<?php

declare(strict_types=1);

namespace App\Http\Controllers\Api\V1;

use App\Http\Controllers\Controller;
use App\Http\Requests\Api\V1\ReorderFestivalSectionsRequest;
use App\Http\Requests\Api\V1\StoreFestivalSectionRequest;
use App\Http\Requests\Api\V1\UpdateFestivalSectionRequest;
use App\Http\Requests\Api\V1\UpdateRegistrationSettingsRequest;
use App\Http\Resources\Api\V1\FestivalSectionResource;
use App\Models\Event;
use App\Models\FestivalSection;
use Illuminate\Http\JsonResponse;
use Illuminate\Http\Resources\Json\AnonymousResourceCollection;
use Illuminate\Support\Facades\Gate;

final class FestivalSectionController extends Controller
{
    public function index(Event $event): AnonymousResourceCollection
    {
        Gate::authorize('viewAny', [FestivalSection::class, $event]);

        $sections = $event->festivalSections()->ordered()->get();

        // For sub-events, also include cross_event sections from the parent festival
        if ($event->isSubEvent()) {
            $parentCrossEventSections = $event->parent
                ->festivalSections()
                ->where('type', 'cross_event')
                ->ordered()
                ->get();

            $sections = $parentCrossEventSections->merge($sections)->sortBy('sort_order')->values();
        }

        return FestivalSectionResource::collection($sections);
    }

    public function store(StoreFestivalSectionRequest $request, Event $event): JsonResponse
    {
        Gate::authorize('create', [FestivalSection::class, $event]);

        $data = $request->validated();
        $redirectedToParent = false;

        if (($data['type'] ?? 'standard') === 'cross_event') {
            if ($event->isFlatEvent()) {
                return $this->error(
                    'Overkoepelende secties kunnen alleen worden aangemaakt bij festivals met programmaonderdelen.',
                    422,
                );
            }

            if ($event->isSubEvent()) {
                $event = $event->parent;
                Gate::authorize('create', [FestivalSection::class, $event]);
                $redirectedToParent = true;
            }
        }

        $section = $event->festivalSections()->create($data);

        $response = $this->created(new FestivalSectionResource($section));

        if ($redirectedToParent) {
            $original = $response->getData(true);
            $original['meta'] = [
                'redirected_to_parent' => true,
                'parent_event_name' => $event->name,
            ];

            return response()->json($original, 201);
        }

        return $response;
    }

    public function update(UpdateFestivalSectionRequest $request, Event $event, FestivalSection $section): JsonResponse
    {
        Gate::authorize('update', [$section, $event]);

        $section->update($request->validated());

        return $this->success(new FestivalSectionResource($section->fresh()));
    }

    public function destroy(Event $event, FestivalSection $section): JsonResponse
    {
        Gate::authorize('delete', [$section, $event]);

        $section->delete();

        return response()->json(null, 204);
    }

    public function registrationSettings(Event $event): JsonResponse
    {
        Gate::authorize('viewAny', [FestivalSection::class, $event]);

        $sections = $this->getFestivalSections($event);

        $grouped = $sections->groupBy('name')->map(function ($group) {
            $first = $group->first();

            return [
                'name' => $first->name,
                'category' => $first->category,
                'icon' => $first->icon,
                'show_in_registration' => $group->contains('show_in_registration', true),
                'registration_description' => $group->whereNotNull('registration_description')->first()?->registration_description,
                'section_count' => $group->count(),
                'section_ids' => $group->pluck('id')->values()->toArray(),
            ];
        })->values();

        return response()->json(['data' => $grouped]);
    }

    public function updateRegistrationSettings(UpdateRegistrationSettingsRequest $request, Event $event): JsonResponse
    {
        Gate::authorize('create', [FestivalSection::class, $event]);

        $validated = $request->validated();
        $sections = $this->getFestivalSections($event);

        $matching = $sections->where('name', $validated['name']);

        if ($matching->isEmpty()) {
            return $this->error('Sectie niet gevonden.', 404);
        }

        FestivalSection::whereIn('id', $matching->pluck('id'))
            ->update([
                'show_in_registration' => $validated['show_in_registration'],
                'registration_description' => $validated['registration_description'],
            ]);

        activity('section_management')
            ->performedOn($event)
            ->causedBy(auth()->user())
            ->withProperties([
                'section_name' => $validated['name'],
                'show_in_registration' => $validated['show_in_registration'],
                'sections_updated' => $matching->count(),
            ])
            ->log('section.registration_settings_updated');

        // Return updated settings
        return $this->registrationSettings($event);
    }

    /**
     * Get all sections across the festival context (parent + children).
     */
    private function getFestivalSections(Event $event): \Illuminate\Support\Collection
    {
        $eventIds = collect([$event->id]);

        if ($event->isSubEvent()) {
            $parentId = $event->parent_event_id;
            $eventIds = Event::where('parent_event_id', $parentId)
                ->orWhere('id', $parentId)
                ->pluck('id');
        } elseif ($event->hasChildren()) {
            $childIds = $event->children()->pluck('id');
            $eventIds = $childIds->push($event->id);
        }

        return FestivalSection::whereIn('event_id', $eventIds)->ordered()->get();
    }

    public function reorder(ReorderFestivalSectionsRequest $request, Event $event): JsonResponse
    {
        Gate::authorize('reorder', [FestivalSection::class, $event]);

        foreach ($request->validated('sections') as $index => $id) {
            $event->festivalSections()
                ->where('id', $id)
                ->update(['sort_order' => $index]);
        }

        $sections = $event->festivalSections()->ordered()->get();

        return $this->success(FestivalSectionResource::collection($sections));
    }
}