<?php

namespace App\Http\Controllers;

use App\Models\PeopleProcess;
use App\Models\User;
use App\Services\PeopleAccess;
use App\Services\PeopleApplicationReport;
use App\Services\PeopleDeadlineReport;
use App\Services\PeopleHiring;
use App\Services\PeopleSelectionReport;
use App\Services\PeopleWorkdesk;
use Illuminate\Http\Request;
use Illuminate\Pagination\LengthAwarePaginator;
use Illuminate\Support\Facades\DB;
use Illuminate\Validation\Rule;
use Inertia\Inertia;
use Symfony\Component\HttpFoundation\Response;

class PeopleReportController extends Controller
{
    public function index(Request $request): Response
    {
        return DB::transaction(function () use ($request) {
            if (DB::getDriverName() === 'pgsql' && DB::transactionLevel() === 1) {
                DB::statement('SET TRANSACTION ISOLATION LEVEL REPEATABLE READ READ ONLY');
            }
            $actor = $request->user('web');
            abort_unless($actor instanceof User, 403);
            $kinds = app(PeopleHiring::class)->kinds($actor);
            abort_unless($kinds !== [], 403);
            $filters = $request->validate([
                'view' => 'nullable|in:processes,applications,selections,deadlines',
                'deadline_window' => 'nullable|in:all,overdue,today,future,undated',
                'deadline_page' => 'nullable|integer|min:1|max:100000',
                'kind' => ['nullable', Rule::in($kinds)], 'status' => ['nullable', Rule::in(PeopleWorkdesk::STATES)],
                'search' => 'nullable|string|max:100', 'from' => 'nullable|date_format:Y-m-d',
                'to' => ['nullable', 'date_format:Y-m-d', Rule::when($request->filled('from'), 'after_or_equal:from')],
            ]);
            $query = app(PeopleAccess::class)->visible(PeopleProcess::query()->whereIn('kind', $kinds), $actor);
            foreach (['kind', 'status'] as $field) {
                if (! empty($filters[$field])) {
                    $query->where($field, $filters[$field]);
                }
            }
            if (! empty($filters['search'])) {
                $search = $filters['search'];
                $query->where(function ($q) use ($search) {
                    $q->whereLike('title', '%'.$search.'%');
                    if (preg_match('/^(?:PES-)?([1-9][0-9]*)$/D', $search, $matches)) {
                        $id = filter_var($matches[1], FILTER_VALIDATE_INT, ['options' => ['min_range' => 1]]);
                        if ($id !== false) {
                            $q->orWhere('id', $id);
                        }
                    }
                });
            }
            if (! empty($filters['from'])) {
                $query->whereDate('created_at', '>=', $filters['from']);
            }
            if (! empty($filters['to'])) {
                $query->whereDate('created_at', '<=', $filters['to']);
            }
            $columns = ['id', 'title', 'kind', 'status', 'closes_on', 'created_at'];
            $page = $request->routeIs('people.reports.csv') ? null : (clone $query)->latest('id')->paginate(25, $columns)->withQueryString();
            $applications = ($filters['view'] ?? 'processes') === 'applications';
            $selections = ($filters['view'] ?? 'processes') === 'selections';
            $deadlines = ($filters['view'] ?? 'processes') === 'deadlines';
            $deadlineReport = $deadlines ? app(PeopleDeadlineReport::class)->build(clone $query, $actor, $filters['deadline_window'] ?? 'all') : null;
            if ($deadlineReport !== null && ! $request->routeIs('people.reports.csv')) {
                $number = (int) ($filters['deadline_page'] ?? 1);
                $pager = (new LengthAwarePaginator(array_slice($deadlineReport['items'], ($number - 1) * 25, 25), $deadlineReport['total_items'], 25, $number,
                    ['path' => $request->url(), 'pageName' => 'deadline_page']))->appends($request->except('deadline_page'));
                $deadlineReport['items'] = $pager->items();
                $deadlineReport['pagination'] = ['current_page' => $pager->currentPage(), 'last_page' => $pager->lastPage(), 'prev_page_url' => $pager->previousPageUrl(), 'next_page_url' => $pager->nextPageUrl()];
            }
            $metrics = [];
            if ($applications || $selections) {
                $metricQuery = clone $query;
                if ($page !== null) {
                    $metricQuery->whereIn('id', $page->getCollection()->modelKeys());
                }
                foreach ($metricQuery->orderBy('id')->lazyById(100) as $process) {
                    $metrics[$process->id] = $applications ? app(PeopleApplicationReport::class)->counts($process, $actor) : app(PeopleSelectionReport::class)->facts($process, $actor);
                }
            }
            if ($request->routeIs('people.reports.csv') && $deadlineReport !== null) {
                $response = $this->deadlineCsv($deadlineReport);
            } elseif ($request->routeIs('people.reports.csv')) {
                // Materialise within the read-only snapshot; streaming runs after the transaction.
                $rows = (clone $query)->orderBy('id')->get($columns);
                $response = response()->streamDownload(function () use ($rows, $applications, $selections, $metrics) {
                    $file = fopen('php://output', 'w');
                    if ($file === false) {
                        throw new \RuntimeException('Não foi possível abrir a exportação.');
                    }
                    fwrite($file, "\xEF\xBB\xBF");
                    $extra = ['Registadas para avaliação', 'Avaliação completa', 'Por concluir avaliação', 'Sem avaliação', 'Avaliação em curso', 'Base da avaliação', 'Recebidas no portal', 'Admitidas para análise no portal', 'Não admitidas no portal', 'Triagem pendente'];
                    $selectionColumns = ['Situação da selecção', 'Proposta em', 'Decisão em', 'Pendência', 'Acesso à minuta', 'Referência da minuta', 'Minuta preparada em', 'Início previsto na minuta'];
                    fputcsv($file, ['Referência', 'Título', 'Percurso', 'Estado', 'Fecho de candidaturas', 'Criado em', ...($applications ? $extra : ($selections ? $selectionColumns : []))], ';', '"', '');
                    foreach ($rows as $row) {
                        $title = preg_match('/^[\s]*[=+@-]/u', $row->title) ? "'".$row->title : $row->title;
                        $counts = $metrics[$row->id] ?? [];
                        $values = $applications ? array_values(array_map(fn ($value) => $value === null ? 'Sem acesso' : ($value === 'selection_snapshot' ? 'Selecção preservada' : ($value === 'current_eligibility' ? 'Elegibilidade actual' : $value)), $counts)) : [];
                        if ($selections) {
                            $values = array_values(array_map(fn ($value) => $value === null ? 'Não registado' : (is_string($value) && preg_match('/^[\s]*[=+@-]/u', $value) ? "'".$value : $value), $counts));
                        }
                        fputcsv($file, ['PES-'.$row->id, $title, $row->kind === 'service' ? 'Serviços individuais' : 'Recrutamento e selecção', self::states()[$row->status] ?? $row->status, $row->closes_on, $row->created_at?->toDateString(), ...$values], ';', '"', '');
                    }
                    fclose($file);
                }, 'relatorio-pessoas.csv', ['Content-Type' => 'text/csv; charset=UTF-8']);
            } else {
                $summary = (clone $query)->selectRaw('kind, status, count(*) as total')->groupBy('kind', 'status')->get();
                Inertia::encryptHistory();
                $response = Inertia::render('people/reports', [
                    'filters' => $filters, 'kinds' => $kinds, 'summary' => $summary,
                    'applicationMetrics' => $applications ? $metrics : [],
                    'selectionMetrics' => $selections ? $metrics : [],
                    'deadlineReport' => $deadlineReport,
                    'generatedAt' => now()->toIso8601String(),
                    'processes' => $page,
                ])->toResponse($request);
            }
            $response->headers->set('Cache-Control', 'private, no-store, max-age=0');

            return $response;
        });
    }

    /** @param array<string,mixed> $report */
    private function deadlineCsv(array $report): Response
    {
        return response()->streamDownload(function () use ($report) {
            $file = fopen('php://output', 'w');
            if ($file === false) {
                throw new \RuntimeException('Não foi possível abrir a exportação.');
            }
            fwrite($file, "\xEF\xBB\xBF");
            fputcsv($file, ['Referência', 'Processo', 'Categoria', 'Intervenção', 'Responsabilidade', 'Prazo', 'Dias de atraso', 'Consulta em', 'Filtro de prazo'], ';', '"', '');
            $windows = ['all' => 'Todos', 'overdue' => 'Vencidos', 'today' => 'Hoje', 'future' => 'Futuros', 'undated' => 'Sem prazo definido'];
            foreach ($report['items'] as $item) {
                $values = [$item['reference'], $item['title'], $item['category'], $item['label'], $item['responsibility'], $item['due_on'] ?? 'Sem prazo definido', $item['days_overdue'] ?? 'Não determinável', $report['as_of'], $windows[$report['window']]];
                $values = array_map(fn ($value) => is_string($value) && preg_match('/^[\s]*[=+@-]/u', $value) ? "'".$value : $value, $values);
                fputcsv($file, $values, ';', '"', '');
            }
            fclose($file);
        }, 'relatorio-prazos-pessoas.csv', ['Content-Type' => 'text/csv; charset=UTF-8']);
    }

    /** @return array<string,string> */
    private static function states(): array
    {
        return ['draft' => 'Abertura por conferir', 'open' => 'Recepção de candidaturas', 'assessment' => 'Avaliação',
            'selection_review' => 'Selecção por conferir', 'selected' => 'Selecção aprovada', 'contract_draft' => 'Minuta contratual preparada'];
    }
}