/*
 * Copyright 2021-2023 Robert Tari <robert@tari.in>
 *
 * This program is free software: you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 3, as published
 * by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranties of
 * MERCHANTABILITY, SATISFACTORY QUALITY, 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 <act/act.h>
#include <xkbcommon/xkbregistry.h>
#include <glib-object.h>
#include "languages.h"
#include "keyboard.h"

enum
{
    LAYOUT_CHANGED,
    CONFIG_CHANGED,
    LAST_SIGNAL
};

static guint m_lSignals[LAST_SIGNAL];

struct _KeyboardPrivate
{
    GHashTable *lLayouts;
    guint nLayout;
    GSList *lLayoutRec;
    GSList *lUsers;
};

typedef KeyboardPrivate priv_t;

G_DEFINE_TYPE_WITH_PRIVATE(Keyboard, keyboard, G_TYPE_OBJECT)

typedef struct _Layout
{
    gchar *sId;
    gchar *sLanguage;
    gchar *sDescription;

} Layout;

static int emitDelayedSignal(Keyboard *pKeyboard)
{
    g_signal_emit(pKeyboard, m_lSignals[CONFIG_CHANGED], 0);

    return G_SOURCE_REMOVE;
}

static gboolean isGreeter()
{
    const char *sUser = g_get_user_name();

    return g_str_equal(sUser, "lightdm");
}

static void setAccountsService(Keyboard *pKeyboard)
{
    // TODO
}

static void getAccountsService(Keyboard *pKeyboard)
{
    gboolean bChanged = FALSE;

    for (GSList *lUser = pKeyboard->pPrivate->lUsers; lUser; lUser = lUser->next)
    {
        ActUser *pUser = lUser->data;
        gboolean bIsUserLoaded = act_user_is_loaded(pUser);

        if (bIsUserLoaded)
        {
            gint nUid = act_user_get_uid(pUser);
            gchar *sPath = g_strdup_printf("/org/freedesktop/Accounts/User%i", nUid);
            GDBusConnection *pConnection = g_bus_get_sync(G_BUS_TYPE_SYSTEM, NULL, NULL);
            GDBusProxy *pProxy = g_dbus_proxy_new_sync(pConnection, G_DBUS_PROXY_FLAGS_NONE, NULL, "org.freedesktop.Accounts", sPath, "org.freedesktop.DBus.Properties", NULL, NULL);
            GVariant *pValue = g_dbus_proxy_call_sync(pProxy, "Get", g_variant_new("(ss)", "org.ayatana.indicator.keyboard.AccountsService", "Layouts"), G_DBUS_CALL_FLAGS_NONE, -1, NULL, NULL);
            GVariant *pChild0 = g_variant_get_child_value(pValue, 0);
            GVariant *pChild1 = g_variant_get_child_value(pChild0, 0);

            GVariantIter *pIter;

            g_variant_get(pChild1, "as", &pIter);

            gchar *sLayout;

            while (g_variant_iter_loop(pIter, "s", &sLayout))
            {
                if (g_slist_find_custom(pKeyboard->pPrivate->lLayoutRec, sLayout, (GCompareFunc)g_strcmp0) == NULL)
                {
                    pKeyboard->pPrivate->lLayoutRec = g_slist_append(pKeyboard->pPrivate->lLayoutRec, g_strdup(sLayout));
                    bChanged = TRUE;
                }
            }

            g_variant_iter_free(pIter);
            g_variant_unref(pChild1);
            g_variant_unref(pChild0);
            g_variant_unref(pValue);
            g_object_unref(pConnection);
            g_free(sPath);
        }
    }

    if (bChanged == TRUE)
    {
        g_timeout_add(500, (GSourceFunc)emitDelayedSignal, pKeyboard);
    }
}

static void onUserLoaded(Keyboard *pKeyboard, ActUser *pUser)
{
    gboolean bIsUserLoaded = act_user_is_loaded(pUser);

    if (bIsUserLoaded)
    {
        getAccountsService(pKeyboard);
        g_signal_handlers_disconnect_by_func(G_OBJECT(pUser), G_CALLBACK(onUserLoaded), pKeyboard);
    }
}

static void onManagerLoaded(Keyboard *pKeyboard)
{
    ActUserManager *pManager = act_user_manager_get_default();
    gboolean bIsLoaded;
    g_object_get(pManager, "is-loaded", &bIsLoaded, NULL);

    if (bIsLoaded)
    {
        pKeyboard->pPrivate->lUsers = act_user_manager_list_users(pManager);

        for (GSList *lUser = pKeyboard->pPrivate->lUsers; lUser; lUser = lUser->next)
        {
            ActUser *pUser = lUser->data;
            gboolean bIsUserLoaded = act_user_is_loaded(pUser);

            if (bIsUserLoaded)
            {
                getAccountsService(pKeyboard);
            }
            else
            {
                g_signal_connect_swapped(pUser, "notify::is-loaded", G_CALLBACK(onUserLoaded), pKeyboard);
            }
        }
    }
}

static void freeLayout(gpointer pData)
{
    Layout *pLayout = pData;

    g_return_if_fail(pLayout != NULL);

    g_free(pLayout->sId);
    g_free(pLayout->sLanguage);
    g_free(pLayout->sDescription);
    g_slice_free(Layout, pLayout);
}

void keyboard_AddSource(Keyboard *pKeyboard)
{
    return;
}

guint keyboard_GetNumLayouts(Keyboard *pKeyboard)
{
    if (isGreeter())
    {
        return g_slist_length(pKeyboard->pPrivate->lLayoutRec);
    }
    else
    {
        // TODO
        return 1;
    }
}

guint keyboard_GetLayoutIndex (Keyboard *pKeyboard)
{
    return pKeyboard->pPrivate->nLayout;
}

void keyboard_GetLayout(Keyboard *pKeyboard, gint nLayout, gchar **pLanguage, gchar **pDescription)
{
    if (nLayout == -1)
    {
        nLayout = pKeyboard->pPrivate->nLayout;
    }

    gchar *sId = NULL;

    if (isGreeter() == TRUE)
    {
        gchar *sLayout = g_slist_nth_data(pKeyboard->pPrivate->lLayoutRec, nLayout);
        sId = g_strdup(sLayout);
    }
    else
    {
        // TODO
        gchar *sLayout = "us";
        gchar *sVariant = "";

        if (sVariant && strlen(sVariant))
        {
            sId = g_strconcat(sLayout, "+", sVariant, NULL);
        }
        else
        {
            sId = g_strdup(sLayout);
        }
    }

    const Layout *pLayout;
    g_hash_table_lookup_extended(pKeyboard->pPrivate->lLayouts, sId, NULL, (gpointer*)&pLayout);

    if (pLanguage != NULL)
    {
        *pLanguage = g_strdup(pLayout->sLanguage);
    }

    if (pDescription != NULL)
    {
        *pDescription = g_strdup(pLayout->sDescription);
    }

    g_free(sId);
}

void keyboard_SetLayout(Keyboard *pKeyboard, gint nLayout)
{
    if (isGreeter() == FALSE)
    {
        // TODO
    }
    else
    {
        // TODO
        gchar *sCommand;
        gchar *sId = g_slist_nth_data(pKeyboard->pPrivate->lLayoutRec, nLayout);
        gchar **lParamas = g_strsplit(sId, "+", -1);
        guint nParams = g_strv_length(lParamas);

        if (nParams == 1)
        {
            sCommand = g_strdup_printf("setxkbmap -layout %s", lParamas[0]);
        }
        else
        {
            sCommand = g_strdup_printf("setxkbmap -layout %s -variant %s", lParamas[0], lParamas[1]);
        }

        g_strfreev(lParamas);

        gchar *sOutput = NULL;
        GError *pError = NULL;
        gboolean bResult = g_spawn_command_line_sync(sCommand, &sOutput, NULL, NULL, &pError);
        g_free(sCommand);

        if (bResult == FALSE)
        {
            g_message("COMMAND 01 %s: %s", sOutput, pError->message);

            return;
        }
    }

    pKeyboard->pPrivate->nLayout = nLayout;
    g_signal_emit(pKeyboard, m_lSignals[LAYOUT_CHANGED], 0);
}

static void onDispose(GObject *pObject)
{
    Keyboard *self = G_KEYBOARD(pObject);

    if (self->pPrivate->lLayouts)
    {
        g_hash_table_destroy(self->pPrivate->lLayouts);
    }

    if (self->pPrivate->lLayoutRec)
    {
        g_slist_free_full(self->pPrivate->lLayoutRec, g_free);
    }

    if (self->pPrivate->lUsers)
    {
        g_slist_free(self->pPrivate->lUsers);
    }

    G_OBJECT_CLASS(keyboard_parent_class)->dispose(pObject);
}

static void keyboard_class_init(KeyboardClass *klass)
{
    GObjectClass *pClass = G_OBJECT_CLASS(klass);
    pClass->dispose = onDispose;
    m_lSignals[LAYOUT_CHANGED] = g_signal_new(KEYBOARD_LAYOUT_CHANGED, G_TYPE_FROM_CLASS(klass), G_SIGNAL_RUN_LAST, 0, NULL, NULL, NULL, G_TYPE_NONE, 0);
    m_lSignals[CONFIG_CHANGED] = g_signal_new(KEYBOARD_CONFIG_CHANGED, G_TYPE_FROM_CLASS(klass), G_SIGNAL_RUN_LAST, 0, NULL, NULL, NULL, G_TYPE_NONE, 0);
}

Keyboard* keyboard_new()
{
    GObject *pObject = g_object_new(G_TYPE_KEYBOARD, NULL);

    return G_KEYBOARD(pObject);
}

static void keyboard_init(Keyboard *self)
{
    self->pPrivate = keyboard_get_instance_private(self);
    self->pPrivate->lLayouts = g_hash_table_new_full(g_str_hash, g_str_equal, NULL, freeLayout);

    // Read all available layouts
    struct rxkb_context *pContext = rxkb_context_new(RXKB_CONTEXT_LOAD_EXOTIC_RULES);
    g_assert(pContext);

    if (!rxkb_context_include_path_append_default(pContext))
    {
        g_warning("Failed to include default paths");
    }

    if (!rxkb_context_parse(pContext, "evdev"))
    {
        g_warning("Failed to parse XKB descriptions");
    }

    struct rxkb_layout *pRxkbLayout = rxkb_layout_first(pContext);

    while (pRxkbLayout != NULL)
    {
        const gchar *sLayout = rxkb_layout_get_name(pRxkbLayout);
        const gchar *sVariant = rxkb_layout_get_variant(pRxkbLayout);
        const gchar *sDescription = rxkb_layout_get_description(pRxkbLayout);
        const gchar *sTranslated = g_dgettext("xkeyboard-config", sDescription);
        sDescription = sTranslated;
        Layout *pLayout = g_slice_new0(Layout);

        if (sVariant != NULL && strlen(sVariant) > 0)
        {
            pLayout->sId = g_strjoin("+", sLayout, sVariant, NULL);
            pLayout->sLanguage = g_strdup(lookupLanguage(pLayout->sId));
            pLayout->sDescription = g_strdup(sDescription);
        }
        else
        {
            pLayout->sId = g_strdup(sLayout);
            pLayout->sLanguage = g_strdup(lookupLanguage(pLayout->sId));
            pLayout->sDescription = g_strdup(sDescription);
        }

        g_hash_table_replace(self->pPrivate->lLayouts, pLayout->sId, pLayout);

        pRxkbLayout = rxkb_layout_next(pRxkbLayout);
    }

    rxkb_context_unref(pContext);

    if (isGreeter() == FALSE)
    {
        // TODO
        self->pPrivate->nLayout = 0;

        setAccountsService(self);
    }
    else
    {
        // Get layouts from /etc/default/keyboard
        gchar *sFile;
        g_file_get_contents ("/etc/default/keyboard", &sFile, NULL, NULL);
        gchar **lLines = g_strsplit(sFile, "\n", -1);
        guint nLines = g_strv_length(lLines);
        gchar **lLayouts = NULL;
        gchar **lVariants = NULL;

        for (guint nLine = 0; nLine < nLines; nLine++)
        {
            gboolean bIsLayout = g_str_has_prefix(lLines[nLine], "XKBLAYOUT");

            if (bIsLayout == TRUE)
            {
                gboolean bQuoted = g_strrstr(lLines[nLine], "\"") != NULL;
                gchar *sLayout = NULL;

                if (bQuoted == TRUE)
                {
                    sLayout = (lLines[nLine] + 11);
                    guint nLength = strlen(sLayout);
                    sLayout[nLength - 1] = '\0';
                }
                else
                {
                    sLayout = (lLines[nLine] + 10);
                }

                lLayouts = g_strsplit(sLayout, ",", -1);

                continue;
            }

            gboolean bIsVariant = g_str_has_prefix(lLines[nLine], "XKBVARIANT");

            if (bIsVariant == TRUE)
            {
                gboolean bQuoted = g_strrstr(lLines[nLine], "\"") != NULL;
                gchar *sVariant = NULL;

                if (bQuoted == TRUE)
                {
                    sVariant = (lLines[nLine] + 12);
                    guint nLength = strlen(sVariant);
                    sVariant[nLength - 1] = '\0';
                }
                else
                {
                    sVariant = (lLines[nLine] + 11);
                }

                lVariants = g_strsplit(sVariant, ",", -1);

                continue;
            }
        }

        guint nVariants = 0;

        if (lVariants != NULL)
        {
            g_strv_length(lVariants);
        }

        if (lLayouts != NULL)
        {
            guint nLayouts = g_strv_length(lLayouts);

            for (guint nLayout = 0; nLayout < nLayouts; nLayout++)
            {
                gchar *sId = NULL;

                if (nVariants > nLayout)
                {
                    guint nVariant = strlen(lVariants[nLayout]);

                    if (nVariants == nLayouts && nVariant > 0)
                    {
                        sId = g_strconcat(lLayouts[nLayout], "+", lVariants[nLayout], NULL);
                    }
                    else
                    {
                        sId = g_strdup(lLayouts[nLayout]);
                    }
                }
                else
                {
                    sId = g_strdup(lLayouts[nLayout]);
                }

                self->pPrivate->lLayoutRec = g_slist_append(self->pPrivate->lLayoutRec, sId);
            }

            self->pPrivate->nLayout = 0;

            g_strfreev(lLayouts);
        }

        if (lVariants != NULL)
        {
            g_strfreev(lVariants);
        }

        g_strfreev(lLines);
        g_free(sFile);

        ActUserManager *pManager = act_user_manager_get_default();
        gboolean bIsLoaded;
        g_object_get(pManager, "is-loaded", &bIsLoaded, NULL);

        if (bIsLoaded)
        {
            self->pPrivate->lUsers = act_user_manager_list_users(pManager);

            for (GSList *lUser = self->pPrivate->lUsers; lUser; lUser = lUser->next)
            {
                ActUser *pUser = lUser->data;
                gboolean bIsUserLoaded = act_user_is_loaded(pUser);

                if (bIsUserLoaded)
                {
                    getAccountsService(self);
                }
                else
                {
                    g_signal_connect_swapped(pUser, "notify::is-loaded", G_CALLBACK(onUserLoaded), self);
                }
            }
        }
        else
        {
            g_signal_connect_object(pManager, "notify::is-loaded", G_CALLBACK(onManagerLoaded), self, G_CONNECT_SWAPPED);
        }
    }
}