** fossil source code base.  Nothing in this file depends on anything
** else in fossil.
*/
#include <stdio.h>
#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include "delta.h"

/*
** Macros for turning debugging printfs on and off
*/
#if 0
# define DEBUG1(X) X
#else

  zBuf[i] = 0;
  return zBuf;
}
#else
# define DEBUG2(X)
#endif

#if INTERFACE
/*
** The "u32" type must be an unsigned 32-bit integer.  Adjust this
*/
typedef unsigned int u32;

/*
** Must be a 16-bit value 
*/
typedef short int s16;
typedef unsigned short int u16;

#endif /* INTERFACE */

/*
** The width of a hash window in bytes.  The algorithm only works if this
** is a power of 2.
*/
#define NHASH 16

/*
** Copyright (c) 2010 D. Richard Hipp
**
** This program is free software; you can redistribute it and/or
** modify it under the terms of the GNU General Public
** License version 2 as published by the Free Software Foundation.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
** General Public License for more details.
** 
** You should have received a copy of the GNU General Public
** License along with this library; if not, write to the
** Free Software Foundation, Inc., 59 Temple Place - Suite 330,
** Boston, MA  02111-1307, USA.
**
** Author contact information:
**   drh@hwaci.com
**   http://www.hwaci.com/drh/
**
*******************************************************************************
**
** This file contains code to compute a revision history graph.
*/
#include "config.h"
#include "graph.h"
#include <assert.h>

#if INTERFACE

#define GR_MAX_PARENT 10
#define GR_MAX_RAIL   32

/* The graph appears vertically beside a timeline.  Each row in the
** timeline corresponds to a row in the graph.
*/
struct GraphRow {
  int rid;                    /* The rid for the check-in */
  int isLeaf;                 /* True if the check-in is an open leaf */
  int nParent;                /* Number of parents */
  int aParent[GR_MAX_PARENT]; /* Array of parents.  0 element is primary .*/
  char *zBranch;              /* Branch name */

  GraphRow *pNext;            /* Next row down in the list of all rows */
  GraphRow *pPrev;            /* Previous row */
  
  int idx;                    /* Row index.  First is 1.  0 used for "none" */
  int iRail;                  /* Which rail this check-in appears on. 0-based.*/
  int aiRaiser[GR_MAX_RAIL];  /* Raisers from this node to a higher row. */
  int bDescender;             /* Raiser from bottom of graph to here. */
  u32 mergeIn;                /* Merge in from other rails */
  int mergeOut;               /* Merge out to this rail */
  int mergeUpto;              /* Draw the merge rail up to this level */

  u32 railInUse;              /* Mask of occupied rails */
};

/* Context while building a graph
*/
struct GraphContext {
  int nErr;             /* Number of errors encountered */
  int mxRail;           /* Number of rails required to render the graph */
  GraphRow *pFirst;     /* First row in the list */
  GraphRow *pLast;      /* Last row in the list */
  int nBranch;          /* Number of distinct branches */
  char **azBranch;      /* Names of the branches */
  int railMap[GR_MAX_RAIL];  /* Rail order mapping */
};

#endif

/*
** Malloc for zeroed space.  Panic if unable to provide the
** requested space.
*/
void *safeMalloc(int nByte){
  void *p = malloc(nByte);
  if( p==0 ) fossil_panic("out of memory");
  memset(p, 0, nByte);
  return p;
}

/*
** Create and initialize a GraphContext
*/
GraphContext *graph_init(void){
  return (GraphContext*)safeMalloc( sizeof(GraphContext) );
}

/*
** Destroy a GraphContext;
*/
void graph_free(GraphContext *p){
  int i;
  GraphRow *pRow;
  while( p->pFirst ){
    pRow = p->pFirst;
    p->pFirst = pRow->pNext;
    free(pRow);
  }
  for(i=0; i<p->nBranch; i++) free(p->azBranch[i]);
  free(p->azBranch);
  free(p);
}

/*
** Return the canonical pointer for a given branch name.
** Multiple calls to this routine with equivalent strings
** will return the same pointer.
*/
static char *persistBranchName(GraphContext *p, const char *zBranch){
  int i;
  for(i=0; i<p->nBranch; i++){
    if( strcmp(zBranch, p->azBranch[i])==0 ) return p->azBranch[i];
  }
  p->nBranch++;
  p->azBranch = realloc(p->azBranch, sizeof(char*)*p->nBranch);
  if( p->azBranch==0 ) fossil_panic("out of memory");
  p->azBranch[p->nBranch-1] = mprintf("%s", zBranch);
  return p->azBranch[p->nBranch-1];
}

/*
** Add a new row t the graph context.  Rows are added from top to bottom.
*/
void graph_add_row(
  GraphContext *p,     /* The context to which the row is added */
  int rid,             /* RID for the check-in */
  int isLeaf,          /* True if the check-in is an leaf */
  int nParent,         /* Number of parents */
  int *aParent,        /* Array of parents */
  const char *zBranch  /* Branch for this check-in */
){
  GraphRow *pRow;

  if( p->nErr ) return;
  if( nParent>GR_MAX_PARENT ){ p->nErr++; return; }
  pRow = (GraphRow*)safeMalloc( sizeof(GraphRow) );
  pRow->rid = rid;
  pRow->isLeaf = isLeaf;
  pRow->nParent = nParent;
  pRow->zBranch = persistBranchName(p, zBranch);
  memcpy(pRow->aParent, aParent, sizeof(aParent[0])*nParent);
  if( p->pFirst==0 ){
    p->pFirst = pRow;
  }else{
    p->pLast->pNext = pRow;
  }
  p->pLast = pRow;
}

/*
** Return the index of a rail currently not in use for any row between
** top and bottom, inclusive.  
*/
static int findFreeRail(GraphContext *p, int top, int btm){
  u32 inUseMask = 0;
  GraphRow *pRow;
  int i;
  for(pRow=p->pFirst; pRow && pRow->idx<top; pRow=pRow->pNext){}
  while( pRow && pRow->idx<=btm ){
    inUseMask |= pRow->railInUse;
    pRow = pRow->pNext;
  }
  for(i=0; i<32; i++){
    if( (inUseMask & (1<<i))==0 ) return i;
  }
  p->nErr++;
  return 0;
}

/*
** Compute the complete graph
*/
void graph_finish(GraphContext *p){
  GraphRow *pRow, *pDesc;
  Bag allRids;
  int i;
  int nRow;
  u32 mask;

  if( p==0 || p->pFirst==0 || p->nErr ) return;

  /* Initialize all rows */
  bag_init(&allRids);
  nRow = 0;
  for(pRow=p->pFirst; pRow; pRow=pRow->pNext){
    if( pRow->pNext ) pRow->pNext->pPrev = pRow;
    pRow->idx = ++nRow;
    pRow->iRail = -1;
    pRow->mergeOut = -1;
    bag_insert(&allRids, pRow->rid);
  }
  p->mxRail = -1;

  /* Purge merge-parents that are out-of-graph
  */
  for(pRow=p->pFirst; pRow; pRow=pRow->pNext){
    for(i=1; i<pRow->nParent; i++){
      if( !bag_find(&allRids, pRow->aParent[i]) ){
        pRow->aParent[i] = pRow->aParent[--pRow->nParent];
        i--;
      }
    }
  }

  /* Identify rows where the primary parent is off screen.  Assign
  ** each to a rail and draw descenders to the bottom of the screen.
  */
  for(pRow=p->pFirst; pRow; pRow=pRow->pNext){
    if( pRow->nParent>0 && !bag_find(&allRids,pRow->aParent[0]) ){
      pRow->iRail = ++p->mxRail;
      pRow->bDescender = 1;
      mask = 1<<(pRow->iRail);
      for(pDesc=pRow; pDesc; pDesc=pDesc->pNext){
        pDesc->railInUse |= mask;
      }
    }
  }

  /* Assign rails to all rows that are still unassigned.
  ** The first primary child of a row goes on the same rail as
  ** that row.
  */
  for(pRow=p->pLast; pRow; pRow=pRow->pPrev){
    int parentRid;
    if( pRow->iRail>=0 ) continue;
    assert( pRow->nParent>0 );
    parentRid = pRow->aParent[0];
    assert( bag_find(&allRids, parentRid) );
    for(pDesc=pRow->pNext; pDesc && pDesc->rid!=parentRid; pDesc=pDesc->pNext){}
    assert( pDesc!=0 );
    if( pDesc->aiRaiser[pDesc->iRail]==0 && pDesc->zBranch==pRow->zBranch ){
      pRow->iRail = pDesc->iRail;
    }else{
      pRow->iRail = findFreeRail(p, 0, pDesc->idx);
    }
    pDesc->aiRaiser[pRow->iRail] = pRow->idx;
    mask = 1<<pRow->iRail;
    for(pDesc = pRow; ; pDesc=pDesc->pNext){
      assert( pDesc!=0 );
      pDesc->railInUse |= mask;
      if( pDesc->rid==parentRid ) break;
    }
  }

  /*
  ** Insert merge rails and merge arrows
  */
  for(pRow=p->pFirst; pRow; pRow=pRow->pNext){
    for(i=1; i<pRow->nParent; i++){
      int parentRid = pRow->aParent[i];
      for(pDesc=pRow->pNext; pDesc && pDesc->rid!=parentRid;
          pDesc=pDesc->pNext){}
      if( pDesc==0 ) continue;
      if( pDesc->mergeOut<0 ){
        pDesc->mergeOut = findFreeRail(p, pRow->idx, pDesc->idx);
        pDesc->mergeUpto = pRow->idx;
      }
      pRow->mergeIn |= 1<<pDesc->mergeOut;
    }
  }

  /*
  ** Sort the rail numbers
  */
#if 0
  p->mxRail = -1;
  mask = 0;
  for(pRow=p->pLast; pRow; pRow=pRow->pPrev){
    if( (mask & (1<<pRow->iRail))==0 ){
      p->railMap[pRow->iRail] = ++p->mxRail;
      mask |= 1<<pRow->iRail;
    }
    if( pRow->mergeOut>=0 && (mask & (1<<pRow->mergeOut))==0 ){
      p->railMap[pRow->mergeOut] = ++p->mxRail;
      mask |= 1<<pRow->mergeOut;
    }
  }
#else
  for(i=0; i<GR_MAX_RAIL; i++) p->railMap[i] = i;
  p->mxRail = 0;
  for(pRow=p->pFirst; pRow; pRow=pRow->pNext){
    if( pRow->iRail>p->mxRail ) p->mxRail = pRow->iRail;
    if( pRow->mergeOut>p->mxRail ) p->mxRail = pRow->mergeOut;
  }
#endif
}

  $(SRCDIR)/descendants.c \
  $(SRCDIR)/diff.c \
  $(SRCDIR)/diffcmd.c \
  $(SRCDIR)/doc.c \
  $(SRCDIR)/encode.c \
  $(SRCDIR)/file.c \
  $(SRCDIR)/finfo.c \
  $(SRCDIR)/graph.c \
  $(SRCDIR)/http.c \
  $(SRCDIR)/http_socket.c \
  $(SRCDIR)/http_transport.c \
  $(SRCDIR)/info.c \
  $(SRCDIR)/login.c \
  $(SRCDIR)/main.c \
  $(SRCDIR)/manifest.c \

  descendants_.c \
  diff_.c \
  diffcmd_.c \
  doc_.c \
  encode_.c \
  file_.c \
  finfo_.c \
  graph_.c \
  http_.c \
  http_socket_.c \
  http_transport_.c \
  info_.c \
  login_.c \
  main_.c \
  manifest_.c \

  descendants.o \
  diff.o \
  diffcmd.o \
  doc.o \
  encode.o \
  file.o \
  finfo.o \
  graph.o \
  http.o \
  http_socket.o \
  http_transport.o \
  info.o \
  login.o \
  main.o \
  manifest.o \

#
$(SRCDIR)/../manifest:	
	# noop

clean:	
	rm -f *.o *_.c $(APPNAME) VERSION.h
	rm -f translate makeheaders mkindex page_index.h headers
	rm -f add.h allrepo.h bag.h blob.h branch.h browse.h captcha.h cgi.h checkin.h checkout.h clearsign.h clone.h comformat.h configure.h construct.h content.h db.h delta.h deltacmd.h descendants.h diff.h diffcmd.h doc.h encode.h file.h finfo.h graph.h http.h http_socket.h http_transport.h info.h login.h main.h manifest.h md5.h merge.h merge3.h name.h pivot.h pqueue.h printf.h rebuild.h report.h rss.h rstats.h schema.h search.h setup.h sha1.h shun.h skins.h stat.h style.h sync.h tag.h th_main.h timeline.h tkt.h tktsetup.h undo.h update.h url.h user.h verify.h vfile.h wiki.h wikiformat.h winhttp.h xfer.h zip.h

page_index.h: $(TRANS_SRC) mkindex
	./mkindex $(TRANS_SRC) >$@
headers:	page_index.h makeheaders VERSION.h
	./makeheaders  add_.c:add.h allrepo_.c:allrepo.h bag_.c:bag.h blob_.c:blob.h branch_.c:branch.h browse_.c:browse.h captcha_.c:captcha.h cgi_.c:cgi.h checkin_.c:checkin.h checkout_.c:checkout.h clearsign_.c:clearsign.h clone_.c:clone.h comformat_.c:comformat.h configure_.c:configure.h construct_.c:construct.h content_.c:content.h db_.c:db.h delta_.c:delta.h deltacmd_.c:deltacmd.h descendants_.c:descendants.h diff_.c:diff.h diffcmd_.c:diffcmd.h doc_.c:doc.h encode_.c:encode.h file_.c:file.h finfo_.c:finfo.h graph_.c:graph.h http_.c:http.h http_socket_.c:http_socket.h http_transport_.c:http_transport.h info_.c:info.h login_.c:login.h main_.c:main.h manifest_.c:manifest.h md5_.c:md5.h merge_.c:merge.h merge3_.c:merge3.h name_.c:name.h pivot_.c:pivot.h pqueue_.c:pqueue.h printf_.c:printf.h rebuild_.c:rebuild.h report_.c:report.h rss_.c:rss.h rstats_.c:rstats.h schema_.c:schema.h search_.c:search.h setup_.c:setup.h sha1_.c:sha1.h shun_.c:shun.h skins_.c:skins.h stat_.c:stat.h style_.c:style.h sync_.c:sync.h tag_.c:tag.h th_main_.c:th_main.h timeline_.c:timeline.h tkt_.c:tkt.h tktsetup_.c:tktsetup.h undo_.c:undo.h update_.c:update.h url_.c:url.h user_.c:user.h verify_.c:verify.h vfile_.c:vfile.h wiki_.c:wiki.h wikiformat_.c:wikiformat.h winhttp_.c:winhttp.h xfer_.c:xfer.h zip_.c:zip.h $(SRCDIR)/sqlite3.h $(SRCDIR)/th.h VERSION.h
	touch headers
headers: Makefile
Makefile:
add_.c:	$(SRCDIR)/add.c translate
	./translate $(SRCDIR)/add.c >add_.c

add.o:	add_.c add.h  $(SRCDIR)/config.h

finfo_.c:	$(SRCDIR)/finfo.c translate
	./translate $(SRCDIR)/finfo.c >finfo_.c

finfo.o:	finfo_.c finfo.h  $(SRCDIR)/config.h
	$(XTCC) -o finfo.o -c finfo_.c

finfo.h:	headers
graph_.c:	$(SRCDIR)/graph.c translate
	./translate $(SRCDIR)/graph.c >graph_.c

graph.o:	graph_.c graph.h  $(SRCDIR)/config.h
	$(XTCC) -o graph.o -c graph_.c

graph.h:	headers
http_.c:	$(SRCDIR)/http.c translate
	./translate $(SRCDIR)/http.c >http_.c

http.o:	http_.c http.h  $(SRCDIR)/config.h
	$(XTCC) -o http.o -c http_.c

http.h:	headers

  descendants
  diff
  diffcmd
  doc
  encode
  file
  finfo
  graph
  http
  http_socket
  http_transport
  info
  login
  main
  manifest

/*
** Allowed flags for the tmFlags argument to www_print_timeline
*/
#if INTERFACE
#define TIMELINE_ARTID    0x0001  /* Show artifact IDs on non-check-in lines */
#define TIMELINE_LEAFONLY 0x0002  /* Show "Leaf", but not "Merge", "Fork" etc */
#define TIMELINE_BRIEF    0x0004  /* Combine adjacent elements of same object */
#define TIMELINE_GRAPH    0x0008  /* Compute a graph */
#endif

/*
** Output a timeline in the web format given a query.  The query
** should return these columns:
**
**    0.  rid

){
  int wikiFlags;
  int mxWikiLen;
  Blob comment;
  int prevTagid = 0;
  int suppressCnt = 0;
  char zPrevDate[20];
  GraphContext *pGraph = 0;

  zPrevDate[0] = 0;
  mxWikiLen = db_get_int("timeline-max-comment", 0);
  if( db_get_boolean("timeline-block-markup", 0) ){
    wikiFlags = WIKI_INLINE;
  }else{
    wikiFlags = WIKI_INLINE | WIKI_NOBLOCK;
  }
  if( tmFlags & TIMELINE_GRAPH ){
    pGraph = graph_init();
    @ <div id="canvas" style="position:relative;width:1px;height:1px;"></div>
  }

  db_multi_exec(
     "CREATE TEMP TABLE IF NOT EXISTS seen(rid INTEGER PRIMARY KEY);"
     "DELETE FROM seen;"
  );
  @ <table cellspacing=0 border=0 cellpadding=0>
  blob_zero(&comment);
  while( db_step(pQuery)==SQLITE_ROW ){
    int rid = db_column_int(pQuery, 0);
    const char *zUuid = db_column_text(pQuery, 1);
    int nPChild = db_column_int(pQuery, 5);
    int nParent = db_column_int(pQuery, 6);
    int isLeaf = db_column_int(pQuery, 7);
    const char *zBgClr = db_column_text(pQuery, 8);
    const char *zDate = db_column_text(pQuery, 2);
    const char *zType = db_column_text(pQuery, 9);
    const char *zUser = db_column_text(pQuery, 4);
    const char *zTagList = db_column_text(pQuery, 10);
    int tagid = db_column_int(pQuery, 11);
    int commentColumn = 3;    /* Column containing comment text */
    char zTime[8];
    if( tagid ){
      if( tagid==prevTagid ){
        if( tmFlags & TIMELINE_BRIEF ){
          suppressCnt++;
          continue;
        }else{
          commentColumn = 12;

    if( strcmp(zType,"div")==0 ){
      @ <tr><td colspan=3><hr></td></tr>
      continue;
    }
    db_multi_exec("INSERT OR IGNORE INTO seen VALUES(%d)", rid);
    if( memcmp(zDate, zPrevDate, 10) ){
      sprintf(zPrevDate, "%.10s", zDate);
      @ <tr><td>
      @   <div class="divider"><nobr>%s(zPrevDate)</nobr></div>
      @ </td></tr>
    }
    memcpy(zTime, &zDate[11], 5);
    zTime[5] = 0;
    @ <tr>
    @ <td valign="top" align="right">%s(zTime)</td>
    @ <td width="20" align="center" valign="top">
    @ <div id="m%d(rid)"></div>
    if( zBgClr && zBgClr[0] ){
      @ <td valign="top" align="left" bgcolor="%h(zBgClr)">
    }else{
      @ <td valign="top" align="left">
    }
    if( zType[0]=='c' ){
      const char *azTag[5];
      int nTag = 0;
      hyperlink_to_uuid(zUuid);
      if( (tmFlags & TIMELINE_LEAFONLY)==0 ){
        if( nParent>1 ){
          azTag[nTag++] = "Merge";
        }
        if( nPChild>1 ){
          if( count_nonbranch_children(rid)>1 ){
            azTag[nTag++] = "Fork";

      }
      if( nTag>0 ){
        int i;
        for(i=0; i<nTag; i++){
          @ <b>%s(azTag[i])%s(i==nTag-1?"":",")</b>
        }
      }
      if( pGraph ){
        int nParent = 0;
        int aParent[32];
        const char *zBr;
        static Stmt qparent;
        static Stmt qbranch;
        db_static_prepare(&qparent,
          "SELECT pid FROM plink WHERE cid=:rid ORDER BY isprim DESC"
        );
        db_static_prepare(&qbranch,
          "SELECT value FROM tagxref WHERE tagid=%d AND tagtype>0 AND rid=:rid",
          TAG_BRANCH
        );
        db_bind_int(&qparent, ":rid", rid);
        while( db_step(&qparent)==SQLITE_ROW && nParent<32 ){
          aParent[nParent++] = db_column_int(&qparent, 0);
        }
        db_reset(&qparent);
        db_bind_int(&qbranch, ":rid", rid);
        if( db_step(&qbranch)==SQLITE_ROW ){
          zBr = db_column_text(&qbranch, 0);
        }else{
          zBr = "trunk";
        }
        graph_add_row(pGraph, rid, isLeaf, nParent, aParent, zBr);
        db_reset(&qbranch);
      }
    }else if( (tmFlags & TIMELINE_ARTID)!=0 ){
      hyperlink_to_uuid(zUuid);
    }
    db_column_blob(pQuery, commentColumn, &comment);
    if( mxWikiLen>0 && blob_size(&comment)>mxWikiLen ){
      Blob truncated;
      blob_zero(&truncated);

    @ </td></tr>
  }
  if( suppressCnt ){
    @ <tr><td><td><td>
    @ <small><i>... %d(suppressCnt) similar
    @ event%s(suppressCnt>1?"s":"") omitted.</i></small></tr>
    suppressCnt = 0;
  }
  if( pGraph ){
    graph_finish(pGraph);
    if( pGraph->nErr ){
      graph_free(pGraph);
      pGraph = 0;
    }else{
      @ <tr><td><td><div style="width:%d(pGraph->mxRail*20+30)px;"></div>
    }
  }
  @ </table>
  if( pGraph && pGraph->nErr==0 ){
    GraphRow *pRow;
    int i;
    char cSep;
    @ <script type="text/JavaScript">
    cgi_printf("var rowinfo = [\n");
    for(pRow=pGraph->pFirst; pRow; pRow=pRow->pNext){
      cgi_printf("{id:\"m%d\",r:%d,d:%d,mo:%d,mu:%d,u:%d,au:",
        pRow->rid,
        pRow->iRail,
        pRow->bDescender,
        pRow->mergeOut,
        pRow->mergeUpto,
        pRow->aiRaiser[pRow->iRail]
      );
      cSep = '[';
      for(i=0; i<GR_MAX_RAIL; i++){
        if( i==pRow->iRail ) continue;
        if( pRow->aiRaiser[i]>0 ){
          cgi_printf("%c%d,%d", cSep, pGraph->railMap[i], pRow->aiRaiser[i]);
          cSep = ',';
        }
      }
      if( cSep=='[' ) cgi_printf("[");
      cgi_printf("],mi:");
      cSep = '[';
      for(i=0; i<GR_MAX_RAIL; i++){
        if( pRow->mergeIn & (1<<i) ){
          cgi_printf("%c%d", cSep, pGraph->railMap[i]);
          cSep = ',';
        }
      }
      if( cSep=='[' ) cgi_printf("[");
      cgi_printf("]}%s", pRow->pNext ? ",\n" : "];\n");
    }
    cgi_printf("var nrail = %d\n", pGraph->mxRail+1);
    graph_free(pGraph);
    @ var canvasDiv = document.getElementById("canvas");
    @ function drawBox(color,x0,y0,x1,y1){
    @   var n = document.createElement("div");
    @   if( x0>x1 ){ var t=x0; x0=x1; x1=t; }
    @   if( y0>y1 ){ var t=y0; y0=y1; y1=t; }
    @   var w = x1-x0+1;
    @   var h = y1-y0+1;
    @   n.setAttribute("style",
    @     "position:absolute;"+
    @     "left:"+x0+"px;"+
    @     "top:"+y0+"px;"+
    @     "width:"+w+"px;"+
    @     "height:"+h+"px;"+
    @     "background-color:"+color+";"
    @   );
    @   canvasDiv.appendChild(n);
    @ }
    @ function absoluteY(id){
    @   var obj = document.getElementById(id);
    @   if( !obj ) return;
    @   var top = 0;
    @   if( obj.offsetParent ){
    @     do{
    @       top += obj.offsetTop;
    @     }while( obj = obj.offsetParent );
    @   }
    @   return top;
    @ }
    @ function absoluteX(id){
    @   var obj = document.getElementById(id);
    @   if( !obj ) return;
    @   var left = 0;
    @   if( obj.offsetParent ){
    @     do{
    @       left += obj.offsetLeft;
    @     }while( obj = obj.offsetParent );
    @   }
    @   return left;
    @ }
    @ function drawUpArrow(x,y0,y1){
    @   drawBox("black",x,y0,x+1,y1);
    @   if( y0+8>=y1 ){
    @     drawBox("black",x-1,y0+1,x+2,y0+2);
    @     drawBox("black",x-2,y0+3,x+3,y0+4);
    @   }else{
    @     drawBox("black",x-1,y0+2,x+2,y0+4);
    @     drawBox("black",x-2,y0+5,x+3,y0+7);
    @   }
    @ }
    @ function drawThinArrow(y,xFrom,xTo){
    @   if( xFrom<xTo ){
    @     drawBox("black",xFrom,y,xTo,y);
    @     drawBox("black",xTo-4,y-1,xTo-2,y+1);
    @     if( xTo>xFrom-8 ) drawBox("black",xTo-6,y-2,xTo-5,y+2);
    @   }else{
    @     drawBox("black",xTo,y,xFrom,y);
    @     drawBox("black",xTo+2,y-1,xTo+4,y+1);
    @     if( xTo+8<xFrom ) drawBox("black",xTo+5,y-2,xTo+6,y+2);
    @   }
    @ }
    @ function drawThinLine(x0,y0,x1,y1){
    @   drawBox("black",x0,y0,x1,y1);
    @ }
    @ function drawNode(p, left, btm){
    @   drawBox("black",p.x-5,p.y-5,p.x+6,p.y+6);
    @   drawBox("white",p.x-4,p.y-4,p.x+5,p.y+5);
    @   if( p.u>0 ){
    @     var u = rowinfo[p.u-1];
    @     drawUpArrow(p.x, u.y+6, p.y-5);
    @   }
    @   if( p.d ){
    @     drawUpArrow(p.x, p.y+6, btm);
    @   } 
    @   if( p.mo>=0 ){
    @     var x1 = p.mo*20 + left;
    @     var y1 = p.y-3;
    @     var x0 = x1>p.x ? p.x+7 : p.x-6;
    @     var u = rowinfo[p.mu-1];
    @     var y0 = u.y+5;
    @     drawThinLine(x0,y1,x1,y1);
    @     drawThinLine(x1,y0,x1,y1);
    @   }
    @   var n = p.au.length;
    @   for(var i=0; i<n; i+=2){
    @     var x1 = p.au[i]*20 + left;
    @     var x0 = x1>p.x ? p.x+7 : p.x-6;
    @     drawBox("black",x0,p.y,x1,p.y+1);
    @     var u = rowinfo[p.au[i+1]-1];
    @     drawUpArrow(x1, u.y+6, p.y);
    @   }
    @   for(var j in p.mi){
    @     var y0 = p.y+5;
    @     var mx = p.mi[j]*20 + left;
    @     if( mx>p.x ){
    @       drawThinArrow(y0,mx,p.x+5);
    @     }else{
    @       drawThinArrow(y0,mx,p.x-5);
    @     }
    @   }
    @ }
    @ function renderGraph(){
    @   var canvasY = absoluteY("canvas");
    @   var left = absoluteX(rowinfo[0].id) - absoluteX("canvas") + 15;
    @   for(var i in rowinfo){
    @     rowinfo[i].y = absoluteY(rowinfo[i].id) + 10 - canvasY;
    @     rowinfo[i].x = left + rowinfo[i].r*20;
    @   }
    @   var btm = rowinfo[rowinfo.length-1].y + 20;
    @   for(var i in rowinfo){
    @     drawNode(rowinfo[i], left, btm);
    @   }
    @ }
    @ renderGraph();
    @ </script>
  }
}

/*
** Create a temporary table suitable for storing timeline data.
*/
static void timeline_temp_table(void){
  static const char zSql[] = 

  if( !g.okRead && !g.okRdTkt && !g.okRdWiki ){ login_needed(); return; }
  if( zTagName && g.okRead ){
    tagid = db_int(0, "SELECT tagid FROM tag WHERE tagname='sym-%q'", zTagName);
  }else{
    tagid = 0;
  }
  if( zType[0]=='a' ){
    tmFlags = TIMELINE_BRIEF | TIMELINE_GRAPH;
  }else{
    tmFlags = TIMELINE_GRAPH;
  }

  style_header("Timeline");
  login_anonymous_available();
  timeline_temp_table();
  blob_zero(&sql);
  blob_zero(&desc);

      blob_appendf(&desc, "%d %ss", n, zEType);
    }
    if( zUser ){
      blob_appendf(&desc, " by user %h", zUser);
    }
    if( tagid>0 ){
      blob_appendf(&desc, " tagged with \"%h\"", zTagName);
      tmFlags &= ~TIMELINE_GRAPH;
    }
    if( zAfter ){
      blob_appendf(&desc, " occurring on or after %h.<br>", zAfter);
    }else if( zBefore ){
      blob_appendf(&desc, " occurring on or before %h.<br>", zBefore);
    }else if( zCirca ){
      blob_appendf(&desc, " occurring around %h.<br>", zCirca);

  }
  blob_zero(&sql);
  db_prepare(&q, "SELECT * FROM timeline ORDER BY timestamp DESC");
  @ <h2>%b(&desc)</h2>
  blob_reset(&desc);
  www_print_timeline(&q, tmFlags, 0);
  db_finalize(&q);





























































































  style_footer();
}

/*
** The input query q selects various records.  Print a human-readable
** summary of those records.
**