import {useState} from 'react';
import {useTranslation} from 'react-i18next';
import {ArrowDown, ArrowUp, Check, EyeOff, Loader2, Plus, RotateCcw, X} from 'lucide-react';

import {Button} from '@/components/ui/button';
import {Card} from '@/components/ui/card';
import {cn} from '@/lib/utils';
import {SIZES, spanClass} from '../utils/tiles.js';

/**
 * The tiles of a page in their order, in a 12 column grid (one column on a phone). In edit mode each tile gets
 * move, size and hide buttons, and the hidden tiles can be added again; nothing is saved before "Done".
 *
 * @param tiles the tile table (utils/tiles.js)
 * @param titles tile id -> i18n key of its name in the edit mode
 * @param renderTile (id, size) => the tile, or null when it has nothing to show (then it is left out, and in edit
 *                   mode it shows a placeholder so it can still be moved)
 * @param defaultLayout offered as "Reset"; none: no reset
 * @param onSave (layout) => promise; the page ends the edit mode when the save worked
 */
export default function TileGrid({tiles, titles, layout, renderTile, editing, defaultLayout, onSave, onCancel}) {
    if (!editing) {
        return (
            <div className="grid grid-cols-1 gap-6 md:grid-cols-12">
                {layout.map((tile) => {
                    const content = renderTile(tile.id, tile.size);
                    return content && (
                        // *:h-full: the card fills the grid row, as it did as a direct grid item.
                        <div key={tile.id} data-tile={tile.id} className={cn('min-w-0 *:h-full', spanClass(tiles, tile))}>{content}</div>
                    );
                })}
            </div>
        );
    }

    return <TileEditor tiles={tiles} titles={titles} layout={layout} renderTile={renderTile} defaultLayout={defaultLayout}
                       onSave={onSave} onCancel={onCancel}/>;
}

// Mounted per edit session, so every session starts from the saved layout.
function TileEditor({tiles, titles, layout, renderTile, defaultLayout, onSave, onCancel}) {
    const {t} = useTranslation();
    const [shown, setShown] = useState(layout);
    const [saving, setSaving] = useState(false);
    const hidden = Object.keys(tiles).filter((id) => !shown.some((tile) => tile.id === id));
    const move = (index, by) => {
        const next = [...shown];
        [next[index], next[index + by]] = [next[index + by], next[index]];
        setShown(next);
    };
    const save = async () => {
        setSaving(true);
        await onSave(shown);
        setSaving(false);
    };

    return (
        <div className="space-y-6">
            <div className="flex flex-wrap items-center justify-between gap-3 rounded-lg border border-dashed border-primary/50 px-4 py-3">
                <p className="text-sm text-muted-foreground">{t('TILES.EDIT_HINT')}</p>
                <div className="flex flex-wrap gap-2">
                    {defaultLayout && (
                        <Button variant="ghost" size="sm" disabled={saving} onClick={() => setShown(defaultLayout)}>
                            <RotateCcw/>{t('TILES.RESET')}
                        </Button>
                    )}
                    <Button variant="outline" size="sm" disabled={saving} onClick={onCancel}><X/>{t('TILES.CANCEL')}</Button>
                    <Button size="sm" disabled={saving} onClick={save}>
                        {saving ? <Loader2 className="animate-spin"/> : <Check/>}{t('TILES.DONE')}
                    </Button>
                </div>
            </div>

            <div className="grid grid-cols-1 gap-6 md:grid-cols-12">
                {shown.map((tile, index) => {
                    const name = t(titles[tile.id]);
                    const sizes = SIZES.filter((size) => tiles[tile.id][size]);
                    return (
                        <div key={tile.id} data-tile={tile.id} className={cn('min-w-0 space-y-2', spanClass(tiles, tile))}>
                            <div className="flex flex-wrap items-center gap-1 rounded-md bg-muted px-2 py-1">
                                <span className="mr-auto truncate text-sm font-medium">{name}</span>
                                <Button variant="ghost" size="icon" className="size-7" disabled={index === 0}
                                        aria-label={t('TILES.MOVE_UP', {name})} onClick={() => move(index, -1)}><ArrowUp/></Button>
                                <Button variant="ghost" size="icon" className="size-7" disabled={index === shown.length - 1}
                                        aria-label={t('TILES.MOVE_DOWN', {name})} onClick={() => move(index, 1)}><ArrowDown/></Button>
                                {sizes.length > 1 && (
                                    <div role="group" aria-label={t('TILES.SIZE', {name})} className="flex">
                                        {sizes.map((size) => (
                                            <Button key={size} variant={tile.size === size ? 'default' : 'ghost'} size="sm"
                                                    className="h-7 px-2" aria-pressed={tile.size === size}
                                                    aria-label={t(`TILES.SIZE_${size}`)}
                                                    onClick={() => setShown(shown.map((other) => other.id === tile.id ? {...other, size} : other))}>
                                                {size}
                                            </Button>
                                        ))}
                                    </div>
                                )}
                                <Button variant="ghost" size="icon" className="size-7" aria-label={t('TILES.HIDE', {name})}
                                        onClick={() => setShown(shown.filter((other) => other.id !== tile.id))}><EyeOff/></Button>
                            </div>
                            {/* inert: a click on a game in the tile must not leave the edit mode. */}
                            <div inert className="opacity-80">
                                {renderTile(tile.id, tile.size) || (
                                    <Card className="items-center p-6 text-sm text-muted-foreground">{t('TILES.NO_DATA')}</Card>
                                )}
                            </div>
                        </div>
                    );
                })}
            </div>

            {hidden.length > 0 && (
                <div className="space-y-2">
                    <p className="text-sm font-medium">{t('TILES.HIDDEN')}</p>
                    <div className="flex flex-wrap gap-2">
                        {hidden.map((id) => (
                            <Button key={id} variant="outline" size="sm" onClick={() => setShown([...shown, {id, size: 'M'}])}>
                                <Plus/>{t(titles[id])}
                            </Button>
                        ))}
                    </div>
                </div>
            )}
        </div>
    );
}