<?php

namespace App\Http\Controllers\Api;

use App\Http\Controllers\Controller;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Schema;

class WorkPermitHierarchyController extends Controller
{
    /**
     * Get Work Permit Hierarchy
     * 
     * Returns a structured hiearchy of work permit projects, companies, and personnel.
     */
    public function index(Request $request)
    {
        try {
            // Get all column names from both tables for placeholders
            $workPermitColumns = Schema::getColumnListing('work_permit_documents');
            $subcontractorColumns = Schema::getColumnListing('subcontractors');

            $query = DB::table("work_permit_documents")
                ->select([
                    'work_permit_documents.id',
                    'work_permit_documents.name_surname',
                    'work_permit_documents.company',
                    'work_permit_documents.certificates_number',
                    'work_permit_documents.duty',
                    'work_permit_documents.document_number',
                    'work_permit_documents.attorney',
                    'work_permit_documents.attorney_date',
                    'work_permit_documents.zone as project',
                    'work_permit_documents.sign_order as personnel_sign_order',
                    'subcontractors.company_name_ru',
                    'subcontractors.company_name_en',
                    'subcontractors.job_description',
                    'subcontractors.company_code',
                    'subcontractors.operation_type',
                    'subcontractors.city',
                    'subcontractors.address',
                    'subcontractors.logo',
                    'subcontractors.sign_order as company_sign_order'
                ])
                ->join("subcontractors", "work_permit_documents.company", "subcontractors.company_name_ru")
                ->orderBy('subcontractors.operation_type')
                ->orderBy('work_permit_documents.sign_order');

            // Apply project filter if provided
            if ($request->has('project') && !empty($request->project)) {
                $query->where('work_permit_documents.zone', 'LIKE', '%' . $request->project . '%');
            }

            $workPermitUsers = $query->get();

            $projectMapping = [];

            // Parse comma-separated projects and organize
            foreach ($workPermitUsers as $user) {
                $projectParts = explode(',', $user->project);
                foreach ($projectParts as $singleProject) {
                    $singleProject = trim($singleProject);
                    if (empty($singleProject)) continue;

                    if ($request->has('project') && !empty($request->project)) {
                        if (stripos($singleProject, $request->project) === false) {
                            continue;
                        }
                    }

                    if (!isset($projectMapping[$singleProject])) {
                        $projectMapping[$singleProject] = [];
                    }

                    // Avoid duplicates in mapping
                    $found = false;
                    foreach ($projectMapping[$singleProject] as $existingUser) {
                        if ($existingUser->name_surname === $user->name_surname && 
                            $existingUser->operation_type === $user->operation_type &&
                            $existingUser->personnel_sign_order === $user->personnel_sign_order) {
                            $found = true;
                            break;
                        }
                    }

                    if (!$found) {
                        // Enhance user object with placeholders
                        $user->placeholders = $this->generatePlaceholders($user, $workPermitColumns, $subcontractorColumns);
                        $projectMapping[$singleProject][] = $user;
                    }
                }
            }

            // Group into hiearchy: Project -> Operation Type -> Companies -> Users
            $response = [];
            foreach ($projectMapping as $projectName => $users) {
                $operationGroups = collect($users)->groupBy('operation_type');
                
                $projectData = [
                    'project_name' => $projectName,
                    'operation_types' => []
                ];

                foreach ($operationGroups as $operationType => $operationGroup) {
                    $companies = [];
                    $byCompany = collect($operationGroup)->groupBy('company_name_ru');

                    foreach ($byCompany as $companyName => $companyUsers) {
                        $companies[] = [
                            'company_name' => $companyName,
                            'company_sign_order' => $companyUsers->first()->company_sign_order,
                            'users' => $companyUsers->sortBy('personnel_sign_order')->values()->all()
                        ];
                    }

                    $projectData['operation_types'][] = [
                        'type' => $operationType,
                        'companies' => $companies
                    ];
                }

                $response[] = $projectData;
            }

            // Sort alphabetical by project name
            usort($response, function($a, $b) {
                return strcmp($a['project_name'], $b['project_name']);
            });

            return response()->json([
                'status' => 'success',
                'data' => $response
            ]);

        } catch (\Exception $e) {
            return response()->json([
                'status' => 'error',
                'message' => $e->getMessage()
            ], 500);
        }
    }

    /**
     * Generate placeholders for a user
     */
    private function generatePlaceholders($user, $wpColumns, $sbColumns)
    {
        $job = $user->job_description ?? '';
        $fso = $user->company_sign_order ?? '';
        $pso = $user->personnel_sign_order ?? '';
        
        $prefix = "{$job}{$fso}_{$pso}_";
        
        $placeholders = [
            'work_permit' => [],
            'subcontractor' => [],
            'common' => [
                'name_surname' => "{" . $prefix . "name_surname}",
                'company_name' => "{" . $prefix . "company_name}",
                'certificate_no' => "{" . $prefix . "certificate_no}",
                'duty' => "{" . $prefix . "duty}",
            ]
        ];

        foreach ($wpColumns as $col) {
            $placeholders['work_permit'][$col] = "{" . $prefix . $col . "}";
        }

        foreach ($sbColumns as $col) {
            $placeholders['subcontractor'][$col] = "{" . $prefix . "sub_" . $col . "}";
        }

        return $placeholders;
    }
}