use strict;

use File::Temp qw(tmpnam tempfile tempdir);
use IO::Socket::UNIX;
use POSIX qw(mkfifo);

use Irssi;

our $VERSION = '1.00';
our %IRSSI = {
	authors     => 'Teddy Wing',
	contact     => 'irssi@teddywing.com',
	name        => 'Vimput',
	description => '',
	license     => 'GPL',
};


use constant VIMPUT_IPC_COMMAND_PREFIX => '%%%___VIMPUT___%%%: ';
use constant CTRL_X => 24;


# The location of the temporary file where prompt contents are written.
sub vimput_file {
	Irssi::get_irssi_dir() . '/VIMPUT_MSG';
}


# Write the given string to our vimput_file.
sub write_input {
	my ($message) = @_;

	open my $handle, '>', vimput_file or die $!;
	print $handle $message;
	close $handle;
}


# Open a Tmux split containing a Vim instance editing the vimput_file.
sub open_tmux_split {
	my ($fifo) = @_;

	if (!$ENV{TMUX}) {
		print 'no tmux'; # TODO: Replace with Irssi print
						 # MSGLEVEL_CLIENTERROR
		return;
	}

	my $random_unused_filename = tmpnam();

	my $command = "vim -c 'set buftype=acwrite' -c 'read ${\vimput_file}' -c '1 delete _' -c 'autocmd BufWriteCmd <buffer> :write $fifo | set nomodified' $random_unused_filename";
	system('tmux', 'split-window', $command);
}


sub update_input_line_when_finished {
	my ($read_handle, $write_handle, $command_handle, $fuckface);

	pipe($read_handle, $write_handle);
	pipe($fuckface, $command_handle);

	my $pid = fork();

	if (!defined $pid) {
		print "Failed to fork: $!";  # TODO: Irssi print
		close $read_handle;
		close $write_handle;
		close $command_handle;
		close $fuckface;
		return;
	}

if ($pid == 0) {
	my $fifo_path = tmpnam();
	close $command_handle;

	open_tmux_split($fifo_path);

	mkfifo($fifo_path, 0600) or die $!;

	open my $fifo, '<', $fifo_path or die $!;
	$fifo->autoflush(1);

	while (<$fifo>) {
		print $write_handle $_;
	}

	close $fifo;

	close $write_handle;

	POSIX::_exit(0);
}
else {
	close $write_handle;
	close $command_handle;

	Irssi::pidwait_add($pid);

	my $pipe_tag;
	my @args = ($read_handle, \$pipe_tag);
	$pipe_tag = Irssi::input_add(
		fileno $read_handle,
		Irssi::INPUT_READ,
		\&pipe_input,
		\@args,
	);
	my $p2;
	my @ar2 = ($fuckface, \$p2);
	$p2 = Irssi::input_add(
		fileno $fuckface,
		Irssi::INPUT_READ,
		\&pipe_open_tmux_split,
		\@ar2,
	);
}
}


sub pipe_input {
	my ($args) = @_;
	my ($read_handle, $pipe_tag) = @$args;

	my $input = <$read_handle>;
	chomp $input;

	Irssi::gui_input_set($input);

	# TODO: Add $forked to not spawn more than one children unnecessarily

	close $read_handle;
	Irssi::input_remove($$pipe_tag);
}


sub pipe_open_tmux_split {
	my ($args) = @_;
	my ($read_handle, $pipe_tag) = @$args;

	my $fifo_path = <$read_handle>;

	# open_tmux_split('rando', $fifo_path);

	# TODO: Add $forked to not spawn more than one children unnecessarily

	close $read_handle;
	Irssi::input_remove($$pipe_tag);
}


# TODO: Find out if it's possible to do this is a command
Irssi::signal_add_last 'gui key pressed' => sub {
	my ($key) = @_;

	if ($key eq CTRL_X) {
		write_input(Irssi::parse_special('$L', undef, 0));
		update_input_line_when_finished();
	}
};