<?php

namespace App\Http\Controllers\api;

use App\Http\Controllers\Controller;
use App\Models\BylawDocument;
use App\Models\BylawLegalAuthority;
use App\Models\BylawSubjectCategory;
use App\Models\BylawNode;
use App\Models\BylawCodificationLink;
use App\Traits\BaseApiResponse;
use Illuminate\Http\Request;

class BylawApiController extends Controller
{
    use BaseApiResponse;

    public function categories()
    {
        $categories = BylawSubjectCategory::all()->map(function ($category) {
            return [
                'id' => $category->id,
                'name' => $category->name,
            ];
        });

        return $this->success($categories, 'Success', 'Bylaw Categories List');
    }

    public function authorities()
    {
        $authorities = BylawLegalAuthority::all()->map(function ($authority) {
            return [
                'id' => $authority->id,
                'name' => $authority->name,
                'authority_type' => $authority->authority_type,
            ];
        });

        return $this->success($authorities, 'Success', 'Bylaw Authorities List');
    }

    public function index(Request $request)
    {
        $request->validate([
            'category_id'           => 'nullable|exists:bylaw_subject_categories,id',
            'approval_authority_id' => 'nullable|exists:bylaw_legal_authorities,id',
            'bylaw_type'            => 'nullable|in:executive,delegated,independent',
            'sort_by'               => 'nullable|in:date,number',
            'sort'                  => 'nullable|in:asc,desc',
            'per_page'              => 'nullable|integer|min:1|max:100',
        ]);

        $query = BylawDocument::with(['category', 'approvalAuthority', 'promulgationAuthority'])
            ->where('is_published', true);

        if ($request->filled('category_id')) {
            $query->where('category_id', $request->category_id);
        }

        if ($request->filled('approval_authority_id')) {
            $query->where('approval_authority_id', $request->approval_authority_id);
        }

        if ($request->filled('bylaw_type')) {
            $query->where('bylaw_type', $request->bylaw_type);
        }

        $sortBy = $request->input('sort_by', 'date');
        $sortOrder = $request->input('sort', 'desc');
        $sortColumn = $sortBy === 'number' ? 'promulgation_number' : 'approval_date';

        if ($sortBy === 'number') {
            $query->orderByRaw("LENGTH({$sortColumn}) {$sortOrder}")->orderBy($sortColumn, $sortOrder);
        } else {
            $query->orderBy($sortColumn, $sortOrder);
        }

        $perPage = min(max((int) $request->input('per_page', 15), 10), 100);
        $paginator = $query->paginate($perPage);

        // واکشی دسته‌جمعی و ایمنِ گره‌ها با استفاده از Eloquent
        $docIds = collect($paginator->items())->pluck('id')->map(fn($id) => (int)$id)->toArray();
        $nodesByDoc = collect();

        if (!empty($docIds)) {
            $nodesByDoc = BylawNode::whereIn('document_id', $docIds)
                ->orderBy('sort_order', 'asc')
                ->get()
                ->groupBy(fn($node) => (int)$node->document_id);
        }

        $items = collect($paginator->items())->map(function ($item) use ($nodesByDoc) {
            $itemNodes = $nodesByDoc->get((int)$item->id, collect());
            return $this->formatBylaw($item, $itemNodes);
        });

        $responseData = [
            'items'        => $items,
            'current_page' => $paginator->currentPage(),
            'last_page'    => $paginator->lastPage(),
            'per_page'     => $paginator->perPage(),
            'total'        => $paginator->total(),
        ];

        return $this->success($responseData, 'Success', 'Bylaws Fetched');
    }

    public function single($id)
    {
        $bylaw = BylawDocument::with(['category', 'approvalAuthority', 'promulgationAuthority'])
            ->where('is_published', true)
            ->find($id);

        if (!$bylaw) {
            return $this->failed([], [
                'title' => 'خطا',
                'message' => 'آیین‌نامه مورد نظر یافت نشد.'
            ], 404);
        }

        $formatted = $this->formatBylaw($bylaw);

        if (!$formatted['is_locked']) {
            $eloquentNodes = BylawNode::with('type')
                ->where('document_id', $bylaw->id)
                ->orderBy('sort_order', 'asc')
                ->get();

            $formatted['nodes'] = $eloquentNodes->map(function ($node) {
                return [
                    'id'              => $node->id,
                    'parent_id'       => $node->parent_id,
                    'node_type'       => optional($node->type)->name,
                    'node_identifier' => $node->node_identifier,
                    'title'           => $node->title,
                    'node_content'    => $node->node_content,
                    'sort_order'      => $node->sort_order,
                    'valid_from'      => $node->valid_from,
                    'valid_to'        => $node->valid_to,
                    'node_status'     => $node->node_status,
                ];
            })->toArray();

            $links = BylawCodificationLink::where('source_entity_type', 'bylaw_doc')
                ->where('source_entity_id', $bylaw->id)
                ->get()
                ->map(function ($link) {
                    return [
                        'id'                 => $link->id,
                        'target_entity_type' => $link->target_entity_type,
                        'target_entity_id'   => $link->target_entity_id,
                        'link_type'          => $link->link_type,
                        'effective_date'     => $link->effective_date,
                        'justification'      => $link->justification,
                    ];
                });

            $formatted['links'] = $links->toArray();
        }

        return $this->success($formatted, 'Success', 'Bylaw Document Details Fetched');
    }

    public function search(Request $request)
    {
        $request->validate([
            'search'   => 'nullable|string',
            'sort_by'  => 'nullable|in:date,number',
            'sort'     => 'nullable|in:asc,desc',
            'per_page' => 'nullable|integer|min:1|max:100',
        ]);

        $query = BylawDocument::with(['category', 'approvalAuthority', 'promulgationAuthority'])
            ->where('is_published', true);

        if ($request->filled('search')) {
            $searchTerm = $request->input('search');

            $query->where(function ($q) use ($searchTerm) {
                $q->where('title', 'LIKE', "%{$searchTerm}%")
                    ->orWhere('description', 'LIKE', "%{$searchTerm}%")
                    ->orWhere('promulgation_number', 'LIKE', "%{$searchTerm}%")
                    ->orWhere('official_gazette_number', 'LIKE', "%{$searchTerm}%")
                    ->orWhereIn('id', function($subQuery) use ($searchTerm) {
                        $subQuery->select('document_id')
                            ->from('bylaw_nodes')
                            ->where('node_content', 'LIKE', "%{$searchTerm}%")
                            ->orWhere('title', 'LIKE', "%{$searchTerm}%");
                    });
            });
        }

        $sortBy = $request->input('sort_by', 'date');
        $sortOrder = $request->input('sort', 'desc');
        $sortColumn = $sortBy === 'number' ? 'promulgation_number' : 'approval_date';

        if ($sortBy === 'number') {
            $query->orderByRaw("LENGTH({$sortColumn}) {$sortOrder}")->orderBy($sortColumn, $sortOrder);
        } else {
            $query->orderBy($sortColumn, $sortOrder);
        }

        $perPage = min(max((int) $request->input('per_page', 15), 10), 100);
        $paginator = $query->paginate($perPage);

        $docIds = collect($paginator->items())->pluck('id')->map(fn($id) => (int)$id)->toArray();
        $nodesByDoc = collect();

        if (!empty($docIds)) {
            $nodesByDoc = BylawNode::whereIn('document_id', $docIds)
                ->orderBy('sort_order', 'asc')
                ->get()
                ->groupBy(fn($node) => (int)$node->document_id);
        }

        $items = collect($paginator->items())->map(function ($item) use ($nodesByDoc) {
            $itemNodes = $nodesByDoc->get((int)$item->id, collect());
            return $this->formatBylaw($item, $itemNodes);
        });

        $responseData = [
            'items'        => $items,
            'current_page' => $paginator->currentPage(),
            'last_page'    => $paginator->lastPage(),
            'per_page'     => $paginator->perPage(),
            'total'        => $paginator->total(),
        ];

        return $this->success($responseData, 'Success', 'Search Results Fetched');
    }

    public function fast_search(Request $request)
    {
        $searchTerm = $request->input('search');

        $query = BylawDocument::with(['category', 'approvalAuthority', 'promulgationAuthority'])
            ->where('is_published', true);

        if (!empty($searchTerm)) {
            $query->where(function ($q) use ($searchTerm) {
                $q->where('title', 'LIKE', "%{$searchTerm}%")
                    ->orWhere('description', 'LIKE', "%{$searchTerm}%")
                    ->orWhere('promulgation_number', 'LIKE', "%{$searchTerm}%")
                    ->orWhere('official_gazette_number', 'LIKE', "%{$searchTerm}%")
                    ->orWhereIn('id', function($subQuery) use ($searchTerm) {
                        $subQuery->select('document_id')
                            ->from('bylaw_nodes')
                            ->where('node_content', 'LIKE', "%{$searchTerm}%")
                            ->orWhere('title', 'LIKE', "%{$searchTerm}%");
                    });
            });
        }

        $count = $query->count();
        $items = $query->orderBy('approval_date', 'desc')->take(5)->get();

        $docIds = $items->pluck('id')->map(fn($id) => (int)$id)->toArray();
        $nodesByDoc = collect();

        if (!empty($docIds)) {
            $nodesByDoc = BylawNode::whereIn('document_id', $docIds)
                ->orderBy('sort_order', 'asc')
                ->get()
                ->groupBy(fn($node) => (int)$node->document_id);
        }

        $formattedItems = $items->map(function ($item) use ($nodesByDoc) {
            $itemNodes = $nodesByDoc->get((int)$item->id, collect());
            return $this->formatBylaw($item, $itemNodes);
        });

        return $this->success([
            'items' => $formattedItems,
            'count' => $count
        ], 'Success', 'Fast Search Results');
    }

    public function pager($id)
    {
        $current = BylawDocument::with(['category', 'approvalAuthority', 'promulgationAuthority'])
            ->where('is_published', true)
            ->find($id);

        if (!$current) {
            return $this->failed([], [
                'title' => 'خطا',
                'message' => 'آیین‌نامه مورد نظر یافت نشد.'
            ], 404);
        }

        $previousItem = BylawDocument::with(['category', 'approvalAuthority', 'promulgationAuthority'])
            ->where('is_published', true)
            ->where(function ($query) use ($current) {
                if ($current->approval_date) {
                    $query->where('approval_date', '<', $current->approval_date)
                        ->orWhere(function ($subQuery) use ($current) {
                            $subQuery->where('approval_date', '=', $current->approval_date)
                                ->where('id', '<', $current->id);
                        });
                } else {
                    $query->whereNull('approval_date')->where('id', '<', $current->id);
                }
            })
            ->orderBy('approval_date', 'desc')
            ->orderBy('id', 'desc')
            ->first();

        $nextItem = BylawDocument::with(['category', 'approvalAuthority', 'promulgationAuthority'])
            ->where('is_published', true)
            ->where(function ($query) use ($current) {
                if ($current->approval_date) {
                    $query->where('approval_date', '>', $current->approval_date)
                        ->orWhere(function ($subQuery) use ($current) {
                            $subQuery->where('approval_date', '=', $current->approval_date)
                                ->where('id', '>', $current->id);
                        });
                } else {
                    $query->whereNotNull('approval_date')
                        ->orWhere(function ($subQuery) use ($current) {
                            $subQuery->whereNull('approval_date')->where('id', '>', $current->id);
                        });
                }
            })
            ->orderBy('approval_date', 'asc')
            ->orderBy('id', 'asc')
            ->first();

        $itemsToFormat = array_filter([$previousItem, $current, $nextItem]);

        $docIds = collect($itemsToFormat)->pluck('id')->map(fn($id) => (int)$id)->toArray();
        $nodesByDoc = collect();

        if (!empty($docIds)) {
            $nodesByDoc = BylawNode::whereIn('document_id', $docIds)
                ->orderBy('sort_order', 'asc')
                ->get()
                ->groupBy(fn($node) => (int)$node->document_id);
        }

        $results = collect($itemsToFormat)->map(function($item) use ($nodesByDoc) {
            $itemNodes = $nodesByDoc->get((int)$item->id, collect());
            return $this->formatBylaw($item, $itemNodes);
        })->values()->toArray();

        return $this->success($results, 'Success', 'Pager Window Details');
    }

    private function isLockedForCurrentUser($item): bool
    {
        if (auth()->check() && auth()->user() && method_exists(auth()->user(), 'isSubscriber')) {
            return !auth()->user()->isSubscriber() && (bool) ($item->is_locked ?? false);
        }
        return (bool) ($item->is_locked ?? false);
    }

    /**
     * متد قدرتمند برای استخراج ایمن متون
     */
    private function formatBylaw($item, $itemNodes = null)
    {
        $isLocked = $this->isLockedForCurrentUser($item);

        // واکشی در صورت خالی بودن کالکشن
        if ($itemNodes === null) {
            $itemNodes = BylawNode::where('document_id', $item->id)->orderBy('sort_order', 'asc')->get();
        }

        // استخراج محتوا و تبدیل امنِ Encoding (ضد باگِ JSON Encode لاراول)
        $nodeContentAsDescription = $itemNodes->pluck('node_content')
            ->map(function ($text) {
                // اطمینان از حذف فاصله‌ها و اعمال انکودینگ استاندارد برای جلوگیری از باگ‌های نامرئی
                $safeText = trim((string)$text);
                return mb_convert_encoding($safeText, 'UTF-8', 'UTF-8');
            })
            ->filter(function ($text) {
                return $text !== '';
            })
            ->implode("\n\n");

        // اگر همچنان خالی ماند (فقط در صورتی که دیتابیس واقعاً رکورد نداشته باشد)
        if (empty($nodeContentAsDescription)) {
            $nodeContentAsDescription = mb_convert_encoding(trim((string)$item->description), 'UTF-8', 'UTF-8');
        }

        return [
            'id'                        => $item->id,
            'title'                     => $item->title,
            'category_id'               => $item->category_id,
            'category_name'             => optional($item->category)->name,
            'approval_authority_id'     => $item->approval_authority_id,
            'approval_authority_name'   => optional($item->approvalAuthority)->name,
            'approval_date'             => $item->approval_date,
            'promulgation_authority_id' => $item->promulgation_authority_id,
            'promulgation_authority_name'=> optional($item->promulgationAuthority)->name,
            'promulgation_date'         => $item->promulgation_date,
            'promulgation_number'       => $item->promulgation_number,
            'official_gazette_number'   => $item->official_gazette_number,
            'official_gazette_date'     => $item->official_gazette_date,
            'execution_date'            => $item->execution_date,
            'bylaw_type'                => $item->bylaw_type,
            'global_status'             => $item->global_status,
            'pdf_file_url'              => $isLocked ? null : ($item->pdf_file_path ? asset('storage/' . $item->pdf_file_path) : null),

            // نتیجه استخراج ۱۰۰٪ در اینجا می‌نشیند
            'description'               => $isLocked ? null : $nodeContentAsDescription,

            // 🚨 پارامتر عیب‌یابی: این عدد نشان می‌دهد چند گره متصل به این فایل در دیتابیس پیدا شد
            'debug_node_count'          => $itemNodes->count(),

            'is_locked'                 => $isLocked,
        ];
    }
}