use strict;
use warnings;

use Irssi;
use Irssi::TextUI;              # for sbar_items_redraw
use Data::Dumper;
use Term::Size;



our $VERSION = "0.1";
our %IRSSI =
  (
   authors         => "shabble",
   contact         => 'shabble+irssi@metavore.org, shabble@#irssi/Freenode',
   name            => "prompt_info",
   description     => "Helper script for dynamically adding text "
   . "into the input-bar prompt.",
   license         => "Public Domain",
   changed         => "24/7/2010"
  );

sub DEBUG () { 1 }
#sub DEBUG () { 0 }

my $prompt_data = undef;
my $prompt_item = undef;

my $vis_enabled = 0;

my ($term_w, $term_h) = (0, 0);

my ($region_start, $region_end) = (0, 0);

init();

sub update_terminal_size {

    my @stty_lines = qx/stty -a/;
    my $line = $stty_lines[0];
    @stty_lines = ();           # don't need the rest.

    if ($line =~ m/\s*(\d+)\s*rows\s*;\s*(\d+)\s*columns\s*;/) {
        $term_h = $1;
        $term_w = $2;
    } else {
        print "Failed to detect terminal size";
    }
}

sub init {

    Irssi::command_bind('prompt_on', \&replace_prompt_items);
    Irssi::command_bind('prompt_off', \&restore_prompt_items);

    Irssi::command_bind('menu', \&draw_menu);

    Irssi::command_bind('prompt_set',
                        sub {
                            my $data = shift;
                            $prompt_data = $data;
                            refresh_prompt();
                        });

    Irssi::command_bind('prompt_clear',
                        sub {
                            $prompt_data = undef;
                            refresh_prompt();
                        });

    Irssi::command_bind('visual', \&cmd_toggle_visual);
    Irssi::command("^BIND meta-l /visual");

    Irssi::signal_add_last('command redraw', sub {
                               print "Redrawing";
                               refresh_prompt();
                               Irssi::timeout_add_once(10, \&refresh_inputline, 0);
                               });

    Irssi::statusbar_item_register ('new_prompt', 0, 'new_prompt_render');

    Irssi::signal_add_first('gui key pressed', \&ctrl_l_intercept);
    Irssi::signal_add_last ('gui key pressed', \&key_pressed);

    Irssi::signal_add('window changed', \&refresh_prompt);
    Irssi::signal_add('window name changed', \&refresh_prompt);
    Irssi::signal_add('window changed automatic', \&refresh_prompt);
    Irssi::signal_add('window item changed', \&refresh_prompt);

    Irssi::signal_add('terminal resized', \&update_terminal_size);

    update_terminal_size();
    replace_prompt_items();
}


sub UNLOAD {
    restore_prompt_items();
}

sub cmd_toggle_visual {
    $vis_enabled = not $vis_enabled;
    if ($vis_enabled) {
        $region_start = _pos();
        $region_end   = 0; # reset end marker.
        print "visual mode started at $region_start";
    } else {
        $region_end = _pos();
        print "Visual mode ended at $region_end";

        if ($region_end > $region_start) {
            my $input = Irssi::parse_special('$L', 0, 0);
            my $str = substr($input, $region_start, $region_end - $region_start);
            print "Region selected: $str";
        } else {
            print "Invalid region selection: [ $region_start - $region_end ]";
            $region_start = $region_end = 0;
        }
    }

}

sub refresh_prompt {
    Irssi::statusbar_items_redraw('new_prompt');
}

sub ctrl_l_intercept {
    my $key = shift;

    if ($key == 12) {
        print "C-l pressed";
        Irssi::command("redraw");
        Irssi::signal_stop();
    }
    if ($key == 10) {
        $region_end = $region_start = 0;
    }
}

sub key_pressed {
    my $key = shift;
    return unless $vis_enabled;
    refresh_inputline();
}

sub refresh_inputline {

    my $end_pos = $region_end;
    $end_pos  ||= _pos(); # if not set, take current position as end.

    my $len = $end_pos - $region_start;
    return unless $len; # no point drawing an empty overlay

    my $input = Irssi::parse_special('$L');
    my $offset = $prompt_item->{size} + $region_start;

    my $text = substr($input, $region_start, $len);

    print "printing '$text' at $offset [$region_start, $end_pos] ($len)";

    $text = '%k%2' . $text . '%n';
    _draw_overlay($offset, $text, $len);

}

sub _draw_overlay {
    my ($offset, $text, $len) = @_;
    Irssi::gui_printtext($offset, $term_h, $text);
}

sub draw_menu {

    my $w = 10;

    my @lines = (
                 '+' . ('-' x $w) . '+',
                 sprintf('|%*s|', $w, 'bacon'),
                 sprintf('|%*s|', $w, 'bacon'),
                 sprintf('|%*s|', $w, 'bacon'),
                 sprintf('|%*s|', $w, 'bacon'),
                 sprintf('|%*s|', $w, 'bacon'),
                 sprintf('|%*s|', $w, 'bacon'),
                 '+' . ('-' x $w) . '+',
                );
    my $i = 10; # start vert offset.
    for my $line (@lines) {
        Irssi::gui_printtext(int ($term_w / 2), $i++, $line);
    }
}

sub new_prompt_render {
    my ($sb_item, $get_size_only) = @_;


    my $default_prompt = '';

    my $window = Irssi::active_win();
    if (scalar( () = $window->items )) {
        $default_prompt = '{prompt $[.15]itemname}';
    } else {
        $default_prompt = '{prompt $winname}';
    }

    my $p_copy = $prompt_data;
    if (defined $prompt_data) {
        # check if we have a marker
        $p_copy =~ s/\$p/$default_prompt/;
    } else {
        $p_copy = $default_prompt;
    }
    print "Redrawing with: $p_copy, size-only: $get_size_only";

    $prompt_item = $sb_item;

    $sb_item->default_handler($get_size_only, $p_copy, '', 0);
}

sub replace_prompt_items {
    # remove existing ones.
    print "Removing original prompt" if DEBUG;

    _sbar_command('prompt', 'remove', 'prompt');
    _sbar_command('prompt', 'remove', 'prompt_empty');

    # add the new one.

    _sbar_command('prompt', 'add', 'new_prompt',
                  qw/-alignment left -before input -priority 0/);

}

sub restore_prompt_items {

    _sbar_command('prompt', 'remove', 'new_prompt');

    print "Restoring original prompt" if DEBUG;
    _sbar_command('prompt', 'add', 'prompt',
                  qw/-alignment left -before input -priority 0/);
    _sbar_command('prompt', 'add', 'prompt_empty',
                  qw/-alignment left -after prompt -priority 0/);
}


sub _sbar_command {
    my ($bar, $cmd, $item, @args) = @_;

    my $args_str = join ' ', @args;

    $args_str .= ' ' if length $args_str;

    my $command = sprintf 'STATUSBAR %s %s %s%s',
      $bar, $cmd, $args_str, defined($item)?$item:'';

    print "Running command: $command" if DEBUG;
    Irssi::command($command);
}


sub _pos {
    return Irssi::gui_input_get_pos();
}


# my $prompt_additional_content = '';

# Irssi::expando_create('prompt_additional', \&expando_prompt, {});

# sub expando_prompt {
#     my ($server, $witem, $arg) = @_;
#     return $prompt_additional_content;
#     #return Irssi::current_theme->format_expand("{sb
#     #$prompt_additional_content}", 0x0f);
# }

# sub redraw_prompts {
#     Irssi::statusbar_items_redraw ('prompt');
#     Irssi::statusbar_items_redraw ('prompt_empty');
# }

# sub handle_change_prompt_sig {
#     my ($text) = @_;

#     my $expanded_text = Irssi::parse_special($text);

#     print "Got prompt change sig with: $text -> $expanded_text" if DEBUG;

#     my $changed = ($expanded_text ne $prompt_additional_content);

#     $prompt_additional_content = $expanded_text;

#     if ($changed) {
#         print "Redrawing prompts" if DEBUG;
#         redraw_prompts();
#     }
# }

# sub prompt_additional_cmd {
#     my ($str) = @_;
#     print "Setting prompt to: $str" if DEBUG;
#     Irssi::signal_emit('change prompt', $str);
# }

# test_abstract_setup();
# Irssi::signal_register({'change prompt' => [qw/string/]});
# Irssi::signal_add('change prompt' => \&handle_change_prompt_sig);

# Irssi::command_bind('set_prompt' => \&prompt_additional_cmd);

# sub test_abstract_setup {
#     my $theme = Irssi::current_theme();
#     my $prompt = $theme->format_expand('{prompt}', 0);
#     if ($prompt !~ m/\$prompt_additional/) {
#         print "Prompt_Info: It looks like you haven't modified your theme"
#           . " to include the \$prompt_additional expando.  You will not see"
#             . " any prompt info messages until you do. See script comments"
#               . "for details";
#     }
# }