#include "bluetooth.h"
#include "../util.h"

#include <dirent.h>
#include <gio/gio.h>

static long long powered_devices = 0;

static GPtrArray *get_bluetooth_device_paths() {
    DIR *dir = opendir("/sys/class/bluetooth");
    if (!dir) {
        return NULL;
    }
    GPtrArray *arr = g_ptr_array_new();
    struct dirent *current;
    while ((current = readdir(dir))) {
        if (strcmp(current->d_name, ".") != 0 &&
            strcmp(current->d_name, "..") != 0) {
            char *path = g_strdup_printf("/org/bluez/%s", current->d_name);
            g_ptr_array_add(arr, path);
        }
    }
    closedir(dir);
    return arr;
}

static void load_initial_device_states(GDBusConnection *dbus,
                                       GPtrArray *devices) {
    gsize i;
    for (i = 0; i < devices->len; ++i) {
        const char *path = g_ptr_array_index(devices, i);
        GError *err = NULL;
        GVariant *response = g_dbus_connection_call_sync(
            dbus, "org.bluez", path, "org.freedesktop.DBus.Properties", "Get",
            g_variant_new_parsed("('org.bluez.Adapter1', 'Powered')"),
            (GVariantType *)"(v)", G_DBUS_CALL_FLAGS_NONE, -1, NULL, &err);
        if (err) {
            qtb_log("checking bluetooth adapter power state failed\n-> %s", err->message);
            g_error_free(err);
            err = NULL;
            qtb_die();
        }
        if (response) {
            GVariant *wrapper = g_variant_get_child_value(response, 0);
            GVariant *value = g_variant_get_child_value(wrapper, 0);
            gboolean powered = g_variant_get_boolean(value);
            if (powered) {
                ++powered_devices;
            } /* sice powered_devices is already 0, we dont have to increment it
              if the device is not powered */
            g_variant_unref(value);
            g_variant_unref(wrapper);
            g_variant_unref(response);
        }
    }
    qtb_signal_modules(4);
}

static void device_changed_callback(GDBusConnection *dbus,
                                    const char *sender_name,
                                    const char *object_path,
                                    const char *interface_name,
                                    const char *signal_name, GVariant *params,
                                    gpointer user_data) {
    GVariant *changed = g_variant_get_child_value(params, 1);
    GVariant *value_wrapper = g_variant_lookup_value(changed, "Powered", G_VARIANT_TYPE_BOOLEAN);
    if (value_wrapper) {
        gboolean powered = g_variant_get_boolean(value_wrapper);
        if (powered) {
            ++powered_devices;
        } else {
            --powered_devices;
        }
        g_variant_unref(value_wrapper);
    }
    g_variant_unref(changed);
    qtb_signal_modules(4);
}

static void subscribe_to_events(GDBusConnection *dbus, GPtrArray *devices) {
    gsize i;
    for (i = 0; i < devices->len; ++i) {
        const char *path = g_ptr_array_index(devices, i);
        g_dbus_connection_signal_subscribe(
            dbus, NULL, "org.freedesktop.DBus.Properties", "PropertiesChanged",
            path, "org.bluez.Adapter1", G_DBUS_SIGNAL_FLAGS_NONE,
            &device_changed_callback, NULL, NULL);
    }
}

static void *thread_action() {
    GMainContext *context = g_main_context_new();
    g_main_context_push_thread_default(context);
    GError *err = NULL;
    GDBusConnection *dbus = g_bus_get_sync(G_BUS_TYPE_SYSTEM, NULL, &err);
    if (err) {
        qtb_log("could not connect to bluez on the system bus: %s",
                err->message);
        qtb_die();
    }
    GPtrArray *devices = get_bluetooth_device_paths();
    load_initial_device_states(dbus, devices);
    subscribe_to_events(dbus, devices);
    gsize i;
    for (i = 0; i < devices->len; ++i) {
        g_free(g_ptr_array_index(devices, i));
    }
    g_ptr_array_free(devices, TRUE);
    GMainLoop *main_loop = g_main_loop_new(context, FALSE);
    g_main_loop_run(main_loop);
    return NULL;
}

void bluetooth_module_init() {
    g_thread_new("bluetooth-module", &thread_action, NULL);
}

char *bluetooth_module_poll() {
    char *output = NULL;
    if (powered_devices != 0) {
        output = qtb_strdup(" ");
    }
    return output;
}