/* -*- Mode: C++; indent-tabs-mode: nil; tab-width: 4 -*-
 * -*- coding: utf-8 -*-
 *
 * Copyright (C) 2023 KylinSoft Co., Ltd.
 *
 * 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 3 of the License, or
 * 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, see <http://www.gnu.org/licenses/>.
 */

#include "usd-disk-space.h"
#include <QDebug>
#include "qtimer.h"
#include "syslog.h"
#include "clib-syslog.h"

#define GIGABYTE                   1024 * 1024 * 1024

#define CHECK_EVERY_X_SECONDS      120 * 1000

#define DISK_SPACE_ANALYZER        "ukui-disk-usage-analyzer"

#define SETTINGS_HOUSEKEEPING_SCHEMA      "org.ukui.SettingsDaemon.plugins.housekeeping"
#define SETTINGS_FREE_PC_NOTIFY_KEY       "free-percent-notify"
#define SETTINGS_FREE_PC_NOTIFY_AGAIN_KEY "free-percent-notify-again"
#define SETTINGS_FREE_SIZE_NO_NOTIFY      "free-size-gb-no-notify"
#define SETTINGS_MIN_NOTIFY_PERIOD        "min-notify-period"
#define SETTINGS_IGNORE_PATHS             "ignore-paths"

static guint64 *time_read;

DiskSpace::DiskSpace()
{

    ldsm_timeout_cb = new QTimer();
    trash_empty=new LdsmTrashEmpty();
    ldsm_notified_hash=NULL;
    ldsm_monitor = NULL;
    free_percent_notify = 0.05;
    free_percent_notify_again = 0.01;
    free_size_gb_no_notify = 2;
    min_notify_period = 10;
    ignore_paths = NULL;
    done = FALSE;

    connect(ldsm_timeout_cb, &QTimer::timeout,
            this, &DiskSpace::ldsm_check_all_mounts);

    ldsm_timeout_cb->start();

    if (QGSettings::isSchemaInstalled(SETTINGS_HOUSEKEEPING_SCHEMA)) {
        settings = new QGSettings(SETTINGS_HOUSEKEEPING_SCHEMA);
    }
    this->dialog = nullptr;
}

DiskSpace::~DiskSpace()
{
    delete trash_empty;
    delete settings;
}

static gint
ldsm_ignore_path_compare (gconstpointer a,
                          gconstpointer b)
{
    return g_strcmp0 ((const gchar *)a, (const gchar *)b);
}


bool DiskSpace::ldsm_mount_is_user_ignore (const char *path)
{
    if (g_slist_find_custom (ignore_paths, path, (GCompareFunc) ldsm_ignore_path_compare) != NULL)
        return TRUE;
    else
        return FALSE;
}

//static gboolean
//ldsm_is_hash_item_in_ignore_paths (gpointer key,
//                                   gpointer value,
//                                   gpointer user_data)
//{
//    return this->ldsm_mount_is_user_ignore ((char *)key);
//}

void DiskSpace::usdLdsmGetConfig()
{
    // 先取得清理提醒的百分比时机
    free_percent_notify = settings->get(SETTINGS_FREE_PC_NOTIFY_KEY).toDouble();
    if (free_percent_notify >= 1 || free_percent_notify < 0) {
        /* FIXME define min and max in gschema! */
        qWarning ("housekeeping: Invalid configuration of free_percent_notify: %f\n" \
                   "Using sensible default", free_percent_notify);
        free_percent_notify = 0.05;
    }
    // 取得第二次提醒的百分比时机
    free_percent_notify_again = settings->get(SETTINGS_FREE_PC_NOTIFY_AGAIN_KEY).toDouble();
    if (free_percent_notify_again >= 1 || free_percent_notify_again < 0) {
        /* FIXME define min and max in gschema! */
        qWarning ("housekeeping: Invalid configuration of free_percent_notify_again: %f\n" \
                   "Using sensible default\n", free_percent_notify_again);
        free_percent_notify_again = 0.01;
    }

    // 取得不通知的g
    free_size_gb_no_notify = settings->get(SETTINGS_FREE_SIZE_NO_NOTIFY).toUInt();
    // 取得最小通知周期
    min_notify_period = settings->get(SETTINGS_MIN_NOTIFY_PERIOD).toInt();
    USD_LOG(LOG_DEBUG,"free_percent_notify:%f,free_size_gb_no_notify:%d",free_percent_notify,free_size_gb_no_notify);
    if (ignore_paths != NULL) {
        g_slist_foreach (ignore_paths, (GFunc) g_free, NULL);
        g_slist_free (ignore_paths);
        ignore_paths = NULL;
    }
}

static void
ldsm_free_mount_info (gpointer data)
{
    LdsmMountInfo *mount = (LdsmMountInfo *)data;

    g_return_if_fail (mount != NULL);
    g_unix_mount_free (mount->mount);
    g_free (mount);
}

void DiskSpace::usdLdsmUpdateConfig(QString key)
{
    usdLdsmGetConfig();
}


static gboolean is_hash_item_not_in_mounts(QHash<const char*, LdsmMountInfo*> &hash, GList* user_data) {
    for (GList *l = (GList *) user_data; l != NULL; l = l->next) {
        GUnixMountEntry *mount = (GUnixMountEntry *)l->data;
        const char *path;

        path = g_unix_mount_get_mount_path (mount);
        // 找到了，返回false
        if (hash.find(path) !=hash.end() )
            return FALSE;
    }
    return TRUE;
}

static gboolean
is_in (const gchar *value, const gchar *set[])
{
    int i;
    for (i = 0; set[i] != NULL; i++)
    {
        if (strcmp (set[i], value) == 0)
            return TRUE;
    }
    return FALSE;
}

bool DiskSpace::ldsm_mount_should_ignore (GUnixMountEntry *mount)
{
    const gchar *fs, *device, *path;

    path = g_unix_mount_get_mount_path (mount);
    if (ldsm_mount_is_user_ignore (path))
        return TRUE;

    /* This is borrowed from GLib and used as a way to determine
     * which mounts we should ignore by default. GLib doesn't
     * expose this in a way that allows it to be used for this
     * purpose
     */

    /* We also ignore network filesystems */

    const gchar *ignore_fs[] = {
        "adfs",
        "afs",
        "auto",
        "autofs",
        "autofs4",
        "cifs",
        "cxfs",
        "devfs",
        "devpts",
        "ecryptfs",
        "fdescfs",
        "gfs",
        "gfs2",
        "kernfs",
        "linprocfs",
        "linsysfs",
        "lustre",
        "lustre_lite",
        "ncpfs",
        "nfs",
        "nfs4",
        "nfsd",
        "ocfs2",
        "proc",
        "procfs",
        "ptyfs",
        "rpc_pipefs",
        "selinuxfs",
        "smbfs",
        "sysfs",
        "tmpfs",
        "usbfs",
        "zfs",
        NULL
    };
    const gchar *ignore_devices[] = {
        "none",
        "sunrpc",
        "devpts",
        "nfsd",
        "/dev/loop",
        "/dev/vn",
        NULL
    };

    fs = g_unix_mount_get_fs_type (mount);
    device = g_unix_mount_get_device_path (mount);

    if (is_in (fs, ignore_fs))
        return TRUE;

    if (is_in (device, ignore_devices))
        return TRUE;

    return FALSE;
}

bool  DiskSpace::ldsm_mount_has_space (LdsmMountInfo *mount)
{
    double free_space;
    bool percent_flag = false;
    bool size_falg = false;
    free_space = (double) mount->buf.f_bavail / (double) mount->buf.f_blocks;

    /* enough free space, nothing to do */
    if (free_space > free_percent_notify)
        percent_flag = true;

    if (((gint64) mount->buf.f_frsize * (gint64) mount->buf.f_bavail) > ((gint64) free_size_gb_no_notify * GIGABYTE) ||
            ((double) mount->buf.f_blocks *(gint64) mount->buf.f_frsize) < ((gint64) free_size_gb_no_notify * GIGABYTE)) {
            size_falg = true;
    }

    USD_LOG(LOG_DEBUG,"%s:(percent_flag:%d，size_falg:%d),f_frsize:%d,f_bavail:%d,f_blocks:%d,%f",g_unix_mount_get_mount_path(mount->mount),percent_flag,size_falg,
            mount->buf.f_frsize,mount->buf.f_bavail,mount->buf.f_blocks,free_percent_notify);
    /* If it returns false, then this volume is low on space */
    return (percent_flag && size_falg);
}

static bool ldsm_mount_is_virtual (LdsmMountInfo *mount)
{
    if (mount->buf.f_blocks == 0) {
        /* Filesystems with zero blocks are virtual */
        return true;
    }
    return false;
}

static gchar* ldsm_get_fs_id_for_path (const gchar *path)
{
    GFile *file;
    GFileInfo *fileinfo;
    gchar *attr_id_fs;

    file = g_file_new_for_path (path);
    fileinfo = g_file_query_info (file, G_FILE_ATTRIBUTE_ID_FILESYSTEM,
                                  G_FILE_QUERY_INFO_NOFOLLOW_SYMLINKS,
                                  NULL, NULL);
    if (fileinfo) {
        attr_id_fs = g_strdup (g_file_info_get_attribute_string (fileinfo, G_FILE_ATTRIBUTE_ID_FILESYSTEM));
        g_object_unref (fileinfo);
    } else {
        attr_id_fs = NULL;
    }

    g_object_unref (file);

    return attr_id_fs;
}

static gboolean ldsm_mount_has_trash (LdsmMountInfo *mount)
{
    const gchar *user_data_dir;
    gchar *user_data_attr_id_fs;
    gchar *path_attr_id_fs;
    gboolean mount_uses_user_trash = FALSE;
    gchar *trash_files_dir;
    gboolean has_trash = FALSE;
    GDir *dir;
    const gchar *path;

    user_data_dir = g_get_user_data_dir ();
    user_data_attr_id_fs = ldsm_get_fs_id_for_path (user_data_dir);

    path = g_unix_mount_get_mount_path (mount->mount);
    path_attr_id_fs = ldsm_get_fs_id_for_path (path);

    if (g_strcmp0 (user_data_attr_id_fs, path_attr_id_fs) == 0) {
        /* The volume that is low on space is on the same volume as our home
         * directory. This means the trash is at $XDG_DATA_HOME/Trash,
         * not at the root of the volume which is full.
         */
        mount_uses_user_trash = TRUE;
    }

    g_free (user_data_attr_id_fs);
    g_free (path_attr_id_fs);

    /* I can't think of a better way to find out if a volume has any trash. Any suggestions? */
    if (mount_uses_user_trash) {
        trash_files_dir = g_build_filename (g_get_user_data_dir (), "Trash", "files", NULL);
    } else {
        gchar *uid;

        uid = g_strdup_printf ("%d", getuid ());
        trash_files_dir = g_build_filename (path, ".Trash", uid, "files", NULL);
        if (!g_file_test (trash_files_dir, G_FILE_TEST_IS_DIR)) {
            gchar *trash_dir;

            g_free (trash_files_dir);
            trash_dir = g_strdup_printf (".Trash-%s", uid);
            trash_files_dir = g_build_filename (path, trash_dir, "files", NULL);
            g_free (trash_dir);
            if (!g_file_test (trash_files_dir, G_FILE_TEST_IS_DIR)) {
                g_free (trash_files_dir);
                g_free (uid);
                return has_trash;
            }
        }
        g_free (uid);
    }

    dir = g_dir_open (trash_files_dir, 0, NULL);
    if (dir) {
        if (g_dir_read_name (dir))
            has_trash = TRUE;
        g_dir_close (dir);
    }

    g_free (trash_files_dir);

    return has_trash;
}

static void ldsm_analyze_path (const gchar *path)
{

    const gchar *argv[] = { DISK_SPACE_ANALYZER, path, NULL };

    g_spawn_async (NULL, (gchar **) argv, NULL, G_SPAWN_SEARCH_PATH,
                   NULL, NULL, NULL, NULL);

}

bool DiskSpace::ldsm_notify_for_mount (LdsmMountInfo *mount,
                                       bool       multiple_volumes,
                                       bool       other_usable_volumes)
{
    gchar  *name, *program;
    signed long free_space;
    int   response;
    bool  has_trash;
    bool  has_disk_analyzer;
    bool  retval = TRUE;
    char  *path;

    /* Don't show a dialog if one is already displayed */
    if (dialog)
        return retval;

    name = g_unix_mount_guess_name (mount->mount);
    free_space = (gint64) mount->buf.f_frsize * (gint64) mount->buf.f_bavail;
    has_trash = ldsm_mount_has_trash (mount);
    path = g_strdup (g_unix_mount_get_mount_path (mount->mount));

    program = g_find_program_in_path (DISK_SPACE_ANALYZER);
    has_disk_analyzer = (program != NULL);
    g_free (program);

    dialog = new LdsmDialog (other_usable_volumes,
                             multiple_volumes,
                             has_disk_analyzer,
                             has_trash,
                             free_space,
                             name,
                             path);
    g_free (name);

//    dialog->show();
    response = dialog->exec();
    delete dialog;
    dialog = nullptr;

    switch (response) {
    case GTK_RESPONSE_CANCEL:
        retval = false;
        break;
    case LDSM_DIALOG_RESPONSE_ANALYZE:
        retval = false;
        ldsm_analyze_path (path);
        break;
    case LDSM_DIALOG_RESPONSE_EMPTY_TRASH:
        retval = false;
        trash_empty->usdLdsmTrashEmpty();//调清空回收站dialog
        break;
    case GTK_RESPONSE_NONE:
    case GTK_RESPONSE_DELETE_EVENT:
        retval = true;
        break;
    case LDSM_DIALOG_IGNORE:
        retval = true;
        break;
    default:
        retval = false;
    }
    free (path);
    return retval;
}

// 目前希望吧GList mounts替换为QList
void DiskSpace::ldsm_maybe_warn_mounts (GList *mounts,
                                        bool multiple_volumes,
                                        bool other_usable_volumes)
{
    GList *l;

    for (l = mounts; l != NULL; l = l->next) {
        LdsmMountInfo *mount_info = (LdsmMountInfo  *)l->data;
        LdsmMountInfo *previous_mount_info;
        gdouble free_space;
        gdouble previous_free_space;
        time_t curr_time;
        const char *path;
        gboolean show_notify;
        QString every_two_minutes_check;
        gdouble free_space_check;

        if (done) {
            /* Don't show any more dialogs if the user took action with the last one. The user action
             * might free up space on multiple volumes, making the next dialog redundant.
             */
            ldsm_free_mount_info (mount_info);
            continue;
        }

        path = g_unix_mount_get_mount_path (mount_info->mount);

        previous_mount_info = (LdsmMountInfo *)g_hash_table_lookup (ldsm_notified_hash, path);
        if (previous_mount_info != NULL)
            previous_free_space = (gdouble) previous_mount_info->buf.f_bavail / (gdouble) previous_mount_info->buf.f_blocks;
        //        liutong
        // 找m_notified_hash中(mount_info->mount)得到的path
        QHash<const char*, LdsmMountInfo*>::iterator it = m_notified_hash.find(path);
        if (it != m_notified_hash.end()) {
            // 如果找到了，就计算上一次的

            //LdsmMountInfo* ptmp = it.value()
            previous_free_space = (gdouble) ((*it)->buf.f_bavail) / (gdouble) ((*it)->buf.f_blocks);
        }
        free_space = (gdouble) mount_info->buf.f_bavail / (gdouble) mount_info->buf.f_blocks;

        if (previous_mount_info == NULL) {
            /* We haven't notified for this mount yet */
            show_notify = TRUE;
            mount_info->notify_time = time (NULL);

            m_notified_hash.insert(path, mount_info);
        } else if ((previous_free_space - free_space) > free_percent_notify_again) {
            /* We've notified for this mount before and free space has decreased sufficiently since last time to notify again */
            curr_time = time (NULL);
            if (difftime (curr_time, previous_mount_info->notify_time) > (gdouble)(min_notify_period * 60)) {
                show_notify = TRUE;
                mount_info->notify_time = curr_time;
            }else {
                /* It's too soon to show the dialog again. However, we still replace the LdsmMountInfo
                 * struct in the hash table, but give it the notfiy time from the previous dialog.
                 * This will stop the notification from reappearing unnecessarily as soon as the timeout expires.
                 */
                show_notify = FALSE;
                mount_info->notify_time = previous_mount_info->notify_time;
            }
            m_notified_hash.insert(path, mount_info);
        } else {
            /* We've notified for this mount before, but the free space hasn't decreased sufficiently to notify again */
            ldsm_free_mount_info (mount_info);
            show_notify = FALSE;
        }

        if (show_notify) {
            if (ldsm_notify_for_mount (mount_info, multiple_volumes, other_usable_volumes))
                done = TRUE;
        }

        free_space_check = (gint64) mount_info->buf.f_frsize * (gint64) mount_info->buf.f_bavail;
//        every_two_minutes_check = QString().sprintf("The volume \"%1\" has %s disk space remaining.",
//                                       g_format_size(free_space_check)).arg(g_unix_mount_guess_name(mount_info->mount));
//        printf("%s\n",every_two_minutes_check.toStdString().data());
    }
}

bool DiskSpace::ldsmGetIgnorePath(const gchar *path)
{
    // 取得清理忽略的目录
    QStringList ignoreList = settings->get(SETTINGS_IGNORE_PATHS).toStringList();
    for (QString it : ignoreList) {
        if (it.compare(path) == 0)
            return true;
    }
    return false;
}

bool DiskSpace::ldsm_check_all_mounts ()
{
    GList *mounts;
    GList *l;
    GList *check_mounts = NULL;
    GList *full_mounts = NULL;
    guint number_of_mounts;
    guint number_of_full_mounts;
    gboolean multiple_volumes = FALSE;
    gboolean other_usable_volumes = FALSE;
    /* We iterate through the static mounts in /etc/fstab first, seeing if
     * they're mounted by checking if the GUnixMountPoint has a corresponding GUnixMountEntry.
     * Iterating through the static mounts means we automatically ignore dynamically mounted media.
     */
    ldsm_timeout_cb->stop();
    ldsm_timeout_cb->start(CHECK_EVERY_X_SECONDS);
    mounts = g_unix_mount_points_get (time_read);

    for (l = mounts; l != NULL; l = l->next) {
        GUnixMountPoint *mount_point = (GUnixMountPoint *)l->data;
        GUnixMountEntry *mount;
        LdsmMountInfo *mount_info;
        const gchar *path;

        path = g_unix_mount_point_get_mount_path (mount_point);
        mount = g_unix_mount_at (path, time_read);
        USD_LOG(LOG_DEBUG,"find path:%s ",path);
        g_unix_mount_point_free (mount_point);

        if (mount == NULL) {
            USD_LOG(LOG_DEBUG,"skip path:%s cuz can't find mount",path);
            /* The GUnixMountPoint is not mounted */
            continue;
        }

        mount_info = g_new0 (LdsmMountInfo, 1);
        mount_info->mount = mount;

        path = g_unix_mount_get_mount_path (mount);
        if (g_strcmp0 (path, "/boot/efi") == 0 ||
            g_strcmp0 (path, "/boot") == 0 ){
            USD_LOG(LOG_DEBUG,"skip path:%s ",path);
            ldsm_free_mount_info (mount_info);

            continue;
        }

        if (ldsmGetIgnorePath(path)){
            USD_LOG(LOG_DEBUG,"skip path:%s cuz ldsmGetIgnorePath",path);
            ldsm_free_mount_info (mount_info);
            continue;
        }

        if (g_unix_mount_is_readonly (mount)) {
            USD_LOG(LOG_DEBUG,"skip path:%s cuz g_unix_mount_is_readonly",path);
            ldsm_free_mount_info (mount_info);
            continue;
        }

        if (ldsm_mount_should_ignore (mount)) {
            ldsm_free_mount_info (mount_info);
            USD_LOG(LOG_DEBUG,"skip path:%s cuz ldsm_mount_should_ignore",path);
            continue;
        }

        if (statvfs (path, &mount_info->buf) != 0) {
            USD_LOG(LOG_DEBUG,"skip path:%s cuz statvfs",path);
            ldsm_free_mount_info (mount_info);
            continue;
        }

        if (ldsm_mount_is_virtual (mount_info)) {
            USD_LOG(LOG_DEBUG,"skip path:%s cuz ldsm_mount_is_virtual",path);
            ldsm_free_mount_info (mount_info);
            continue;
        }

        check_mounts = g_list_prepend (check_mounts, mount_info);

    }
    g_list_free (mounts);

    number_of_mounts = g_list_length (check_mounts);
    if (number_of_mounts > 1)
        multiple_volumes = TRUE;

    for (l = check_mounts; l != NULL; l = l->next) {
        LdsmMountInfo *mount_info = (LdsmMountInfo *)l->data;
        if (!ldsm_mount_has_space (mount_info)) {
            full_mounts = g_list_prepend (full_mounts, mount_info);
        } else {
            ldsm_free_mount_info (mount_info);
        }
    }

    number_of_full_mounts = g_list_length (full_mounts);
    if (number_of_mounts > number_of_full_mounts){
        other_usable_volumes = TRUE;
    }

    ldsm_maybe_warn_mounts (full_mounts, multiple_volumes,
                            other_usable_volumes);

    g_list_free (check_mounts);
    g_list_free (full_mounts);

    return TRUE;
}

void DiskSpace::ldsm_mounts_changed (GObject  *monitor,gpointer  data,DiskSpace *disk)
{
    GList *mounts;
    /* remove the saved data for mounts that got removed */
    mounts = g_unix_mounts_get (time_read);

    is_hash_item_not_in_mounts(disk->m_notified_hash, mounts);
    g_list_free_full (mounts, (GDestroyNotify) g_unix_mount_free);

    /* check the status now, for the new mounts */
    disk->ldsm_check_all_mounts();
}

void DiskSpace::UsdLdsmSetup(bool check_now)
{
    if (!m_notified_hash.empty() || ldsm_timeout_cb || ldsm_monitor) {
        qWarning ("Low disk space monitor already initialized.");
        //return;
    }
    usdLdsmGetConfig();
    connect(settings, SIGNAL(changed(QString)), this, SLOT(usdLdsmUpdateConfig(QString)));
#if GLIB_CHECK_VERSION (2, 44, 0)
    ldsm_monitor = g_unix_mount_monitor_get ();
#else
    ldsm_monitor = g_unix_mount_monitor_new ();
    g_unix_mount_monitor_set_rate_limit (ldsm_monitor, 1000);
#endif
    /*g_signal_connect (ldsm_monitor, "mounts-changed",
                      G_CALLBACK (DIskSpace::ldsm_mounts_changed), this);*/
    if (check_now)
        ldsm_check_all_mounts ();
    //ldsm_timeout_cb->start(CHECK_EVERY_X_SECONDS);
}

void DiskSpace::cleanNotifyHash() {
    for(auto it=m_notified_hash.begin();it!=m_notified_hash.end();it++) {
        auto p = it.value();
        if (nullptr != p) {
            delete p;
        }
    }
    m_notified_hash.clear();
}

void DiskSpace::UsdLdsmClean()
{
    cleanNotifyHash();

    if (ldsm_monitor)
        g_object_unref (ldsm_monitor);
    ldsm_monitor = NULL;

    if (settings) {
        g_object_unref (settings);
    }
    if (ignore_paths) {
        g_slist_foreach (ignore_paths, (GFunc) g_free, NULL);
        g_slist_free (ignore_paths);
        ignore_paths = NULL;
    }
}

#ifdef TEST
int main (int    argc, char **argv)
{
    GMainLoop *loop;
    DIskSpace *mDisk;
    mDisk = DIskSpace::DiskSpaceNew();
    gtk_init (&argc, &argv);

    loop = g_main_loop_new (NULL, FALSE);

    mDisk->UsdLdsmSetup (true);

    g_main_loop_run (loop);

    mDisk->UsdLdsmClean ();

    g_main_loop_unref (loop);

    delete mDisk;
    return 0;
}
#endif