<?php

namespace App\Http\Controllers;

use App\Models\Budget;
use App\Models\Service;
use App\Models\LigneBudget;
use App\Exports\BudgetExecutionExport;
use Illuminate\Http\Request;
use Inertia\Inertia;
use Maatwebsite\Excel\Facades\Excel;
use Barryvdh\DomPDF\Facade\Pdf;

class BudgetController extends Controller
{
    public function index(Request $request)
    {
        $user = $request->user();
        
        $query = Budget::with(['service', 'lignes', 'commune']);

        // Le responsable ne voit que les budgets de son service
        if (!$user->hasRole(['admin', 'directeur', 'raf'])) {
            $query->where('service_id', $user->service_id);
        }

        $annee = $request->get('annee', now()->year);
        $query->where('annee', $annee);

        $budgets = $query->orderBy('annee', 'desc')->get()->map(function ($budget) {
            return [
                'id' => $budget->id,
                'service' => $budget->service->nom,
                'commune' => $budget->commune?->nom,
                'annee' => $budget->annee,
                'type_budget' => $budget->type_budget,
                'statut' => $budget->statut,
                'total_invest_propose' => $budget->totalPropose('investissement'),
                'total_fonct_propose' => $budget->totalPropose('fonctionnement'),
                'total_invest_arbitre' => $budget->totalArbitre('investissement'),
                'total_fonct_arbitre' => $budget->totalArbitre('fonctionnement'),
            ];
        });

        return Inertia::render('Budgets/Index', [
            'budgets' => $budgets,
            'services' => Service::all(),
            'communes' => \App\Models\Commune::orderBy('nom')->get(),
            'filters' => ['annee' => $annee]
        ]);
    }

    public function store(Request $request)
    {
        $request->validate([
            'service_id' => 'required|exists:services,id',
            'annee' => 'required|integer',
            'type_budget' => 'required|in:agglo,mutualise',
        ]);

        Budget::create($request->all());

        return redirect()->back()->with('success', 'Enveloppe budgétaire créée avec succès.');
    }

    public function show(Budget $budget, Request $request)
    {
        $user = $request->user();
        if (!$user->hasRole(['admin', 'directeur', 'raf']) && $budget->service_id !== $user->service_id) {
            abort(403);
        }

        $budget->load(['service', 'lignes.commandes', 'lignes.historique.user']);

        $totals = [
            'invest_propose' => $budget->totalPropose('investissement'),
            'invest_arbitre' => $budget->totalArbitre('investissement'),
            'fonct_propose' => $budget->totalPropose('fonctionnement'),
            'fonct_arbitre' => $budget->totalArbitre('fonctionnement'),
        ];

        $lignes = $budget->lignes->map(function ($ligne) {
            return array_merge($ligne->toArray(), [
                'historique' => $ligne->historique->map(fn($h) => [
                    'id'                     => $h->id,
                    'ancien_statut'          => $h->ancien_statut,
                    'nouveau_statut'         => $h->nouveau_statut,
                    'ancien_montant_arbitre' => $h->ancien_montant_arbitre,
                    'nouveau_montant_arbitre'=> $h->nouveau_montant_arbitre,
                    'commentaire'            => $h->commentaire,
                    'user'                   => $h->user->name,
                    'created_at'             => $h->created_at->format('d/m/Y H:i'),
                ]),
            ]);
        });

        return Inertia::render('Budgets/Show', [
            'budget'  => $budget,
            'lignes'  => $lignes,
            'totals'  => $totals,
            'communes'=> \App\Models\Commune::orderBy('nom')->get(),
        ]);
    }

    public function update(Request $request, Budget $budget)
    {
        $this->authorize('update', $budget);

        $request->validate([
            'statut' => 'required|in:preparation,arbitrage_dsi,arbitrage_direction,valide,cloture',
        ]);

        $budget->update(['statut' => $request->statut]);

        return redirect()->back()->with('success', 'Statut du budget mis à jour.');
    }

    public function execution(Request $request)
    {
        $user = $request->user();
        $annee = $request->get('annee', now()->year);

        $query = \App\Models\LigneBudget::with(['budget.service', 'commandes.commune'])
            ->whereHas('budget', function($q) use ($annee) {
                $q->where('annee', $annee);
            });

        // Filtrage par service si pas admin/directeur/raf
        if (!$user->hasRole(['admin', 'directeur', 'raf'])) {
            $query->whereHas('budget', function($q) use ($user) {
                $q->where('service_id', $user->service_id);
            });
        }

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

        $lignes = $query->get()->map(function($lb) use ($statutsConsommes, $statutsEngages) {
            // Toutes les commandes déjà chargées en mémoire — zéro requête supplémentaire
            $commandes = $lb->commandes;

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

            // Ventilation par commune — calculée en mémoire
            $ventilation = $commandes
                ->whereNotIn('statut', ['annulee'])
                ->groupBy('commune_id')
                ->map(fn($group, $communeId) => [
                    'commune' => $group->first()->commune?->nom ?? 'Non défini',
                    'total'   => (float) $group->sum('montant_ttc'),
                ])
                ->values();

            // Liste détaillée des commandes pour affichage
            $commandesList = $commandes
                ->whereNotIn('statut', ['annulee'])
                ->map(fn($c) => [
                    'id'         => $c->id,
                    'reference'  => $c->numero_commande ?? 'CMD-'.$c->id,
                    'nom'        => $c->objet,
                    'commune'    => $c->commune?->nom,
                    'montant_ttc'=> (float) $c->montant_ttc,
                    'statut'     => $c->statut,
                ])
                ->values();

            return [
                'id' => $lb->id,
                'nom' => $lb->nom,
                'type_depense' => $lb->type_depense,
                'type_budget' => $lb->budget->type_budget,
                'service' => $lb->budget->service->nom,
                'annee' => $lb->budget->annee,
                'montant_arbitre' => (float) $lb->montant_arbitre,
                'consomme' => $consomme,
                'engage' => $engage,
                'total_cumule' => $totalEngage,
                'reste' => (float) $lb->montant_arbitre - $totalEngage,
                'ventilation' => $ventilation,
                'commandes' => $commandesList
            ];
        });

        return Inertia::render('Budgets/Execution', [
            'lignes' => $lignes,
            'services' => \App\Models\Service::orderBy('nom')->get(),
            'filters' => [
                'annee' => $annee
            ]
        ]);
    }

    private function getExportFilename(string $base, int $annee, array $filters, string $ext): string
    {
        $name = $base . '-' . $annee;
        if ($filters['type']) $name .= '-' . $filters['type'];
        if ($filters['envelope']) $name .= '-' . $filters['envelope'];
        if ($filters['service']) $name .= '-' . \Str::slug($filters['service']);
        return $name . '.' . $ext;
    }

    /**
     * Valide et extrait les filtres d'export depuis la requête.
     * Les valeurs non reconnues sont ignorées pour éviter toute injection de paramètres.
     */
    private function resolveExportFilters(Request $request): array
    {
        $type = $request->get('type');
        $envelope = $request->get('envelope');

        return [
            'type'     => in_array($type, ['investissement', 'fonctionnement']) ? $type : null,
            'envelope' => in_array($envelope, ['agglo', 'mutualise']) ? $envelope : null,
            'service'  => $request->get('service') !== 'all' ? $request->get('service') : null,
        ];
    }

    public function exportExcel(Request $request)
    {
        $annee = (int) $request->get('annee', now()->year);
        $filters = $this->resolveExportFilters($request);
        $filename = $this->getExportFilename('budget-execution', $annee, $filters, 'xlsx');
        return Excel::download(new BudgetExecutionExport($request->user(), $annee, $filters), $filename);
    }

    public function exportOds(Request $request)
    {
        $annee = (int) $request->get('annee', now()->year);
        $filters = $this->resolveExportFilters($request);
        $filename = $this->getExportFilename('budget-execution', $annee, $filters, 'ods');
        return Excel::download(new BudgetExecutionExport($request->user(), $annee, $filters), $filename, \Maatwebsite\Excel\Excel::ODS);
    }

    public function exportPdf(Request $request)
    {
        $user = $request->user();
        $annee = (int) $request->get('annee', now()->year);
        $filters = $this->resolveExportFilters($request);

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

        if (!$user->hasRole(['admin', 'directeur', 'raf'])) {
            $query->whereHas('budget', function($q) use ($user) {
                $q->where('service_id', $user->service_id);
            });
        }

        if ($filters['type']) {
            $query->where('type_depense', $filters['type']);
        }
        if ($filters['envelope']) {
            $query->whereHas('budget', fn($q) => $q->where('type_budget', $filters['envelope']));
        }
        if ($filters['service']) {
            $query->whereHas('budget.service', fn($q) => $q->where('nom', $filters['service']));
        }

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

        $lignes = $query->get()->map(function($lb) use ($statutsConsommes, $statutsEngages) {
            $commandes = $lb->commandes;

            $lb->consomme    = (float) $commandes->whereIn('statut', $statutsConsommes)->sum('montant_ttc');
            $lb->engage      = (float) $commandes->whereIn('statut', $statutsEngages)->sum('montant_ttc');
            $lb->total_cumule = $lb->consomme + $lb->engage;
            $lb->reste       = (float) ($lb->montant_arbitre ?? 0) - $lb->total_cumule;
            return $lb;
        });

        $pdf = Pdf::loadView('exports.budgets_pdf', [
            'lignes'   => $lignes,
            'annee'    => $annee,
            'user'     => $user,
            'type'     => $filters['type'] ? ucfirst($filters['type']) : 'Tous types',
            'envelope' => $filters['envelope'] ? ucfirst($filters['envelope']) : 'Toutes enveloppes',
            'service'  => !$user->hasRole(['admin', 'directeur', 'raf'])
                ? ($user->service->nom ?? 'Inconnu')
                : ($filters['service'] ?? 'Tous les services'),
        ])->setPaper('a4', 'landscape');

        $filename = $this->getExportFilename('rapport-budgetaire', $annee, $filters, 'pdf');
        return $pdf->download($filename);
    }
}