import Clutter from 'gi://Clutter';
import Gio from 'gi://Gio';
import GLib from 'gi://GLib';
import GObject from 'gi://GObject';
import Shell from 'gi://Shell';
import St from 'gi://St';

import * as Dialog from '../dialog.js';
import * as ModalDialog from '../modalDialog.js';
import * as PermissionStore from '../../misc/permissionStore.js';
import {SystemIndicator} from '../quickSettings.js';

import {loadInterfaceXML} from '../../misc/fileUtils.js';

const LOCATION_SCHEMA = 'org.gnome.system.location';
const MAX_ACCURACY_LEVEL = 'max-accuracy-level';
const ENABLED = 'enabled';

const APP_PERMISSIONS_TABLE = 'location';
const APP_PERMISSIONS_ID = 'location';

/** @enum {number} */
const GeoclueAccuracyLevel = {
    NONE: 0,
    COUNTRY: 1,
    CITY: 4,
    NEIGHBORHOOD: 5,
    STREET: 6,
    EXACT: 8,
};

function accuracyLevelToString(accuracyLevel) {
    for (let key in GeoclueAccuracyLevel) {
        if (GeoclueAccuracyLevel[key] === accuracyLevel)
            return key;
    }

    return 'NONE';
}

const GeoclueIface = loadInterfaceXML('org.freedesktop.GeoClue2.Manager');
const GeoclueManager = Gio.DBusProxy.makeProxyWrapper(GeoclueIface);

const AgentIface = loadInterfaceXML('org.freedesktop.GeoClue2.Agent');

let _geoclueAgent = null;

/**
 * @returns {GeoclueAgent} - the GeoclueAgent singleton
 */
export function getGeoclueAgent() {
    if (_geoclueAgent === null)
        _geoclueAgent = new GeoclueAgent();
    return _geoclueAgent;
}

const GeoclueAgent = GObject.registerClass({
    Properties: {
        'enabled': GObject.ParamSpec.boolean(
            'enabled', null, null,
            GObject.ParamFlags.READWRITE,
            false),
        'in-use': GObject.ParamSpec.boolean(
            'in-use', null, null,
            GObject.ParamFlags.READABLE,
            false),
        'max-accuracy-level': GObject.ParamSpec.int(
            'max-accuracy-level', null, null,
            GObject.ParamFlags.READABLE,
            0, 8, 0),
    },
}, class GeoclueAgent extends GObject.Object {
    _init() {
        super._init();

        this._settings = new Gio.Settings({schema_id: LOCATION_SCHEMA});
        this._settings.connectObject(
            `changed::${ENABLED}`, () => this.notify('enabled'),
            `changed::${MAX_ACCURACY_LEVEL}`, () => this._onMaxAccuracyLevelChanged(),
            this);

        this._agent = Gio.DBusExportedObject.wrapJSObject(AgentIface, this);
        this._agent.export(Gio.DBus.system, '/org/freedesktop/GeoClue2/Agent');

        this.connect('notify::enabled', this._onMaxAccuracyLevelChanged.bind(this));

        this._watchId = Gio.bus_watch_name(Gio.BusType.SYSTEM,
            'org.freedesktop.GeoClue2',
            0,
            this._connectToGeoclue.bind(this),
            this._onGeoclueVanished.bind(this));
        this._onMaxAccuracyLevelChanged();
        this._connectToGeoclue();
        this._connectToPermissionStore();
    }

    get enabled() {
        return this._settings.get_boolean(ENABLED);
    }

    set enabled(value) {
        this._settings.set_boolean(ENABLED, value);
    }

    get inUse() {
        return this._managerProxy?.InUse ?? false;
    }

    get maxAccuracyLevel() {
        if (this.enabled) {
            let level = this._settings.get_string(MAX_ACCURACY_LEVEL);

            return GeoclueAccuracyLevel[level.toUpperCase()] ||
                   GeoclueAccuracyLevel.NONE;
        } else {
            return GeoclueAccuracyLevel.NONE;
        }
    }

    async AuthorizeAppAsync(params, invocation) {
        let [desktopId, reqAccuracyLevel] = params;

        let authorizer = new AppAuthorizer(desktopId,
            reqAccuracyLevel, this._permStoreProxy, this.maxAccuracyLevel);

        const accuracyLevel = await authorizer.authorize();
        const ret = accuracyLevel !== GeoclueAccuracyLevel.NONE;
        invocation.return_value(GLib.Variant.new('(bu)', [ret, accuracyLevel]));
    }

    get MaxAccuracyLevel() {
        return this.maxAccuracyLevel;
    }

    _connectToGeoclue() {
        if (this._managerProxy != null || this._connecting)
            return false;

        this._connecting = true;
        new GeoclueManager(Gio.DBus.system,
            'org.freedesktop.GeoClue2',
            '/org/freedesktop/GeoClue2/Manager',
            this._onManagerProxyReady.bind(this));
        return true;
    }

    async _onManagerProxyReady(proxy, error) {
        if (error != null) {
            log(error.message);
            this._connecting = false;
            return;
        }

        this._managerProxy = proxy;
        this._managerProxy.connectObject('g-properties-changed',
            this._onGeocluePropsChanged.bind(this), this);

        this.notify('in-use');

        try {
            await this._managerProxy.AddAgentAsync('gnome-shell');
            this._connecting = false;
            this._notifyMaxAccuracyLevel();
        } catch (e) {
            log(e.message);
        }
    }

    _onGeoclueVanished() {
        this._managerProxy?.disconnectObject(this);
        this._managerProxy = null;

        this.notify('in-use');
    }

    _onMaxAccuracyLevelChanged() {
        this.notify('max-accuracy-level');

        // Gotta ensure geoclue is up and we are registered as agent to it
        // before we emit the notify for this property change.
        if (!this._connectToGeoclue())
            this._notifyMaxAccuracyLevel();
    }

    _notifyMaxAccuracyLevel() {
        let variant = new GLib.Variant('u', this.maxAccuracyLevel);
        this._agent.emit_property_changed('MaxAccuracyLevel', variant);
    }

    _onGeocluePropsChanged(proxy, properties) {
        const inUseChanged = !!properties.lookup_value('InUse', null);
        if (inUseChanged)
            this.notify('in-use');
    }

    _connectToPermissionStore() {
        this._permStoreProxy = null;
        new PermissionStore.PermissionStore(this._onPermStoreProxyReady.bind(this));
    }

    _onPermStoreProxyReady(proxy, error) {
        if (error != null) {
            log(error.message);
            return;
        }

        this._permStoreProxy = proxy;
    }
});

export const Indicator = GObject.registerClass(
class Indicator extends SystemIndicator {
    _init() {
        super._init();

        this._agent = getGeoclueAgent();

        this._indicator = this._addIndicator();
        this._indicator.icon_name = 'location-services-active-symbolic';
        this._agent.bind_property('in-use',
            this._indicator,
            'visible',
            GObject.BindingFlags.SYNC_CREATE);
    }
});

class AppAuthorizer {
    constructor(desktopId, reqAccuracyLevel, permStoreProxy, maxAccuracyLevel) {
        this.desktopId = desktopId;
        this.reqAccuracyLevel = reqAccuracyLevel;
        this._permStoreProxy = permStoreProxy;
        this._maxAccuracyLevel = maxAccuracyLevel;
        this._permissions = {};

        this._accuracyLevel = GeoclueAccuracyLevel.NONE;
    }

    async authorize() {
        let appSystem = Shell.AppSystem.get_default();
        this._app = appSystem.lookup_app(`${this.desktopId}.desktop`);
        if (this._app == null || this._permStoreProxy == null)
            return this._completeAuth();

        try {
            [this._permissions] = await this._permStoreProxy.LookupAsync(
                APP_PERMISSIONS_TABLE,
                APP_PERMISSIONS_ID);
        } catch (error) {
            if (error.domain === Gio.DBusError) {
                // Likely no xdg-app installed, just authorize the app
                this._accuracyLevel = this.reqAccuracyLevel;
                this._permStoreProxy = null;
                return this._completeAuth();
            } else {
                // Currently xdg-app throws an error if we lookup for
                // unknown ID (which would be the case first time this code
                // runs) so we continue with user authorization as normal
                // and ID is added to the store if user says "yes".
                log(error.message);
                this._permissions = {};
            }
        }

        let permission = this._permissions[this.desktopId];

        if (permission == null) {
            await this._userAuthorizeApp();
        } else {
            let [levelStr] = permission || ['NONE'];
            this._accuracyLevel = GeoclueAccuracyLevel[levelStr] ||
                                  GeoclueAccuracyLevel.NONE;
        }

        return this._completeAuth();
    }

    _userAuthorizeApp() {
        let name = this._app.get_name();
        let appInfo = this._app.get_app_info();
        let reason = appInfo.get_locale_string('X-Geoclue-Reason');

        this._dialog =
            new GeolocationDialog(name, reason, this.reqAccuracyLevel);

        return new Promise(resolve => {
            const responseId = this._dialog.connect('response',
                (dialog, level) => {
                    this._dialog.disconnect(responseId);
                    this._accuracyLevel = level;
                    resolve();
                });
            this._dialog.open();
        });
    }

    _completeAuth() {
        if (this._accuracyLevel !== GeoclueAccuracyLevel.NONE) {
            this._accuracyLevel = Math.clamp(this._accuracyLevel,
                0, this._maxAccuracyLevel);
        }
        this._saveToPermissionStore();

        return this._accuracyLevel;
    }

    async _saveToPermissionStore() {
        if (this._permStoreProxy == null)
            return;

        let levelStr = accuracyLevelToString(this._accuracyLevel);
        let dateStr = Math.round(Date.now() / 1000).toString();
        this._permissions[this.desktopId] = [levelStr, dateStr];

        let data = GLib.Variant.new('av', {});

        try {
            await this._permStoreProxy.SetAsync(
                APP_PERMISSIONS_TABLE,
                true,
                APP_PERMISSIONS_ID,
                this._permissions,
                data);
        } catch (error) {
            log(error.message);
        }
    }
}

export const GeolocationDialog = GObject.registerClass({
    Signals: {'response': {param_types: [GObject.TYPE_UINT]}},
}, class GeolocationDialog extends ModalDialog.ModalDialog {
    _init(name, reason, reqAccuracyLevel) {
        super._init({styleClass: 'geolocation-dialog'});
        this.reqAccuracyLevel = reqAccuracyLevel;

        let content = new Dialog.MessageDialogContent({
            title: _('Allow location access'),
            /* Translators: %s is an application name */
            description: _('The app %s wants to access your location').format(name),
        });

        let reasonLabel = new St.Label({
            text: reason,
            style_class: 'message-dialog-description',
        });
        content.add_child(reasonLabel);

        let infoLabel = new St.Label({
            text: _('Location access can be changed at any time from the privacy settings'),
            style_class: 'message-dialog-description',
        });
        content.add_child(infoLabel);

        this.contentLayout.add_child(content);

        const button = this.addButton({
            label: _('Deny Access'),
            action: this._onDenyClicked.bind(this),
            key: Clutter.KEY_Escape,
        });
        this.addButton({
            label: _('Grant Access'),
            action: this._onGrantClicked.bind(this),
        });

        this.setInitialKeyFocus(button);
    }

    _onGrantClicked() {
        this.emit('response', this.reqAccuracyLevel);
        this.close();
    }

    _onDenyClicked() {
        this.emit('response', GeoclueAccuracyLevel.NONE);
        this.close();
    }
});
