/*
 *	subtitleeditor -- a tool to create or edit subtitle
 *
 *	http://home.gna.org/subtitleeditor/
 *	https://gna.org/projects/subtitleeditor/
 *
 *	Copyright @ 2005-2009, kitone
 *
 *	This program is free software; you can redistribute it and/or modify
 *	it under the terms of the GNU General Public License as published by
 *	the Free Software Foundation; either version 3 of the License, or
 *	(at your option) any later version.
 *
 *	This program is distributed in the hope that it will be useful,
 *	but WITHOUT ANY WARRANTY; without even the implied warranty of
 *	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *	GNU General Public License for more details.
 *
 *	You should have received a copy of the GNU General Public License
 *	along with this program. If not, see <http://www.gnu.org/licenses/>.
 */
 
#include <extension/action.h>
#include <i18n.h>
#include <debug.h>
#include <utility.h>

class SplitSelectedSubtitlesPlugin : public Action
{
public:

	SplitSelectedSubtitlesPlugin()
	{
		activate();
		update_ui();
	}

	~SplitSelectedSubtitlesPlugin()
	{
		deactivate();
	}

	/*
	 */
	void activate()
	{
		se_debug(SE_DEBUG_PLUGINS);

		// actions
		action_group = Gtk::ActionGroup::create("SplitSelectedSubtitlesPlugin");

		action_group->add(
				Gtk::Action::create("split-selected-subtitles", _("_Split"), _("Split the selected subtitles")),
					sigc::mem_fun(*this, &SplitSelectedSubtitlesPlugin::split_selected_subtitles));

		// ui
		Glib::RefPtr<Gtk::UIManager> ui = get_ui_manager();

		ui_id = ui->new_merge_id();

		ui->insert_action_group(action_group);

		ui->add_ui(ui_id, "/menubar/menu-edit/split-selected-subtitles", "split-selected-subtitles", "split-selected-subtitles");
	}

	/*
	 */
	void deactivate()
	{
		se_debug(SE_DEBUG_PLUGINS);

		Glib::RefPtr<Gtk::UIManager> ui = get_ui_manager();

		ui->remove_ui(ui_id);
		ui->remove_action_group(action_group);
	}

	/*
	 */
	void update_ui()
	{
		se_debug(SE_DEBUG_PLUGINS);

		bool visible = (get_current_document() != NULL);

		action_group->get_action("split-selected-subtitles")->set_sensitive(visible);
	}

	/*
	 */
	void split_selected_subtitles()
	{
		se_debug(SE_DEBUG_PLUGINS);

		Document *doc = get_current_document();

		g_return_if_fail(doc);

		Subtitles subtitles = doc->subtitles();

		std::vector<Subtitle> selection = subtitles.get_selection();

		if(selection.empty())
		{
			doc->flash_message(_("Please select at least two subtitles."));
			return;
		}

		doc->start_command(_("Split subtitles"));

		for(std::vector<Subtitle>::reverse_iterator it=selection.rbegin(); it != selection.rend(); ++it)
		{
			split(subtitles, *it);
		}

		doc->emit_signal("subtitle-time-changed");
		doc->finish_command();
	}

	/*
	 */
	void split(Subtitles& subtitles, Subtitle &sub)
	{
		unsigned int i=0;

		Glib::RefPtr<Glib::Regex> re = Glib::Regex::create("\\n");

		Glib::ustring text = sub.get_text();

		std::vector<Glib::ustring> lines = re->split(text);

		// If there's not at least two lines, it's not necessary to split
		if(lines.size() < 2)
			return;

		fix_multiline_tag(lines);

		// Original values
		Glib::ustring otext = text;
		SubtitleTime ostart = sub.get_start();
		SubtitleTime oduration = sub.get_duration();


		// Array for new subtitles
		std::vector<Subtitle> newsubs;
		// Represente the total number of characters in the original subtitles (without tag)
		unsigned int total_chars = 0;

		// We can add directly the original subtitle, it will be reused
		// we just need to add other lines (size-1)
		newsubs.push_back(sub);

		for(i=1; i < lines.size(); ++i)
		{
			Subtitle next = subtitles.insert_after(newsubs[i-1]);
			sub.copy_to(next); // Copy all values (style, note, ...)
			newsubs.push_back(next);
		}

		// Updated subtitles text with each line
		for(i=0; i< newsubs.size(); ++i)
		{
			newsubs[i].set_text( lines[i] );

			// We take the loop to calculate the total number of characters
			total_chars += utility::get_stripped_text(lines[i]).size();
		}

		// Now we set the time for each subtitle
		// Divides the original duration by using the ratio to the number of characters per line
		// If the total number of characters is equal to 0 (empty lines) we divide by the number of lines

		SubtitleTime start = ostart;
		SubtitleTime dur;

		for(i=0; i< newsubs.size(); ++i)
		{
			if(total_chars > 0)
				dur = oduration * ((double)lines[i].size() / (double)total_chars);
			else
				dur = oduration / newsubs.size();

			newsubs[i].set_start_and_end(start, start + dur);

			start = start + dur; // Update the beginning of the next subtitle
		}

		// Try to apply timing prefs like gap between subs...
		try_to_respect_timing_preferences(newsubs);

		// We add to the selection the new subtitles
		subtitles.select(newsubs);
	}

	/*
	 * Try to apply some timing preferences
	 * - minimum gap between subtitles
	 * - minimum display time (TODO ?)
	 */
	void try_to_respect_timing_preferences(std::vector<Subtitle> &subs)
	{
		//int min_display = get_config().get_value_int("timing", "min-display");
		int min_gap_between_subtitles = get_config().get_value_int("timing", "min-gap-between-subtitles");

		SubtitleTime gap = SubtitleTime(min_gap_between_subtitles) * 0.5;
		SubtitleTime tmp;
		for(unsigned int i=0; i< subs.size(); ++i)
		{
			SubtitleTime start = subs[i].get_start();
			SubtitleTime end = subs[i].get_end();

			if(i > 0) // Move the beginning if it's not the first subtitle
				start = start + gap;				

			if(i < subs.size() -1) // Move the end if it's not the last subtitle
				end = end - gap;

			subs[i].set_start_and_end(start, end);
		}
	}

	/*
	 */
	void fix_multiline_tag(std::vector<Glib::ustring> &lines)
	{
		Glib::RefPtr<Glib::Regex> re_tag_open = Glib::Regex::create("<(\\w+)>");
		
		for(std::vector<Glib::ustring>::iterator it = lines.begin(); it != lines.end(); ++it)
		{
			// Is there a tag open ?
			if(re_tag_open->match(*it))
			{
				std::vector<Glib::ustring> matches = re_tag_open->split(*it);
				
				Glib::ustring tag = matches[1];
	
				Glib::RefPtr<Glib::Regex> re_tag_close = Glib::Regex::create(
						Glib::ustring::compose("</(%1)>", tag));
				
				//The tag open is closed on the same line?
				if(re_tag_close->match(*it) == false)
				{
					// No, we close the tag at the end of this line 
					// and add an opened tag to the start of the next.
					*it = Glib::ustring::compose("%1</%2>", *it, tag);

					std::vector<Glib::ustring>::iterator it_next = it; 
					++it_next;
					if(it_next != lines.end()) // Only if there is a next line
					{
						*it_next = Glib::ustring::compose("<%1>%2", tag, *it_next);
					}
				}
			}
		}
	}

protected:
	Gtk::UIManager::ui_merge_id ui_id;
	Glib::RefPtr<Gtk::ActionGroup> action_group;
};

REGISTER_EXTENSION(SplitSelectedSubtitlesPlugin)
