/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 8 -*- */

/*

 * Copyright (C) 2008 Imendio AB

 * Copyright (C) 2008 Sven Herzberg

 *

 * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307

 * USA

 */

#include "config.h"

#include "dh-assistant-view.h"

#include <string.h>

#include <glib/gi18n-lib.h>

#include "dh-util.h"

#include "dh-book.h"

#include "dh-book-manager.h"

/**

 * SECTION:dh-assistant-view

 * @Title: DhAssistantView

 * @Short_description: A small “assistant” widget for displaying just one hit

 *

 * #DhAssistantView is a subclass of #WebKitWebView for displaying the

 * documentation of just one symbol.

 *

 * A possible use-case: in a text editor, pressing a keyboard shortcut could

 * display this widget for the symbol under the cursor.

 *

 * With the Devhelp application, an assistant can easily be launched with the

 * command line option `--search-assistant`.

 */

typedef struct {

        DhLink *link;

        gchar *current_search;

        guint snippet_loaded : 1;

} DhAssistantViewPrivate;

enum {

        SIGNAL_OPEN_URI,

        N_SIGNALS

};

static guint signals[N_SIGNALS] = { 0 };

G_DEFINE_TYPE_WITH_PRIVATE (DhAssistantView, dh_assistant_view, WEBKIT_TYPE_WEB_VIEW);

static void

view_finalize (GObject *object)

{

        DhAssistantView *view = DH_ASSISTANT_VIEW (object);

        DhAssistantViewPrivate *priv = dh_assistant_view_get_instance_private (view);

        if (priv->link) {

                g_object_unref (priv->link);

        }

        g_free (priv->current_search);

        G_OBJECT_CLASS (dh_assistant_view_parent_class)->finalize (object);

}

static gboolean

assistant_decide_policy (WebKitWebView           *web_view,

                         WebKitPolicyDecision    *decision,

                         WebKitPolicyDecisionType decision_type)

{

        DhAssistantViewPrivate         *priv;

        const gchar                    *uri;

        WebKitNavigationPolicyDecision *navigation_decision;

        WebKitNavigationAction         *navigation_action;

        WebKitNavigationType            navigation_type;

        WebKitURIRequest               *request;

        if (decision_type != WEBKIT_POLICY_DECISION_TYPE_NAVIGATION_ACTION) {

                webkit_policy_decision_ignore (decision);

                return TRUE;

        }

        priv = dh_assistant_view_get_instance_private (DH_ASSISTANT_VIEW (web_view));

        navigation_decision = WEBKIT_NAVIGATION_POLICY_DECISION (decision);

        navigation_action = webkit_navigation_policy_decision_get_navigation_action (navigation_decision);

        navigation_type = webkit_navigation_action_get_navigation_type (navigation_action);

        if (navigation_type != WEBKIT_NAVIGATION_TYPE_LINK_CLICKED) {

                if (! priv->snippet_loaded) {

                        priv->snippet_loaded = TRUE;

                        webkit_policy_decision_use (decision);

                }

                webkit_policy_decision_ignore (decision);

                return TRUE;

        }

        request = webkit_navigation_action_get_request (navigation_action);

        uri = webkit_uri_request_get_uri (request);

        if (strcmp (uri, "about:blank") == 0) {

                webkit_policy_decision_use (decision);

                return TRUE;

        }

        g_signal_emit (web_view, signals[SIGNAL_OPEN_URI], 0, uri);

        webkit_policy_decision_ignore (decision);

        return TRUE;

}

static gboolean

assistant_button_press_event (GtkWidget      *widget,

                              GdkEventButton *event)

{

        /* Block webkit's builtin context menu. */

        if (event->button != 1) {

                return TRUE;

        }

        return GTK_WIDGET_CLASS (dh_assistant_view_parent_class)->button_press_event (widget, event);

}

static void

dh_assistant_view_class_init (DhAssistantViewClass* klass)

{

        GObjectClass       *object_class = G_OBJECT_CLASS (klass);

        GtkWidgetClass     *widget_class = GTK_WIDGET_CLASS (klass);

        WebKitWebViewClass *web_view_class = WEBKIT_WEB_VIEW_CLASS (klass);

        object_class->finalize = view_finalize;

        widget_class->button_press_event = assistant_button_press_event;

        web_view_class->decide_policy = assistant_decide_policy;

        /**

         * DhAssistantView::open-uri:

         * @view: the view on which the signal is emitted

         * @uri: the uri to open

         */

        signals[SIGNAL_OPEN_URI] = g_signal_new ("open-uri",

                                                 G_TYPE_FROM_CLASS (object_class),

                                                 0, 0,

                                                 NULL, NULL,

                                                 NULL,

                                                 G_TYPE_NONE, 1,

                                                 G_TYPE_STRING);

}

static void

dh_assistant_view_init (DhAssistantView *view)

{

}

/**

 * dh_assistant_view_new:

 *

 * Returns: (transfer floating): a new #DhAssistantView widget.

 */

GtkWidget *

dh_assistant_view_new (void)

{

        return g_object_new (DH_TYPE_ASSISTANT_VIEW, NULL);

}

static const gchar *

find_in_buffer (const gchar *buffer,

                const gchar *key,

                gsize        length,

                gsize        key_length)

{

        gsize m = 0;

        gsize i = 0;

        while (i < length) {

                if (key[m] == buffer[i]) {

                        m++;

                        if (m == key_length) {

                                return buffer + i - m + 1;

                        }

                } else {

                        m = 0;

                }

                i++;

        }

        return NULL;

}

/**

 * dh_assistant_view_set_link:

 * @view: a #DhAssistantView.

 * @link: (nullable): a #DhLink to set or %NULL.

 *

 * Open @link in the assistant view, if %NULL the view will be blanked.

 *

 * Returns: %TRUE if the requested link is open, %FALSE otherwise.

 */

gboolean

dh_assistant_view_set_link (DhAssistantView *view,

                            DhLink          *link)

{

        DhAssistantViewPrivate *priv;

        gchar               *uri;

        const gchar         *anchor;

        gchar               *filename;

        GMappedFile         *file;

        const gchar         *contents;

        gsize                length;

        gchar               *key;

        gsize                key_length;

        gsize                offset = 0;

        const gchar         *start;

        const gchar         *end;

        g_return_val_if_fail (DH_IS_ASSISTANT_VIEW (view), FALSE);

        priv = dh_assistant_view_get_instance_private (view);

        if (priv->link == link) {

                return TRUE;

        }

        if (priv->link) {

                dh_link_unref (priv->link);

                priv->link = NULL;

        }

        if (link) {

                link = dh_link_ref (link);

        } else {

                webkit_web_view_load_uri (WEBKIT_WEB_VIEW (view), "about:blank");

                return TRUE;

        }

        /* FIXME uri can be NULL. */

        uri = dh_link_get_uri (link);

        anchor = strrchr (uri, '#');

        if (anchor) {

                filename = g_strndup (uri, anchor - uri);

                anchor++;

        } else {

                g_free (uri);

                return FALSE;

        }

        if (g_str_has_prefix (filename, "file://"))

            offset = 7;

        file = g_mapped_file_new (filename + offset, FALSE, NULL);

        if (!file) {

                g_free (filename);

                g_free (uri);

                return FALSE;

        }

        contents = g_mapped_file_get_contents (file);

        length = g_mapped_file_get_length (file);

        key = g_strdup_printf ("

        g_free (uri);

        key_length = strlen (key);

        start = find_in_buffer (contents, key, length, key_length);

        g_free (key);

        end = NULL;

        if (start) {

                const gchar *start_key;

                const gchar *end_key;

                length -= start - contents;

                start_key = "
";

                start = find_in_buffer (start,

                                        start_key,

                                        length,

                                        strlen (start_key));

                end_key = "

                if (start) {

                        end = find_in_buffer (start, end_key,

                                              length - strlen (start_key),

                                              strlen (end_key));

                        if (!end) {

                                end_key = "

                                end = find_in_buffer (start, end_key,

                                                      length - strlen (start_key),

                                                      strlen (end_key));

                        }

                }

        }

        if (start && end) {

                gchar       *buf;

                gboolean     break_line;

                const gchar *function;

                gchar       *stylesheet;

                gchar       *stylesheet_uri;

                gchar       *stylesheet_html = NULL;

                gchar       *javascript;

                gchar       *javascript_uri;

                gchar       *javascript_html = NULL;

                gchar       *html;

                buf = g_strndup (start, end-start);

                /* Try to reformat function signatures so they take less

                 * space and look nicer. Don't reformat things that don't

                 * look like functions.

                 */

                switch (dh_link_get_link_type (link)) {

                case DH_LINK_TYPE_FUNCTION:

                        break_line = TRUE;

                        function = "onload=\"reformatSignature()\"";

                        break;

                case DH_LINK_TYPE_MACRO:

                        break_line = TRUE;

                        function = "onload=\"cleanupSignature()\"";

                        break;

                case DH_LINK_TYPE_BOOK:

                case DH_LINK_TYPE_PAGE:

                case DH_LINK_TYPE_KEYWORD:

                case DH_LINK_TYPE_STRUCT:

                case DH_LINK_TYPE_ENUM:

                case DH_LINK_TYPE_TYPEDEF:

                case DH_LINK_TYPE_PROPERTY:

                case DH_LINK_TYPE_SIGNAL:

                default:

                        break_line = FALSE;

                        function = "";

                        break;

                }

                if (break_line) {

                        gchar *name;

                        name = strstr (buf, dh_link_get_name (link));

                        if (name && name > buf) {

                                name[-1] = '\n';

                        }

                }

                stylesheet = dh_util_build_data_filename ("devhelp",

                                                          "assistant",

                                                          "assistant.css",

                                                          NULL);

                stylesheet_uri = dh_util_create_data_uri_for_filename (stylesheet,

                                                                       "text/css");

                g_free (stylesheet);

                if (stylesheet_uri)

                        stylesheet_html = g_strdup_printf ("<link rel=\"stylesheet\" type=\"text/css\" href=\"%s\"/>",

                                                           stylesheet_uri);

                g_free (stylesheet_uri);

                javascript = dh_util_build_data_filename ("devhelp",

                                                          "assistant",

                                                          "assistant.js",

                                                          NULL);

                javascript_uri = dh_util_create_data_uri_for_filename (javascript,

                                                                       "application/javascript");

                g_free (javascript);

                if (javascript_uri)

                        javascript_html = g_strdup_printf ("<script src=\"%s\"></script>", javascript_uri);

                g_free (javascript_uri);

                html = g_strdup_printf (

                        "<html>"

                        "<head>"

                        "%s"

                        "%s"

                        "</head>"

                        "<body %s>"

                        "
%s: %s
"

                        "
%s %s
"

                        "
%s
"

                        "</body>"

                        "</html>",

                        stylesheet_html,

                        javascript_html,

                        function,

                        dh_link_type_to_string (dh_link_get_link_type (link)),

                        dh_link_get_uri (link),

                        dh_link_get_name (link),

                        _("Book:"),

                        dh_link_get_book_title (link),

                        buf);

                g_free (buf);

                g_free (stylesheet_html);

                g_free (javascript_html);

                priv->snippet_loaded = FALSE;

                webkit_web_view_load_html (

                        WEBKIT_WEB_VIEW (view),

                        html,

                        filename);

                g_free (html);

        } else {

                webkit_web_view_load_uri (WEBKIT_WEB_VIEW (view), "about:blank");

        }

        g_mapped_file_unref (file);

        g_free (filename);

        return TRUE;

}

/**

 * dh_assistant_view_search:

 * @view: a #DhAssistantView.

 * @str: the search query.

 *

 * Search for @str in the current assistant view.

 *

 * Returns: %TRUE if @str was found, %FALSE otherwise.

 */

gboolean

dh_assistant_view_search (DhAssistantView *view,

                          const gchar     *str)

{

        DhAssistantViewPrivate *priv;

        DhBookManager       *book_manager;

        const gchar         *name;

        DhLink              *link;

        DhLink              *exact_link;

        DhLink              *prefix_link;

        GList               *books;

        g_return_val_if_fail (DH_IS_ASSISTANT_VIEW (view), FALSE);

        g_return_val_if_fail (str, FALSE);

        priv = dh_assistant_view_get_instance_private (view);

        /* Filter out very short strings. */

        if (strlen (str) < 4) {

                return FALSE;

        }

        if (priv->current_search && strcmp (priv->current_search, str) == 0) {

                return FALSE;

        }

        g_free (priv->current_search);

        priv->current_search = g_strdup (str);

        prefix_link = NULL;

        exact_link = NULL;

        book_manager = dh_book_manager_get_singleton ();

        for (books = dh_book_manager_get_books (book_manager);

             !exact_link && books;

             books = g_list_next (books)) {

                GList *l;

                for (l = dh_book_get_links (DH_BOOK (books->data));

                     l && exact_link == NULL;

                     l = l->next) {

                        DhLinkType type;

                        link = l->data;

                        type = dh_link_get_link_type (link);

                        if (type == DH_LINK_TYPE_BOOK ||

                            type == DH_LINK_TYPE_PAGE ||

                            type == DH_LINK_TYPE_KEYWORD) {

                                continue;

                        }

                        name = dh_link_get_name (link);

                        if (strcmp (name, str) == 0) {

                                exact_link = link;

                        }

                        else if (g_str_has_prefix (name, str)) {

                                /* Prefer shorter prefix matches. */

                                if (!prefix_link) {

                                        prefix_link = link;

                                }

                                else if (strlen (dh_link_get_name (prefix_link)) > strlen (name)) {

                                        prefix_link = link;

                                }

                        }

                }

        }

        if (exact_link) {

                /*g_print ("exact hit: '%s' '%s'\n", exact_link->name, str);*/

                dh_assistant_view_set_link (view, exact_link);

        }

        else if (prefix_link) {

                /*g_print ("prefix hit: '%s' '%s'\n", prefix_link->name, str);*/

                dh_assistant_view_set_link (view, prefix_link);

        } else {

                /*g_print ("no hit\n");*/

                /*assistant_view_set_link (view, NULL);*/

                return FALSE;

        }

        return TRUE;

}