ActivityOnly.php

<?php

namespace App\Utilities\Filters;

use Illuminate\Database\Eloquent\Builder;
use Illuminate\Http\Request;

class ActivityOnly implements Filter
{
    /**
     * @inheritDoc
     */
    public static function apply(Builder $builder, Request $filters)
    {
        // Return businesses only by activity
        if ($filters->has('activity') && !$filters->has('q') && !$filters->has('location')) {
            $builder->whereHas('activities', function ($query) use ($filters) {
                $query->where('name', 'LIKE', "%{$filters->activity}%");
            });
        }
    }
}

AllParams.php

<?php

namespace App\Utilities\Filters;

use Illuminate\Database\Eloquent\Builder;
use Illuminate\Http\Request;

class AllParams implements Filter
{
    /**
     * @inheritDoc
     */
    public static function apply(Builder $builder, Request $filters)
    {
        // Everything selected
        if ($filters->has('q') && $filters->has('location') && $filters->has('activity')) {
            $builder->where('name', 'LIKE', "%{$filters->q}%")
                ->whereHas('destinations', function ($query) use ($filters) {
                    $query->where('name', 'LIKE', "%{$filters->location}%");
                })->whereHas('activities', function ($query) use ($filters) {
                    $query->where('name', 'LIKE', "%{$filters->activity}%");
                });
        }
    }
}

Filter.php

<?php

namespace App\Utilities\Filters;

use Illuminate\Http\Request;
use Illuminate\Database\Eloquent\Builder;

interface Filter
{
    /**
     * Apply a given search value to the builder instance.
     *
     * @param  \Illuminate\Database\Eloquent\Builder $builder
     * @param  \Illuminate\Http\Request              $filters
     * @return \Illuminate\Database\Eloquent\Builder
     */
    public static function apply(Builder $builder, Request $filters);
}

SearchQuery.php

<?php

namespace App\Utilities;

use App\Models\Business;
use App\Utilities\Filters\ActivityOnly;
use App\Utilities\Filters\AllParams;
use App\Utilities\Filters\LocationAndActivity;
use App\Utilities\Filters\LocationOnly;
use App\Utilities\Filters\StringAndActivity;
use App\Utilities\Filters\StringAndLocation;
use App\Utilities\Filters\StringOnly;
use Illuminate\Http\Request;

class SearchQuery
{
    /**
     * Apply all the filters from the query string.
     *
     * @param  \Illuminate\Http\Request $filters
     * @return \Illuminate\Database\Eloquent\Builder
     */
    public static function apply(Request $filters)
    {
        $query = Business::query();

        self::filters()->each(function ($filter) use ($query, $filters) {
            $filter::apply($query, $filters);
        });

        return $query->orderByRaw("name {$filters->order}");
    }

    /**
     * All the applicable filters.
     */
    private static function filters(): \Illuminate\Support\Collection
    {
        return collect([
            AllParams::class,
            StringOnly::class,
            ActivityOnly::class,
            LocationOnly::class,
            StringAndLocation::class,
            StringAndActivity::class,
            LocationAndActivity::class,
        ]);
    }
}