<?php

namespace App\Http\Controllers\Api;

use App\Http\Controllers\Controller;
use App\Http\Resources\ExerciseResource;
use App\Models\BodyPart;
use App\Models\Equipment;
use App\Models\Exercise;
use App\Models\Muscle;
use App\Models\WorkoutSessionItem;
use Illuminate\Http\JsonResponse;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\Auth;

class ExerciseController extends Controller
{
    public function index(Request $request): JsonResponse
    {
        $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();

        return response()->json([
            'data' => ExerciseResource::collection($exercises->items()),
            'meta' => [
                'current_page' => $exercises->currentPage(),
                'last_page' => $exercises->lastPage(),
                'per_page' => $exercises->perPage(),
                'total' => $exercises->total(),
            ],
            'filters' => [
                'body_parts' => BodyPart::orderBy('name')->get(['id', 'name', 'slug']),
                'muscles' => Muscle::orderBy('name')->get(['id', 'name', 'slug']),
                'equipments' => Equipment::orderBy('name')->get(['id', 'name', 'slug']),
            ],
        ]);
    }

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

        $targetIds = $exercise->targetMuscles->pluck('id')->all();
        $bodyPartIds = $exercise->bodyParts->pluck('id')->all();
        $equipmentIds = $exercise->equipments->pluck('id')->all();

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

        $personalBest = null;
        if (Auth::check()) {
            $personalBest = WorkoutSessionItem::query()
                ->whereHas('workoutExercise', fn ($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 response()->json([
            'exercise' => new ExerciseResource($exercise),
            'similar_exercises' => ExerciseResource::collection($similarExercises),
            'personal_best' => $personalBest ? [
                'actual_weight' => $personalBest->actual_weight !== null ? (float) $personalBest->actual_weight : null,
                'actual_reps' => $personalBest->actual_reps,
            ] : null,
        ]);
    }
}