#!/usr/bin/perl

#
#  Copyright 2011-2012 Thomas A. Alspaugh.
#
#  This work is licensed under the
#  Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.
#  To view a copy of this license, visit
#  http://creativecommons.org/licenses/by-nc-sa/3.0/
#  or send a letter to Creative Commons, 444 Castro Street, Suite 900,
#  Mountain View, California, 94041, USA.
#
#  Attribution requirements for this file are listed at
#  http://www.thomasalspaugh.org/pub/attribution-by-nc-sa.html
#

#  Timestamp 2013Jul10We14:29


use strict;  use warnings;


my $cmdName = $0;
$cmdName =~ s/^.*\///;

sub help {
  print <<HEREDOCUMENT
$cmdName -- produce ringing charts using a restricted place notation.
Bells change position only by changing places with a bell in an adjacent
position.  For example, the bell in 2nds may change places with the bell
in 1sts (in leads) or in 3rds, but no other bell.
In place notation, a change from one sequence of bells to another
is defined by listing the bells that _don't_ change position.  If each
successive pair of bells change position, this is denoted with 'x'
presumably for "exchange".  Run $cmdName -x to see examples.
  -help  Show this help.
  -Phelp or -x   Show examples for -p=P place notation.
  -b=B   Chart B moving bells.  If absent, B is inferred from the -p value.
  -n=B   Synonym for -b=B.
  -p=P   Chart the bells over place notation P.
         P must match the regular expression
           ([0-9]+|x)(\\.[0-9]+|x)*
         as well as the semantic constraints of ringing.
  -r or -repeat  Repeat the changes until the bells go back into rounds.
  -R or -Repeat  Like -r, but also divide into leads (segments at the
          end of which the treble is back in leads at a backstroke).

More advanced:
  -0=R   Start the bells from row R rather than rounds.
  -beginAtHand or -bh  Begin with a handstroke rather than a backstroke.
  -c or -count  Print an ordinal count for each row.
  -css   Produce only the css for a ringing chart.
  -C=C   Chart with C covers (default is 0).
  -leadend=N or -le=N  Treat row N as a lead end.
  -LE=N  Do not treat row N as a lead end.
  -note1=S  Print S as a note to the right of row 1.
         Similary for -note2, -note3, ....
  -Note1=S  Like -note1=S, but S is shown in double quotes.

Output format (default is text):
  -h or -html  Produce an HTML table element.
  -H or -HTML  Produce a complete HTML file.
  -hHelp or -htmlHelp  Show help describing the HTML output.
  -s or -svg  Produce SVG output.
  -sHelp or -svgHelp  Show help for further SVG options.
HEREDOCUMENT
  ;
}
#  -r=N  Repeat the changes N times.

sub examples {
  print <<HEREDOCUMENT
-- Examples of $cmdName place notation --

1.  x

x means that the bell in leads swaps with the bell in 2nds, the bell
in 3rds with the bell in 4ths, and so on up to the number of bells.

x can only appear if there are an even number of bells.

Example:  -b=6 -p=x

123456
214365


2.  Odd number of bells, all but one change position.

If numbers are given, the numbers identify the positions of the bells
that don't change.  Let n be the lowest position not given;  then the
bells in positions n and n+1 swap.  If n+1 was listed, this is a
semantic error as then n has no bell it can swap with.  Continue
swapping positions with higher pairs of n and n+1 until all bells are
dealt with.

Example:  -b=5 =p=1

12345
13254

Example:  -b=5 =p=2

Error.  The bell in position 1 is not listed, but it has no adjacent bell to
swap with since 2 is listed as staying in the same place.

Example:  -b=5 -p=3

12345
21354


3.  More than one bell does not change position

Example:  -b=5 -p=125

12345
12435

Example:  -b=6 -p=34

123456
213465
HEREDOCUMENT
  ;
}

sub htmlHelp {
  print <<HEREDOCUMENT
Each row of the output is a div of class "row".
  a.  rounds rows     also have class "rounds".
  b.  handstroke rows also have class "hand".
  c.  backstroke rows also have class "back".
  d.  lead ends       also have class "leadEnd".
For all B, bell B is in span of class "bB" (bell 10 is 0 in class b0).
A <!-- --> comment is placed at the end of the HTML file summarizing
the options that produced it.
HEREDOCUMENT
  ;
}

sub css {
  print <<HEREDOCUMENT
    /*
      Bells
    */
    .b1, .b2, .b3, .b4, .b5, .b6, .b7, .b8, .b9, .b0 {
      padding-right: .125em;
    }
    /*
      Rows
    */
    .row {
      border-top: thin solid transparent;
    }
    .back,                .back span.row {  background-color: #f3f3f3;  }
    .segtEnd.back,.segtEnd.back span.row {  background-color: #e7e7e7;  }
    .leadEnd.back,.leadEnd.back span.row {  background-color: #d7d7d7;  }
    div.stroke.back {
      background-color: inherit;
    }
    /*
      Row numbering
    */
    span.rownum {
      display: inline-block;
      width: 2em;
      padding-right: .67em;
      font-size: 70%;
      text-align: right;
    }
    span.rownum .n        {  vertical-align: .2ex;  }
    span.rownum .n:before {  content: '[';  }
    span.rownum .n:after  {  content: ']';  }
    /*
      Calls
    */
    span.call {  padding-left: 0.5em;  }
    /*
      Lead ends
    */
    div.leadEnd span.row, span.leadEnd span.row {
      border-bottom: thin solid #777777;
    }
    div.leadEnd:after, span.leadEnd:after {
      padding-left: .125em;
      border-top: none;
    }
    div.leadsAcross div.lead {
      display: inline-block;
    }
    div.leadsAcross div.leadEnd:first-child,
    /*
      Each chart
    */
    div.chart {
      display: inline-block;
      margin-bottom: .5ex;
    }
    /*
      Groups of charts
    */
    div.Chart {
      float: left;
      margin-right: .4em;
      margin-bottom: 1ex;
      border: thin solid gray;
      padding: .8ex .8em;
      page-break-inside: avoid;
    }
    div.Chart:first-child .deleteThisChart {
      display: none;
    }
    div.Charts {  float: left;  }
    div.Charts div.Chart {  float: none;  }
HEREDOCUMENT
  ;
}

my $svg = "";
my $svgUnit  =              24;
my $svgBellNumYOffset = 0.22*$svgUnit;
my $svgCirclesStr = "";
my $svgColorBackstroke   = "#e7e7e7";
my $svgColorLeadEnd      = "#a7a7a7";
my $svgCrossbarStroke =     $svgUnit/24;
my $svgDotOpacity     = 1.00;
my $svgDotRadius =          $svgUnit/24;
my $svgDotRadius0 = $svgDotRadius;
my $svgFontSize =       0.70*$svgUnit;
my $svgOverTrb = "";
my $svgStrokeWidth =        $svgUnit/3;
my $svgUnit0  = $svgUnit;
my $svgWorkStr = "";
my $svgX0    =          1.50*$svgUnit;
my $svgXStep =          1.00*$svgUnit;
my $svgY0    =          0.50*$svgUnit;
my $svgYStep =          1.00*$svgUnit;
my %svgColors = ();

$svgColors{"1"} = "#000000";
$svgColors{"2"} = "#0000ff";
$svgColors{"3"} = "#00cc00";
$svgColors{"4"} = "#ff6600";
$svgColors{"5"} = "#ff00ff";
$svgColors{"6"} = "#c0c0c0";
$svgColors{"7"} = "#4689ca";
$svgColors{"8"} = "#778899";
$svgColors{"9"} = "#00ffff";
$svgColors{"0"} = "#ff0000";

my %svgCircleColors = ();
$svgCircleColors{"1"} = "";
$svgCircleColors{"2"} = "";
$svgCircleColors{"3"} = "";
$svgCircleColors{"4"} = "";
$svgCircleColors{"5"} = "";
$svgCircleColors{"6"} = "";
$svgCircleColors{"7"} = "";
$svgCircleColors{"8"} = "";
$svgCircleColors{"9"} = "";
$svgCircleColors{"0"} = "";
my $svgColorCrs = "#dbffd4";
my $svgColorAft = "#fbdbe1";


sub svgHelp {
  print <<HEREDOCUMENT
SVG options.  Each -sX option may also be given as -svgX.
  -s1=C  Use C as the color for bell 1's line.
         Similarly for -s2 through -s9, and -s0 for bell 10.
         Defaults are:
HEREDOCUMENT
  ;
  my $k;
  for ($k = 1;  $k <= 10;  ++$k) {
    my $bell = (10 == $k ? "0" : $k);
    my $color = $svgColors{$bell};
    print <<HEREDOCUMENT
           $bell: $color
HEREDOCUMENT
    ;
  }
  print <<HEREDOCUMENT
         -s1=X is shorthand for -s1=transparent.
  -sB  or -sBellNums   Show bell numbers at each row.
  -sB0 or -sBellNums0  Show bell numbers at the top of the chart only.
  -sBackstroke=C  Use C as the background color behind backstrokes.
         Default is $svgColorBackstroke;  can be transparent.
  -sC1=S  Instead of a line for bell 1, draw circles of color S at its places.
         S may be a color or the special strings C for the course color #dbffd4
         or A for the after color #fbdbe1.
         Similarly for -sc2 through -sc9, and -sc0 for bell 10.
  -sLeadEnd=C  Use C as the background color behind lead ends.
         Default is $svgColorLeadEnd;  can be transparent.
  -sRowsExpected=T or -sREx=T Set up -sX0 for T changes.  Default is for two
         digits worth of changes (10-99), resulting in -sX0=$svgX0.
  -sWidth=N  Width of image will be N (useful if notes are added with -note).
  -sWork=B   Show the work or place bell number at each lead end backstroke.
         This is the place bell B is in.  Default is 2 if B is absent.
  -sU=N or -sUnit=N  Use N as the basic unit for the scale of the image.
         Default is $svgUnit.
         Changing this scales all lengths below.

  -sDotRadius=N  Use N as the radius of the dots marking each position.
         Default is $svgDotRadius;  0 means no dots.
  -sStroke=N  Use N as the stroke width for each bell's line.
         Default is $svgStrokeWidth.
  -sX=N  or -sXStep=N  Use N as the X axis step between strokes.  Default is $svgXStep.
  -sY=N  or -sYStep=N  Use N as the Y axis step between bells.  Default is $svgYStep.
  -sX0=N Use N as the X axis offset.  Default is $svgX0.
  -sY0=N Use N as the Y axis offest.  Default is $svgY0.
A <!-- --> comment is placed at the end of the SVG file summarizing the
options that produced it.
HEREDOCUMENT
  ;
  # svgXStep
}

my $verbose = "";

my @changes = ();
my $changesJ = 0;
my $changeStr = "";
my $changeStrJ = 0;
my $changesStr = "";
my $count = "";
my $html = "";
my $indent0 = "";
my $indent  = $indent0;
my $j = 0;
my $leadEnd = "";
my %leadEnds = ();
my $leadEndsOpts = "";
my %leadNonEnds = ();
my $leadTrebleBack = "";
my $leadTrebleHand = "";
my %note = ();
my $noteOpts = "";
my $numBells = 0;
my $numCovers = 0;
my $numWorking = -1;
my $repeat = "";
my $Repeat = "";
my $repetitions = 1;
my $rounds = "";
my $rn = 0;
my $rn0 = 0;
my $row = "";
my $row0Opt = "";
my $rowJ = 0;
my $rowHtml = "";
my $stroke = "back";

my $svgBellNums = "";
my $svgBellNums0 = "";
my $svgBellNumsStr = "";
my $svgNotes = "";
my %svgPath = ();
$svgPath{"1"} = "";
$svgPath{"2"} = "";
$svgPath{"3"} = "";
$svgPath{"4"} = "";
$svgPath{"5"} = "";
$svgPath{"6"} = "";
$svgPath{"7"} = "";
$svgPath{"8"} = "";
$svgPath{"9"} = "";
$svgPath{"0"} = "";
my $svgRowBars = "\n";
my $svgWidth = "";
my $svgWorkBell = 0;

if (0 == scalar @ARGV) {
  &help;
  exit;
}

my $sOpts = "";
my $arg;
foreach $arg (@ARGV) {
  if    ($arg =~  /^-+help$/) {
    &help;
    exit;
  }
  elsif ($arg =~  /^-+(Phelp|x)$/) {
    &examples;
    exit;
  }
  elsif ($arg =~  /^-+v$/) {
    $verbose = "y";
  }
  elsif ($arg =~  /^-+0=([0-9]+)$/) {  $row = $arg;
    $row      =~ s/^-+0=([0-9]+)$/$1/;
    if ($row !~ /1/) {  die "Initial row must contain 1 ($row).\n";  }
    if ($row !~ /2/) {  die "Initial row must contain 2 ($row).\n";  }
    my $ck = $row;
    $ck =~ s/1//;  $ck =~ s/2//;  $ck =~ s/3//;  $ck =~ s/4//;  $ck =~ s/5//;
    $ck =~ s/6//;  $ck =~ s/7//;  $ck =~ s/8//;  $ck =~ s/9//;  $ck =~ s/0//;
    if ($ck) {
      die "Initial row contains duplicates for $ck ($row).\n";
    }
    $ck = $row;
    $ck =~ s/1//;  $ck =~ s/2//;
    if ($ck =~ /3/) {  $ck =~ s/3//;
      if ($ck =~ /4/) {  $ck =~ s/4//;
        if ($ck =~ /5/) {  $ck =~ s/5//;
          if ($ck =~ /6/) {  $ck =~ s/6//;
            if ($ck =~ /7/) {  $ck =~ s/7//;
              if ($ck =~ /8/) {  $ck =~ s/8//;
                if ($ck =~ /9/) {  $ck =~ s/9//;
                  if ($ck =~ /0/) {  $ck =~ s/0//;
                    if ($ck) {  die "Assertion failed \"$ck\" ($arg).\n";  }
                    $numWorking = 10;
                  }
                  else {  $numWorking = 9;
                    if ($ck) {  die "Assertion failed \"$ck\" ($arg).\n";  }
                  }
                }
                else {  $numWorking = 8;
                  if ($ck) {  die "Initial row is missing the 9 ($row).\n";  }
                }
              }
              else {  $numWorking = 7;
                if ($ck) {  die "Initial row is missing the 8 ($row).\n";  }
              }
            }
            else {  $numWorking = 6;
              if ($ck) {  die "Initial row is missing the 7 ($row).\n";  }
            }
          }
          else {  $numWorking = 5;
            if ($ck) {  die "Initial row is missing the 6 ($row).\n";  }
          }
        }
        else {  $numWorking = 4;
          if ($ck) {  die "Initial row is missing the 5 ($row).\n";  }
        }
      }
      else {  $numWorking = 3;
        if ($ck) {  die "Initial row is missing the 4 ($row).\n";  }
      }
    }
    else {  $numWorking = 2;
      if ($ck) {  die "Initial row is missing the 3 ($row).\n";  }
    }
    if (10 < $numWorking - -$numCovers) {
      die "Only up to ten bells are allowed ($numWorking + $numCovers).\n"
    }
    $row0Opt = "$arg ";
  }
  elsif ($arg =~  /^-+(beginAtHand|bh)$/) {
    $rn = 1;
    $rn0 = 1;
  }
  elsif ($arg =~  /^-+[bn]=([0-9]+)$/) {  my $nn = $arg;
    $nn       =~ s/^-+[bn]=([0-9]+)$/$1/;
    if ($verbose) {  print STDERR "Number of bells:  $nn\n";  }
    if ($nn < 2) {
      die "Minimum number of bells allowed is 2 ($nn).\n"
    }
    if (-1 < $numWorking && $nn != $numWorking) {
      die "Number of bells $numWorking already inferred from other options ($nn).\n";
    }
    $numWorking = $nn;
    if (10 < $numWorking - -$numCovers) {
      die "Only up to ten bells are allowed ($numWorking + $numCovers).\n"
    }
  }
  elsif ($arg =~  /^-+c(ount)?$/) {
    $count = "y";
  }
  elsif ($arg =~  /^-+c(ount)?=([0-9]+)$/) {  my $nn = $arg;
    $nn       =~ s/^-+c(ount)?=([0-9]+)$/$2/;
    if ($verbose) {  print STDERR "Beginning at row $nn\n";  }
    $rn = "$nn";
    $rn0 = "$nn";
    $count = "y";
  }
  elsif ($arg =~  /^-+css$/) {
    &css();
    exit;
  }
  elsif ($arg =~  /^-+C=([0-9]+)$/) {  my $nn = $arg;
    $nn       =~ s/^-+C=([0-9]+)$/$1/;
    if ($verbose) {  print STDERR "Number of covers:  $nn\n";  }
    if ($nn < 0) {
      die "Minimum number of bells allowed is 0 ($nn).\n"
    }
    $numCovers = $nn;
    if (10 < $numWorking - -$numCovers) {
      die "Only up to ten bells are allowed ($numWorking + $numCovers).\n"
    }
  }
  elsif ($arg =~  /^-+h(tml)?$/) {
                      $html = "y";
                      $svg  = "";
  }
  elsif ($arg =~  /^-+H(TML)?$/) {
                      $html = "Y";
                      $svg  = "";
  }
  elsif ($arg =~  /^-+h(tml)?[hH]elp$/) {
    &htmlHelp();
    exit;
  }
  elsif ($arg =~  /^-+l(ead)?e(nd)?=([0-9]+)$/) {  my $nn = $arg;
    $nn       =~ s/^-+l(ead)?e(nd)?=([0-9]+)$/$3/;
    if ($nn%2) {
      die "Lead ends only allowed for backstrokes (even-numbered rows):  $arg\n";
    }
    $leadEnds{$nn} = "$nn";
    $leadEndsOpts = "$leadEndsOpts$arg ";
  }
  elsif ($arg =~  /^-+LE=([0-9]+)$/) {  my $nn = $arg;
    $nn       =~ s/^-+LE=([0-9]+)$/$1/;
    $leadNonEnds{$nn} = "$nn";
    $leadEndsOpts = "$leadEndsOpts$arg ";
  }
  elsif ($arg =~  /^-+[nN]ote([0-9]+)=(.+)$/) {  my $nn = $arg;  my $note = $arg;
    $nn       =~ s/^-+[nN]ote([0-9]+)=(.+)$/$1/;
    $note     =~ s/^-+[nN]ote([0-9]+)=(.+)$/$2/;
    $note =~ s/_/ /g;
    if ($arg =~ /^-+N/) {
      $note = "“$note”";
    }
    $note{$nn} = $note;
    $noteOpts = "$noteOpts$arg ";
  }
  elsif ($arg   =~  /^-+p=([.0-9x]+)$/) {  $changesStr = $arg;
    $changesStr =~ s/^-+p=([.0-9x]+)$/$1/;
    if ($numWorking < 0) {
      for ($j = 0;  $j < length($changesStr);  ++$j) {
        my $cc = substr($changesStr, $j, 1);
        if ($cc =~ /[0-9]/) {
          if    ("0" eq $cc && $numWorking < 10) {
            $numWorking = 10;
            if ($verbose) {
              print STDERR "Inferred number of bells is at least $numWorking\n";
            }
          }
          elsif ($numWorking < $cc) {
            $numWorking = $cc;
            if ($verbose) {
              print STDERR "Inferred number of bells is at least $numWorking\n";
            }
          }
        }
      }
    }
    if ($verbose) {  print STDERR "Changes:  $changesStr\n";  }
    my $str = $changesStr;
    while (-1 < ($j = index($str, "."))) {
      $changeStr = substr($str, 0, $j);
      if ($verbose) {  print STDERR "  change $changeStr\n";  }
      push @changes, $changeStr;
      $str = substr($str, 1+$j);
    }
    if ("" ne $str) {
      push @changes, $str;
      if ($verbose) {  print STDERR "  change $str\n";  }
    }
    if ($verbose) {  print STDERR "Changes:  " . scalar @changes . "\n";  }
  }
  elsif ($arg =~  /^-+r(epeat)?$/) {
                      $repeat = "y";
  }
  elsif ($arg =~  /^-+R(epeat)?$/) {
                      $Repeat = "y";
                      $repeat = "y";
    $indent = "$indent0  ";
  }
  elsif ($arg =~  /^-+s(vg)?$/) {
                      $svg  = "y";
                      $html = "";
  }
  elsif ($arg =~  /^-+s(vg)?B(ellNums)?0?$/) {
    if  ($arg =~  /^-+s(vg)?B(ellNums)?0$/) {
      $svgBellNums0 = "y";
      $svgDotRadius0 = $svgFontSize*.5;
    }
    else {
      $svgBellNums = "y";
      $svgDotOpacity = .85;
      $svgDotRadius = $svgFontSize*.5;
    }
    $svgBellNumsStr = "\n";
  }
  elsif ($arg =~   /^-+s(vg)?(Color)?Backstroke=(.+)$/) {
    $svgColorBackstroke = $arg;
    $svgColorBackstroke
                   =~ s/^-+s(vg)?(Color)?Backstroke=(.+)$/$3/;
  }
  elsif ($arg =~       /^-+s(vg)?DotRadius=([0-9.]+)$/) {  $svgDotRadius = $arg;
    $svgDotRadius  =~ s/^-+s(vg)?DotRadius=([0-9.]+)$/$2/;
  }
  elsif ($arg =~  /^-+s(vg)?[hH]elp$/ ||
         $arg =~  /^-+helpSvg/) {
    &svgHelp();
    exit;
  }
  elsif ($arg =~         /^-+s(vg)?(Color)?LeadEnd=(.+)$/) {
    $svgColorLeadEnd = $arg;
    $svgColorLeadEnd =~ s/^-+s(vg)?(Color)?LeadEnd=(.+)$/$3/;
    $sOpts = "$sOpts-sLeadEnd=$svgColorLeadEnd ";
  }
  elsif ($arg =~  /^-+s(vg)?R(ows)?Ex(pected)?=([0-9]+)$/) {
    $arg =~      s/^-+s(vg)?R(ows)?Ex(pected)?=([0-9]+)$/$4/;
    $sOpts = "$sOpts-sREx=$arg ";
    if    ($arg <  10) {
      $svgX0 = 1.50*$svgUnit;
      #print STDERR "### svgX0 set to $svgX0\n";
    }
    elsif ($arg < 100) {
      $svgX0 = 1.84*$svgUnit;
      #print STDERR "### svgX0 set to $svgX0\n";
    }
    else {
      $svgX0 = 2.25*$svgUnit;
    }
  }
  elsif ($arg =~        /^-+s(vg)?Stroke(Width)?=([0-9.]+)$/) {
    $svgStrokeWidth = $arg;
    $svgStrokeWidth =~ s/^-+s(vg)?Stroke(Width)?=([0-9.]+)$/$3/;
    $sOpts = "$sOpts-sStroke=$svgStrokeWidth ";
  }
  elsif ($arg =~  /^-+s(vg)?U(nit)?=([0-9.]+)$/) {  $svgUnit = $arg;
    $svgUnit  =~ s/^-+s(vg)?U(nit)?=([0-9.]+)$/$3/;
    $svgBellNumYOffset *= $svgUnit/$svgUnit0;
    $svgCrossbarStroke *= $svgUnit/$svgUnit0;
    $svgDotRadius      *= $svgUnit/$svgUnit0;
    $svgFontSize       *= $svgUnit/$svgUnit0;
    $svgStrokeWidth    *= $svgUnit/$svgUnit0;
    $svgX0             *= $svgUnit/$svgUnit0;
    $svgXStep          *= $svgUnit/$svgUnit0;
    $svgY0             *= $svgUnit/$svgUnit0;
    $svgYStep          *= $svgUnit/$svgUnit0;
    $sOpts = "$sOpts-sUnit=$svgUnit ";
  }
  elsif ($arg =~  /^-+s(vg)?Width=([0-9.]+)$/) {  $svgWidth = $arg;
    $svgWidth =~ s/^-+s(vg)?Width=([0-9.]+)$/$2/;
    $sOpts = "$sOpts-sWidth=$svgWidth ";
  }
  elsif ($arg =~  /^-+s(vg)?X(Step)?=([0-9.]+)$/) {  $svgXStep = $arg;
    $svgXStep =~ s/^-+s(vg)?X(Step)?=([0-9.]+)$/$3/;
    $sOpts = "$sOpts-sX=$svgXStep ";
  }
  elsif ($arg =~  /^-+s(vg)?X0=([0-9.]+)$/) {  $svgX0 = $arg;
    $svgX0    =~ s/^-+s(vg)?X0=([0-9.]+)$/$2/;
    $sOpts = "$sOpts-sX0=$svgX0 ";
  }
  elsif ($arg =~  /^-+s(vg)?Y(Step)?=([0-9.]+)$/) {  $svgYStep = $arg;
    $svgYStep =~ s/^-+s(vg)?Y(Step)?=([0-9.]+)$/$3/;
    $sOpts = "$sOpts-sY=$svgYStep ";
  }
  elsif ($arg =~  /^-+s(vg)?Y0=([0-9.]+)$/) {  $svgY0 = $arg;
    $svgY0    =~ s/^-+s(vg)?Y0=([0-9.]+)$/$2/;
    $sOpts = "$sOpts-sY0=$svgY0 ";
  }
  elsif ($arg =~  /^-+s(vg)?([0-9])=(.+)$/) {
    my $bell = $arg;
    my $clr  = $arg;
    $bell =~     s/^-+s(vg)?([0-9])=(.+)$/$2/;
    $clr  =~     s/^-+s(vg)?([0-9])=(.+)$/$3/;
    if ($clr eq "X") {
      $clr = "transparent";
    }
    $svgColors{$bell} = $clr;
    $sOpts = "$sOpts-s$bell=$clr ";
  }
  elsif ($arg =~  /^-+s(vg)?C([0-9])=(.+)$/) {
    my $bell = $arg;
    my $clr  = $arg;
    $bell =~     s/^-+s(vg)?C([0-9])=(.+)$/$2/;
    $clr  =~     s/^-+s(vg)?C([0-9])=(.+)$/$3/;
    if    ($clr eq "C") {
      $clr = $svgColorCrs;
      $svgOverTrb = "C";
    }
    elsif ($clr eq "A") {
      $clr = $svgColorAft;
      $svgOverTrb = "A";
    }
    $svgColors{$bell} = "transparent";
    $svgCircleColors{$bell} = $clr;
    $sOpts = "$sOpts-sC$bell=$clr ";
  }
  elsif ($arg =~  /^-+s(vg)?Work$/) {
    $svgWorkBell = 2;
    $sOpts = "$sOpts-sWork ";
  }
  elsif ($arg =~  /^-+s(vg)?Work=(.+)$/) {
    my $bell = $arg;
    $bell =~     s/^-+s(vg)?Work=(.+)$/$2/;
    $svgWorkBell = $bell;
    $sOpts = "$sOpts-sWork=$bell ";
  }
  else {
    die "Unexpected argument \"$arg\".\n";
  }
}

if ($numWorking < 0) {
  $numWorking = 6;
  if (10 < $numWorking - -$numCovers) {
    die "Only up to ten bells are allowed ($numWorking + $numCovers).\n"
  }
}
$numBells = $numWorking - -$numCovers;

if ($html eq "Y") {
  print <<HEREDOCUMENT
<!DOCTYPE html PUBLIC '-//W3C//DTD XHTML 1.1//EN'
     'http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd'>
<html xmlns='http://www.w3.org/1999/xhtml' xml:lang='en' lang='en'>
<head>
  <style type='text/css'>
    div.chart {
      font-family: Georgia, "Times New Roman", Times, serif;
    }
    span.times:before {  content: '(';  }
    span.times:after  {  content: ' times)';  }

HEREDOCUMENT
  ;
  &css();
  print <<HEREDOCUMENT
  </style>
</head>
<body>

<div class='chart B2'>
HEREDOCUMENT
  ;
}
if ($html) {
  print "$indent0<!-- $cmdName -b=$numWorking -C=$numCovers -p=$changesStr " .
      ($repeat ? ($Repeat ? "-R ": "-r ") : "") .
      ($html eq "Y" ? "-H " : "-h ") . "-->\n";
}

#  Initialize to rounds
for ($j = 0;  $j < $numBells;  ++$j) {
  if    ($j < 9) {
    $rounds = $rounds . (1+$j);
  }
  elsif (9 == $j) {
    $rounds = $rounds . "0";
  }
  else {
    die "Only up to ten bells ($numBells).\n"
  }
}
if (!$row) {
  $row = $rounds;
}

if (!$count) {
  $svgX0 = $svgXStep/2;
}
my $rectXx = $svgX0 - $svgXStep/2;
my $barWidth = $svgXStep*$numBells;

sub handleRow {
  my $leadEndClass = ($leadEnd ? " leadEnd" : "");
  my $leadEndSpace = ($leadEnd ? "" : "        ");
  my $roundsClass  = ($row eq $rounds ? " rounds" : "");
  my $roundsSpace  = ($row eq $rounds ? "" : "       ");
  #
  #  HTML
  #
  if    ($html) {
    $rowHtml = $row;
    for ($j = 1;  $j <= $numBells;  ++$j) {
      my $bell = (10 == $j ? "0" : $j);
      $rowHtml =~ s/$bell/<span class='b$bell'>$bell<\/span>/;
    }
    print "$indent<div ";
    print "class='stroke $stroke$roundsClass$leadEndClass'$roundsSpace$leadEndSpace>";
    print "<span class='rownum'>";
    if (0 == $rn) {
      print "<span><!--row 0--></span>";
    }
    else {
      my $rN = ($rn < 10 ? " $rn" : $rn);
      print "<span class='n'>$rN</span>";
    }
    print "</span>";
    print "<span class='row'>$rowHtml</span>";
    if (exists $note{$rn}) {
      print " " . $note{$rn};
    }
    print "</div>\n";
  }
  #
  #  SVG
  #
  elsif ($svg) {
    my $placeOfWorkBell = index($row, $svgWorkBell);
    for ($j = 1;  $j <= $numBells;  ++$j) {
      my $bell = (10 == $j ? "0" : $j);
      my $cu = index($row, $bell);
      my $xx = $cu*$svgXStep + $svgX0;
      my $yy = $svgYStep*($rn - $rn0) + $svgY0;
      if ($rn0 == $rn) {
        $svgPath{$bell} =
            "  <path fill='transparent' stroke='" . $svgColors{$bell} . "'\n" .
            "    stroke-width='$svgStrokeWidth' stroke-linecap='round'\n" .
            "    d='M $xx $yy";
      }
      else {
        $svgPath{$bell} = $svgPath{$bell} . " L $xx $yy";
      }
      if ($svgBellNums || ($svgBellNums0 && ($rn0 == $rn))) {
        $yy = $yy + $svgBellNumYOffset;
        $svgBellNumsStr = $svgBellNumsStr .
            "  <text x='$xx' y='$yy' font-size='$svgFontSize' " .
            "text-anchor='middle'>$bell</text>\n";
      }
      if ($svgCircleColors{$bell}) {
        if    (($svgColorCrs eq $svgCircleColors{$bell} ||
                $svgColorAft eq $svgCircleColors{$bell}) &&
                $placeOfWorkBell - 1 == $cu) {
          $svgCirclesStr = $svgCirclesStr .
            "  <circle cx='$xx' cy='$yy' r='" . 1.25*$svgStrokeWidth .
              "' stroke='black' stroke-width='0.5'\n" .
              "    fill='" . $svgCircleColors{$bell} . "' />\n" .
            "  <text x='$xx' y='" . ($yy + 0.21*$svgYStep) . "' " .
              "text-anchor='middle' fill='black'\n" .
            "    font-family='sans-serif' font-weight='lighter' " .
              "font-size='" . (0.67*$svgYStep) . "'>" .
              ($svgColorCrs eq $svgCircleColors{$bell} ? "C" : "A") .
              "</text>\n";
        }
        elsif ($svgColorCrs eq $svgCircleColors{$bell} &&
                $placeOfWorkBell - 1 == $cu) {
        }
        else {
          $svgCirclesStr = $svgCirclesStr .
                "  <circle cx='$xx' cy='$yy' r='" . 0.5*$svgStrokeWidth .
                "' stroke='black' stroke-width='0.25'\n" .
                "    fill='" . $svgCircleColors{$bell} . "' />\n";
        }
      }
      if ($svgOverTrb && 1 == $bell && $placeOfWorkBell - 1 == $cu) {
          $svgCirclesStr = $svgCirclesStr .
            "  <path d='M$xx," . ($yy + $svgStrokeWidth) .
              " a$svgStrokeWidth,$svgStrokeWidth 0 1,1 0,-" . (2*$svgStrokeWidth) .
              " h$svgXStep" .
              " a$svgStrokeWidth,$svgStrokeWidth 0 1,1 0," . (2*$svgStrokeWidth) .
              " h-$svgXStep'\n" .
            "    fill='transparent' stroke='#ff0000' stroke-width='2' />\n";
      }
    }
    if ($svgRowBars && (0 == $rn%2)) {  # && $rn
      my $yy = $svgYStep*(($rn - $rn0) - .5) + $svgY0;
      $leadEnd = ($leadEndsOpts
                    ? exists $leadEnds{$rn}
                    : (0 == $rn%(scalar @changes)) &&
                      ($row =~ /^1/));
      if ($leadEnd && exists $leadNonEnds{$rn}) {
        $leadEnd = "";
        if ($verbose) {
          print "Would have been a lead end at row $rn but -LE option blocked it.\n";
        }
      }
      my $color = ($leadEnd ? $svgColorLeadEnd : $svgColorBackstroke);
      if ($leadEnd && $rn) {
        $svgRowBars = $svgRowBars .
          "  <line x1='$rectXx' y1='$yy' x2='" . ($rectXx + $barWidth) .
            "' y2='$yy' stroke='black' stroke-width='$svgCrossbarStroke' />\n";
      }
      if ($leadEnd && $svgWorkBell) {
        my $workPlace = index($row, $svgWorkBell) + 1;
        my $workXx = $rectXx + $barWidth + 0.75*$svgYStep;
        my $workYy = $yy + $svgYStep/2;
        my $workRr = 0.42*$svgYStep;
        $svgWorkStr = $svgWorkStr .
          "  <circle cx='$workXx' cy='$workYy' r='$workRr'\n" .
          "    stroke='black' stroke-width='0.5' fill='transparent' />\n" .
          "  <text x='$workXx' y='" . ($workYy + .33*$svgFontSize) .
            "' text-anchor='middle'\n" .
          "    font-family='sans-serif' font-size='$svgFontSize' " .
            ">$workPlace</text>\n";
      }
      $svgRowBars = $svgRowBars .
        "  <rect x='$rectXx' y='$yy' width='$barWidth' height='$svgYStep'\n" .
        "    stroke='transparent' fill='$color' />\n";
    }
    if (exists $note{$rn}) {
      my $xx = ($numBells)*$svgXStep + $svgX0;
      my $yy = $svgYStep*(($rn - $rn0) + .167) + $svgY0;
      $svgNotes = $svgNotes .
            "  <text x='$xx' y='$yy' font-size='$svgFontSize'>" .
            $note{$rn} . "</text>\n";
    }
  }
  #
  #  Text
  #
  else {
    my $note = (exists $note{$rn} ? "  " . $note{$rn} : "");
    if ($count) {
      if ($rn < 10) {
        print "[ $rn]  $row$note\n";
      }
      else {
        print "[$rn]  $row$note\n";
      }
    }
    else {
      print "$row$note\n";
    }
  }
}


# if ($Repeat && $html) {
#   print "$indent0<div class='lead'>\n";         # ### Lead
# }

&handleRow;

if (0 < scalar @changes) {
  if ($verbose) {  print STDERR "Beginning the changes\n";  }
  $changesJ = 0;
  while (1) {
    if ($#changes < $changesJ) {  #  $# last index, not size
      if ($repeat) {
        $changesJ = 0;
        ++$repetitions;
      }
      else {
        last;
      }
    }
    $stroke = ("back" eq $stroke ? "hand" : "back");
    ++$rn;
    if ($verbose) {  print STDERR "Row number $rn\n";  }
    $changeStr = $changes[$changesJ];
    if ($verbose) {  print STDERR "change: $changeStr\n";  }
    if    ($changeStr eq "x") {
      if ($numWorking != 2*($numWorking/2)) {
        die "Change x, but odd number of bells ($numWorking).\n";
      }
      for ($rowJ = 0;  $rowJ < $numWorking;  $rowJ += 2) {
        substr($row, $rowJ, 2) = substr($row, 1+$rowJ, 1) . substr($row, $rowJ, 1);
      }
    }
    else {
      $changeStrJ = 0;
      for ($rowJ = 0;  $rowJ < $numWorking;  ++$rowJ) {
        my $skip = substr($changeStr, $changeStrJ, 1);
        if ($verbose) {  print STDERR "'skip' bell is '$skip'\n";  }
        if ("0" eq $skip) {  $skip = 10;  }
        if    (length($changeStr) <= $changeStrJ || 1+$rowJ < $skip) {
          if  ($changeStrJ < length($changeStr) && 2+$rowJ == $skip) {
            die "Impossible change \"$changeStr\" requires " . (1+$rowJ) .
                " to change with non-adjacent bell.\n";
          }
          if ($verbose) {  print STDERR ":: Exchanging " . (1+$rowJ) . " and " .
                              (2+$rowJ) . "...\n";  }
          substr($row, $rowJ, 2) =
              substr($row, 1+$rowJ, 1) . substr($row, $rowJ, 1);
          ++$rowJ;
        }
        elsif (1+$rowJ == $skip) {
          ++$changeStrJ;
        }
        else {
          die "\n### Whoops:  $rowJ $skip\n\n";
        }
      }
    }
    if ($stroke eq "hand") {
      $leadTrebleHand = ($row =~ /^1/);
      $leadEnd = "";
    }
    else {
      $leadEnd = ($leadEndsOpts ? exists $leadEnds{$rn}
                                   : $leadTrebleHand && ($row =~ /^1/));
    }
    &handleRow;
    if ($Repeat && $leadEnd && $html && $row ne $rounds) {
      # print "$indent0</div><!--  lead  -->\n";  # ### Lead
      # print "$indent0<div class='lead'>\n";     # ### Lead
      &handleRow;
    }
    if ($row eq $rounds && $#changes == $changesJ) {
      last;
    }
    ++$changesJ;
  }

}

# if ($Repeat && $html) {
#   print "$indent0</div><!--  lead  -->\n";      # ### Lead
# }
if ($html) {
  print "$indent0<!--  Repetitions: $repetitions  -->\n";
}
if ($html eq "Y") {
  print <<HEREDOCUMENT
</div><!--chart-->

</body>
</html>

HEREDOCUMENT
  ;
}

if ($svg) {
  if ($verbose) {  print STDERR "Starting svg-only work:\n";  }
  if ($verbose) {  print STDERR "Rows: " . ($rn - $rn0) . "\n";  }
  my $xx0 = $svgX0 +
              ($numBells - .5)*$svgXStep +
              ($svgWorkBell ? 1.25*$svgYStep + 1 : 0);
  my $yy  = $svgY0 + (($rn - $rn0) + 0.5)*$svgYStep;
  my $xx = ($svgWidth ? $svgWidth : $xx0);
  if ($verbose) {  print STDERR "Width $xx, height $yy\n";  }
  print <<HEREDOCUMENT
<?xml version='1.0' standalone='no'?>
<svg width='$xx' height='$yy' version='1.1' xmlns='http://www.w3.org/2000/svg'>
  <!-- xx0=$xx0 svgX0=$svgX0 svgXStep=$svgXStep svgUnit=$svgUnit -->
HEREDOCUMENT
  ;
  if ($svgWidth) {
    print "  <!-- Calculated width was $xx0 -->\n";
  }
  if (    $svgRowBars) {
    print $svgRowBars;
  }
  my $x0 = $svgX0 - .5*$svgXStep;
  my $x1 = $svgX0 + ($numBells - .5)*$svgXStep;
  $yy = $svgY0 + $svgYStep/2;
  $xx = $svgX0 + ($numBells - .5)*$svgXStep;
  $yy = $svgYStep*(0 - .5) + $svgY0;
  $yy = $svgY0 + .5*$svgYStep;
  my $nXx = $svgX0 - 1*$svgFontSize;
  my $k = 0;
  if ($count) {
    for ($k = $rn0 - -1;  $k <= ($rn - $rn0);  ++$k) {
      $yy = $svgYStep*$k + $svgY0 + $svgFontSize/4;
      print "  <text font-size='" . $svgFontSize*.8 .
              "' text-anchor='end'\n" .
            "    x='$nXx' y='$yy'><tspan fill='gray'>[$k]</tspan></text>\n";
    }
  }
  print "\n";
  for ($j = 1;  $j <= $numBells;  ++$j) {
    my $bell = (10 == $j ? "0" : $j);
    $xx = $svgX0 + $svgXStep*($j - 1);
    $yy = $svgY0 - .4*$svgFontSize;
    print $svgPath{$bell} . "' />\n";
  }
  print "\n";
  #print "\n";
  if ($svgDotRadius) {
    for ($k = 0;  $k <= ($rn - $rn0);  ++$k) {
      my $opacity = (0 == $k ? 1.0 : $svgDotOpacity);
      my $radius  = (0 == $k && $svgBellNums0 ? $svgDotRadius0 : $svgDotRadius);
      $yy = $svgY0 + $svgYStep*$k;
      for ($j = 1;  $j <= $numBells;  ++$j) {
        $xx = $svgX0 + ($j - 1)*$svgXStep;
        print "  <circle r='$radius' cx='$xx' cy='$yy'" .
                " stroke='transparent' fill='white' fill-opacity='$opacity' />\n";
      }
    }
  }
  if (    $svgCirclesStr) {
    print "  <!-- Circles and racetracks -->\n";
    print $svgCirclesStr;
  }
  if (    $svgBellNumsStr) {
    print "  <!-- Bell numbers -->\n";
    print $svgBellNumsStr;
  }
  if (    $svgWorkStr) {
    print "  <!-- Work numbers -->\n";
    print $svgWorkStr;
  }
  if (    $svgNotes) {
    print "  <!-- Notes -->\n";
    print "\n" . $svgNotes . "\n";
  }
  my $rr = ($repeat ? ($Repeat ? "-R": "-r") : "");
  print <<HEREDOCUMENT
  <!-- $cmdName -b=$numWorking $leadEndsOpts$row0Opt-p=$changesStr $rr$noteOpts $sOpts-s -->
</svg>

HEREDOCUMENT
  ;
}