#!/usr/bin/perl

use strict;
use warnings;
use Carp;
#use HTML::Template;

$SIG{__WARN__} = sub { die @_; };

sub DisplayUsage
{
    my $options_ref = shift;
    my @options = @$options_ref;

    print "Usage:\n";
    for my $opt (@options)
    {
        my $opt_str = "  " . (defined $opt->{sopt} ? "-$opt->{sopt}, " : "    ");
        $opt_str   .=        (defined $opt->{lopt} ? "--$opt->{lopt}"  : "");

        if (lc $opt->{arg} eq "required")
        {
            $opt_str .= "=<value>";
        }
        elsif (lc $opt->{arg} eq "optional")
        {
            $opt_str .= "[=<value>]";
        }

        print $opt_str . "\n      " . ($opt->{desc} // "") . "\n\n";
    }

    exit 0;
}

sub HandleArgs
{
    my ($args_ref, $options_ref) = @_;

    my @args = @$args_ref;
    my @options = @$options_ref;

    for my $arg (@args)
    {
        if ($arg =~ m@^(-(?<sopts>\w{2,})|-(?<sopt>\w)|-+(?<lopt>[\w-]+))(=(?<optarg>.+))?\z@i)
        {
            my @soptlist;
            @soptlist = split //, $+{sopts} if defined $+{sopts};
            
            my $optarg;
            my $handled = 1;
            
            DisplayUsage($options_ref)
                if ((defined $+{sopt} and $+{sopt} eq "h") or
                    (defined $+{lopt} and $+{lopt} eq "help"));
            
            for my $opt (@options)
            {
                die "No option name to handle!"
                    unless defined $opt->{lopt} or defined $opt->{sopt};
                
                if (defined $opt->{sopt})
                {
                    if (grep { $_ eq $opt->{sopt} // () } @soptlist)
                    {
                        die "Option -$opt->{sopt} cannot be in a list as it requires an argument!\n"
                            if $opt->{arg} eq "required";
                        
                        $opt->{handler}();
                    }
                    # will make these look better later
                    elsif (defined $+{sopt} and defined $+{sopt}
                           and $+{sopt} eq $opt->{sopt})
                    {
                        $optarg = $+{optarg} // ();
                        $opt->{handler}($optarg);
                    }
                }
                
                if (defined $opt->{lopt} and defined $+{lopt}
                    and $+{lopt} eq $opt->{lopt})
                {
                    $optarg = $+{optarg} // ();
                    $opt->{handler}($optarg);
                }
            }
            
            die "Unrecognized option: $arg\n"
                unless $handled;
        }
    }
}

sub HandleConf
{
    my $filename = shift;
    print "Loading configuration from: $filename\n";
}

my @optArray = (
    {
        lopt    => "config",
        sopt    => "c",
        desc    => "Loads a custom config file at a specified path.",
        arg     => "required",
        handler => \&HandleConf
    },
    {
        lopt    => "new-post",
        sopt    => "n",
        desc    => "Create a new post.",
        arg     => "none",
        handler => sub { print "do something\n"; }
    },
    {
        lopt    => "build",
        sopt    => "b",
        desc    => "Build all posts and templates into HTML.",
        arg     => "optional",
        handler => sub { print "do something\n"; }
    },
    {
        lopt    => "publish",
        sopt    => "p",
        desc    => "Publish built files.",
        arg     => "none",
        handler => sub { print "do something\n"; }
    },
);

sub Main
{
    HandleArgs(\@ARGV, \@optArray);
}

&Main();
exit 0;