/*
 * Copyright (C) 2008-2014 David Robillard <d@drobilla.net>
 * Copyright (C) 2008-2016 Paul Davis <paul@linuxaudiosystems.com>
 * Copyright (C) 2009-2010 Carl Hetherington <carl@carlh.net>
 * Copyright (C) 2012-2016 Tim Mayberry <mojofunk@gmail.com>
 * Copyright (C) 2014-2017 Robin Gareus <robin@gareus.org>
 *
 * 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 2 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, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include <iostream>
#include <sstream>
#include <unistd.h>
#include <cstdlib>
#include <cstdio> /* for snprintf, grrr */

#include <cairo/cairo.h>

#include <pango/pangoft2.h> // for fontmap resolution control for GnomeCanvas
#include <pango/pangocairo.h> // for fontmap resolution control for GnomeCanvas

#include <glibmm/miscutils.h>

#include <gtkmm/settings.h>

#include "pbd/convert.h"
#include "pbd/error.h"
#include "pbd/failed_constructor.h"
#include "pbd/file_utils.h"
#include "pbd/gstdio_compat.h"
#include "pbd/unwind.h"
#include "pbd/xml++.h"

#include "ardour/filesystem_paths.h"
#include "ardour/search_paths.h"
#include "ardour/revision.h"
#include "ardour/utils.h"
#include "ardour/types_convert.h"

#include "gtkmm2ext/rgb_macros.h"
#include "gtkmm2ext/gtk_ui.h"

#include "ui_config.h"

#include "pbd/i18n.h"

using namespace std;
using namespace PBD;
using namespace ARDOUR;
using namespace Gtkmm2ext;

static const char* ui_config_file_name = "ui_config";
static const char* default_ui_config_file_name = "default_ui_config";

static const double hue_width = 18.0;
std::string UIConfiguration::color_file_suffix = X_(".colors");

UIConfiguration&
UIConfiguration::instance ()
{
	static UIConfiguration s_instance;
	_instance = &s_instance;
	return s_instance;
}

UIConfiguration::UIConfiguration ()
	:
#undef  UI_CONFIG_VARIABLE
#define UI_CONFIG_VARIABLE(Type,var,name,val) var (name,val),
#define CANVAS_FONT_VARIABLE(var,name) var (name),
#include "ui_config_vars.h"
#include "canvas_vars.h"
#undef  UI_CONFIG_VARIABLE
#undef  CANVAS_FONT_VARIABLE

	_dirty (false),
	aliases_modified (false),
	colors_modified (false),
	modifiers_modified (false),
	block_save (0)
{
	load_state();

	ColorsChanged.connect (boost::bind (&UIConfiguration::colors_changed, this));

	ParameterChanged.connect (sigc::mem_fun (*this, &UIConfiguration::parameter_changed));
}

UIConfiguration::~UIConfiguration ()
{
}

void
UIConfiguration::colors_changed ()
{
	reset_gtk_theme ();

	/* In theory, one of these ought to work:

	   gtk_rc_reparse_all_for_settings (gtk_settings_get_default(), true);
	   gtk_rc_reset_styles (gtk_settings_get_default());

	   but in practice, neither of them do. So just reload the current
	   GTK RC file, which causes a reset of all styles and a redraw
	*/

	parameter_changed ("ui-rc-file");
}

void
UIConfiguration::parameter_changed (string param)
{
	_dirty = true;

	if (param == "ui-rc-file") {
		load_rc_file (true);
	} else if (param == "color-file") {
		load_color_theme (true);
	}

	save_state ();
}

void
UIConfiguration::reset_gtk_theme ()
{
	std::string color_scheme_string("gtk_color_scheme = \"");

	for (ColorAliases::iterator g = color_aliases.begin(); g != color_aliases.end(); ++g) {

		if (g->first.find ("gtk_") == 0) {
			const string gtk_name = g->first.substr (4);
			Gtkmm2ext::Color a_color = color (g->second);

			color_scheme_string += gtk_name + ":#" + color_to_hex_string_no_alpha (a_color) + ';';
		}
	}

	color_scheme_string += '"';

	/* reset GTK color scheme */

	Gtk::Settings::get_default()->property_gtk_color_scheme() = color_scheme_string;
}

void
UIConfiguration::reset_dpi ()
{
	long val = get_font_scale();

	/* FT2 rendering - used by GnomeCanvas, sigh */

#ifndef PLATFORM_WINDOWS
	pango_ft2_font_map_set_resolution ((PangoFT2FontMap*) pango_ft2_font_map_new(), val/1024, val/1024); // XXX pango_ft2_font_map_new leaks
#endif

	/* Cairo rendering, in case there is any */

	pango_cairo_font_map_set_resolution ((PangoCairoFontMap*) pango_cairo_font_map_get_default(), val/1024);

	/* Xft rendering */

	gtk_settings_set_long_property (gtk_settings_get_default(),
					"gtk-xft-dpi", val, "ardour");
	DPIReset(); //Emit Signal
}

float
UIConfiguration::get_ui_scale ()
{
	return get_font_scale () / 102400.;
}

void
UIConfiguration::map_parameters (boost::function<void (std::string)>& functor)
{
#undef  UI_CONFIG_VARIABLE
#define UI_CONFIG_VARIABLE(Type,var,Name,value) functor (Name);
#include "ui_config_vars.h"
#undef  UI_CONFIG_VARIABLE
}

int
UIConfiguration::pre_gui_init ()
{
#ifdef CAIRO_SUPPORTS_FORCE_BUGGY_GRADIENTS_ENVIRONMENT_VARIABLE
	if (get_buggy_gradients()) {
		g_setenv ("FORCE_BUGGY_GRADIENTS", "1", 1);
	}
#endif
#ifndef USE_CAIRO_IMAGE_SURFACE
	if (get_cairo_image_surface()) {
		g_setenv ("ARDOUR_IMAGE_SURFACE", "1", 1);
	}
#endif
	return 0;
}

UIConfiguration*
UIConfiguration::post_gui_init ()
{
	load_color_theme (true);
	return this;
}

int
UIConfiguration::load_defaults ()
{
	std::string rcfile;
	int ret = -1;

	if (find_file (ardour_config_search_path(), default_ui_config_file_name, rcfile) ) {
		XMLTree tree;

		info << string_compose (_("Loading default ui configuration file %1"), rcfile) << endmsg;

		if (!tree.read (rcfile.c_str())) {
			error << string_compose(_("cannot read default ui configuration file \"%1\""), rcfile) << endmsg;
		} else {
			if (set_state (*tree.root(), Stateful::loading_state_version)) {
				error << string_compose(_("default ui configuration file \"%1\" not loaded successfully."), rcfile) << endmsg;
			} else {
				_dirty = false;
				ret = 0;
			}
		}

	} else {
		warning << string_compose (_("Could not find default UI configuration file %1"), default_ui_config_file_name) << endmsg;
	}

	if (ret == 0) {
		/* reload color theme */
		load_color_theme (false);
	}

	return ret;
}

std::string
UIConfiguration::color_file_name (bool use_my, bool with_version) const
{
	string basename;

	if (use_my) {
		basename += "my-";
	}

	std::string color_name = color_file.get();
	size_t sep = color_name.find_first_of("-");
	if (sep != string::npos) {
		color_name = color_name.substr (0, sep);
	}

	basename += color_name;
	basename += "-";
	basename += downcase(std::string(PROGRAM_NAME));

	std::string rev (revision);
	std::size_t pos = rev.find_first_of("-");

	if (with_version && pos != string::npos && pos > 0) {
		basename += "-";
		basename += rev.substr (0, pos); // COLORFILE_VERSION - program major.minor
	}

	basename += color_file_suffix;
	return basename;
}

int
UIConfiguration::load_color_file (string const & path)
{
	XMLTree tree;

	info << string_compose (_("Loading color file %1"), path) << endmsg;

	if (!tree.read (path.c_str())) {
		error << string_compose(_("cannot read color file \"%1\""), path) << endmsg;
		return -1;
	}

	if (set_state (*tree.root(), Stateful::loading_state_version)) {
		error << string_compose(_("color file \"%1\" not loaded successfully."), path) << endmsg;
		return -1;
	}

	return 0;
}

int
UIConfiguration::load_color_theme (bool allow_own)
{
	std::string cfile;
	bool found = false;
	/* ColorsChanged() will trigger a  parameter_changed () which
	 * in turn calls save_state()
	 */
	PBD::Unwinder<uint32_t> uw (block_save, block_save + 1);

	if (find_file (theme_search_path(), color_file_name (false, true), cfile)) {
		found = true;
	}

	if (!found) {
		if (find_file (theme_search_path(), color_file_name (false, false), cfile)) {
			found = true;
		}
	}

	if (!found) {
		warning << string_compose (_("Color file for %1 not found along %2"), color_file.get(), theme_search_path().to_string()) << endmsg;
		return -1;
	}

	(void) load_color_file (cfile);

	if (allow_own) {

		found = false;

		PBD::Searchpath sp (user_config_directory());

		/* user's own color files never have the program name in them */

		if (find_file (sp, color_file_name (true, true), cfile)) {
			found = true;
		}

		if (!found) {
			if (find_file (sp, color_file_name (true, false), cfile)) {
				found = true;
			}
		}

		if (found) {
			(void) load_color_file (cfile);
		}

	}

	ColorsChanged ();

	return 0;
}

int
UIConfiguration::store_color_theme ()
{
	XMLNode* root;

	root = new XMLNode("Ardour");

	XMLNode* parent = new XMLNode (X_("Colors"));
	for (Colors::const_iterator i = colors.begin(); i != colors.end(); ++i) {
		XMLNode* node = new XMLNode (X_("Color"));
		node->set_property (X_("name"), i->first);
		node->set_property (X_("value"), color_to_hex_string (i->second));
		parent->add_child_nocopy (*node);
	}
	root->add_child_nocopy (*parent);

	parent = new XMLNode (X_("ColorAliases"));
	for (ColorAliases::const_iterator i = color_aliases.begin(); i != color_aliases.end(); ++i) {
		XMLNode* node = new XMLNode (X_("ColorAlias"));
		node->set_property (X_("name"), i->first);
		node->set_property (X_("alias"), i->second);
		parent->add_child_nocopy (*node);
	}
	root->add_child_nocopy (*parent);

	parent = new XMLNode (X_("Modifiers"));
	for (Modifiers::const_iterator i = modifiers.begin(); i != modifiers.end(); ++i) {
		XMLNode* node = new XMLNode (X_("Modifier"));
		node->set_property (X_("name"), i->first);
		node->set_property (X_("modifier"), i->second.to_string());
		parent->add_child_nocopy (*node);
	}
	root->add_child_nocopy (*parent);

	XMLTree tree;
	std::string colorfile = Glib::build_filename (user_config_directory(), color_file_name (true, true));;

	tree.set_root (root);

	if (!tree.write (colorfile.c_str())){
		error << string_compose (_("Color file %1 not saved"), colorfile) << endmsg;
		return -1;
	}

	return 0;
}

int
UIConfiguration::load_state ()
{
	bool found = false;

	std::string rcfile;

	if (find_file (ardour_config_search_path(), default_ui_config_file_name, rcfile)) {
		XMLTree tree;
		found = true;

		info << string_compose (_("Loading default ui configuration file %1"), rcfile) << endmsg;

		if (!tree.read (rcfile.c_str())) {
			error << string_compose(_("cannot read default ui configuration file \"%1\""), rcfile) << endmsg;
			return -1;
		}

		if (set_state (*tree.root(), Stateful::loading_state_version)) {
			error << string_compose(_("default ui configuration file \"%1\" not loaded successfully."), rcfile) << endmsg;
			return -1;
		}
	}

	if (find_file (ardour_config_search_path(), ui_config_file_name, rcfile)) {
		XMLTree tree;
		found = true;

		info << string_compose (_("Loading user ui configuration file %1"), rcfile) << endmsg;

		if (!tree.read (rcfile)) {
			error << string_compose(_("cannot read ui configuration file \"%1\""), rcfile) << endmsg;
			return -1;
		}

		if (set_state (*tree.root(), Stateful::loading_state_version)) {
			error << string_compose(_("user ui configuration file \"%1\" not loaded successfully."), rcfile) << endmsg;
			return -1;
		}

		_dirty = false;
	}

	if (!found) {
		error << _("could not find any ui configuration file, canvas will look broken.") << endmsg;
	}

	return 0;
}

int
UIConfiguration::save_state()
{
	if (block_save != 0) {
		return -1;
	}

	if (_dirty) {
		std::string rcfile = Glib::build_filename (user_config_directory(), ui_config_file_name);

		XMLTree tree;

		tree.set_root (&get_state());

		if (!tree.write (rcfile.c_str())){
			error << string_compose (_("Config file %1 not saved"), rcfile) << endmsg;
			return -1;
		}

		_dirty = false;
	}

	if (aliases_modified || colors_modified || modifiers_modified) {

		if (store_color_theme ()) {
			error << string_compose (_("Color file %1 not saved"), color_file.get()) << endmsg;
			return -1;
		}

		aliases_modified = false;
		colors_modified = false;
		modifiers_modified = false;
	}


	return 0;
}

XMLNode&
UIConfiguration::get_state ()
{
	XMLNode* root;

	root = new XMLNode("Ardour");

	root->add_child_nocopy (get_variables ("UI"));
	root->add_child_nocopy (get_variables ("Canvas"));

	if (_extra_xml) {
		root->add_child_copy (*_extra_xml);
	}

	return *root;
}

XMLNode&
UIConfiguration::get_variables (std::string which_node)
{
	XMLNode* node;

	node = new XMLNode (which_node);

#undef  UI_CONFIG_VARIABLE
#undef  CANVAS_FONT_VARIABLE
#define UI_CONFIG_VARIABLE(Type,var,Name,value) if (node->name() == "UI") { var.add_to_node (*node); }
#define CANVAS_FONT_VARIABLE(var,Name) if (node->name() == "Canvas") { var.add_to_node (*node); }
#include "ui_config_vars.h"
#include "canvas_vars.h"
#undef  UI_CONFIG_VARIABLE
#undef  CANVAS_FONT_VARIABLE

	return *node;
}

int
UIConfiguration::set_state (const XMLNode& root, int /*version*/)
{
	/* this can load a generic UI configuration file or a colors file */

	if (root.name() != "Ardour") {
		return -1;
	}

	Stateful::save_extra_xml (root);

	XMLNodeList nlist = root.children();
	XMLNodeConstIterator niter;
	XMLNode *node;

	for (niter = nlist.begin(); niter != nlist.end(); ++niter) {

		node = *niter;

		if (node->name() == "Canvas" ||  node->name() == "UI") {
			set_variables (*node);

		}
	}

	XMLNode* colors = find_named_node (root, X_("Colors"));

	if (colors) {
		load_colors (*colors);
	}

	XMLNode* aliases = find_named_node (root, X_("ColorAliases"));

	if (aliases) {
		load_color_aliases (*aliases);
	}

	XMLNode* modifiers = find_named_node (root, X_("Modifiers"));

	if (modifiers) {
		load_modifiers (*modifiers);
	}

	return 0;
}

void
UIConfiguration::load_color_aliases (XMLNode const & node)
{
	XMLNodeList const nlist = node.children();
	XMLNodeConstIterator niter;
	XMLProperty const *name;
	XMLProperty const *alias;

	for (niter = nlist.begin(); niter != nlist.end(); ++niter) {
		XMLNode const * child = *niter;
		if (child->name() != X_("ColorAlias")) {
			continue;
		}
		name = child->property (X_("name"));
		alias = child->property (X_("alias"));

		if (name && alias) {
			color_aliases[name->value()] = alias->value();
		}
	}
}

void
UIConfiguration::load_colors (XMLNode const & node)
{
	XMLNodeList const nlist = node.children();
	XMLNodeConstIterator niter;
	XMLProperty const *name;
	XMLProperty const *color;

	/* don't clear colors, so that we can load > 1 color file and have
	   the subsequent ones overwrite the later ones.
	*/

	for (niter = nlist.begin(); niter != nlist.end(); ++niter) {
		XMLNode const * child = *niter;
		if (child->name() != X_("Color")) {
			continue;
		}
		name = child->property (X_("name"));
		color = child->property (X_("value"));

		if (name && color) {
			Gtkmm2ext::Color c;
			c = strtoul (color->value().c_str(), 0, 16);
			/* insert or replace color name definition */
			colors[name->value()] =  c;
		}
	}
}

void
UIConfiguration::load_modifiers (XMLNode const & node)
{
	XMLNodeList const nlist = node.children();
	XMLNodeConstIterator niter;
	XMLProperty const *name;
	XMLProperty const *mod;

	for (niter = nlist.begin(); niter != nlist.end(); ++niter) {
		XMLNode const * child = *niter;
		if (child->name() != X_("Modifier")) {
			continue;
		}

		name = child->property (X_("name"));
		mod = child->property (X_("modifier"));

		if (name && mod) {
			SVAModifier svam (mod->value());
			modifiers[name->value()] = svam;
		}
	}
}

void
UIConfiguration::set_variables (const XMLNode& node)
{
#undef  UI_CONFIG_VARIABLE
#define UI_CONFIG_VARIABLE(Type,var,name,val) if (var.set_from_node (node)) { ParameterChanged (name); }
#define CANVAS_FONT_VARIABLE(var,name)        if (var.set_from_node (node)) { ParameterChanged (name); }
#include "ui_config_vars.h"
#include "canvas_vars.h"
#undef  UI_CONFIG_VARIABLE
#undef  CANVAS_FONT_VARIABLE
}

Gtkmm2ext::SVAModifier
UIConfiguration::modifier (string const & name) const
{
	Modifiers::const_iterator m = modifiers.find (name);
	if (m != modifiers.end()) {
		return m->second;
	}
	return SVAModifier ();
}

Gtkmm2ext::Color
UIConfiguration::color_mod (std::string const & colorname, std::string const & modifiername) const
{
	return HSV (color (colorname)).mod (modifier (modifiername)).color ();
}

Gtkmm2ext::Color
UIConfiguration::color_mod (const Gtkmm2ext::Color& color, std::string const & modifiername) const
{
	return HSV (color).mod (modifier (modifiername)).color ();
}

Gtkmm2ext::Color
UIConfiguration::color (const std::string& name, bool* failed) const
{
	ColorAliases::const_iterator e = color_aliases.find (name);

	if (failed) {
		*failed = false;
	}

	if (e != color_aliases.end ()) {
		Colors::const_iterator rc = colors.find (e->second);
		if (rc != colors.end()) {
			return rc->second;
		}
	} else {
		/* not an alias, try directly */
		Colors::const_iterator rc = colors.find (name);
		if (rc != colors.end()) {
			return rc->second;
		}
	}

	if (!failed) {
		/* only show this message if the caller wasn't interested in
		   the fail status.
		*/
		cerr << string_compose (_("Color %1 not found"), name) << endl;
	}

	if (failed) {
		*failed = true;
	}

	return rgba_to_color ((g_random_int()%256)/255.0,
			      (g_random_int()%256)/255.0,
			      (g_random_int()%256)/255.0,
			      0xff);
}

Color
UIConfiguration::quantized (Color c) const
{
	HSV hsv (c);
	hsv.h = hue_width * (round (hsv.h/hue_width));
	return hsv.color ();
}

void
UIConfiguration::set_color (string const& name, Gtkmm2ext::Color color)
{
	Colors::iterator i = colors.find (name);
	if (i == colors.end()) {
		return;
	}
	i->second = color;
	colors_modified = true;

	ColorsChanged (); /* EMIT SIGNAL */
}

void
UIConfiguration::set_alias (string const & name, string const & alias)
{
	ColorAliases::iterator i = color_aliases.find (name);
	if (i == color_aliases.end()) {
		return;
	}

	i->second = alias;
	aliases_modified = true;

	ColorsChanged (); /* EMIT SIGNAL */
}

void
UIConfiguration::set_modifier (string const & name, SVAModifier svam)
{
	Modifiers::iterator m = modifiers.find (name);

	if (m == modifiers.end()) {
		return;
	}

	m->second = svam;
	modifiers_modified = true;

	ColorsChanged (); /* EMIT SIGNAL */
}

void
UIConfiguration::load_rc_file (bool themechange, bool allow_own)
{
	string basename = ui_rc_file.get();
	std::string rc_file_path;

	if (!find_file (ardour_config_search_path(), basename, rc_file_path)) {
		warning << string_compose (_("Unable to find UI style file %1 in search path %2. %3 will look strange"),
                                           basename, ardour_config_search_path().to_string(), PROGRAM_NAME)
				<< endmsg;
		return;
	}

	info << string_compose (_("Loading ui configuration file %1"), rc_file_path) << endmsg;

	Gtkmm2ext::UI::instance()->load_rcfile (rc_file_path, themechange);
}

std::string
UIConfiguration::color_to_hex_string (Gtkmm2ext::Color c)
{
	char buf[16];
	int retval = g_snprintf (buf, sizeof(buf), "%08x", c);

	if (retval < 0 || retval >= (int)sizeof(buf)) {
		assert(false);
	}
	return buf;
}

std::string
UIConfiguration::color_to_hex_string_no_alpha (Gtkmm2ext::Color c)
{
	c >>= 8; // shift/remove alpha
	char buf[16];
	int retval = g_snprintf (buf, sizeof(buf), "%06x", c);

	if (retval < 0 || retval >= (int)sizeof(buf)) {
		assert(false);
	}
	return buf;
}