/*
 *      symbols.c - this file is part of Geany, a fast and lightweight IDE
 *
 *      Copyright 2006-2007 Enrico Tröger <enrico.troeger@uvena.de>
 *      Copyright 2006-2007 Nick Treleaven <nick.treleaven@btinternet.com>
 *
 *      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.
 *
 * $Id$
 */

/*
 * Tagmanager related convenience functions.
 * Tagmanager parses tags in the current documents, known as the workspace, plus global tags,
 * which are lists of tags for each filetype. Global tags are loaded when a document with a
 * matching filetype is first loaded.
 */

#include "geany.h"

#include <ctype.h>
#include <string.h>
#include <stdlib.h>

#include "symbols.h"
#include "utils.h"
#include "filetypes.h"
#include "encodings.h"
#include "document.h"
#include "support.h"
#include "msgwindow.h"
#include "treeviews.h"

const guint TM_GLOBAL_TYPE_MASK =
	tm_tag_class_t | tm_tag_enum_t | tm_tag_interface_t |
	tm_tag_struct_t | tm_tag_typedef_t | tm_tag_union_t;


static gchar **html_entities = NULL;

typedef struct
{
	gboolean	tags_loaded;
	const gchar	*tag_file;
} TagFileInfo;

enum	// Geany tag files
{
	GTF_C,
	GTF_PASCAL,
	GTF_PHP,
	GTF_HTML_ENTITIES,
	GTF_LATEX,
	GTF_MAX
};

static TagFileInfo tag_file_info[GTF_MAX] =
{
	{FALSE, "global.tags"},
	{FALSE, "pascal.tags"},
	{FALSE, "php.tags"},
	{FALSE, "html_entities.tags"},
	{FALSE, "latex.tags"}
};

static gchar *user_tags_dir;


static void html_tags_loaded();
static void load_user_tags(filetype_id ft_id);


// Ensure that the global tags file for the file_type_idx filetype is loaded.
void symbols_global_tags_loaded(gint file_type_idx)
{
	TagFileInfo *tfi;
	gint tag_type;

	if (app->ignore_global_tags) return;

	load_user_tags(file_type_idx);

	switch (file_type_idx)
	{
		case GEANY_FILETYPES_PHP:
		case GEANY_FILETYPES_HTML:
			html_tags_loaded();
	}
	switch (file_type_idx)
	{
		case GEANY_FILETYPES_CPP:
			symbols_global_tags_loaded(GEANY_FILETYPES_C);	// load C global tags
			// no C++ tagfile yet
			return;
		case GEANY_FILETYPES_C:		tag_type = GTF_C; break;
		case GEANY_FILETYPES_PASCAL:tag_type = GTF_PASCAL; break;
		case GEANY_FILETYPES_PHP:	tag_type = GTF_PHP; break;
		case GEANY_FILETYPES_LATEX:	tag_type = GTF_LATEX; break;
		default:
			return;
	}
	tfi = &tag_file_info[tag_type];

	if (! tfi->tags_loaded)
	{
		gchar *fname = g_strconcat(app->datadir, G_DIR_SEPARATOR_S, tfi->tag_file, NULL);
		gint tm_lang;

		tm_lang = filetypes[file_type_idx]->lang;
		tm_workspace_load_global_tags(fname, tm_lang);
		tfi->tags_loaded = TRUE;
		g_free(fname);
	}
}


// HTML tagfile is just a list of entities for autocompletion (e.g. '&amp;')
static void html_tags_loaded()
{
	TagFileInfo *tfi;

	if (app->ignore_global_tags) return;

	tfi = &tag_file_info[GTF_HTML_ENTITIES];
	if (! tfi->tags_loaded)
	{
		gchar *file = g_strconcat(app->datadir, G_DIR_SEPARATOR_S, tfi->tag_file, NULL);

		html_entities = utils_read_file_in_array(file);
		tfi->tags_loaded = TRUE;
		g_free(file);
	}
}


GString *symbols_find_tags_as_string(GPtrArray *tags_array, guint tag_types)
{
	guint j;
	GString *s = NULL;
	GPtrArray *typedefs;

	g_return_val_if_fail(tags_array != NULL, NULL);

	typedefs = tm_tags_extract(tags_array, tag_types);

	if ((typedefs) && (typedefs->len > 0))
	{
		s = g_string_sized_new(typedefs->len * 10);
		for (j = 0; j < typedefs->len; ++j)
		{
			if (!(TM_TAG(typedefs->pdata[j])->atts.entry.scope))
			{
				if (TM_TAG(typedefs->pdata[j])->name)
				{
					if (j != 0)
						g_string_append_c(s, ' ');
					g_string_append(s, TM_TAG(typedefs->pdata[j])->name);
				}
			}
		}
	}
	g_ptr_array_free(typedefs, TRUE);
	return s;
}


const gchar *symbols_get_context_separator(filetype_id ft_id)
{
	gchar *cosep;

	switch (ft_id)
	{
		case GEANY_FILETYPES_C:	// for C++ .h headers or C structs
		case GEANY_FILETYPES_CPP:
		{
			static gchar cc[] = "::";

			cosep = cc;
		}
		break;

		default:
		{
			static gchar def[] = ".";

			cosep = def;
		}
	}
	return cosep;	// return ptr to static string
}


GString *symbols_get_macro_list()
{
	guint j, i;
	const GPtrArray *tags;
	GPtrArray *ftags;
	GString *words;

	if (app->tm_workspace->work_objects == NULL)
		return NULL;

	ftags = g_ptr_array_sized_new(50);
	words = g_string_sized_new(200);

	for (j = 0; j < app->tm_workspace->work_objects->len; j++)
	{
		tags = tm_tags_extract(TM_WORK_OBJECT(app->tm_workspace->work_objects->pdata[j])->tags_array,
			tm_tag_enum_t | tm_tag_variable_t | tm_tag_macro_t | tm_tag_macro_with_arg_t);
		if (NULL != tags)
		{
			for (i = 0; ((i < tags->len) && (i < GEANY_MAX_AUTOCOMPLETE_WORDS)); ++i)
			{
				g_ptr_array_add(ftags, (gpointer) tags->pdata[i]);
			}
		}
	}
	tm_tags_sort(ftags, NULL, FALSE);
	for (j = 0; j < ftags->len; j++)
	{
		if (j > 0) g_string_append_c(words, ' ');
		g_string_append(words, TM_TAG(ftags->pdata[j])->name);
	}
	g_ptr_array_free(ftags, TRUE);
	return words;
}


static TMTag *
symbols_find_tm_tag(const GPtrArray *tags, const gchar *tag_name)
{
	guint i;
	g_return_val_if_fail(tags != NULL, NULL);

	for (i = 0; i < tags->len; ++i)
	{
		if (utils_str_equal(TM_TAG(tags->pdata[i])->name, tag_name))
			return TM_TAG(tags->pdata[i]);
	}
	return NULL;
}


TMTag *symbols_find_in_workspace(const gchar *tag_name, gint type)
{
	guint j;
	const GPtrArray *tags;
	TMTag *tmtag;

	if (app->tm_workspace->work_objects != NULL)
	{
		for (j = 0; j < app->tm_workspace->work_objects->len; j++)
		{
			tags = tm_tags_extract(
				TM_WORK_OBJECT(app->tm_workspace->work_objects->pdata[j])->tags_array,
				type);
			if (tags == NULL) continue;

			tmtag = symbols_find_tm_tag(tags, tag_name);
			if (tmtag != NULL)
				return tmtag;
		}
	}
	return NULL;	// not found
}


const gchar **symbols_get_html_entities()
{
	if (html_entities == NULL)
		html_tags_loaded(); // if not yet created, force creation of the array but shouldn't occur

	return (const gchar **) html_entities;
}


void symbols_finalize()
{
	g_strfreev(html_entities);
}


// small struct to track tag name and type together
typedef struct GeanySymbol
{
	gchar	*str;
	gint	 type;
	gint	 line;
} GeanySymbol;


/* wrapper function to let strcmp work with GeanySymbol struct */
static gint compare_symbol(const GeanySymbol *a, const GeanySymbol *b)
{
	gint ret;

	if (a == NULL || b == NULL) return 0;

	ret = strcmp(a->str, b->str);
	if (ret == 0)
	{
		return a->line - b->line;
	}
	return ret;
}


static const GList *
get_tag_list(gint idx, guint tag_types)
{
	static GList *tag_names = NULL;

	if (idx >= 0 && doc_list[idx].is_valid && doc_list[idx].tm_file &&
		doc_list[idx].tm_file->tags_array)
	{
		TMTag *tag;
		guint i;
		GeanySymbol *symbol;
		gboolean doc_is_utf8 = FALSE;
		gchar *utf8_name;
		const gchar *cosep =
			symbols_get_context_separator(FILETYPE_ID(doc_list[idx].file_type));

		if (tag_names)
		{
			GList *tmp;
			for (tmp = tag_names; tmp; tmp = g_list_next(tmp))
			{
				g_free(((GeanySymbol*)tmp->data)->str);
				g_free(tmp->data);
			}
			g_list_free(tag_names);
			tag_names = NULL;
		}

		// do this comparison only once
		if (utils_str_equal(doc_list[idx].encoding, "UTF-8")) doc_is_utf8 = TRUE;

		for (i = 0; i < (doc_list[idx].tm_file)->tags_array->len; ++i)
		{
			tag = TM_TAG((doc_list[idx].tm_file)->tags_array->pdata[i]);
			if (tag == NULL)
				return NULL;

			if (tag->type & tag_types)
			{
				if (! doc_is_utf8) utf8_name = encodings_convert_to_utf8_from_charset(tag->name,
															-1, doc_list[idx].encoding, TRUE);
				else utf8_name = tag->name;

				symbol = g_new0(GeanySymbol, 1);
				if ((tag->atts.entry.scope != NULL) && isalpha(tag->atts.entry.scope[0]))
				{
					symbol->str = g_strconcat(tag->atts.entry.scope, cosep, utf8_name, NULL);
				}
				else
				{
					symbol->str = g_strdup(utf8_name);
				}
				symbol->type = tag->type;
				symbol->line = tag->atts.entry.line;
				tag_names = g_list_prepend(tag_names, symbol);

				if (! doc_is_utf8) g_free(utf8_name);
			}
		}
		tag_names = g_list_sort(tag_names, (GCompareFunc) compare_symbol);
		return tag_names;
	}
	else
		return NULL;
}


struct TreeviewSymbols
{
	GtkTreeIter		 tag_function;
	GtkTreeIter		 tag_class;
	GtkTreeIter		 tag_macro;
	GtkTreeIter		 tag_member;
	GtkTreeIter		 tag_variable;
	GtkTreeIter		 tag_namespace;
	GtkTreeIter		 tag_struct;
	GtkTreeIter		 tag_other;
} tv_iters;


static void init_tag_iters()
{
	// init all GtkTreeIters with -1 to make them invalid to avoid crashes when switching between
	// filetypes(e.g. config file to Python crashes Geany without this)
	tv_iters.tag_function.stamp = -1;
	tv_iters.tag_class.stamp = -1;
	tv_iters.tag_member.stamp = -1;
	tv_iters.tag_macro.stamp = -1;
	tv_iters.tag_variable.stamp = -1;
	tv_iters.tag_namespace.stamp = -1;
	tv_iters.tag_struct.stamp = -1;
	tv_iters.tag_other.stamp = -1;
}


/* Adds symbol list groups in (iter*, title) pairs.
 * The list must be ended with NULL. */
static void G_GNUC_NULL_TERMINATED
tag_list_add_groups(GtkTreeStore *tree_store, ...)
{
	va_list args;
	GtkTreeIter *iter;
	static GtkIconTheme *icon_theme = NULL;
	static gint x, y;

	if (icon_theme == NULL)
	{
		gtk_icon_size_lookup(GTK_ICON_SIZE_MENU, &x, &y);
		icon_theme = gtk_icon_theme_get_default();
#ifdef G_OS_WIN32
		gtk_icon_theme_append_search_path(icon_theme, "share\\icons");
#else
		gtk_icon_theme_append_search_path(icon_theme, PACKAGE_DATA_DIR "/icons");
#endif
	}

    va_start(args, tree_store);
    for (; iter = va_arg(args, GtkTreeIter*), iter != NULL;)
    {
		gchar *title = va_arg(args, gchar*);
		gchar *icon_name = va_arg(args, gchar *);
		GdkPixbuf *icon = NULL;

		if (icon_name)
		{
			icon = gtk_icon_theme_load_icon(icon_theme, icon_name, x, 0, NULL);
		}

    	g_assert(title != NULL);
		gtk_tree_store_append(tree_store, iter, NULL);

		if (G_IS_OBJECT(icon)) {
			gtk_tree_store_set(tree_store, iter, SYMBOLS_COLUMN_ICON, icon,
			                   SYMBOLS_COLUMN_NAME, title, -1);
			g_object_unref(icon);
		} else
			gtk_tree_store_set(tree_store, iter, SYMBOLS_COLUMN_NAME, title, -1);
	}
	va_end(args);
}


static void init_tag_list(gint idx)
{
	filetype_id ft_id = doc_list[idx].file_type->id;
	GtkTreeStore *tag_store = doc_list[idx].tag_store;

	init_tag_iters();

	switch (ft_id)
	{
		case GEANY_FILETYPES_DIFF:
		{
			tag_list_add_groups(tag_store,
				&(tv_iters.tag_function), _("Files"), NULL, NULL);
			break;
		}
		case GEANY_FILETYPES_DOCBOOK:
		{
			tag_list_add_groups(tag_store,
				&(tv_iters.tag_function), _("Chapter"), NULL,
				&(tv_iters.tag_class), _("Section"), NULL,
				&(tv_iters.tag_member), _("Sect1"), NULL,
				&(tv_iters.tag_macro), _("Sect2"), NULL,
				&(tv_iters.tag_variable), _("Sect3"), NULL,
				&(tv_iters.tag_struct), _("Appendix"), NULL,
				&(tv_iters.tag_other), _("Other"), NULL,
				NULL);
			//	&(tv_iters.tag_namespace), _("Other"), NULL, NULL);
			break;
		}
		case GEANY_FILETYPES_HASKELL:
			tag_list_add_groups(tag_store,
				&tv_iters.tag_namespace, _("Module"), NULL,
				&tv_iters.tag_struct, _("Types"), NULL,
				&tv_iters.tag_macro, _("Type constructors"), NULL,
				&tv_iters.tag_function, _("Functions"), "classviewer-method",
				NULL);
			break;
		case GEANY_FILETYPES_CONF:
			tag_list_add_groups(tag_store,
				&tv_iters.tag_namespace, _("Sections"), NULL,
				&tv_iters.tag_macro, _("Keys"), NULL,
				NULL);
			break;
		case GEANY_FILETYPES_LATEX:
		{
			tag_list_add_groups(tag_store,
				&(tv_iters.tag_function), _("Command"), NULL,
				&(tv_iters.tag_class), _("Environment"), NULL,
				&(tv_iters.tag_member), _("Section"), NULL,
				&(tv_iters.tag_macro), _("Subsection"), NULL,
				&(tv_iters.tag_variable), _("Subsubsection"), NULL,
				&(tv_iters.tag_struct), _("Label"), NULL,
				&(tv_iters.tag_namespace), _("Chapter"), NULL,
				&(tv_iters.tag_other), _("Other"), NULL,
				NULL);
			break;
		}
		case GEANY_FILETYPES_PERL:
		{
			tag_list_add_groups(tag_store,
				&(tv_iters.tag_class), _("Package"), NULL,
				&(tv_iters.tag_function), _("Functions"), "classviewer-method",
				&(tv_iters.tag_member), _("My"), NULL,
				&(tv_iters.tag_macro), _("Local"), NULL,
				&(tv_iters.tag_variable), _("Our"), NULL,
				NULL);
				//&(tv_iters.tag_struct), _("Label"), NULL,
				//&(tv_iters.tag_namespace), _("Begin"), NULL,
				//&(tv_iters.tag_other), _("Other"), NULL, NULL);
			break;
		}
		case GEANY_FILETYPES_PHP:
		{
			tag_list_add_groups(tag_store,
				&(tv_iters.tag_class), _("Classes"), "classviewer-class",
				&(tv_iters.tag_function), _("Functions"), "classviewer-method",
				&(tv_iters.tag_macro), _("Constants"), NULL,
				&(tv_iters.tag_variable), _("Variables"), "classviewer-var",
				NULL);
				//&(tv_iters.tag_struct), _("Label"),
				//&(tv_iters.tag_namespace), _("Begin"),
				//&(tv_iters.tag_other), _("Other"), NULL);
			break;
		}
		case GEANY_FILETYPES_RUBY:
		{
			tag_list_add_groups(tag_store,
				&(tv_iters.tag_class), _("Classes"), "classviewer-class",
				&(tv_iters.tag_member), _("Singletons"), NULL,
				&(tv_iters.tag_macro), _("Mixins"), NULL,
				&(tv_iters.tag_function), _("Methods"), "classviewer-method",
				&(tv_iters.tag_struct), _("Members"), "classviewer-member",
				&(tv_iters.tag_variable), _("Variables"), "classviewer-var",
				NULL);
				//&(tv_iters.tag_namespace), _("Begin"),
				//&(tv_iters.tag_other), _("Other"), NULL);
			break;
		}
		case GEANY_FILETYPES_PYTHON:
		{
			tag_list_add_groups(tag_store,
				&(tv_iters.tag_class), _("Classes"), "classviewer-class",
				&(tv_iters.tag_member), _("Methods"), "classviewer-member",
				&(tv_iters.tag_function), _("Functions"), "classviewer-method",
				NULL);
				//&(tv_iters.tag_macro), _("Mixin"),
				//&(tv_iters.tag_variable), _("Variables"),
				//&(tv_iters.tag_struct), _("Members"),
				//&(tv_iters.tag_namespace), _("Begin"),
				//&(tv_iters.tag_other), _("Other"), NULL);
			break;
		}
		case GEANY_FILETYPES_VHDL:
		{
			tag_list_add_groups(tag_store,
				&(tv_iters.tag_function), _("Functions"), "classviewer-method",
				//&(tv_iters.tag_class), _("Constants"),
				//&(tv_iters.tag_member), _("Members"),
				//&(tv_iters.tag_macro), _("Macros"),
				&(tv_iters.tag_variable), _("Variables"), "classviewer-var",
				NULL);
				//&(tv_iters.tag_namespace), _("Namespaces"),
				//&(tv_iters.tag_struct), _("Signals"),
				//&(tv_iters.tag_other), _("Other"), NULL);
			break;
		}
		case GEANY_FILETYPES_JAVA:
		{
			tag_list_add_groups(tag_store,
				&(tv_iters.tag_namespace), _("Package"), NULL,
				&(tv_iters.tag_struct), _("Interfaces"), NULL,
				&(tv_iters.tag_class), _("Classes"), "classviewer-class",
				&(tv_iters.tag_function), _("Methods"), "classviewer-method",
				&(tv_iters.tag_member), _("Members"), "classviewer-member",
			//	&(tv_iters.tag_macro), _("Macros"),
			//	&(tv_iters.tag_variable), _("Variables"),
				&(tv_iters.tag_other), _("Other"), "classviewer-other",
				NULL);
			break;
		}
		case GEANY_FILETYPES_D:
		default:
		{
			if (ft_id == GEANY_FILETYPES_D)
				tag_list_add_groups(tag_store,
					&(tv_iters.tag_namespace), _("Module"), NULL, NULL);
			else
				tag_list_add_groups(tag_store,
					&(tv_iters.tag_namespace), _("Namespaces"), "classviewer-namespace", NULL);

			tag_list_add_groups(tag_store,
				&(tv_iters.tag_class), _("Classes"), "classviewer-class",
				&(tv_iters.tag_function), _("Functions"), "classviewer-method",
				&(tv_iters.tag_member), _("Members"), "classviewer-member",
				&(tv_iters.tag_struct), _("Structs / Typedefs"), "classviewer-struct",
				NULL);

			if (ft_id != GEANY_FILETYPES_D)
			{
				tag_list_add_groups(tag_store,
					&(tv_iters.tag_macro), _("Macros"), "classviewer-macro", NULL);
			}
			tag_list_add_groups(tag_store,
				&(tv_iters.tag_variable), _("Variables"), "classviewer-var",
				&(tv_iters.tag_other), _("Other"), "classviewer-other", NULL);
		}
	}
}


gboolean symbols_recreate_tag_list(gint idx)
{
	GList *tmp;
	const GList *tags;
	GtkTreeIter iter;
	GtkTreeModel *model;

	g_return_val_if_fail(DOC_IDX_VALID(idx), FALSE);

	tags = get_tag_list(idx, tm_tag_max_t);
	if (doc_list[idx].tm_file == NULL || tags == NULL) return FALSE;

	gtk_tree_store_clear(doc_list[idx].tag_store);
	// unref the store to speed up the filling(from TreeView Tutorial)
	model = gtk_tree_view_get_model(GTK_TREE_VIEW(doc_list[idx].tag_tree));
	g_object_ref(model); // Make sure the model stays with us after the tree view unrefs it
	gtk_tree_view_set_model(GTK_TREE_VIEW(doc_list[idx].tag_tree), NULL); // Detach model from view

	init_tag_list(idx);
	for (tmp = (GList*)tags; tmp; tmp = g_list_next(tmp))
	{
		gchar buf[100];
		const GeanySymbol *symbol = (GeanySymbol*)tmp->data;
		GtkTreeIter *parent = NULL;
		GdkPixbuf *icon = NULL;

		g_snprintf(buf, sizeof(buf), "%s [%d]", symbol->str, symbol->line);

		switch (symbol->type)
		{
			case tm_tag_prototype_t:
			case tm_tag_method_t:
			case tm_tag_function_t:
			{
				if (tv_iters.tag_function.stamp == -1) break;
				parent = &(tv_iters.tag_function);
				break;
			}
			case tm_tag_macro_t:
			case tm_tag_macro_with_arg_t:
			{
				if (tv_iters.tag_macro.stamp == -1) break;
				parent = &(tv_iters.tag_macro);
				break;
			}
			case tm_tag_class_t:
			{
				if (tv_iters.tag_class.stamp == -1) break;
				parent = &(tv_iters.tag_class);
				break;
			}
			case tm_tag_member_t:
			case tm_tag_field_t:
			{
				if (tv_iters.tag_member.stamp == -1) break;
				parent = &(tv_iters.tag_member);
				break;
			}
			case tm_tag_typedef_t:
			case tm_tag_enum_t:
			case tm_tag_union_t:
			case tm_tag_struct_t:
			case tm_tag_interface_t:
			{
				if (tv_iters.tag_struct.stamp == -1) break;
				parent = &(tv_iters.tag_struct);
				break;
			}
			case tm_tag_variable_t:
			{
				if (tv_iters.tag_variable.stamp == -1) break;
				parent = &(tv_iters.tag_variable);
				break;
			}
			case tm_tag_namespace_t:
			case tm_tag_package_t:
			{
				if (tv_iters.tag_namespace.stamp == -1) break;
				parent = &(tv_iters.tag_namespace);
				break;
			}
			default:
			{
				if (tv_iters.tag_other.stamp == -1) break;
				parent = &(tv_iters.tag_other);
			}
		}

		if (parent)
		{
			gtk_tree_model_get(GTK_TREE_MODEL(doc_list[idx].tag_store), parent,
		 	                   SYMBOLS_COLUMN_ICON, &icon, -1);
			gtk_tree_store_append(doc_list[idx].tag_store, &iter, parent);
			gtk_tree_store_set(doc_list[idx].tag_store, &iter,
		 	                  SYMBOLS_COLUMN_ICON, icon,
                              SYMBOLS_COLUMN_NAME, buf,
                              SYMBOLS_COLUMN_LINE, symbol->line, -1);

			if (G_LIKELY(G_IS_OBJECT(icon)))
				g_object_unref(icon);
		}
	}
	gtk_tree_view_set_model(GTK_TREE_VIEW(doc_list[idx].tag_tree), model); // Re-attach model to view
	g_object_unref(model);
	gtk_tree_view_expand_all(GTK_TREE_VIEW(doc_list[idx].tag_tree));
	return TRUE;
}


/* Detects a global tags filetype from the *.lang.* language extension.
 * Returns NULL if there was no matching TM language. */
static filetype *detect_global_tags_filetype(const gchar *utf8_filename)
{
	gchar *tags_ext;
	gchar *shortname = g_strdup(utf8_filename);
	filetype *ft = NULL;

	tags_ext = strstr(shortname, ".tags");
	if (tags_ext)
	{
		*tags_ext = '\0';	// remove .tags extension
		ft = filetypes_detect_from_filename(shortname);
	}
	g_free(shortname);

	if (ft == NULL || ! filetype_has_tags(ft))
		return NULL;
	return ft;
}


/* Adapted from anjuta-2.0.2/global-tags/tm_global_tags.c, thanks.
 * Needs full paths for filenames, except for C/C++ tag files, when CFLAGS includes
 * the relevant path.
 * Example:
 * CFLAGS=-I/home/user/libname-1.x geany -g libname.d.tags libname.h */
int symbols_generate_global_tags(int argc, char **argv)
{
	/* -E pre-process, -dD output user macros, -p prof info (?),
	 * -undef remove builtin macros (seems to be needed with FC5 gcc 4.1.1 */
	const char pre_process[] = "gcc -E -dD -p -undef";

	if (argc > 2)
	{
		/* Create global taglist */
		int status;
		char *command;
		const char *tags_file = argv[1];
		char *utf8_fname;
		filetype *ft;

		utf8_fname = utils_get_utf8_from_locale(tags_file);
		ft = detect_global_tags_filetype(utf8_fname);
		g_free(utf8_fname);

		if (ft == NULL)
		{
			g_printerr(_("Unknown filetype extension for \"%s\".\n"), tags_file);
			return 1;
		}
		if (ft->lang == 0 || ft->lang == 1)	/* C/C++ */
			command = g_strdup_printf("%s %s", pre_process, NVL(getenv("CFLAGS"), ""));
		else
			command = NULL;	// don't preprocess

		geany_debug("Generating %s tags file.", ft->name);
		status = tm_workspace_create_global_tags(command,
												 (const char **) (argv + 2),
												 argc - 2, tags_file, ft->lang);
		g_free(command);
		if (! status)
		{
			g_printerr(_("Failed to create tags file.\n"));
			return 1;
		}
	}
	else
	{
		g_printerr(_("Usage: %s -g <Tag File> <File list>\n\n"), argv[0]);
		g_printerr(_("Example:\n"
			"CFLAGS=`pkg-config gtk+-2.0 --cflags` %s -g gtk2.c.tags"
			" /usr/include/gtk-2.0/gtk/gtk.h\n"), argv[0]);
		return 1;
	}
	return 0;
}


void symbols_show_load_tags_dialog()
{
	GtkWidget *dialog;
	GtkFileFilter *filter;

	dialog = gtk_file_chooser_dialog_new(_("Load Tags"), GTK_WINDOW(app->window),
		GTK_FILE_CHOOSER_ACTION_OPEN,
		GTK_STOCK_CANCEL, GTK_RESPONSE_CANCEL,
		GTK_STOCK_OPEN, GTK_RESPONSE_OK,
		NULL);
	gtk_widget_set_name(dialog, "GeanyDialog");
	filter = gtk_file_filter_new();
	gtk_file_filter_set_name(filter, _("Geany tag files (*.tags)"));
	gtk_file_filter_add_pattern(filter, "*.tags");
	gtk_file_chooser_add_filter(GTK_FILE_CHOOSER(dialog), filter);

	if (gtk_dialog_run(GTK_DIALOG(dialog)) == GTK_RESPONSE_OK)
	{
		GSList *flist = gtk_file_chooser_get_filenames(GTK_FILE_CHOOSER(dialog));
		GSList *item;

		for (item = flist; item != NULL; item = g_slist_next(item))
		{
			gchar *fname = item->data;
			gchar *utf8_fname;
			filetype *ft;

			utf8_fname = utils_get_utf8_from_locale(fname);
			ft = detect_global_tags_filetype(utf8_fname);

			if (ft != NULL && tm_workspace_load_global_tags(fname, ft->lang))
				msgwin_status_add(_("Loaded %s tags file '%s'."), ft->name, utf8_fname);
			else
				msgwin_status_add(_("Could not load tags file '%s'."), utf8_fname);

			g_free(utf8_fname);
			g_free(fname);
		}
		g_slist_free(flist);
	}
	gtk_widget_destroy(dialog);
}


/* Fills a hash table with filetype keys that hold a linked list of filenames. */
static GHashTable *get_tagfile_hash(const GSList *file_list)
{
	const GSList *node;
	GHashTable *hash = g_hash_table_new(NULL, NULL);

	for (node = file_list; node != NULL; node = g_slist_next(node))
	{
		GList *fnames;
		gchar *fname = node->data;
		gchar *utf8_fname = utils_get_utf8_from_locale(fname);
		filetype *ft = detect_global_tags_filetype(utf8_fname);

		g_free(utf8_fname);

		if (FILETYPE_ID(ft) < GEANY_FILETYPES_ALL)
		{
			fnames = g_hash_table_lookup(hash, ft);	// may be NULL
			fnames = g_list_append(fnames, fname);
			g_hash_table_insert(hash, ft, fnames);
		}
		else
			geany_debug("Unknown filetype for file '%s'.", fname);
	}
	return hash;
}


static GHashTable *init_user_tags()
{
	GSList *file_list;
	GHashTable *lang_hash;

	user_tags_dir = g_strconcat(app->configdir, G_DIR_SEPARATOR_S, "tags", NULL);
	file_list = utils_get_file_list(user_tags_dir, NULL, NULL);
	lang_hash = get_tagfile_hash(file_list);

	// don't need to delete list contents because they are now used for hash contents
	g_slist_free(file_list);

	// create the tags dir for next time if it doesn't exist
	if (! g_file_test(user_tags_dir, G_FILE_TEST_IS_DIR))
	{
		utils_mkdir(user_tags_dir, FALSE);
	}
	return lang_hash;
}


static void load_user_tags(filetype_id ft_id)
{
	static guchar tags_loaded[GEANY_FILETYPES_ALL] = {0};
	static GHashTable *lang_hash = NULL;
	GList *fnames;
	const GList *node;
	const filetype *ft = filetypes[ft_id];

	g_return_if_fail(ft_id < GEANY_FILETYPES_ALL);

	if (tags_loaded[ft_id])
		return;
	tags_loaded[ft_id] = TRUE;	// prevent reloading

	if (lang_hash == NULL)
		lang_hash = init_user_tags();

	fnames = g_hash_table_lookup(lang_hash, ft);

	for (node = fnames; node != NULL; node = g_list_next(node))
	{
		const gint tm_lang = ft->lang;
		gchar *fname;

		fname = g_strconcat(user_tags_dir, G_DIR_SEPARATOR_S, node->data, NULL);
		tm_workspace_load_global_tags(fname, tm_lang);
		geany_debug("Loaded %s (%s).", fname, ft->name);
		g_free(fname);
	}
	g_list_foreach(fnames, (GFunc) g_free, NULL);
	g_list_free(fnames);
	g_hash_table_remove(lang_hash, (gpointer) ft);
}