<?php

namespace App\Exports;

use App\Models\LigneBudget;
use Maatwebsite\Excel\Concerns\FromCollection;
use Maatwebsite\Excel\Concerns\WithHeadings;
use Maatwebsite\Excel\Concerns\WithMapping;
use Maatwebsite\Excel\Concerns\ShouldAutoSize;
use Maatwebsite\Excel\Concerns\WithTitle;

class BudgetExecutionExport implements FromCollection, WithHeadings, WithMapping, ShouldAutoSize, WithTitle
{
    protected $user;
    protected $annee;
    protected $filters;

    public function __construct($user, $annee, $filters = [])
    {
        $this->user = $user;
        $this->annee = $annee;
        $this->filters = $filters;
    }

    public function title(): string
    {
        $parts = ['Exécution Budgétaire', $this->annee];
        
        if (!empty($this->filters['type'])) {
            $parts[] = ucfirst($this->filters['type']);
        }
        
        if (!empty($this->filters['envelope'])) {
            $parts[] = ucfirst($this->filters['envelope']);
        }

        if (!empty($this->filters['service'])) {
            $parts[] = $this->filters['service'];
        }

        return substr(implode(' - ', $parts), 0, 31); // Max 31 chars for Excel sheet title
    }

    public function collection()
    {
        $query = LigneBudget::with(['budget.service', 'commandes'])
            ->whereHas('budget', function($q) {
                $q->where('annee', $this->annee);
            });

        // Role based access
        if (!$this->user->hasRole(['admin', 'directeur'])) {
            $query->whereHas('budget', function($q) {
                $q->where('service_id', $this->user->service_id);
            });
        }

        // Dynamic filters
        if (!empty($this->filters['type'])) {
            $query->where('type_depense', $this->filters['type']);
        }

        if (!empty($this->filters['envelope'])) {
            $query->whereHas('budget', function($q) {
                $q->where('type_budget', $this->filters['envelope']);
            });
        }

        if (!empty($this->filters['service'])) {
            $query->whereHas('budget.service', function($q) {
                $q->where('nom', $this->filters['service']);
            });
        }

        $statutsConsommes = ['validee', 'commandee', 'partiellement_recue', 'recue_complete', 'cloturee'];
        $statutsEngages   = ['brouillon', 'en_attente_validation'];

        return $query->get()->map(function($lb) use ($statutsConsommes, $statutsEngages) {
            // Travail en mémoire sur la relation déjà eager-loadée — zéro requête supplémentaire
            $commandes = $lb->commandes;

            $consomme = (float) $commandes->whereIn('statut', $statutsConsommes)->sum('montant_ttc');
            $engage   = (float) $commandes->whereIn('statut', $statutsEngages)->sum('montant_ttc');

            $lb->consomme    = $consomme;
            $lb->engage      = $engage;
            $lb->total_cumule = $consomme + $engage;
            $lb->reste       = (float) ($lb->montant_arbitre ?? 0) - $lb->total_cumule;
            $lb->percent     = ($lb->montant_arbitre ?? 0) > 0
                ? round(($lb->total_cumule / $lb->montant_arbitre) * 100, 2)
                : 0;

            return $lb;
        });
    }

    public function headings(): array
    {
        return [
            'ID',
            'Service',
            'Type Budget',
            'Ligne Budgétaire',
            'Type Dépense',
            'Enveloppe Arbitrée (€)',
            'Consommé (€)',
            'Engagé (€)',
            'Total Engagé (€)',
            'Reste (€)',
            'Taux d\'exécution (%)'
        ];
    }

    public function map($lb): array
    {
        return [
            $lb->id,
            $lb->budget->service->nom ?? 'Agglo',
            $lb->budget->type_budget === 'agglo' ? 'Agglomération' : 'Mutualisé',
            $lb->nom,
            $lb->type_depense === 'fonctionnement' ? 'Fonctionnement' : 'Investissement',
            $lb->montant_arbitre,
            $lb->consomme,
            $lb->engage,
            $lb->total_cumule,
            $lb->reste,
            $lb->percent . '%'
        ];
    }
}