/*
 * e-shell-migrate.c
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) version 3.
 *
 * 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with the program; if not, see <http://www.gnu.org/licenses/>
 *
 *
 * Copyright (C) 1999-2008 Novell, Inc. (www.novell.com)
 *
 */

#include "e-shell-migrate.h"

#include <errno.h>
#include <string.h>
#include <unistd.h>
#include <glib/gi18n.h>
#include <glib/gstdio.h>
#include <libedataserver/e-xml-utils.h>

#include "e-util/e-alert-dialog.h"
#include "e-util/e-file-utils.h"
#include "e-util/e-util.h"

#include "es-event.h"

#define GCONF_VERSION_KEY	"/apps/evolution/version"
#define GCONF_LAST_VERSION_KEY	"/apps/evolution/last_version"

/******************** Begin XDG Base Directory Migration ********************/

/* These are the known EShellBackend names as of Evolution 3.0 */
static const gchar *shell_backend_names[] =
	{ "addressbook", "calendar", "mail", "memos", "tasks", NULL };

static gboolean
shell_xdg_migrate_rename (const gchar *old_filename,
                          const gchar *new_filename)
{
	gboolean success = TRUE;

	if (g_file_test (old_filename, G_FILE_TEST_EXISTS)) {
		g_print ("  mv %s %s\n", old_filename, new_filename);
		if (g_rename (old_filename, new_filename) < 0) {
			g_printerr ("  FAILED: %s\n", g_strerror (errno));
			success = FALSE;
		}
	}

	return success;
}

static gboolean
shell_xdg_migrate_rmdir (const gchar *dirname)
{
	GDir *dir = NULL;
	gboolean success = TRUE;

	if (g_file_test (dirname, G_FILE_TEST_IS_DIR)) {
		g_print ("  rmdir %s\n", dirname);
		if (g_rmdir (dirname) < 0) {
			g_printerr ("  FAILED: %s", g_strerror (errno));
			if (errno == ENOTEMPTY) {
				dir = g_dir_open (dirname, 0, NULL);
				g_printerr (" (contents follows)");
			}
			g_printerr ("\n");
			success = FALSE;
		}
	}

	/* List the directory's contents to aid debugging. */
	if (dir != NULL) {
		const gchar *basename;

		/* Align the filenames beneath the error message. */
		while ((basename = g_dir_read_name (dir)) != NULL)
			g_print ("          %s\n", basename);

		g_dir_close (dir);
	}

	return success;
}

static void
shell_xdg_migrate_process_corrections (GHashTable *corrections)
{
	GHashTableIter iter;
	gpointer old_filename;
	gpointer new_filename;

	g_hash_table_iter_init (&iter, corrections);

	while (g_hash_table_iter_next (&iter, &old_filename, &new_filename)) {
		gboolean is_directory;

		is_directory = g_file_test (old_filename, G_FILE_TEST_IS_DIR);

		/* If the old filename is a directory and the new filename
		 * is NULL, treat it as a request to remove the directory. */
		if (is_directory && new_filename == NULL)
			shell_xdg_migrate_rmdir (old_filename);
		else
			shell_xdg_migrate_rename (old_filename, new_filename);

		g_hash_table_iter_remove (&iter);
	}
}

static gboolean
shell_xdg_migrate_move_contents (const gchar *src_directory,
                                 const gchar *dst_directory)
{
	GDir *dir;
	GHashTable *corrections;
	const gchar *basename;

	dir = g_dir_open (src_directory, 0, NULL);
	if (dir == NULL)
		return FALSE;

	/* This is to avoid renaming files which we're iterating over the
	 * directory.  POSIX says the outcome of that is unspecified. */
	corrections = g_hash_table_new_full (
		g_str_hash, g_str_equal,
		(GDestroyNotify) g_free,
		(GDestroyNotify) g_free);

	g_mkdir_with_parents (dst_directory, 0700);

	while ((basename = g_dir_read_name (dir)) != NULL) {
		gchar *old_filename;
		gchar *new_filename;

		old_filename = g_build_filename (src_directory, basename, NULL);
		new_filename = g_build_filename (dst_directory, basename, NULL);

		g_hash_table_insert (corrections, old_filename, new_filename);
	}

	g_dir_close (dir);

	shell_xdg_migrate_process_corrections (corrections);
	g_hash_table_destroy (corrections);

	/* It's tempting to want to remove the source directory here.
	 * Don't.  We might be iterating over the source directory's
	 * parent directory, and removing the source directory would
	 * screw up the iteration. */

	return TRUE;
}

static void
shell_xdg_migrate_cache_dir (EShell *shell,
                             const gchar *old_base_dir)
{
	const gchar *new_cache_dir;
	gchar *old_cache_dir;
	gchar *old_filename;
	gchar *new_filename;

	old_cache_dir = g_build_filename (old_base_dir, "cache", NULL);
	new_cache_dir = e_get_user_cache_dir ();

	g_print ("Migrating cached data\n");

	g_mkdir_with_parents (new_cache_dir, 0700);

	old_filename = g_build_filename (old_cache_dir, "http", NULL);
	new_filename = g_build_filename (new_cache_dir, "http", NULL);
	shell_xdg_migrate_rename (old_filename, new_filename);
	g_free (old_filename);
	g_free (new_filename);

	/* Try to remove the old cache directory.  Good chance this will
	 * fail on the first try, since E-D-S puts stuff here too. */
	shell_xdg_migrate_rmdir (old_cache_dir);

	g_free (old_cache_dir);
}

static void
shell_xdg_migrate_config_dir_common (EShell *shell,
                                     const gchar *old_base_dir,
                                     const gchar *backend_name)
{
	GDir *dir;
	const gchar *user_config_dir;
	gchar *old_config_dir;
	gchar *new_config_dir;
	gchar *old_filename;
	gchar *new_filename;
	gchar *dirname;

	user_config_dir = e_get_user_config_dir ();

	old_config_dir = g_build_filename (old_base_dir, backend_name, NULL);
	new_config_dir = g_build_filename (user_config_dir, backend_name, NULL);

	g_mkdir_with_parents (new_config_dir, 0700);

	old_filename = g_build_filename (old_config_dir, "views", NULL);
	new_filename = g_build_filename (new_config_dir, "views", NULL);
	shell_xdg_migrate_rename (old_filename, new_filename);
	g_free (old_filename);
	g_free (new_filename);

	old_filename = g_build_filename (old_config_dir, "searches.xml", NULL);
	new_filename = g_build_filename (new_config_dir, "searches.xml", NULL);
	shell_xdg_migrate_rename (old_filename, new_filename);
	g_free (old_filename);
	g_free (new_filename);

	/* Subtle name change: config/state --> state.ini */
	old_filename = g_build_filename (old_config_dir, "config", "state", NULL);
	new_filename = g_build_filename (new_config_dir, "state.ini", NULL);
	shell_xdg_migrate_rename (old_filename, new_filename);
	g_free (old_filename);
	g_free (new_filename);

	/* GIO had a bug for awhile where it would leave behind an empty
	 * temp file with the pattern .goutputstream-XXXXXX if an output
	 * stream operation was cancelled.  We've had several reports of
	 * these files in config directories, so remove any we find. */
	dirname = g_build_filename (old_config_dir, "config", NULL);
	dir = g_dir_open (dirname, 0, NULL);
	if (dir != NULL) {
		const gchar *basename;

		while ((basename = g_dir_read_name (dir)) != NULL) {
			gchar *filename;
			struct stat st;

			if (!g_str_has_prefix (basename, ".goutputstream"))
				continue;

			filename = g_build_filename (dirname, basename, NULL);

			/* Verify the file is indeed empty. */
			if (g_stat (filename, &st) == 0 && st.st_size == 0)
				g_unlink (filename);

			g_free (filename);
		}

		g_dir_close (dir);
	}
	g_free (dirname);

	g_free (old_config_dir);
	g_free (new_config_dir);
}

static void
shell_xdg_migrate_config_dir_calendar (EShell *shell,
                                       const gchar *old_base_dir)
{
	const gchar *user_config_dir;
	gchar *old_config_dir;
	gchar *new_config_dir;
	gchar *old_filename;
	gchar *new_filename;

	user_config_dir = e_get_user_config_dir ();

	old_config_dir = g_build_filename (old_base_dir, "calendar", NULL);
	new_config_dir = g_build_filename (user_config_dir, "calendar", NULL);

	old_filename = g_build_filename (old_config_dir, "config", "TaskPad", NULL);
	new_filename = g_build_filename (new_config_dir, "TaskPad", NULL);
	shell_xdg_migrate_rename (old_filename, new_filename);
	g_free (old_filename);
	g_free (new_filename);

	old_filename = g_build_filename (old_config_dir, "config", "MemoPad", NULL);
	new_filename = g_build_filename (new_config_dir, "MemoPad", NULL);
	shell_xdg_migrate_rename (old_filename, new_filename);
	g_free (old_filename);
	g_free (new_filename);

	g_free (old_config_dir);
	g_free (new_config_dir);
}

static void
shell_xdg_migrate_config_dir_mail (EShell *shell,
                                   const gchar *old_base_dir)
{
	const gchar *user_config_dir;
	gchar *old_config_dir;
	gchar *new_config_dir;
	gchar *old_filename;
	gchar *new_filename;

	user_config_dir = e_get_user_config_dir ();

	old_config_dir = g_build_filename (old_base_dir, "mail", NULL);
	new_config_dir = g_build_filename (user_config_dir, "mail", NULL);

	old_filename = g_build_filename (old_config_dir, "filters.xml", NULL);
	new_filename = g_build_filename (new_config_dir, "filters.xml", NULL);
	shell_xdg_migrate_rename (old_filename, new_filename);
	g_free (old_filename);
	g_free (new_filename);

	old_filename = g_build_filename (old_config_dir, "vfolders.xml", NULL);
	new_filename = g_build_filename (new_config_dir, "vfolders.xml", NULL);
	shell_xdg_migrate_rename (old_filename, new_filename);
	g_free (old_filename);
	g_free (new_filename);

	/* I hate this file.  GtkHtml uses style properties for fonts. */
	old_filename = g_build_filename (old_config_dir, "config", "gtkrc-mail-fonts", NULL);
	new_filename = g_build_filename (new_config_dir, "gtkrc-mail-fonts", NULL);
	shell_xdg_migrate_rename (old_filename, new_filename);
	g_free (old_filename);
	g_free (new_filename);

	/* Everything else in the "config" directory just should be
	 * per-folder ETree files recording the expanded state of mail
	 * threads.  Rename this directory to "folders". */
	old_filename = g_build_filename (old_config_dir, "config", NULL);
	new_filename = g_build_filename (new_config_dir, "folders", NULL);
	shell_xdg_migrate_rename (old_filename, new_filename);
	g_free (old_filename);
	g_free (new_filename);

	g_free (old_config_dir);
	g_free (new_config_dir);
}

static void
shell_xdg_migrate_config_dir_cleanup (EShell *shell,
                                      const gchar *old_base_dir,
                                      const gchar *backend_name)
{
	gchar *dirname;

	dirname = g_build_filename (
		old_base_dir, backend_name, "config", NULL);

	shell_xdg_migrate_rmdir (dirname);

	g_free (dirname);
}

static void
shell_xdg_migrate_config_dir (EShell *shell,
                              const gchar *old_base_dir)
{
	const gchar *old_config_dir;
	const gchar *new_config_dir;
	gchar *old_filename;
	gchar *new_filename;
	gint ii;

	g_print ("Migrating config data\n");

	/* Some files are common to all shell backends. */
	for (ii = 0; shell_backend_names[ii] != NULL; ii++)
		shell_xdg_migrate_config_dir_common (
			shell, old_base_dir, shell_backend_names[ii]);

	/* Handle backend-specific files. */
	shell_xdg_migrate_config_dir_calendar (shell, old_base_dir);
	shell_xdg_migrate_config_dir_mail (shell, old_base_dir);

	/* Remove leftover "config" directories. */
	for (ii = 0; shell_backend_names[ii] != NULL; ii++)
		shell_xdg_migrate_config_dir_cleanup (
			shell, old_base_dir, shell_backend_names[ii]);

	/*** Miscellaneous configuration files. ***/

	old_config_dir = old_base_dir;
	new_config_dir = e_get_user_config_dir ();

	/* Subtle name change: datetime-formats --> datefime-formats.ini */
	old_filename = g_build_filename (old_config_dir, "datetime-formats", NULL);
	new_filename = g_build_filename (new_config_dir, "datetime-formats.ini", NULL);
	shell_xdg_migrate_rename (old_filename, new_filename);
	g_free (old_filename);
	g_free (new_filename);

	/* Subtle name change: printing --> printing.ini */
	old_filename = g_build_filename (old_config_dir, "printing", NULL);
	new_filename = g_build_filename (new_config_dir, "printing.ini", NULL);
	shell_xdg_migrate_rename (old_filename, new_filename);
	g_free (old_filename);
	g_free (new_filename);
}

static void
shell_xdg_migrate_data_dir (EShell *shell,
                            const gchar *old_base_dir)
{
	GDir *dir;
	GHashTable *corrections;
	const gchar *basename;
	const gchar *old_data_dir;
	const gchar *new_data_dir;
	gchar *src_directory;
	gchar *dst_directory;

	g_print ("Migrating local user data\n");

	old_data_dir = old_base_dir;
	new_data_dir = e_get_user_data_dir ();

	/* The mail hierarchy is complex and Camel doesn't distinguish
	 * between user data files and disposable cache files, so just
	 * move everything to the data directory for now.  We'll sort
	 * it out sometime down the road. */

	src_directory = g_build_filename (old_data_dir, "mail", NULL);
	dst_directory = g_build_filename (new_data_dir, "mail", NULL);

	dir = g_dir_open (src_directory, 0, NULL);
	if (dir == NULL)
		goto skip_mail;

	/* This is to avoid removing directories while we're iterating
	 * over the parent directory.  POSIX says the outcome of that
	 * is unspecified. */
	corrections = g_hash_table_new_full (
		g_str_hash, g_str_equal,
		(GDestroyNotify) g_free,
		(GDestroyNotify) g_free);

	/* Iterate over the base CamelProvider directories. */
	while ((basename = g_dir_read_name (dir)) != NULL) {
		gchar *provider_src_directory;
		gchar *provider_dst_directory;

		provider_src_directory =
			g_build_filename (src_directory, basename, NULL);
		provider_dst_directory =
			g_build_filename (dst_directory, basename, NULL);

		if (!g_file_test (provider_src_directory, G_FILE_TEST_IS_DIR)) {
			g_free (provider_src_directory);
			g_free (provider_dst_directory);
			continue;
		}

		shell_xdg_migrate_move_contents (
			provider_src_directory, provider_dst_directory);

		g_hash_table_insert (corrections, provider_src_directory, NULL);
		g_free (provider_dst_directory);
	}

	g_dir_close (dir);

	/* Remove the old base CamelProvider directories. */
	shell_xdg_migrate_process_corrections (corrections);
	g_hash_table_destroy (corrections);

skip_mail:

	g_free (src_directory);
	g_free (dst_directory);

	/* We don't want to move the source directory directly because the
	 * destination directory may already exist with content.  Instead
	 * we want to merge the content of the source directory into the
	 * destination directory.
	 *
	 * For example, given:
	 *
	 *    $(src_directory)/A   and   $(dst_directory)/B
	 *    $(src_directory)/C
	 *
	 * we want to end up with:
	 *
	 *    $(dst_directory)/A
	 *    $(dst_directory)/B
	 *    $(dst_directory)/C
	 *
	 * Any name collisions will be left in the source directory.
	 */

	src_directory = g_build_filename (old_data_dir, "signatures", NULL);
	dst_directory = g_build_filename (new_data_dir, "signatures", NULL);

	shell_xdg_migrate_move_contents (src_directory, dst_directory);
	shell_xdg_migrate_rmdir (src_directory);

	g_free (src_directory);
	g_free (dst_directory);

	/* Move all remaining regular files to the new data directory. */

	dir = g_dir_open (old_data_dir, 0, NULL);
	if (dir == NULL)
		return;

	/* This is to avoid renaming files while we're iterating over the
	 * directory.  POSIX says the outcome of that is unspecified. */
	corrections = g_hash_table_new_full (
		g_str_hash, g_str_equal,
		(GDestroyNotify) g_free,
		(GDestroyNotify) g_free);

	while ((basename = g_dir_read_name (dir)) != NULL) {
		gchar *old_filename;
		gchar *new_filename;

		old_filename = g_build_filename (old_data_dir, basename, NULL);
		new_filename = g_build_filename (new_data_dir, basename, NULL);

		/* If we encounter a directory, try removing it.  This
		 * will only work if the directory is empty, so there's
		 * no risk of data loss. */
		if (g_file_test (old_filename, G_FILE_TEST_IS_DIR)) {
			shell_xdg_migrate_rmdir (old_filename);
			g_free (old_filename);
			g_free (new_filename);
			continue;
		}

		g_hash_table_insert (corrections, old_filename, new_filename);
	}

	g_dir_close (dir);

	shell_xdg_migrate_process_corrections (corrections);
	g_hash_table_destroy (corrections);
}

static void
shell_migrate_to_xdg_base_dirs (EShell *shell)
{
	const gchar *home_dir;
	gchar *old_base_dir;

	g_return_if_fail (E_IS_SHELL (shell));

	/* XXX This blocks, but it's all just local file
	 *     renames so it should be nearly instantaneous. */

	home_dir = g_get_home_dir ();
	old_base_dir = g_build_filename (home_dir, ".evolution", NULL);

	/* Is there even anything to migrate? */
	if (!g_file_test (old_base_dir, G_FILE_TEST_IS_DIR))
		goto exit;

	shell_xdg_migrate_cache_dir (shell, old_base_dir);
	shell_xdg_migrate_config_dir (shell, old_base_dir);
	shell_xdg_migrate_data_dir (shell, old_base_dir);

	/* Try to remove the old base directory.  Good chance this will
	 * fail on the first try, since Evolution puts stuff here too. */
	g_rmdir (old_base_dir);

exit:
	g_free (old_base_dir);
}

/********************* End XDG Base Directory Migration *********************/

static gboolean
shell_migrate_attempt (EShell *shell,
                       gint major,
                       gint minor,
                       gint micro)
{
	GtkWindow *parent;
	GList *backends;
	gboolean success = TRUE;

	parent = e_shell_get_active_window (shell);
	backends = e_shell_get_shell_backends (shell);

	/* New user accounts have nothing to migrate. */
	if (major == 0 && minor == 0 && micro == 0)
		return TRUE;

	/* We only support migrating from version 2 now. */
	if (major < 2) {
		gchar *version;
		gint response;

		version = g_strdup_printf ("%d.%d", major, minor);
		response = e_alert_run_dialog_for_args (
			parent, "shell:upgrade-version-too-old",
			version, NULL);
		g_free (version);

		return (response == GTK_RESPONSE_OK);
	}

	/* Ask each of the shell backends to migrate their own data.
	 * XXX If something fails the user may end up with only partially
	 *     migrated data.  Need transaction semantics here, but how? */
	while (success && backends != NULL) {
		EShellBackend *shell_backend = backends->data;
		GError *error = NULL;

		success = e_shell_backend_migrate (
			shell_backend, major, minor, micro, &error);

		if (error != NULL) {
			gint response;

			response = e_alert_run_dialog_for_args (
				parent, "shell:upgrade-failed",
				error->message, NULL);

			success = (response == GTK_RESPONSE_OK);

			g_error_free (error);
		}

		backends = g_list_next (backends);
	}

	return success;
}

static void
shell_migrate_get_version (EShell *shell,
                           gint *major,
                           gint *minor,
                           gint *micro)
{
	GConfClient *client;
	const gchar *key;
	gchar *string;

	key = GCONF_VERSION_KEY;
	client = e_shell_get_gconf_client (shell);
	string = gconf_client_get_string (client, key, NULL);

	if (string != NULL) {
		/* Since 1.4.0 we've kept the version key in GConf. */
		sscanf (string, "%d.%d.%d", major, minor, micro);
		g_free (string);

	} else {
		/* Otherwise, assume it's a new installation. */
		*major = 0;
		*minor = 0;
		*micro = 0;
	}
}

static void
change_dir_modes (const gchar *path)
{
	GDir *dir;
	GError *err = NULL;
	const gchar *file = NULL;

	dir = g_dir_open (path, 0, &err);
	if (err) {
		g_warning ("Error opening directory %s: %s \n", path, err->message);
		g_clear_error (&err);
		return;
	}

	while ((file = g_dir_read_name (dir))) {
		gchar *full_path = g_build_filename (path, file, NULL);

		if (g_file_test (full_path, G_FILE_TEST_IS_DIR))
			change_dir_modes (full_path);

		g_free (full_path);
	}

	g_chmod (path, 0700);
	g_dir_close (dir);
}

static void
fix_folder_permissions (const gchar *data_dir)
{
	struct stat sb;

	if (g_stat (data_dir, &sb) == -1) {
		g_warning ("error stat: %s \n", data_dir);
		return;
	}

	if (((guint32) sb.st_mode & 0777) != 0700)
		change_dir_modes (data_dir);
}

gboolean
e_shell_migrate_attempt (EShell *shell)
{
	ESEvent *ese;
	GConfClient *client;
	const gchar *key;
	gint major, minor, micro;
	gint last_major, last_minor, last_micro;
	gint curr_major, curr_minor, curr_micro;
	gboolean migrated = FALSE;
	gchar *string;

	g_return_val_if_fail (E_IS_SHELL (shell), FALSE);

	client = e_shell_get_gconf_client (shell);

	if (sscanf (BASE_VERSION, "%d.%d", &curr_major, &curr_minor) != 2) {
		g_warning ("Could not parse BASE_VERSION (%s)", BASE_VERSION);
		return TRUE;
	}

	curr_micro = atoi (UPGRADE_REVISION);

	shell_migrate_get_version (shell, &major, &minor, &micro);

	/* Migrate to XDG Base Directories first, so shell backends
	 * don't have to deal with legacy data and cache directories. */
	shell_migrate_to_xdg_base_dirs (shell);

	/* This sets the folder permissions to S_IRWXU if needed */
	if (curr_major <= 2 && curr_minor <= 30)
		fix_folder_permissions (e_get_user_data_dir ());

	if (!(curr_major > major ||
		(curr_major == major && curr_minor > minor) ||
		(curr_major == major && curr_minor == minor && curr_micro > micro)))
		goto check_old;

	if (!shell_migrate_attempt (shell, major, minor, micro))
		_exit (EXIT_SUCCESS);

	/* Record a successful migration. */
	string = g_strdup_printf (
		"%d.%d.%d", curr_major, curr_minor, curr_micro);
	gconf_client_set_string (client, GCONF_VERSION_KEY, string, NULL);
	g_free (string);

	migrated = TRUE;

check_old:

	key = GCONF_LAST_VERSION_KEY;

	/* Try to retrieve the last migrated version from GConf. */
	string = gconf_client_get_string (client, key, NULL);
	if (migrated || string == NULL || sscanf (string, "%d.%d.%d",
		&last_major, &last_minor, &last_micro) != 3) {
		last_major = major;
		last_minor = minor;
		last_micro = micro;
	}
	g_free (string);

	string = g_strdup_printf (
		"%d.%d.%d", last_major, last_minor, last_micro);
	gconf_client_set_string (client, key, string, NULL);
	g_free (string);

	/** @Event: Shell attempted upgrade
	 * @Id: upgrade.done
	 * @Target: ESMenuTargetState
	 *
	 * This event is emitted whenever the shell successfully attempts
	 * an upgrade.
	 **/
	ese = es_event_peek ();
	e_event_emit (
		(EEvent *) ese, "upgrade.done",
		(EEventTarget *) es_event_target_new_upgrade (
		ese, curr_major, curr_minor, curr_micro));

	return TRUE;
}

GQuark
e_shell_migrate_error_quark (void)
{
	static GQuark quark = 0;

	if (G_UNLIKELY (quark == 0))
		quark = g_quark_from_static_string (
			"e-shell-migrate-error-quark");

	return quark;
}