<?php

namespace App\Http\Controllers\Admin;

use App\Http\Controllers\Controller;
use App\Models\Exercise;
use Illuminate\Http\RedirectResponse;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Storage;
use Illuminate\Support\Str;
use Illuminate\View\View;

class ExerciseController extends Controller
{
    public function index(Request $request): View
    {
        $q = trim((string) $request->query('q', ''));
        $exercises = Exercise::query()
            ->when($q !== '', function ($qb) use ($q) {
                $qb->where('name', 'like', "%{$q}%")
                   ->orWhere('slug', 'like', "%{$q}%");
            })
            ->orderBy('name')
            ->paginate(20)
            ->withQueryString();

        return view('admin.exercises.index', compact('exercises', 'q'));
    }

    public function create(): View
    {
        return view('admin.exercises.create');
    }

    public function store(Request $request): RedirectResponse
    {
        $data = $request->validate([
            'name' => ['required', 'string', 'max:255'],
            'slug' => ['nullable', 'string', 'max:255', 'unique:exercises,slug'],
            'gif_url' => ['nullable', 'string', 'max:2048'],
            'poster_image' => ['nullable', 'string', 'max:2048'],
            'poster_image_file' => ['nullable', 'image', 'mimes:jpeg,jpg,png,webp,avif,gif', 'max:8192'],
            'instructions' => ['nullable', 'string'],
        ]);

        $name = trim($data['name']);
        $slug = trim((string) ($data['slug'] ?? ''));
        if ($slug === '') {
            $slug = $this->uniqueSlug($name);
        }

        // Determine poster image value (uploaded file takes precedence)
        $posterImageValue = $data['poster_image'] ?? null;
        if ($request->hasFile('poster_image_file')) {
            $path = $request->file('poster_image_file')->store('exercises/posters', 'public');
            $posterImageValue = $path; // store relative path; use Storage::url to display
        }

        Exercise::create([
            'name' => $name,
            'slug' => $slug,
            'gif_url' => $data['gif_url'] ?? null,
            'poster_image' => $posterImageValue,
            'instructions' => $data['instructions'] ?? null,
        ]);

        return redirect()->route('admin.exercises.index')->with('status', 'Exercise created');
    }

    public function edit(Exercise $exercise): View
    {
        return view('admin.exercises.edit', compact('exercise'));
    }

    public function update(Request $request, Exercise $exercise): RedirectResponse
    {
        $data = $request->validate([
            'name' => ['required', 'string', 'max:255'],
            'slug' => ['nullable', 'string', 'max:255', 'unique:exercises,slug,' . $exercise->id],
            'gif_url' => ['nullable', 'string', 'max:2048'],
            'poster_image' => ['nullable', 'string', 'max:2048'],
            'poster_image_file' => ['nullable', 'image', 'mimes:jpeg,jpg,png,webp,avif,gif', 'max:8192'],
            'instructions' => ['nullable', 'string'],
        ]);

        $name = trim($data['name']);
        $slug = trim((string) ($data['slug'] ?? ''));
        if ($slug === '') {
            // only (re)generate if empty
            $slug = $this->uniqueSlug($name, $exercise->id);
        }

        // Determine poster image value for update (uploaded file > provided URL > keep existing)
        $posterImageValue = $data['poster_image'] ?? $exercise->poster_image;
        if ($request->hasFile('poster_image_file')) {
            $path = $request->file('poster_image_file')->store('exercises/posters', 'public');
            $posterImageValue = $path;
        }

        $exercise->update([
            'name' => $name,
            'slug' => $slug,
            'gif_url' => $data['gif_url'] ?? null,
            'poster_image' => $posterImageValue,
            'instructions' => $data['instructions'] ?? null,
        ]);

        return redirect()->route('admin.exercises.index')->with('status', 'Exercise updated');
    }

    public function destroy(Exercise $exercise): RedirectResponse
    {
        // Safely remove related data to avoid FK constraint errors
        DB::transaction(function () use ($exercise) {
            // Detach pivot relations if defined
            try { $exercise->bodyParts()->detach(); } catch (\Throwable $e) {}
            try { $exercise->targetMuscles()->detach(); } catch (\Throwable $e) {}
            try { $exercise->secondaryMuscles()->detach(); } catch (\Throwable $e) {}
            try { $exercise->equipments()->detach(); } catch (\Throwable $e) {}
            try { $exercise->favoritedBy()->detach(); } catch (\Throwable $e) {}
            // Delete aliases and workout_exercises if relations exist
            try { $exercise->aliases()->delete(); } catch (\Throwable $e) {}
            try { $exercise->workoutExercises()->delete(); } catch (\Throwable $e) {}

            $exercise->delete();
        });

        return redirect()->route('admin.exercises.index')->with('status', 'Exercise deleted');
    }

    protected function uniqueSlug(string $name, ?int $ignoreId = null): string
    {
        $base = Str::slug($name);
        if ($base === '') { $base = 'exercise'; }
        $slug = $base;
        $i = 1;
        while (Exercise::where('slug', $slug)
            ->when($ignoreId, fn($q)=>$q->where('id','!=',$ignoreId))
            ->exists()) {
            $slug = $base . '-' . (++$i);
        }
        return $slug;
    }
}