fitness/app/Http/Controllers/ExerciseController.php

<?php

namespace App\Http\Controllers;

use App\Models\BodyPart;
use App\Models\Equipment;
use App\Models\Exercise;
use App\Models\Muscle;
use App\Models\WorkoutSessionItem;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\Auth;

class ExerciseController extends Controller
{
    public function index(Request $request)
    {
        $q = trim((string) $request->query('q', ''));
        $bodypart = (string) $request->query('bodypart', '');
        $muscle = (string) $request->query('muscle', '');
        $equipment = (string) $request->query('equipment', '');
        $perPage = (int) ($request->query('per_page', 12));
        if ($perPage < 6 || $perPage > 60) { $perPage = 12; }

        $query = Exercise::query()
            ->with(['bodyParts:id,name,slug', 'targetMuscles:id,name,slug', 'secondaryMuscles:id,name,slug', 'equipments:id,name,slug']
                + (Auth::check() ? ['aliases' => function($rel){ $rel->where('user_id', Auth::id()); }] : []))
            ->when($q !== '', function ($qBuilder) use ($q) {
                $qBuilder->where(function ($sub) use ($q) {
                    $sub->where('name', 'like', "%{$q}%")
                        ->orWhere('instructions', 'like', "%{$q}%");
                });
            })
            ->when($bodypart !== '', function ($qBuilder) use ($bodypart) {
                $qBuilder->whereHas('bodyParts', function ($rel) use ($bodypart) {
                    $rel->where('slug', $bodypart);
                });
            })
            ->when($muscle !== '', function ($qBuilder) use ($muscle) {
                $qBuilder->where(function ($sub) use ($muscle) {
                    $sub->whereHas('targetMuscles', function ($rel) use ($muscle) { $rel->where('slug', $muscle); })
                        ->orWhereHas('secondaryMuscles', function ($rel) use ($muscle) { $rel->where('slug', $muscle); });
                });
            })
            ->when($equipment !== '', function ($qBuilder) use ($equipment) {
                $qBuilder->whereHas('equipments', function ($rel) use ($equipment) {
                    $rel->where('slug', $equipment);
                });
            })
            ->orderBy('name');

        $exercises = $query->paginate($perPage)->withQueryString();

        $bodyParts = BodyPart::query()->orderBy('name')->get(['id','name','slug']);
        $muscles = Muscle::query()->orderBy('name')->get(['id','name','slug']);
        $equipments = Equipment::query()->orderBy('name')->get(['id','name','slug']);

        return view('exercises.index', [
            'exercises' => $exercises,
            'filters' => [
                'q' => $q,
                'bodypart' => $bodypart,
                'muscle' => $muscle,
                'equipment' => $equipment,
                'per_page' => $perPage,
            ],
            'bodyParts' => $bodyParts,
            'muscles' => $muscles,
            'equipments' => $equipments,
        ]);
    }

    public function show(Exercise $exercise)
    {
        $exercise->load(['bodyParts:id,name,slug', 'targetMuscles:id,name,slug', 'secondaryMuscles:id,name,slug', 'equipments:id,name,slug']
            + (Auth::check() ? ['aliases' => function($rel){ $rel->where('user_id', Auth::id()); }] : []));

        // Find similar exercises by shared target muscles, body parts, or equipment
        $targetIds = $exercise->targetMuscles->pluck('id')->all();
        $bodyPartIds = $exercise->bodyParts->pluck('id')->all();
        $equipmentIds = $exercise->equipments->pluck('id')->all();

        $similarQuery = Exercise::query()
            ->with(['bodyParts:id,name,slug', 'targetMuscles:id,name,slug', 'equipments:id,name,slug']
                + (Auth::check() ? ['aliases' => function($rel){ $rel->where('user_id', Auth::id()); }] : []))
            ->where('id', '!=', $exercise->id)
            ->where(function ($q) use ($targetIds, $bodyPartIds, $equipmentIds) {
                if (!empty($targetIds)) {
                    $q->orWhereHas('targetMuscles', function ($rel) use ($targetIds) {
                        $rel->whereIn('id', $targetIds);
                    });
                }
                if (!empty($bodyPartIds)) {
                    $q->orWhereHas('bodyParts', function ($rel) use ($bodyPartIds) {
                        $rel->whereIn('id', $bodyPartIds);
                    });
                }
                if (!empty($equipmentIds)) {
                    $q->orWhereHas('equipments', function ($rel) use ($equipmentIds) {
                        $rel->whereIn('id', $equipmentIds);
                    });
                }
            })
            ->orderBy('name')
            ->limit(9);

        $similarExercises = $similarQuery->get();

        $personalBest = null;
        if (Auth::check()) {
            $personalBest = WorkoutSessionItem::query()
                ->with('session')
                ->whereHas('workoutExercise', fn ($q) => $q->where('exercise_id', $exercise->id))
                ->whereHas('session', fn ($q) => $q->where('user_id', Auth::id()))
                ->where('done', true)
                ->whereNotNull('actual_weight')
                ->orderByDesc('actual_weight')
                ->orderByDesc('actual_reps')
                ->first();
        }

        return view('exercises.show', [
            'exercise' => $exercise,
            'similarExercises' => $similarExercises,
            'personalBest' => $personalBest,
        ]);
    }
}