<?php

namespace App\Services;

use Illuminate\Support\Facades\Schema;
use Illuminate\Validation\ValidationException;

class AdministrativeGeography
{
    public const ISSUES = [
        'blank_designation' => 'Designação vazia',
        'incomplete_code_path' => 'Percurso de códigos incompleto',
        'duplicate_code_path' => 'Código repetido',
        'missing_parent' => 'Nível superior ausente',
        'ambiguous_parent' => 'Nível superior ambíguo',
        'ancestor_requires_review' => 'Ascendente por rever',
    ];

    /** @var array<string,mixed>|null */
    private ?array $data = null;

    /** @return array<string,mixed> */
    public function catalogue(): array
    {
        if ($this->data === null) {
            $content = file_get_contents(resource_path('data/geography/cartografia-moz.json'));
            abort_unless(is_string($content) && hash_equals((string) config('geography.catalogue_sha256'), hash('sha256', $content)), 503, 'A integridade do catálogo precisa de verificação.');
            $data = json_decode($content, true, 32, JSON_THROW_ON_ERROR);
            abort_unless(is_array($data) && ($data['manifest']['source_sha256'] ?? null) === config('geography.source_sha256'), 503, 'Catálogo geográfico indisponível.');
            $this->data = $data;
        }

        return $this->data;
    }

    public function enabled(): bool
    {
        return config('geography.enabled') === true
            && Schema::hasColumn('suppliers', 'geography_reference')
            && Schema::hasColumn('tenants', 'geography_reference');
    }

    public function availableFor(string $table): bool
    {
        return in_array($table, ['tenants', 'suppliers', 'warehouses', 'equipment'], true)
            && (! in_array($table, ['warehouses', 'equipment'], true) || config('geography.operational_enabled') === true)
            && $this->enabled() && Schema::hasColumn($table, 'geography_reference');
    }

    /** @return array<string,string> */
    public function referenceRules(string $table): array
    {
        return ['geography_reference' => $this->availableFor($table) ? 'sometimes|nullable|array:country,catalogue,record_id' : 'prohibited',
            'geography_reference.catalogue' => 'required_with:geography_reference|string|size:64',
            'geography_reference.record_id' => 'required_with:geography_reference|string|regex:/^[0-9]+$/D|max:20'];
    }

    /** @param array<string,mixed>|null $reference
     * @return array<string,mixed>|null
     */
    public function canonicalFor(string $table, ?array $reference): ?array
    {
        abort_unless($this->availableFor($table), 503, 'A localização deste cadastro ainda não está instalada.');

        return $this->canonical($reference);
    }

    /** @return array<string,mixed> */
    public function record(string $id): array
    {
        foreach ($this->catalogue()['records'] as $record) {
            if ($record['id'] === $id) {
                return $record;
            }
        }

        throw ValidationException::withMessages(['geography_reference' => 'Localização não encontrada no catálogo.']);
    }

    /** @param array<string,mixed>|null $reference
     * @return array<string,mixed>|null
     */
    public function canonical(?array $reference): ?array
    {
        abort_unless($this->enabled(), 503, 'A localização administrativa ainda não está disponível.');
        if ($reference === null) {
            return null;
        }
        if (($reference['catalogue'] ?? null) !== $this->catalogue()['manifest']['source_sha256']) {
            throw ValidationException::withMessages(['geography_reference' => 'O catálogo foi alterado. Reabra a ficha antes de guardar.']);
        }
        $record = $this->record((string) ($reference['record_id'] ?? ''));
        if (! $record['selectable']) {
            throw ValidationException::withMessages(['geography_reference' => 'Este registo ou a sua hierarquia precisa de revisão. Escolha um nível superior confirmado.']);
        }

        return ['country' => 'MZ', 'catalogue' => $reference['catalogue'], 'record_id' => $record['id']];
    }

    /** @param array<string,mixed>|null $reference
     * @return array<string,mixed>|null
     */
    public function describe(?array $reference): ?array
    {
        if ($reference === null) {
            return null;
        }
        if (($reference['catalogue'] ?? null) !== $this->catalogue()['manifest']['source_sha256']) {
            return ['reference' => $reference, 'path' => [], 'requires_review' => true];
        }
        $record = $this->record((string) $reference['record_id']);
        $path = [$record];
        while ($record['parent_id'] !== null) {
            $record = $this->record($record['parent_id']);
            array_unshift($path, $record);
        }

        return ['reference' => $reference, 'path' => array_map(fn ($node) => $this->summary($node), $path), 'requires_review' => ! $path[count($path) - 1]['selectable']];
    }

    /** @param array<string,mixed> $record
     * @return array<string,mixed>
     */
    private function summary(array $record): array
    {
        return array_intersect_key($record, array_flip(['id', 'name', 'level', 'parent_id']));
    }

    /** @return array<string,mixed> */
    public function children(?string $parent, int $page = 1): array
    {
        if ($parent !== null && ! $this->record($parent)['selectable']) {
            throw ValidationException::withMessages(['parent' => 'Hierarquia pendente de revisão.']);
        }
        $records = array_values(array_filter($this->catalogue()['records'], fn ($record) => $record['selectable'] && $record['parent_id'] === $parent));
        usort($records, fn ($a, $b) => strcmp($a['name'], $b['name']) ?: strcmp($a['id'], $b['id']));

        return ['data' => array_map(fn ($record) => $this->summary($record), array_slice($records, ($page - 1) * 50, 50)), 'page' => $page, 'has_more' => count($records) > $page * 50, 'catalogue' => $this->catalogue()['manifest']['source_sha256']];
    }

    /** @return list<string> */
    public function descendants(string $id): array
    {
        $root = $this->record($id);
        if (! $root['selectable']) {
            throw ValidationException::withMessages(['location' => 'Localização pendente de revisão.']);
        }
        $prefix = array_slice($root['codes'], 0, $root['level']);

        return array_values(array_map(fn ($record) => $record['id'], array_filter($this->catalogue()['records'], fn ($record) => $record['selectable'] && array_slice($record['codes'], 0, count($prefix)) === $prefix)));
    }

    /** @param array<string,mixed> $filters
     * @return list<array<string,mixed>>
     */
    public function inconsistencies(array $filters): array
    {
        $search = trim($filters['search'] ?? '');
        $issue = $filters['issue'] ?? '';

        return array_values(array_filter($this->catalogue()['records'], fn ($record) => ! $record['selectable']
            && ($issue === '' || in_array($issue, $record['issues'], true))
            && ($search === '' || $record['id'] === $search || mb_stripos($record['name'], $search) !== false)));
    }
}