#!/usr/bin/perl -w
#connex.pl Nightfall Express (nex://) browser
#TODO: Some branding (status popup on load?, Connex menu item?), About dialog 
#TODO: Help dialog

use strict;
use warnings;
use strict;
use Curses::UI;
use Net::Telnet;
use URI::Split qw(uri_split uri_join);
use URI ();

my $HOST_DEFAULT = "nightfall.city";
my $PATHSPEC_DEFAULT = '';
my $PORT_DEFAULT = 1900;
my $SCHEME_NEX = "nex";

my $host = "nightfall.city";
my $port = "1900";
my $pathspec = "";
my $docname; # = "";
my $doctype = "txt";
my $dot_ext = ".";


my $HOME_URL = uri_join($SCHEME_NEX,$HOST_DEFAULT);

#if argument entered, it should be a nex url:
my $full_url= $ARGV[0];
if (defined $full_url){	
	my $uri=URI->new($full_url, $SCHEME_NEX);
	if ($uri->scheme ne $SCHEME_NEX){
		die "need a $SCHEME_NEX url, or start without supplying URL argument.\n";
	}
	$full_url= $uri->as_string;		
}else{
	$full_url = $HOME_URL;
}

my @history;
my @page_links;

my $statusbar;
my $navwindow;
my $win1;
my $cui = new Curses::UI( -color_support => 1 );
my $connect = new Net::Telnet (Timeout => 10,
                      Errmode => 'return');
my @menu = (
  { -label => 'File', 
    -submenu => [
   { -label => 'Choose Link    >', -value => \&goto_link_dialog },
   { -label => 'Back        ^B/<', -value => \&goto_back  },
   { -label => 'Go to Link    ^G', -value => \&navigate_link_dialog },
   { -label => 'Page Links    ^P', -value => \&page_links_dialog  },
   { -label => 'History       ^Y', -value => \&history_status_dialog  },
   { -label => 'Exit          ^Q', -value => \&exit_dialog  }
                ]
   },
   { -label => 'Help',
	 -submenu => [
   { -label => 'Help  ^H', -value => \&help_dialog },
   { -label => 'About   ', -value => \&about_dialog },
				]
   }, 

);

sub exit_dialog()
{
        my $return = $cui->dialog(
                -title   => "Quit Connex?",
                -message     => "Are you sure?", 
                -buttons   => ['yes', 'no'],
 
        );
 
exit(0) if $return;
}


sub links_dialog()
{
        my $return = $cui->dialog(
                -message   => page_links_list(),
                -title     => "Page Links", 
                -buttons   => ['ok'],
 
        );
 
}

sub unsupported_dialog
{
		my $scheme = shift;
        my $return = $cui->dialog(
                -message   => "$scheme protocol not supported.",
                -title     => "Bad Navigation", 
                -buttons   => ['ok'],
 
        );

}

sub navigate_link_dialog()
{
	my $return = $cui->question(-question => "This is [$full_url]. Enter destination link:",
								-answer => $full_url,
							); 
	#if not user canceled then navigate
	if($return){
		navigate($return);
		update_status_bar();
	}
}


sub goto_link_dialog()
{	
	my $return = $cui->question(-question => "Enter link #:",
							); 
	#if not canceled, or too big or too small, goto link
	if($return){
		my $linkcount = scalar @page_links;
		if($return <= $linkcount && $return >0){
			goto_link($return);
			update_status_bar();
		}else{
			#$browser->focus();
			my $return1 = $cui->status("there is no link # " . $return);
		}
	#do nothing on cancel
	}
}





sub goto_back()
{
	my $fetched = fetch_history();
	#if($fetched) {
		$full_url =$fetched;
		load($full_url,0); #don't move back to top
		update_status_bar();
		history_status_dialog();
	#}

}



sub goto_link{
	my $linknum = shift;
	my $linkcount = scalar @page_links;
	
 	#my $element=$linknum -1; #offset for array element
 	#if ($element <=  $#page_links){  #such a perlism, this is highest INDEX of array

 	if ($linknum <=  $linkcount){  #such a perlism, this is highest INDEX of array
		 navigate($page_links[$linknum-1]);	#offset from count to index
 	}else{
		#my $browser = $win1->getobj("browser");	
		#$browser->focus();
		my $return = $cui->status("no link # " . $linknum);
	}

}


sub navigate{
	my $link = shift;
	add_history($full_url);  #add last link to history before going forward!
	$full_url = $link;
	load($full_url, 1); #new URL go to top of page
 
}


sub update_status_bar
{
	my $browser = $win1->getobj("browser");
	my $statusbar = $win1->getobj("status");
	#$full_url = construct_valid_url($SCHEME_NEX, $host, $pathspec, $docname);
	$statusbar->text("$full_url" . " | Press '>' key to enter link #. ctl-x for Menu. '<' to go back.");
	$statusbar->draw();
	$browser->focus();
	

}


sub add_history
{
	my $link = shift;
	push(@history, $link);
	history_status_dialog();
	return;
}

sub fetch_history
{
	my $latest;
	if(@history) {
		$latest = pop(@history);
		return $latest;
	}else{
    	return($HOME_URL);
	}
}


sub history_status_dialog
{
	if(@history){
		my $browser = $win1->getobj("browser");	
		$browser->focus();
		my $history_list = join("\n", @history);
		my $return = $cui->status("history:\n$history_list");
	}
}


sub page_links_dialog
{
	if(@page_links){
		my $browser = $win1->getobj("browser");	
		$browser->focus();
		#my $link_list = join("\n", @page_links);
		my $link_list = page_links_list();
		my $return = $cui->status("links on this page:\n$link_list");
	}
}


sub page_links_list
{
	if(@page_links){
		my $browser = $win1->getobj("browser");	
		$browser->focus();
		#my $link_list = join("\n", @page_links);
		my $link_list="";
		my $link;
		my $count=0;
		foreach $link (@page_links){
			$count+=1;
			$link_list = $link_list . "[$count] $link\n";
		}
		return  $link_list;
	}
}

sub about_dialog
{
	my $browser = $win1->getobj("browser");	
	$browser->focus();
	my $return = $cui->status("Connex browser\n by gorf\@rawtext.club\n 2024");
}

sub help_dialog
{
	my $browser = $win1->getobj("browser");	
	$browser->focus();
	my $message = <<'END_MESSAGE';
Navigation:
Press '>' key to select a '[>#]link by #
Press '<' key to go back to previous page

Program Features:
Press ctl-x for menu
END_MESSAGE
	
    my $return = $cui->dialog(
	    -message   => $message,
        -title     => "Connex Help", 
        -buttons   => ['ok'],
 
        );

}

my $menu = $cui->add(
        'menu','Menubar', 
        -menu => \@menu,
        -fg  => "blue",
);


$win1 = $cui->add(
                     'win1', 'Window',
                     -title => "Connex, a Nightfall Express (nex://) browser",
                     -border => 1,
                     -y    => 1,
                     -bfg  => 'red',
                     -vscrollbar => 'right',
                     );


                     

my $texteditor = $win1->add("browser", "TextViewer",
                        -text => "Start Page",
                        -border 	 => 1,
                       	-padtop		 => 0,	
                   		-padbottom 	 => 3,
            			-showlines	 => 0,
                     	-sbborder	 => 0,
                  		-vscrollbar	 => 1,
              			-hscrollbar	 => 1, 
          				-showhardreturns => 0,
                   		-wrapping        => 0, # wrapping slows down the editor :-(
                         );


$statusbar = $win1->add("status", "TextViewer",
	                     -border => 1,
        	             -bfg  => 'red',
        	             -y => -1,
        	             -height => 1,
        	             -width => -1,
        	             -reverse => 1,
        	             -paddingspaces => 1,
                         -text => "$full_url | Press '>' key to enter link #; ctl-x for menu; '<' to go back.",
                         );
                         

#key bindings, should match menu items
$cui->set_binding(sub {$menu->focus()}, "\cX");
$cui->set_binding( \&exit_dialog , "\cQ");
$cui->set_binding( \&navigate_link_dialog , "\cG");
$cui->set_binding( \&goto_back , "\cB");
$cui->set_binding( \&goto_back , "<");
$cui->set_binding( \&goto_link_dialog , ">");
$cui->set_binding( \&page_links_dialog , "\cP");
$cui->set_binding( \&history_status_dialog , "\cY");
$cui->set_binding( \&help_dialog , "\cH");
$cui->set_binding(sub {
        my $cui = shift;
        $cui->layout;
        $cui->draw;
}, "\cL");



# There is no need for the editor widget to loose focus, so
# the "loose-focus" binding is disabled here. This also enables the
# use of the "TAB" key in the editor, which is nice to have.
#$texteditor->clear_binding('loose-focus');

#start up
$texteditor->focus();

navigate($full_url);
$cui->mainloop();


#make nex:// urls from parts, relative urls
sub construct_valid_url #scheme, host, pathspec, docname
{
	my $scheme = shift;
	my $host = shift;
	my $pathspec = shift;
	my $docname = shift;
	if (defined($docname)){
		$pathspec= $pathspec . '/' . $docname; #this is just local pathspec
	}
	my $url = uri_join($scheme, $host, $pathspec);
 	return $url;
}

sub is_path_index{
	my $path = shift;
	my $result = 1;
	if ($path !~ /\/$/ && $path =~ /\.[a-zA-Z]*$/){
		$result =0;
	}
	return($result);
}

sub add_page_link{
	my $linkline = shift;
	my $base_url = shift;
	my $uri_object;
	#my $link= $linkline=~ s/^=>[ ]*(.*$)/$1/r;
	local $URI::ABS_ALLOW_RELATIVE_SCHEME = 1;
	local $URI::ABS_REMOTE_LEADING_DOTS = 1;
	$uri_object=URI->new_abs($linkline=~ /^=>[ ]+([^ ]*)/,$base_url);
	
	push(@page_links, $uri_object->as_string);
	my $count = scalar @page_links; #scalar is size/count of links, but $#page_links is highest INDEX
	return $linkline =~ s/(^=>.*$)/$1 [\>$count\]/r;

}


sub load
{
    my @lines;
	my $ok;
	my $url = shift;
	my $top = shift;
	#my $scheme, $host, $path, $query, $frag;
	my ($scheme, $host, $path, $query, $frag) = uri_split($url);
	#what happens with different scheme?
	if ($scheme eq $SCHEME_NEX){
		$connect->host($host);
		$connect->port($port);
		$ok= $connect->open($host);
		$ok= $connect->print($path);
		@lines =$connect->getlines(ErrMode=> 'return');
    	print $connect->eof();
		#handle non-existant request?
    	die unless $connect->eof();
		$connect->close();
    	my $widget= $texteditor;

    	#loop through nex response and load into text editor. Identify, mark and store link lines for index pages
    	#TODO: store link lines for index pages
    	my $page_contents =""; #this is the page contents
    	my $currentline;
    	my $count=0;
    	my $is_index= is_path_index($path);
    	undef @page_links; #clear list
		foreach $currentline (@lines){
			if ($currentline =~ m/^=>/){
				if ($is_index){
					$currentline = add_page_link($currentline, $url);
				}
   	     	}
			$page_contents= $page_contents . $currentline;
		}
	 	$widget->text($page_contents);
	 	$widget->draw();
	 	if ($top){
			$widget->pos(0);
	 	}
	 }else{
	 	#can't load non-nex as of now
		my $browser = $win1->getobj("browser");	
		$browser->focus();
		my $return = unsupported_dialog($scheme);
		#pop and trash history
	    my $fetched = fetch_history();
		
	 }


}