valInt(p->y);

    if ( max(f->start, x) < min(f->start + f->length, y) )
      succeed;
  }

  fail;
}



static StringObj
getStringFragment(Fragment f)
{ int len = f->length;
  int i = f->start;
  TextBuffer tb = f->textbuffer;
  string s;

  str_sub_text_buffer(tb, &s, i, len);
  answer(StringToString(&s));
}


static StringObj
getSubFragment(Fragment f, Int start, Int end)
{ int x = valInt(start), y;
  TextBuffer tb = f->textbuffer;
  int i, len;
  string s;

  y = (isDefault(end) ? f->length : valInt(end));
  if ( x < 0 || y > f->length || x > y )
    fail;

  i = f->start + x;
  len = y - x;
  str_sub_text_buffer(tb, &s, i, len);
  answer(StringToString(&s));
}


static status
stringFragment(Fragment f, CharArray ca)
{ TextBuffer tb = f->textbuffer;
  int start = f->start;
  int len = f->length;
  int calen = ca->data.s_size;

  insertTextBuffer(tb, toInt(start), ca, ONE);
  startFragment(f, toInt(start), OFF);		/* TBD */
  lengthFragment(f, toInt(calen));
  deleteTextBuffer(tb, toInt(start + calen), toInt(len));

  succeed;
}


static status
insertFragment(Fragment f, Int idx, CharArray txt)
{ int where = (isDefault(idx) ? f->length : valInt(idx));
  int l = f->length;
  int start = f->start;

  if ( where < 0 )
    where = 0;
  else if ( where > l )
    where = l;

  insertTextBuffer(f->textbuffer, toInt(start + where), txt, ONE);
  f->start = start;			/* moves otherwise! */
  f->length = l + valInt(getSizeCharArray(txt));

  succeed;
}


static status
deleteFragment(Fragment f, Int from, Int len)
{ int s = valInt(from);
  int size = f->length;
  int e = (isDefault(len) ? size : valInt(len)) + s - 1;
  int d;

  if ( s <  0    ) s = 0;
  if ( s >= size ) succeed;
  if ( e <  s    ) succeed;
  if ( e >= size )
    e = size - 1;
  d = e - s + 1;

  deleteTextBuffer(f->textbuffer, toInt(s + f->start), toInt(d));
  f->length = size - d;

  succeed;
}

		 /*******************************
		 *	       VISUAL		*
		 *******************************/

static Any
getContainedInFragment(Fragment f)
{ TextBuffer tb = f->textbuffer;

  if ( tb && notNil(tb) &&
       notNil(tb->editors) &&
       !emptyChain(tb->editors) )
    answer(getHeadChain(tb->editors));

  fail;
}


		 /*******************************
		 *	 CLASS DECLARATION	*
		 *******************************/

/* Type declarations */

static char *T_insert[] =
        { "[int]", "char_array" };
static char *T_delete[] =
        { "from=int", "length=[int]" };
static char *T_start[] =
        { "int", "move_end=[bool]" };
static char *T_convertOldSlot[] =
        { "name", "any" };
static char *T_sub[] =
        { "start=int", "end=[int]" };
static char *T_initialise[] =
        { "text=text_buffer", "start=int", "length=int", "style=[name]" };
static char *T_include[] =
        { "what=[{start,end,both}]", "include=[bool]" };

/* Instance Variables */

static vardecl var_fragment[] =
{ IV(NAME_textBuffer, "text_buffer", IV_GET,
     NAME_whole, "Text_buffer I'm a range of"),
  IV(NAME_next, "fragment*", IV_NONE,
     NAME_list, "Next in double-linked chain"),
  IV(NAME_previous, "fragment*", IV_NONE,
     NAME_list, "Previous in double-linked chain"),
  SV(NAME_style, "[name]", IV_GET|IV_STORE, styleFragment,
     NAME_appearance, "Visual feedback: name of style in editor"),
  IV(NAME_start, "alien:long", IV_NONE,
     NAME_dimension, "Start index (0-based)"),
  IV(NAME_length, "alien:long", IV_NONE,
     NAME_dimension, "Length in characters"),
  IV(NAME_attributes, "alien:long", IV_NONE,
     NAME_internal, "Various packed attributes")
};

/* Send Methods */

static senddecl send_fragment[] =
{ SM(NAME_initialise, 4, T_initialise, initialiseFragment,
     DEFAULT, "Create from text_buffer, start, length, style"),
  SM(NAME_unlink, 0, NULL, unlinkFragment,
     DEFAULT, "Unlink from the text_buffer"),
  SM(NAME_overlap, 1, "int|fragment|point", overlapFragment,
     NAME_compare, "Test if overlap with argument"),
  SM(NAME_convertOldSlot, 2, T_convertOldSlot, convertOldSlotFragment,
     NAME_compatibility, "Convert start and length slots"),
  SM(NAME_delete, 2, T_delete, deleteFragment,
     NAME_contents, "Delete range of characters"),
  SM(NAME_insert, 2, T_insert, insertFragment,
     NAME_contents, "Insert text at location [append]"),
  SM(NAME_string, 1, "char_array", stringFragment,
     NAME_contents, "Replace text by argument"),
  SM(NAME_end, 1, "int", endFragment,
     NAME_dimension, "End (changes <-length)"),
  SM(NAME_length, 1, "int", lengthFragment,
     NAME_dimension, "Length in characters"),
  SM(NAME_start, 2, T_start, startFragment,
     NAME_dimension, "Start index (0-based)"),
#if O_STATISTICS
  SM(NAME_dumpMap, 0, NULL, dumpMisFragment,
     NAME_internal, "Debugging: dump `mis' info"),
#endif
  SM(NAME_doesInclude, 1, "what={start,end}", doesIncludeFragment,
     NAME_update, "Test whether start or end is included"),
  SM(NAME_include, 2, T_include, includeFragment,
     NAME_update, "Define whether start and end are included"),
  SM(NAME_emptied, 0, NULL, succeedObject,
     NAME_virtual, "Called if text is killed/deleted")
};

/* Get Methods */

static getdecl get_fragment[] =
{ GM(NAME_containedIn, 0, "editor", NULL, getContainedInFragment,
     DEFAULT, "editor object I'm contained in"),
  GM(NAME_string, 0, "string", NULL, getStringFragment,
     NAME_contents, "New string with contents"),
  GM(NAME_sub, 2, "string", T_sub, getSubFragment,
     NAME_contents, "New string with contents in range"),
  GM(NAME_end, 0, "int", NULL, getEndFragment,
     NAME_dimension, "End (<-start + <-length) of fragment"),
  GM(NAME_length, 0, "int", NULL, getLengthFragment,
     NAME_dimension, "Length in characters"),
  GM(NAME_start, 0, "int", NULL, getStartFragment,
     NAME_dimension, "Start index (0-based)"),
  GM(NAME_next, 1, "fragment", "condition=[code]", getNextFragment,
     NAME_list, "Next in list for which condition is true"),
  GM(NAME_previous, 1, "fragment", "condition=[code]", getPreviousFragment,
     NAME_list, "Previous in list for which condition is true")
};

/* Resources */

#define rc_fragment NULL
/*
static classvardecl rc_fragment[] =
{
};
*/

/* Class Declaration */

static Name fragment_termnames[] = { NAME_textBuffer, NAME_start, NAME_length, NAME_style };

ClassDecl(fragment_decls,
          var_fragment, send_fragment, get_fragment, rc_fragment,
          4, fragment_termnames,
          "$Rev$");

status
makeClassFragment(Class class)
{ declareClass(class, &fragment_decls);
  setLoadStoreFunctionClass(class, loadFragment, storeFragment);

  succeed;
}