/*
 * Tab
 *
 * Copyright (C) 2017  Patrick McDermott
 *
 * This file is part of Marquee.
 *
 * Marquee 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.
 *
 * Marquee 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 Marquee.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <stdlib.h>

#include <gtk/gtk.h>

#include "tab.h"
#include "tab-chrome.h"
#include "tab-body.h"

static void
foreach_tab(MqTab *node, void (*cb)(MqTab *node))
{
	for (; node; node = node->next) {
		cb(node);
		foreach_tab(node->first_child, cb);
	}
}

static void
update_tab_image(MqTab *tab, GdkPixbuf *favicon)
{
	if (favicon) {
		gtk_image_set_from_pixbuf(GTK_IMAGE(tab->tab_image), favicon);
	} else {
		gtk_image_set_from_icon_name(GTK_IMAGE(tab->tab_image),
			"text-x-generic", GTK_ICON_SIZE_BUTTON);
	}
}

static void
update_tab_label(MqTab *tab)
{
	const gchar *title;
	gchar       *label;

	title = tab->scrolling ? tab->scrolled_title : tab->title;
	label = g_strdup_printf("%d. %s", tab->position, title);
	gtk_label_set_text(GTK_LABEL(tab->tab_label), label);
	gtk_widget_set_tooltip_text(tab->tab, label);
	g_free(label);
}

static void
update_positions(MqTab *node, gint step)
{
	if (node) {
		node->position += step;
		update_tab_label(node);
		if (node->next) {
			update_positions(node->next, step);
		} else if (node->parent && node->parent->next) {
			update_positions(node->parent->next, step);
		}
	}
}

static void
update_tree_sizes(MqTab *node, guint step)
{
	if (node) {
		node->tree_size += step;
		update_tree_sizes(node->parent, step);
	}
}

static void
append_child(MqTab *new_node, MqTab *parent)
{
	new_node->root = parent->root;
	new_node->parent = parent;
	new_node->next = NULL;
	new_node->prev = parent->last_child;  /* May be NULL */
	new_node->first_child = new_node->last_child = NULL;
	new_node->tree_size = 0;  /* Will be updated */
	if (parent->last_child) {
		new_node->position = parent->last_child->position;
		parent->last_child->next = new_node;
	} else {
		new_node->position = parent->position;
		parent->first_child = new_node;
	}
	parent->last_child = new_node;
	update_positions(new_node, 1);
	update_tree_sizes(new_node, 1);
}

static void
append_sibling(MqTab *new_node, MqTab *prev_sibling)
{
	new_node->root = prev_sibling->root;
	new_node->parent = prev_sibling->parent;
	new_node->prev = prev_sibling;
	new_node->next = prev_sibling->next;  /* May be NULL */
	new_node->first_child = new_node->last_child = NULL;
	new_node->position = prev_sibling->position;  /* Will be updated */
	new_node->tree_size = 0;  /* Will be updated */
	if (prev_sibling->next) {
		prev_sibling->next->prev = new_node;
	}
	prev_sibling->next = new_node;
	update_positions(new_node, 1);
	update_tree_sizes(new_node, 1);
}

static void
reload_tab_clicked_cb(GtkWidget G_GNUC_UNUSED *button, MqTab *tab)
{
	webkit_web_view_reload(tab->web_view);
	gtk_widget_hide(tab->popover);
}

static void
new_tab_clicked_cb(GtkWidget G_GNUC_UNUSED *button, MqTab *tab)
{
	mq_tab_new(NULL, tab);
	gtk_widget_hide(tab->popover);
}

static void
new_window_clicked_cb(GtkWidget G_GNUC_UNUSED *button, MqTab *tab)
{
	mq_application_add_window(tab->application, NULL);
	gtk_widget_hide(tab->popover);
}

static void
tab_list_button_toggled_cb(GtkToggleButton *toggle_button, GtkWidget *tab_list)
{
	if (gtk_toggle_button_get_active(toggle_button)) {
		gtk_widget_show(tab_list);
	} else {
		gtk_widget_hide(tab_list);
	}
}

static void
create_tree_model_recurse(MqTab *node, GtkTreeStore *tree_store,
	GtkTreeIter *parent_tree_iter)
{
	GtkTreeIter tree_iter;

	for (; node; node = node->next) {
		gtk_tree_store_append(tree_store, &tree_iter, parent_tree_iter);
		gtk_tree_store_set(tree_store, &tree_iter, 0, node->title, -1);
		create_tree_model_recurse(node->first_child, tree_store,
			&tree_iter);
	}
}

static GtkTreeModel *
create_tree_model(MqTab *tab)
{
	GtkTreeStore *tree_store;

	tree_store = gtk_tree_store_new(1, G_TYPE_STRING);

	create_tree_model_recurse(tab->root->first_child, tree_store, NULL);

	return GTK_TREE_MODEL(tree_store);
}

static void
row_activated_cb(GtkTreeView G_GNUC_UNUSED *tree_view, GtkTreePath *tree_path,
	GtkTreeViewColumn G_GNUC_UNUSED *tree_view_column, MqTab *tab)
{
	gint *indices;
	gint  depth;

	indices = gtk_tree_path_get_indices_with_depth(tree_path, &depth);
	g_assert(depth == 1);
	mq_window_set_current_tab(tab->window, indices[0] + 1);
	gtk_widget_hide(tab->popover);
}

static GtkWidget *
create_tab_list(MqTab *tab)
{
	GtkWidget        *tree_view;
	GtkTreeSelection *tree_selection;
	GtkCellRenderer  *cell_renderer;
	GtkWidget        *scrolled_window;

	tree_view = gtk_tree_view_new_with_model(create_tree_model(tab));
	tree_selection = gtk_tree_view_get_selection(GTK_TREE_VIEW(tree_view));
	gtk_tree_selection_set_mode(tree_selection, GTK_SELECTION_BROWSE);
	gtk_tree_selection_select_path(tree_selection,
		gtk_tree_path_new_from_indices(
			mq_window_get_current_tab(tab->window) - 1, -1));
	gtk_tree_view_set_headers_visible(GTK_TREE_VIEW(tree_view), FALSE);
	gtk_tree_view_set_activate_on_single_click(GTK_TREE_VIEW(tree_view),
		TRUE);
	gtk_tree_view_expand_all(GTK_TREE_VIEW(tree_view));
	gtk_tree_view_set_reorderable(GTK_TREE_VIEW(tree_view), TRUE);
	gtk_tree_view_set_enable_tree_lines(GTK_TREE_VIEW(tree_view), TRUE);
	g_signal_connect(tree_view, "row-activated",
		G_CALLBACK(row_activated_cb), tab);

	cell_renderer = gtk_cell_renderer_text_new();
	gtk_tree_view_insert_column_with_attributes(GTK_TREE_VIEW(tree_view),
		-1, NULL, cell_renderer, "text", 0, NULL);

	scrolled_window = gtk_scrolled_window_new(NULL, NULL);
	gtk_scrolled_window_set_min_content_width(
		GTK_SCROLLED_WINDOW(scrolled_window), 400);
	gtk_scrolled_window_set_min_content_height(
		GTK_SCROLLED_WINDOW(scrolled_window), 200);
	gtk_container_add(GTK_CONTAINER(scrolled_window), tree_view);

	return scrolled_window;
}

#define BUTTON_ROWS 2
#define BUTTON_COLS 4
#define NEW_BUTTON(Y, X, ICON, TOOLTIP) \
	do { \
		buttons[Y * BUTTON_COLS + X] = gtk_button_new_from_icon_name(\
			ICON, GTK_ICON_SIZE_BUTTON); \
		gtk_widget_set_tooltip_text(buttons[Y * BUTTON_COLS + X], \
			TOOLTIP); \
		gtk_widget_set_can_focus(buttons[Y * BUTTON_COLS + X], FALSE); \
		gtk_grid_attach(GTK_GRID(button_grid), \
			buttons[Y * BUTTON_COLS + X], X, Y, 1, 1); \
	} while (0)
#define NEW_TOGGLE(Y, X, ICON, TOOLTIP) \
	do { \
		buttons[Y * BUTTON_COLS + X] = gtk_toggle_button_new(); \
		gtk_button_set_image(GTK_BUTTON(buttons[Y * BUTTON_COLS + X]), \
			gtk_image_new_from_icon_name(ICON, \
				GTK_ICON_SIZE_BUTTON)); \
		gtk_widget_set_tooltip_text(buttons[Y * BUTTON_COLS + X], \
			TOOLTIP); \
		gtk_widget_set_can_focus(buttons[Y * BUTTON_COLS + X], FALSE); \
		gtk_grid_attach(GTK_GRID(button_grid), \
			buttons[Y * BUTTON_COLS + X], X, Y, 1, 1); \
	} while (0)
#define CLICKED_CB(Y, X, CB) \
	g_signal_connect(buttons[Y * BUTTON_COLS + X], "clicked", CB, tab)

static void
create_tab_popover(GtkWidget *widget, MqTab *tab)
{
	GtkWidget *button_grid;
	GtkWidget *buttons[BUTTON_ROWS * BUTTON_COLS];
	GtkWidget *tab_list;
	GtkWidget *tab_list_scrolled_window;
	GtkWidget *box;

	/* Set up button grid. */
	button_grid = gtk_grid_new();
	gtk_widget_set_halign(button_grid, GTK_ALIGN_CENTER);

	/* Set up buttons. */
	NEW_BUTTON(0, 0, "view-refresh",       "Reload tab");
	NEW_BUTTON(0, 1, "edit-copy",          "Duplicate tab");
	NEW_BUTTON(0, 2, "window-new",         "Move tab to new window");
	NEW_BUTTON(0, 3, "window-close",       "Close tab");
	NEW_BUTTON(1, 0, "tab-new-symbolic",   "New tab");
	NEW_BUTTON(1, 1, "window-new",         "New window");
	NEW_BUTTON(1, 2, "edit-undo",          "Undo close tab");
	NEW_TOGGLE(1, 3, "view-list-symbolic", "Tab list...");

	CLICKED_CB(0, 0, G_CALLBACK(reload_tab_clicked_cb));
	CLICKED_CB(1, 0, G_CALLBACK(new_tab_clicked_cb));
	CLICKED_CB(1, 1, G_CALLBACK(new_window_clicked_cb));

	/* Set up the tab list. */
	tab_list = create_tab_list(tab);

	/* Set up the tab list scrolled window.
	 *
	 * The following GtkScrolledWindow widget has a hardcoded minimum size,
	 * because there seems to be (in GTK+ versions before 3.22) no way to
	 * set the natural size of GtkScrolledWindow and its GtkViewport.
	 *
	 * See tab-chrome.c for more information. */
	tab_list_scrolled_window = gtk_scrolled_window_new(NULL, NULL);
	gtk_scrolled_window_set_min_content_width(
		GTK_SCROLLED_WINDOW(tab_list_scrolled_window), 400);
	gtk_scrolled_window_set_min_content_height(
		GTK_SCROLLED_WINDOW(tab_list_scrolled_window), 200);
	gtk_container_add(GTK_CONTAINER(tab_list_scrolled_window), tab_list);

	/* Add tab list toggle button handler. */
	g_signal_connect(buttons[1 * BUTTON_COLS + 3], "toggled",
		G_CALLBACK(tab_list_button_toggled_cb),
		tab_list_scrolled_window);

	/* Set up the button rows box. */
	box = gtk_box_new(GTK_ORIENTATION_VERTICAL, 0);
	gtk_box_pack_start(GTK_BOX(box), button_grid,
		TRUE, FALSE, 0);
	gtk_box_pack_start(GTK_BOX(box), tab_list_scrolled_window,
		TRUE, FALSE, 0);

	/* Set up the popover. */
	tab->popover = gtk_popover_new(widget);
	gtk_container_add(GTK_CONTAINER(tab->popover), box);

	/* NB: gtk_popover_popup() is new in GTK+ 3.22. */
	gtk_widget_show_all(tab->popover);
	gtk_widget_hide(tab_list_scrolled_window);
}

#undef BUTTON_ROWS
#undef BUTTON_COLS
#undef NEW_BUTTON
#undef NEW_TOGGLE
#undef CLICKED_CB

static gboolean
tab_label_button_press_cb(GtkWidget *widget, GdkEvent *event, MqTab *tab)
{
	/* Make sure this is a mouse button press event. */
	if (event->type != GDK_BUTTON_PRESS) {
		return FALSE;
	}

	/* Create a popover menu on right click. */
	if (event->button.button == 3) {
		create_tab_popover(widget, tab);
	}

	return FALSE;
}

static void
mq_tab_populate_tab(MqTab *tab)
{
	GtkWidget *close_button;
	GtkWidget *box;

	tab->title = "New tab";

	/* Set up tab image. */
	tab->tab_image = gtk_image_new_from_icon_name("text-x-generic",
		GTK_ICON_SIZE_BUTTON);

	/* Set up tab label. */
	tab->tab_label = gtk_label_new(NULL);
	gtk_label_set_ellipsize(GTK_LABEL(tab->tab_label),
		PANGO_ELLIPSIZE_END);
	gtk_widget_set_hexpand(tab->tab_label, TRUE);
	gtk_widget_set_size_request(tab->tab_label, 50, 1);

	/* Set up close button. */
	close_button = gtk_button_new_from_icon_name("window-close",
		GTK_ICON_SIZE_BUTTON);
	gtk_widget_set_tooltip_text(close_button, "Close tab");

	/* Pack tab box. */
	box = gtk_box_new(GTK_ORIENTATION_HORIZONTAL, 0);
	gtk_box_pack_start(GTK_BOX(box), tab->tab_image, FALSE, FALSE, 0);
	gtk_box_pack_start(GTK_BOX(box), tab->tab_label, TRUE, TRUE, 0);
	gtk_box_pack_start(GTK_BOX(box), close_button, FALSE, FALSE, 0);
	gtk_widget_show_all(box);

	/* Set up event box. */
	tab->tab = gtk_event_box_new();
	g_signal_connect(tab->tab, "button-press-event",
		G_CALLBACK(tab_label_button_press_cb), tab);
	gtk_event_box_set_visible_window(GTK_EVENT_BOX(tab->tab),
		FALSE);
	gtk_container_add(GTK_CONTAINER(tab->tab), box);
}

static void
favicon_cb(WebKitWebView G_GNUC_UNUSED *web_view,
	GParamSpec G_GNUC_UNUSED *paramspec, MqTab *tab)
{
	cairo_surface_t *surface;
	GdkPixbuf       *pixbuf;
	GdkPixbuf       *scaled_pixbuf;

	surface = webkit_web_view_get_favicon(tab->web_view);
	scaled_pixbuf = NULL;
	if (surface) {
		pixbuf = gdk_pixbuf_get_from_surface(surface, 0, 0,
			cairo_image_surface_get_width(surface),
			cairo_image_surface_get_height(surface));
		if (pixbuf) {
			scaled_pixbuf = gdk_pixbuf_scale_simple(pixbuf, 16, 16,
				GDK_INTERP_BILINEAR);
			g_object_unref(pixbuf);
		}
	}

	update_tab_image(tab, scaled_pixbuf);
}

static void
title_cb(WebKitWebView G_GNUC_UNUSED *web_view,
	GParamSpec G_GNUC_UNUSED *paramspec, MqTab *tab)
{
	tab->title = webkit_web_view_get_title(tab->web_view);
	if (tab->scrolling) {
		tab->scrolled_title = g_strdup_printf("%s    ", tab->title);
	}
	update_tab_label(tab);
	mq_window_update_tab_title(tab->window, tab->position, tab->title);
}

static MqTab *
init_non_root(const gchar *uri, MqTab *source)
{
	MqTab *tab;

	tab = malloc(sizeof(*tab));
	tab->parent = NULL;
	tab->prev = NULL;
	tab->next = NULL;
	tab->first_child = tab->last_child = NULL;
	tab->tree_size = 1;

	tab->window = source->window;
	tab->application = mq_window_get_application(tab->window);

	mq_tab_populate_tab(tab);

	tab->chrome = mq_tab_chrome_new(tab, uri);
	tab->body = mq_tab_body_new(tab, uri);
	tab->web_view = mq_tab_body_get_web_view(tab->body);
	g_signal_connect(tab->web_view, "notify::favicon",
		G_CALLBACK(favicon_cb), tab);
	g_signal_connect(tab->web_view, "notify::title",
		G_CALLBACK(title_cb), tab);
	mq_tab_chrome_set_web_view(tab->chrome, tab->web_view);

	tab->container = gtk_box_new(GTK_ORIENTATION_VERTICAL, 0);
	gtk_box_pack_start(GTK_BOX(tab->container),
		mq_tab_chrome_get_container(tab->chrome), FALSE, FALSE, 0);
	gtk_box_pack_start(GTK_BOX(tab->container),
		mq_tab_body_get_container(tab->body), TRUE, TRUE, 0);

	return tab;
}

static void
scroll_tab_label(MqTab *tab)
{
	gchar c[5];  /* Up to 4 bytes for a UTF-8 character, plus NUL */
	guint i;
	guint j;

	/* Save the first (possibly multibyte) character. */
	c[0] = tab->scrolled_title[0];
	for (i = 1; tab->scrolled_title[i] & 0x80; ++i) {
		c[i] = tab->scrolled_title[i];
	}
	c[i] = '\0';

	/* Shift all characters. */
	for (j = 0; tab->scrolled_title[i]; ++i, ++j) {
		tab->scrolled_title[j] = tab->scrolled_title[i];
	}

	/* Set the last (possibly multibyte) character. */
	for (--j, i = 0; c[i]; ++i, ++j) {
		tab->scrolled_title[j] = c[i];
	}

	update_tab_label(tab);
}

static void
begin_scrolling_tab_label(MqTab *tab)
{
	PangoFontDescription *font_desc;

	tab->scrolling = TRUE;
	tab->scrolled_title = g_strdup_printf("%s    ", tab->title);

	font_desc = pango_font_description_new();
	pango_font_description_set_family_static(font_desc, "monospace");
	gtk_widget_override_font(tab->tab_label, font_desc);
}

static void
end_scrolling_tab_label(MqTab *tab)
{
	tab->scrolling = FALSE;

	gtk_widget_override_font(tab->tab_label, NULL);

	update_tab_label(tab);
}

MqTab *
mq_tab_new(const gchar *uri, MqTab *source)
{
	MqTab *tab;

	tab = init_non_root(uri, source);

	if (mq_application_marquee_mode_on(tab->application)) {
		begin_scrolling_tab_label(tab);
	} else {
		tab->scrolling = FALSE;
	}

	append_sibling(tab, source);

	mq_window_insert_tab(tab->window, tab->container, tab->tab,
		tab->position);

	return tab;
}

MqTab *
mq_tab_new_relative(const gchar *uri, MqTab *source)
{
	MqTab *tab;

	tab = init_non_root(uri, source);

	if (mq_application_marquee_mode_on(tab->application)) {
		begin_scrolling_tab_label(tab);
	} else {
		tab->scrolling = FALSE;
	}

	append_child(tab, source);

	mq_window_insert_tab(tab->window, tab->container, tab->tab,
		tab->position);

	return tab;
}

MqTab *
mq_tab_new_root(MqWindow *window)
{
	MqTab *tab;

	tab = malloc(sizeof(*tab));
	tab->root = tab;
	tab->parent = NULL;
	tab->prev = NULL;
	tab->next = NULL;
	tab->first_child = tab->last_child = NULL;
	tab->position = 0;
	tab->tree_size = 1;
	tab->window = window;

	return tab;
}

MqApplication *
mq_tab_get_application(MqTab *tab)
{
	return tab->application;
}

void
mq_tab_update_position(MqTab *tab, guint position)
{
	tab->position = position;
	update_tab_label(tab);
}

guint
mq_tab_get_position(MqTab *tab)
{
	return tab->position;
}

guint
mq_tab_get_tree_size(MqTab *tab)
{
	return tab->tree_size;
}

const gchar *
mq_tab_get_title(MqTab *tab)
{
	return tab->title;
}

MqTab *
mq_tab_seek(MqTab *node, guint position)
{
	/* Skip forward to the containing subtree. */
	while (node && node->position + node->tree_size <= position) {
		node = node->next;
	}

	/* Check whether we've gone past the end of the tree. */
	if (!node) {
		return NULL;
	}

	/* Check whether the sibling we've reached is the node we want. */
	if (node->position == position) {
		return node;
	}

	/* Recurse down the subtree. */
	return mq_tab_seek(node->first_child, position);
}

void
mq_tab_scroll_tab_labels(MqTab *root)
{
	foreach_tab(root->first_child, scroll_tab_label);
}

void
mq_tab_begin_scrolling_tab_labels(MqTab *root)
{
	foreach_tab(root->first_child, begin_scrolling_tab_label);
}

void
mq_tab_end_scrolling_tab_labels(MqTab *root)
{
	foreach_tab(root->first_child, end_scrolling_tab_label);
}