#!/usr/bin/env perl
#
#  The MIT License
#
#  Copyright (c) 2024-2025 Genome Research Ltd.
#
#  Authors:
#       Petr Danecek <pd3@sanger.ac.uk>
#       Based on code by Jakub Genci, https://github.com/GenciJakub/BcThesis
#
#  Permission is hereby granted, free of charge, to any person obtaining a copy
#  of this software and associated documentation files (the "Software"), to deal
#  in the Software without restriction, including without limitation the rights
#  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
#  copies of the Software, and to permit persons to whom the Software is
#  furnished to do so, subject to the following conditions:
#
#  The above copyright notice and this permission notice shall be included in
#  all copies or substantial portions of the Software.
#
#  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
#  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
#  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
#  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
#  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
#  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
#  THE SOFTWARE.

use strict;
use warnings;
use Data::Dumper;

my $opts = parse_params();
process_data($opts);
generate_html($opts);

exit;

#--------------------------------

sub error
{
    my (@msg) = @_;
    if ( scalar @msg ) { print "@msg\n"; }
    print
        "About: HTML/JavaScript visualization of homozygosity rate and bcftools/roh output\n",
        "Usage: roh-viz [OPTIONS]\n",
        "Options:\n",
        "   -c  --compress 0|1      Compress the embedded data [1]\n",
        "   -e  --embed-d3 0|1      Embed JS libraries for offline rendering [0]\n",
        "   -i, --RoH-file FILE     Output of bcftools/roh\n",
        "   -l, --min-length NUM    Mimimum length of ROH [1e6]\n",
        "   -o, --output FILE       HTML output file\n",
        "   -r, --regions LIST      List of chromosomes/regions\n",
        "   -s, --samples LIST      List of samples to show\n",
        "   -v, --VCF-file FILE     VCF file to determine homozygosity rate\n",
        "   -h, -?, --help          This help message\n",
        "Example:\n",
        "   bcftools roh --AF-dflt 0.5 -G 30 -Or -o roh.txt file.bcf\n",
        "   roh-viz -r roh.txt -v file.bcf -o output.html\n",
        "\n";
    exit -1;
}

sub parse_params
{
    my $opts =
    {
        min_length => 1e6,
        bcftools => 'bcftools',
        outdir => '.',
        d3_url   => 'https://d3js.org/d3.v7.min.js',
        pako_url => 'https://cdnjs.cloudflare.com/ajax/libs/pako/2.0.4/pako.min.js',
        compress => 1,
        embed_d3 => 0,
        bin_size => 100_000,     # bin size
        cmd => join(' ',$0,@ARGV),
    };
    while (defined(my $arg=shift(@ARGV)))
    {
        if ( $arg eq '-e' or $arg eq '--embed-d3' ) { $$opts{embed_d3}=shift(@ARGV); next; }
        if ( $arg eq '-c' or $arg eq '--compress' ) { $$opts{compress}=shift(@ARGV); next; }
        if ( $arg eq '-r' || $arg eq '--regions' ) { $$opts{regions}=shift(@ARGV); next }
        if ( $arg eq '-s' || $arg eq '--samples' ) { $$opts{samples}=shift(@ARGV); next }
        if ( $arg eq '-i' || $arg eq '--RoH-file' ) { $$opts{roh_file}=shift(@ARGV); next }
        if ( $arg eq '-v' || $arg eq '--VCF-file' ) { $$opts{vcf_file}=shift(@ARGV); next }
        if ( $arg eq '-l' || $arg eq '--min-length' ) { $$opts{min_length}=shift(@ARGV); next }
        if ( $arg eq '-o' || $arg eq '--output' ) { $$opts{outfile}=shift(@ARGV); next }
        if ( $arg eq '-?' || $arg eq '-h' || $arg eq '--help' ) { error(); }
        error("Unknown parameter \"$arg\". Run -h for help.\n");
    }
	if ( !exists($$opts{roh_file}) ) { error("Missing the -r option.\n"); }
	if ( !exists($$opts{vcf_file}) ) { error("Missing the -v option.\n"); }
	return $opts;
}

sub cmd
{
    my ($cmd,%args) = @_;

    if ( $args{verbose} ) { print STDERR $cmd,"\n"; }

    # Why not to use backticks? Perl calls /bin/sh, which is often bash. To get the correct
    #   status of failing pipes, it must be called with the pipefail option.

    my $kid_io;
    my $pid = open($kid_io, "-|");
    if ( !defined $pid ) { error("Cannot fork: $!"); }

    my @out;
    if ($pid)
    {
        # parent
        @out = <$kid_io>;
        close($kid_io);
    }
    else
    {
        # child
        exec('bash', '-o','pipefail','-c', $cmd) or error("Failed to run the command [bash -o pipefail -c $cmd]: $!");
    }

    if ( exists($args{exit_on_error}) && !$args{exit_on_error} ) { return @out; }

    my $exit_status = $?;
    my $status = exists($args{require_status}) ? $args{require_status} : 0;
    if ( $status ne $exit_status )
    {
        my $msg;
        if ( $? & 0xff )
        {
            $msg = "The command died with signal ".($? & 0xff);
        }
        else
        {
            $msg = "The command exited with status ".($? >> 8)." (expected $status)";
        }
        $msg .= ":\n\t$cmd\n\n";
        if ( @out ) {  $msg .= join('',@out,"\n\n"); }
        error($msg);
    }
    return @out;
}

sub format_number_with_commas
{
    my ($number) = @_;
    $number =~ s/(?<=\d)(?=(\d{3})+$)/,/g;
    return $number;
}

sub process_data
{
	my ($opts) = @_;

    print STDERR "Parsing $$opts{outdir}/roh.txt\n";
    open(my $in,"zless $$opts{roh_file} |") or error("zless $$opts{roh_file}: $!");
    while (my $line=<$in>)
    {
        chomp($line);

        if ( $line=~/^#/ )
        {
            if ( $line=~/The command line was:\s+/ ) { $$opts{roh_cmd} = $'; }
            next;
        }

        my @col = split(/\t/,$line);
        if ( $col[0] ne 'RG' ) { next; }

        # RG	[2]Sample	[3]Chromosome	[4]Start	[5]End	[6]Length (bp)	[7]Number of markers	[8]Quality (average fwd-bwd phred score)
        my (undef,$smpl,$chr,$beg,$end,undef,$nsnp,$qual) = (@col);
        if ( $end - $beg >= $$opts{min_length} )
        {
            push @{$$opts{roh}{$chr}{$smpl}},"$beg,$end,$nsnp,$qual";
        }
    }
    close($in) or error("close failed: zless $$opts{in_file}");

    my $bin_size = $$opts{bin_size};
    my %chr_len = ();
    my %dat  = ();
    my %smpl = ();
    my $smpl = exists($$opts{samples}) ? "-s $$opts{samples}" : '';
    my $regs = exists($$opts{regions}) ? "-r $$opts{regions}" : '';
    my $cmd  = qq[$$opts{bcftools} query $$opts{vcf_file} -f'[%CHROM\\t%POS\\t%SAMPLE\\t%GT\\n]' -i'GT="alt"' $smpl $regs];
    print STDERR "Parsing $$opts{vcf_file}\n";
    print STDERR "  $cmd\n";
    open($in,"$cmd |") or error("$cmd: $!");
    while (my $line=<$in>)
    {
        chomp($line);
        my ($chr,$pos,$smpl,$gt) = split(/\t/,$line);
        my %gt = ();
        for my $x (split(m{[|/]},$gt)) { $gt{$x}=1; }   # split by the phase symbol, eg 0/1 and 0|1
        my $is_hom = scalar %gt == 1 ? 1 : 0;

        if ( !exists($dat{$chr}) ) { print STDERR "."; }
        my $bin = int($pos/$bin_size)*$bin_size + $bin_size/2;
        $dat{$chr}{$smpl}{$bin}{$is_hom}++;

        if ( !defined $chr_len{$chr} or $pos > $chr_len{$chr} ) { $chr_len{$chr} = $pos; }
        $smpl{$smpl} = 1;
    }
    close($in) or error("close failed: $cmd");
    print STDERR "\n";
    $$opts{dat} = \%dat;
    $$opts{chr} = [sort {$chr_len{$b}<=>$chr_len{$a}} keys %chr_len];
    for my $chr (keys %chr_len)
    {
        my $chr_id = $chr;
        $chr_id =~ s/\./_/g;
        if ( !($chr_id=~/^chr/i) ) { $chr_id = "chr$chr_id"; }
        $$opts{chr_id}{$chr} = $chr_id;
    }
    $$opts{smpl} = [sort keys %smpl];
    $$opts{chr_len} = \%chr_len;
}

sub generate_html
{
    my ($opts) = @_;

    my $d3js = qq[<script type="text/javascript" src="$$opts{d3_url}"></script>];
    my $pakojs = $$opts{compress} ? qq[<script type="text/javascript" src="$$opts{pako_url}"></script>] : '';
    if ( $$opts{embed_d3} )
    {
        $d3js = '<script type="text/javascript">'. embed_js($opts,$$opts{d3_url}) .'</script>';
        $pakojs = $$opts{compress} ? '<script type="text/javascript">'. embed_js($opts,$$opts{pako_url}) .'</script>' : '';
    }

    my $fh = \*STDOUT;
    if ( exists($$opts{outfile}) )
    {
        open($fh,'>',$$opts{outfile}) or error("$$opts{outfile}: $!");
    }
    print {$fh} << "EOT";
<!DOCTYPE html>
<html lang="en">
<head>
  <style>
    input[type="range"] {
        width: 200px;
        height: 20px;
        margin-left: 1rem;
    }

    #slider_div {
        display: flex;
        align-items: center;
        height: 50px;
        width: 100%;
        background-color: #faf3e0;
        padding-left: 50px;
    }
    output {
        margin-left: 1rem;
    }

    svg { font: 10px sans-serif; }

    .axis path,
    .axis line {
      fill: none;
      stroke: #000;
      shape-rendering: crispEdges;
    }

    .y.axis path {
      fill: none;
      stroke: #000;
      shape-rendering: crispEdges;
    }

    .brush .extent {
      stroke: #fff;
      fill-opacity: .125;
      shape-rendering: crispEdges;
    }

    .line { fill: none; }
  </style>

  $d3js
  $pakojs
  <script type="text/javascript" defer>

  var chr_len = [];
  var str_hom_data = [];
  var str_roh_data = [];
  var obj_data = [];
EOT

    my %chr_used = ();

    # The homozygosity rate data
    for my $chr (@{$$opts{chr}})
    {
        my $chr_id = $$opts{chr_id}{$chr};

        my @smpl = (sort keys %{$$opts{dat}{$chr}});
        for my $smpl (@smpl)
        {
            my @bin = (sort {$a<=>$b} keys %{$$opts{dat}{$chr}{$smpl}});
            if ( @bin<2 ) { next; }

            if ( !exists($chr_used{$chr}) )
            {
                $chr_used{$chr} = 1;
                print $fh qq[str_hom_data["$chr_id"] = [];\n];
            }

            my $cmd = $$opts{compress} ? "| gzip -c | base64 | tr -d \\\\n" : '';
            open(my $tmp,"$cmd > $$opts{outfile}.part") or error("$cmd > $$opts{outfile}.part: $!");
            print $tmp qq[midPoint,snpCount,homRate\n];
            for my $bin (@bin)
            {
                my $dat = $$opts{dat}{$chr}{$smpl}{$bin};
                my $nhet = exists($$dat{0}) ? $$dat{0} : 0;
                my $nhom = exists($$dat{1}) ? $$dat{1} : 0;
                if ( $nhet+$nhom==0 ) { next; }
                print $tmp join(',',$bin,$nhet+$nhom,sprintf("%.4f",$nhom/($nhet+$nhom)))."\n";
            }
            close($tmp) or error("close failed: $cmd > $$opts{outfile}.part");
            open($tmp,'<',"$$opts{outfile}.part") or error("$$opts{outfile}.part: $!");
            print $fh qq[str_hom_data["$chr_id"]["$smpl"] = `];
            while (my $line=<$tmp>) { print $fh $line; }
            print $fh qq[`;\n];
            close($tmp) or error("close failed: $$opts{outfile}.part");
            unlink("$$opts{outfile}.part");
        }
    }
    my $max_chr_len = 0;
    my @used = ();
    for my $chr (@{$$opts{chr}})
    {
        if ( !exists($chr_used{$chr}) ) { next; }
        push @used,$chr;
        if ( $max_chr_len < $$opts{chr_len}{$chr} ) { $max_chr_len = $$opts{chr_len}{$chr}; }
        my $chr_id = $$opts{chr_id}{$chr};
        print $fh qq[chr_len["$chr_id"] = $$opts{chr_len}{$chr};\n];
    }
    print $fh qq[var max_chr_len = $max_chr_len;\n];
    $$opts{chr} = \@used;

    # the roh data
    for my $chr (@{$$opts{chr}})
    {
        if ( !$chr_used{$chr} ) { next; }

        my $chr_id = $$opts{chr_id}{$chr};
        print $fh qq[str_roh_data["$chr_id"] = [];\n];

        my @smpl = (sort keys %{$$opts{dat}{$chr}});
        for my $smpl (@smpl)
        {
            my $cmd = $$opts{compress} ? "| gzip -c | base64 | tr -d \\\\n" : '';
            open(my $tmp,"$cmd > $$opts{outfile}.part") or error("$cmd > $$opts{outfile}.part: $!");

            print $tmp qq[start,end,snpCount,qual\n];
            for my $roh (@{$$opts{roh}{$chr}{$smpl}})
            {
                print $tmp $roh."\n";
            }
            close($tmp) or error("close failed: $cmd > $$opts{outfile}.part");
            open($tmp,'<',"$$opts{outfile}.part") or error("$$opts{outfile}.part: $!");
            print $fh qq[str_roh_data["$chr_id"]["$smpl"] = `];
            while (my $line=<$tmp>) { print $fh $line; }
            print $fh qq[`;\n];
            close($tmp) or error("close failed: $$opts{outfile}.part");
            unlink("$$opts{outfile}.part");
        }
    }

    my $d3_parse_hom_data = $$opts{compress} ?
        'pako.inflate(Uint8Array.from(atob(str_hom_data[chr][smpl]),c=>c.charCodeAt(0)),{to:"string"})' :
        'str_hom_data[chr][smpl]';

    my $d3_parse_roh_data = $$opts{compress} ?
        'pako.inflate(Uint8Array.from(atob(str_roh_data[chr][smpl]),c=>c.charCodeAt(0)),{to:"string"})' :
        'str_roh_data[chr][smpl]';

    my $nsmpl = scalar @{$$opts{smpl}};

    # JavaScript part
    print {$fh} << "EOT";

    var chrs = [];
    window.onload = function() {
        document.querySelectorAll(".chr").forEach((x) => {
            var chr = x.id;
            chrs.push(chr);

            // convert from base64, decompress, parse csv
            var obj = {};
            obj.ori_hom_data = [];
            for (smpl in str_hom_data[chr])
            {
                var dat = d3.csvParse($d3_parse_hom_data,function(d) {
                    return {
                        Point : +d.midPoint,
                        SnpCount : +d.snpCount,
                        Rate : +d.homRate
                    }
                });
                obj.ori_hom_data.push({key:smpl, values:dat});
            }
            obj.ori_roh_data = [];
            for (smpl in str_roh_data[chr])
            {
                var dat = d3.csvParse($d3_parse_roh_data,function(d) {
                    return {
                        Start: +d.start,
                        End: +d.end,
                        SnpCount : +d.snpCount,
                        Qual : +d.qual
                    }
                });
                obj.ori_roh_data.push({key:smpl, values:dat});
            }
            obj.scaled_hom_data = obj.ori_hom_data;
            obj.margin = {top:50, right:50, bottom:100, left:60, middle:50};
            var max_width = obj.width = window.innerWidth * 0.9;
            obj.width  = obj.width * (chr_len[chr]/max_chr_len);
            if ( obj.width < 0.25*max_width ) obj.width = 0.25*max_width;
            obj.height_roh = $nsmpl * 5;
            obj.height_hom = 150;
            obj.height = obj.height_roh + obj.height_hom + obj.margin.middle;
            obj.id  = x.id;
            obj.div = d3.select('#'+x.id);
            obj.chr = x.getAttribute('name');
            obj_data[chr] = obj;
            plot_data(obj,obj.ori_hom_data,obj.ori_roh_data);
        });
    }

    var x0,x1;
    function plot_data(obj,hom_data,roh_data)
    {
        obj.x  = d3.scaleLinear().range([ 0, obj.width ]);
        obj.yhom = d3.scaleLinear().range([ obj.height_hom, 0 ]);  // main homRate graph (bottom)
        obj.yroh = d3.scaleLinear().range([ obj.height_roh, 0 ]);  // roh graph (top)
        obj.x.domain(d3.extent(hom_data.flatMap(group=>group.values),d=>d.Point));
        obj.yhom.domain([0,1]);
        obj.yroh.domain([0,1]);
        obj.xAxis  = d3.axisBottom(obj.x);
        obj.yAxis_hom = d3.axisLeft(obj.yhom);
        obj.yAxis_roh = d3.axisLeft(obj.yroh);

        var first_time = obj.svg==undefined ? true : false;
        if ( first_time )
        {
            obj.x0 = obj.x.domain()[0];
            obj.x1 = obj.x.domain()[1];

            obj.svg = obj.div.append("svg")
                .attr("width", obj.width + obj.margin.left + obj.margin.right)
                .attr("height", obj.height + obj.margin.top + obj.margin.bottom);

            obj.graph_roh = obj.svg.append("g")
                .attr("transform", "translate(" + obj.margin.left + "," + (obj.margin.top) + ")");
            obj.graph_hom = obj.svg.append("g")
                .attr("transform", "translate(" + obj.margin.left + "," + (obj.margin.top+obj.margin.middle+obj.height_roh) + ")");

            // info line
            obj.svg
                .append('rect')
                .style("fill", "none")
                .style("pointer-events", "all")
                .style("z-index","1000")
                .attr("transform", "translate(" + obj.margin.left + "," + (obj.margin.top) + ")")
                .attr('width', obj.width)
                .attr('height', obj.height)
                .on("mouseover", function(event) {
                    obj.info_line.style("opacity",1);
                    obj.info_text.style("opacity",1);
                    obj.info_text_bg.style("opacity",0.9);
                })
                .on("mouseout", function(event) {
                    obj.info_line.style("opacity",0);
                    obj.info_text.style("opacity",0);
                    obj.info_text_bg.style("opacity",0);
                })
                .on("mousemove", function(event) { mousemove(obj,d3.pointer(event,this)); });
            obj.info_line = obj.svg
                .append('line')
                .attr("class", "mouse-line")
                .attr("stroke", "black")
                .attr("stroke-width", 1)
                .attr("pointer-events", "none")     // otherwise the line might trigger mouse events
                .style("opacity",0)
                .attr("y1", obj.margin.top - obj.height)
                .attr("y2", obj.margin.top);
            obj.info_text = obj.svg
                .append('text')
                .style("opacity", 0)
                .attr("pointer-events", "none")     // otherwise the line might trigger mouse events
                .attr("text-anchor", "start")
                .attr("alignment-baseline", "middle");
            obj.info_text_bg = obj.svg.insert("rect", "text")   // add background opacity to make the text visible
                .attr("pointer-events", "none")     // otherwise the line might trigger mouse events
                .attr("fill", "white")
                .attr("opacity", 0);

            // x-axis label
            obj.svg.append("text")
                .attr("x", (obj.width/2) )
                .attr("y",  obj.height + 90)
                .style("text-anchor", "middle")
                .text("Position on chromosome " + obj.chr);

            // y-axis label
            obj.svg.append("text")
                .attr("transform", "rotate(-90)")
                .attr("y", 70 - obj.margin.left)
                .attr("x",0 - (obj.margin.top+obj.height_roh+(obj.height+obj.margin.middle)/2))
                .attr("dy", "1em")
                .style("text-anchor", "middle")
                .text("Homozygosity rate");

            // graph title
            obj.graphName = obj.svg.append('g')
                .append('text')
                .attr("x", (obj.width / 2))
                .attr("y", 20)
                .attr("text-anchor", "middle")
                .style("font-size", "16px")
                .text("Chromosome " + obj.chr);

            // color palette
            obj.samples = hom_data.map(function(d){ return d.key }) // list of group names
                obj.colors = d3.scaleOrdinal()
                .domain(obj.samples)
                .range(["#1f77b4","#ff7f0e","#2ca02c","#d62728","#9467bd","#8c564b","#e377c2","#7f7f7f","#bcbd22","#17becf"])//d3-scale-chromatic, Category 10
        }
        else
        {
            //remove drawn paths
            obj.hom_lines.remove();
            obj.roh_lines.remove();
        }

        // the homozygosity rate data
        obj.hom_lines = obj.graph_hom.append("g");
        obj.hom_lines.selectAll(".line")
            .data(hom_data)
            .enter()
            .append("path")
            .attr("class", "line")
            .attr("fill", "none")
            .attr("stroke-width", 1.5)
            .attr("stroke", function(d){ return obj.colors(d.key) })
            .attr("d", function(d){
                x = d3.line()
                    .x(function(d) { return obj.x(d.Point); })
                    .y(function(d) { return obj.yhom(d.Rate); })
                    (d.values);
                return x;
                });

        // the roh data
        obj.roh_lines = obj.graph_roh.append("g");
        obj.roh_lines.selectAll(".group")
            .data(roh_data)     // bind the parent data, each object with a key (sample) and values (data points)
            .enter()
            .append("g")        // create a group for each key (sample)
            .attr("class", "group")
            .each(function(d,groupIndex) {
                d3.select(this)
                    .selectAll(".rect")
                    .data(d.values) // Bind values array for each key
                    .enter()
                    .append("rect")
                    .attr("class", "rect")
                    .attr("x", function(v) { return obj.width*(v.Start - obj.x0)/(obj.x1-obj.x0); })
                    .attr("y", function(v, i) { return groupIndex*5; })
                    .attr("width", function(v) { return obj.width*(v.End - v.Start)/(obj.x1-obj.x0); })
                    .attr("height", 4)
                    .attr("fill", function() { return obj.colors(d.key); });
            });

        if ( first_time )
        {
            obj.graph_hom.append("g")
                .attr("class", "axis axis--x")
                .attr("transform", "translate(0," + (obj.height_hom-1) + ")")
                .call(obj.xAxis);
            obj.graph_hom.append("g")
                .attr("class", "axis axis--y")
                .call(obj.yAxis_hom);

            obj.legend = obj.svg.selectAll(".legend")
                .data(hom_data)
                .enter()
                .append("g")
                .attr("class", "legend")
                .attr("transform", (d,i) => "translate("+obj.width*0.9+","+(10+20*i)+")");
            obj.legend.append("rect")
                .attr("width", 8)
                .attr("height", 8)
                .attr("fill", function(d){ return obj.colors(d.key) })
            obj.legend.append("text")
                .attr("x", 15)
                .attr("y", 10)
                .text(d => d.key)
                .style("font-size", "12px")
                .style("text-anchor", "start");
        }
    }

    // the zoom slider was used, update the view with a new interval size
    var dflt_bin_size = $$opts{bin_size};
    function update_slider(slider,value)
    {
        slider.nextElementSibling.value = value;
        const formattedValue = Number(slider.value).toLocaleString();
        slider.nextElementSibling.value = formattedValue+' bp';
        var bin_size = slider.value;

        for (chr in obj_data)
        {
            var obj = obj_data[chr];
            obj.scaled_hom_data = rescale_hom_data(obj,bin_size);
            plot_data(obj,obj.scaled_hom_data,obj.ori_roh_data);
        }
    }
    function rescale_hom_data(obj,bin_size)
    {
        // slider moved to starting position
        if ( bin_size==dflt_bin_size ) return obj.ori_hom_data;

        var scaled = [];
        for (let ismpl=0; ismpl<obj.ori_hom_data.length; ismpl++)
        {
            var xscaled = [];
            var ntot = 0;
            var nhom = 0;
            var bin  = -1;
            const rec = obj.ori_hom_data[ismpl].values;
            for (let jbin=0; jbin<rec.length; jbin++)
            {
                const x = rec[jbin];
                var xbin = bin_size*Math.round(x.Point/bin_size) + bin_size/2;
                if ( bin==-1 ) bin = xbin;
                if ( bin!=xbin ) // flush
                {
                    var rate = ntot ? nhom/ntot : 0;
                    xscaled.push({Point:xbin,SnpCount:ntot,Rate:rate});
                    ntot = 0;
                    nhom = 0;
                    bin  = xbin;
                }
                ntot += x.SnpCount;
                nhom += x.SnpCount * x.Rate;
            }
            scaled.push({key:obj.ori_hom_data[ismpl].key, values:xscaled});
        }
        return scaled;
    }

    function mousemove(obj,dat)
    {
        var x = dat[0];
        var y = dat[1];
        obj.info_line.attr("transform", "translate("+(x+obj.margin.left)+","+(obj.height)+")");

        var x0 = obj.x0;
        var x1 = obj.x1;

        var pos = Math.round(x0+(x1-x0)*x/obj.width);
        var txt = 'Position '+ pos.toLocaleString() +"\\n";

        var roh_hdr_printed = 0;
        for (let ismpl=0; ismpl<obj.ori_roh_data.length; ismpl++)
        {
            const rec = obj.ori_roh_data[ismpl].values;
            for (let jbin=0; jbin<rec.length; jbin++)
            {
                const x = rec[jbin];
                if ( x.End < pos ) continue;
                if ( x.Start > pos ) break;
                if ( !roh_hdr_printed )
                {
                    roh_hdr_printed = 1;
                    txt += "\\nSample / VariantCount / ROH Call Quality / Start-End\\n";
                }
                txt += "\\t" + obj.ori_roh_data[ismpl].key + " / "+x.SnpCount.toLocaleString()+" / "+x.Qual + " / " + x.Start.toLocaleString() + " - " + x.End.toLocaleString() +"\\n";
            }
        }

        txt += "\\nSample / VariantCount / HomRate\\n";
        for (let ismpl=0; ismpl<obj.scaled_hom_data.length; ismpl++)
        {
            const rec = obj.scaled_hom_data[ismpl].values;
            txt += "\\t" + obj.scaled_hom_data[ismpl].key;
            for (let jbin=0; jbin<rec.length; jbin++)
            {
                const x = rec[jbin];
                if ( x.Point < pos ) continue;
                txt += " / "+x.SnpCount.toLocaleString()+" / "+x.Rate.toFixed(4);
                break;
            }
            txt += "\\n";
        }

        var anchor = x < obj.width*0.5 ? "start" : "end";
        var x_txt  = x < obj.width*0.5 ? x+obj.margin.left+50  : x+obj.margin.left-50;
        obj.info_text
            .html(txt)
            .style("white-space","pre-wrap")
            .attr("text-anchor", anchor)
            .attr("x", x_txt)
            .attr("y", obj.height*0.2+obj.margin.top);

        const bbox = obj.info_text.node().getBBox();
        obj.info_text_bg
            .attr("x", bbox.x - 4) // Add some padding
            .attr("y", bbox.y - 4)
            .attr("width", bbox.width + 4)
            .attr("height", bbox.height + 4);
    }
  </script>
EOT


    # HTML part
    my @cmd = qq[This file was produced with];
    if ( exists($$opts{roh_cmd}) ) { push @cmd,qq[<span style="margin-left:3em;font-family:monospace">$$opts{roh_cmd}</span>]; }
    if ( exists($$opts{cmd}) ) { push @cmd,qq[<span style="margin-left:3em;font-family:monospace">$$opts{cmd}</span>]; }
    my $cmd = join('<br>',@cmd);

    my $bin_size = format_number_with_commas($$opts{bin_size});
    print {$fh} << "EOT";

  </head>
  <body>
  <div id="slider_div">
    Bin size
    <input type="range" min="$$opts{bin_size}" max="2000000" step="$$opts{bin_size}" value="$$opts{bin_size}" oninput="update_slider(this,this.value)">
    <output>$bin_size bp</output>
  </div>

EOT

    for my $chr (@{$$opts{chr}})
    {
        print $fh qq[<div id="$$opts{chr_id}{$chr}" name="$chr" class="chr"></div>\n];
    }

    print {$fh} << "EOT";
  $cmd
</body>
</html>
EOT

    if ( exists($$opts{outfile}) )
    {
        close($fh) or error("close failed: $$opts{outfile}");
    }
}

sub embed_js
{
    my ($opts,$file) = @_;
    if ( $file=~m{^http}i )
    {
        if ( !($file=~m{([^/]+)$}) ) { error("Could not parse the file name: $file"); }
        my $dat;
        my $name = $1;
        if ( -e $name )
        {
            $dat = join('',`cat $name`);
        }
        else
        {
            my $tmp = "$$opts{outfile}.rmme";
            cmd(qq[wget -O $tmp $file]);
            $dat = join('',`cat $tmp`);
            unlink($tmp);
        }
        return $dat;
    }
    return join('',`cat $file`);
}