use strict; 
use warnings; 
use CSS; 
use CSS::Selector::Parser 'parse_selector'; 
use HTML::Selector::XPath 'selector_to_xpath';  
use HTML::TreeBuilder::XPath;  
use Data::Dumper;  
 
# input 
my $input = 
{ 
    filepaths_css  => [ glob( "*.css"  ) ], 
    filepaths_html => [ glob( "*.html" ) ], 
    properties     => [ qw/margin width/ ], 
}; 
 
# output 
my $output = { }; 
 
# iterate over each css file 
for my $filepath_css ( @{$input->{filepaths_css}} ) 
{     
    # create new css object and populate it 
    my $css = CSS->new; $css->read_file( $filepath_css ); 
 
    # iterate over each css block 
    for my $style ( @{$css->{styles}} )  
    {  
        # create list of properties that match those we want 
        my $properties = [ grep { $style->get_property_by_name( $_ ) } @{$input->{properties}} ]; 
 
        # next iteration if list of properties that match is empty 
        next unless @$properties; 
 
        # iterate over each selector 
        for my $selector ( map { $_->{name} } @{$style->{selectors}} ) 
        { 
            # if we have not seen this selector before, populate output with selector and xpath 
            unless ( exists $output->{$selector} ) 
            { 
                $output->{$selector}->{selector} = eval { ( parse_selector( $selector ) )[0] }; 
                $output->{$selector}->{xpath}    = eval { selector_to_xpath( $selector )     }; 
            } 
 
            # populate output with property and css counts 
            $output->{$selector}->{properties}->{$_}++ for @$properties; 
            $output->{$selector}->{css}->{$filepath_css}++; 
        } 
    } 
} 
 
# iterate over each html file 
for my $filepath_html ( @{$input->{filepaths_html}} ) 
{ 
    # create new tree object and populate it 
    my $tree = HTML::TreeBuilder::XPath->new_from_file( $filepath_html ); 
 
    # iterate over each selector 
    for my $selector ( grep { defined $output->{$_}->{xpath} } keys %$output ) 
    { 
        # populate output with html counts 
        my $count = $tree->findnodes( $output->{$selector}->{xpath} )->size; 
        $output->{$selector}->{html}->{$filepath_html} += $count if $count; 
    } 
} 
 
# output 
local $, = "\n"; 
local $\ = "\n"; 
 
for my $selector ( sort keys %$output )  
{ 
    my $ref = $output->{$selector}; 
 
    print "report for selector $selector"; 
 
    ########## 
 
    print "\tclass:"; 
    if ( exists $ref->{selector}->[-1]->{class} ) 
    { 
        if ( @{$ref->{selector}} > 1 ) 
        { 
            print "\t\tthis selector is an indirect class selector that refers to the class $ref->{selector}->[-1]->{class}"; 
        } 
        else 
        { 
            print "\t\tthis selector is a direct class selector that refers to the class $ref->{selector}->[-1]->{class}"; 
        } 
    } 
    else 
    { 
        print "\t\tthis selector is not a class selector"; 
    }     
 
    ########## 
 
    print "\tproperties:";    
    while ( my ( $property, $count ) = each %{$ref->{properties}} ) 
    { 
        print "\t\tthe property $property is referenced $count times across all css files"; 
    } 
 
    ########## 
 
    print "\tcss:"; 
    while ( my ( $filepath_css, $count ) = each %{$ref->{css}} ) 
    { 
        print "\t\tthis selector is referenced $count times in the css file $filepath_css"; 
    } 
 
    ########## 
 
    print "\thtml:"; 
    if ( defined $ref->{xpath} ) 
    { 
        if ( keys %{$ref->{html}} ) 
        { 
            while ( my ( $filepath_html, $count ) = each %{$ref->{html}} ) 
            { 
                print "\t\tthis selector is referenced $count times in the html file $filepath_html"; 
            } 
        } 
        else 
        { 
            print "\t\tthis selector is not referenced in any of the html files"; 
        } 
    } 
    else 
    { 
        print "\t\tthis selector could not be converted to an xpath, therefore we were unable to check if its referenced across any html files"; 
    } 
 
    ########## 
 
    print ''; 
}