import IBus from 'gi://IBus';

import * as Main from 'resource:///org/gnome/shell/ui/main.js';
import {Extension} from 'resource:///org/gnome/shell/extensions/extension.js';
import {
    getInputSourceManager,
    INPUT_SOURCE_TYPE_XKB,
    INPUT_SOURCE_TYPE_IBUS,
} from 'resource:///org/gnome/shell/ui/status/keyboard.js';
import {getIBusManager} from 'resource:///org/gnome/shell/misc/ibusManager.js';

export default class HangulOverviewLatin extends Extension {
    enable() {
        this._showingId = Main.overview.connect('showing',
            () => this._ensureLatin());
    }

    disable() {
        Main.overview.disconnect(this._showingId);
        this._showingId = null;
    }

    _ensureLatin() {
        const ism = getInputSourceManager();
        const src = ism.currentSource;
        if (src?.type !== INPUT_SOURCE_TYPE_IBUS || !src.id.startsWith('hangul'))
            return;

        // ibus-hangul's InputMode handler toggles regardless of the state
        // argument, so only activate it when currently in Hangul mode.
        const prop = this._findProp(src.properties, 'InputMode');
        if (prop) {
            if (prop.get_state() === IBus.PropState.CHECKED) {
                getIBusManager().activateProperty(
                    prop.get_key(), IBus.PropState.UNCHECKED);
            }
            return;
        }

        // No InputMode property: switch to the first xkb source instead
        for (const i of Object.keys(ism.inputSources)) {
            if (ism.inputSources[i].type === INPUT_SOURCE_TYPE_XKB) {
                ism.inputSources[i].activate(true);
                return;
            }
        }
    }

    _findProp(props, key) {
        for (let i = 0, prop; (prop = props?.get(i)); i++) {
            if (prop.get_key() === key)
                return prop;
        }
        return null;
    }
}