<?php

namespace App\Services;

use App\Models\EconomicCluster;
use App\Models\User;
use Illuminate\Database\Query\Builder;
use Illuminate\Support\Arr;
use Illuminate\Support\Facades\Crypt;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Validator;
use Illuminate\Support\Str;
use Illuminate\Validation\ValidationException;

final class ClusterCompetitiveness
{
    public const FORCES = ['rivalry', 'entrants', 'substitutes', 'suppliers', 'buyers'];

    public const FIELDS = ['evidence', 'source', 'period', 'rationale', 'limitations', 'opportunity'];

    private const SOURCE = 'cluster-competitiveness';

    private function events(string $cluster): Builder
    {
        return DB::table('audit_events')->where('source_system', self::SOURCE)
            ->where('entity_type', 'economic_clusters')->where('entity_id', $cluster);
    }

    /**
     * @return array<array-key, mixed>
     */
    private function decode(?\stdClass $event): array
    {
        return $event ? json_decode(Crypt::decryptString(json_decode($event->after_data, true, 512, JSON_THROW_ON_ERROR)['snapshot']), true, 512, JSON_THROW_ON_ERROR)
            : ['version' => 0, 'draft' => null, 'approved' => null];
    }

    /**
     * @return array<array-key, mixed>
     */
    public function current(string $cluster): array
    {
        return $this->decode($this->events($cluster)->orderByRaw("(after_data->>'version')::integer DESC")->first());
    }

    /**
     * @return array<array-key, mixed>
     */
    public function management(string $cluster): array
    {
        $state = $this->current($cluster);
        $state['editorial_enabled'] = $this->editorialEnabled();
        if (isset($state['workflow'])) {
            $record = EconomicCluster::findOrFail($cluster);
            $state['workflow']['fresh'] = hash_equals($state['workflow']['hash'], $this->editionHash($record, $state['draft']));
            $state['workflow']['independent_required'] = $this->independentRequired($state['workflow']);
        }
        $state['history'] = $this->events($cluster)->orderByRaw("(after_data->>'version')::integer DESC")->limit(50)->get()
            ->map(fn ($event) => ['version' => json_decode($event->after_data, true)['version'],
                'action' => $event->action, 'at' => $event->occurred_at, 'actor' => $event->actor_user_id])->all();

        return $state;
    }

    /**
     * @param  array<array-key, mixed>  $draft
     * @return array<array-key, mixed>
     */
    public function validateDraft(array $draft, string $cluster): array
    {
        $rules = ['version' => 'required|integer|in:1', 'clusterId' => 'required|string|in:'.$cluster,
            'sector' => 'present|nullable|string|max:200', 'region' => 'present|nullable|string|max:1000',
            'forces' => 'required|array:'.implode(',', self::FORCES)];
        foreach (self::FORCES as $force) {
            $rules["forces.$force"] = 'required|array:pressure,'.implode(',', self::FIELDS);
            $rules["forces.$force.pressure"] = 'present|nullable|in:low,medium,high';
            foreach (self::FIELDS as $field) {
                $rules["forces.$force.$field"] = 'present|nullable|string|max:5000';
            }
        }
        $clean = Validator::make($draft, $rules)->validate();
        $clean['version'] = 1;
        $clean['sector'] = trim($clean['sector'] ?? '');
        $clean['region'] = trim($clean['region'] ?? '');
        foreach (self::FORCES as $force) {
            foreach (['pressure', ...self::FIELDS] as $field) {
                $clean['forces'][$force][$field] = trim($clean['forces'][$force][$field] ?? '');
            }
        }

        return $clean;
    }

    /**
     * @param  array<array-key, mixed>|null  $draft
     */
    private function assertComplete(?array $draft): void
    {
        $missing = ! $draft || ! $draft['sector'] || ! $draft['region'];
        foreach (self::FORCES as $force) {
            $row = $draft['forces'][$force] ?? [];
            $missing = $missing || ! in_array($row['pressure'] ?? '', ['low', 'medium', 'high'], true);
            foreach (self::FIELDS as $field) {
                $missing = $missing || trim($row[$field] ?? '') === '';
            }
        }
        if ($missing) {
            throw ValidationException::withMessages(['approval' => 'Complete o âmbito e as evidências, fontes, períodos, justificação, limitações e oportunidades das cinco forças antes de aprovar.']);
        }
    }

    /** Reuse the portal's encrypted, append-only audit snapshots; no new schema or mutable publication fields.
     * @param  array<array-key, mixed>  $input
     * @return array<array-key, mixed>
     */
    public function change(EconomicCluster $cluster, int $actor, int $expected, string $action, array $input = []): array
    {
        abort_if(! in_array($action, ['saved', 'restored', 'approved', 'withdrawn'], true) && ! $this->editorialEnabled(), 503, 'Circuito editorial dos clusters ainda não activado.');

        return DB::transaction(function () use ($cluster, $actor, $expected, $action, $input) {
            $cluster = EconomicCluster::whereKey($cluster->id)->lockForUpdate()->firstOrFail();
            $before = $this->current($cluster->id);
            abort_if($before['version'] !== $expected, 409, 'A análise foi alterada. Conserve os campos actuais e compare a versão do servidor antes de voltar a guardar.');
            $state = $before;
            if ($this->editorialEnabled() || isset($before['workflow'])) {
                abort_unless($this->editorialEnabled(), 503, 'Reactive o circuito editorial para continuar esta análise; o histórico e a publicação foram conservados.');
                $state = $this->editorialChange($cluster, $actor, $action, $input, $before);
            } elseif ($action === 'saved') {
                $state['draft'] = $this->validateDraft($input['draft'], $cluster->id);
            } elseif ($action === 'restored') {
                $event = $this->events($cluster->id)->where('after_data->version', $input['revision'])->first();
                abort_unless($event !== null, 404);
                $state['draft'] = $this->decode($event)['draft'];
            } elseif ($action === 'approved') {
                $this->assertComplete($state['draft']);
                $state['approved'] = ['draft' => $state['draft'], 'at' => now()->toISOString(), 'actor' => $actor,
                    'version' => $expected + 1, 'evidence' => $input['reason']];
            } elseif ($action === 'withdrawn') {
                $state['approved'] = null;
            } else {
                throw new \LogicException('Unsupported competitiveness action');
            }
            $state['version']++;
            $eventId = (string) Str::uuid();
            DB::table('audit_events')->insert(['id' => $eventId, 'source_system' => self::SOURCE, 'entity_type' => 'economic_clusters',
                'entity_id' => $cluster->id, 'external_id' => $cluster->id.':'.$state['version'], 'actor_user_id' => $actor,
                'action' => $action, 'data_classification' => 'restricted',
                'before_data' => json_encode(['version' => $before['version']], JSON_THROW_ON_ERROR),
                'after_data' => json_encode(['version' => $state['version'], 'editorial_state' => $state['workflow']['state'] ?? null, 'restored_from' => $input['revision'] ?? null,
                    'reason' => Crypt::encryptString($input['reason'] ?? ''),
                    'snapshot' => Crypt::encryptString(json_encode($state, JSON_THROW_ON_ERROR))], JSON_THROW_ON_ERROR)]);
            if ($this->editorialEnabled()) {
                $user = User::findOrFail($actor);
                app(PortalEditorialNativeNotices::class)->emit($user, $eventId, $state['workflow']['contributors']);
            }

            return $this->management($cluster->id);
        });
    }

    /**
     * @return array<array-key, mixed>|null
     */
    public function publicData(string $cluster): ?array
    {
        $state = $this->current($cluster);
        $approved = isset($state['workflow']) ? $state['published'] : $state['approved'];

        // Explicit projection: never return editor identity, approval evidence, history or the unapproved draft.
        return $approved ? ['draft' => $approved['draft'], 'version' => $approved['version'], 'at' => $approved['at']] : null;
    }

    public function editorialEnabled(): bool
    {
        return (bool) config('editorial_workflow.cluster_competitiveness');
    }

    /** @param array<array-key,mixed>|null $draft */
    private function editionHash(EconomicCluster $cluster, ?array $draft): string
    {
        $context = Arr::only($cluster->getAttributes(), ['id', 'code', 'name', 'sector', 'status', 'primary_territory_id', 'territory_version']);

        return hash('sha256', json_encode(Arr::sortRecursive(['context' => $context, 'draft' => $draft]), JSON_THROW_ON_ERROR));
    }

    /** @param array<array-key,mixed> $input
     * @param  array<array-key,mixed>  $state
     * @return array<array-key,mixed>
     */
    private function editorialChange(EconomicCluster $cluster, int $actorId, string $action, array $input, array $state): array
    {
        $actor = User::whereKey($actorId)->firstOrFail();
        abort_unless($actor->can('manage-portal') && ! app(PortalProfileAccess::class)->has($actor, 'auditor'), 403);
        abort_unless(app(PortalProfileAccess::class)->mfa($actor), 403, 'Confirme o MFA na sessão existente.');
        if (! isset($state['workflow'])) {
            abort_unless(in_array($action, ['saved', 'restored', 'withdrawn'], true), 409, 'Guarde uma edição privada antes de iniciar o novo circuito.');
            // An accepted legacy publication remains public; no retrospective approval is invented.
            $state['published'] = $state['approved'];
            $state['approved'] = null;
            $state['workflow'] = ['state' => 'draft', 'edition' => $state['version'], 'contributors' => [], 'approval' => null,
                'hash' => $this->editionHash($cluster, $state['draft']), 'independent_required' => false];
        }
        $workflow = $state['workflow'];
        if (in_array($action, ['saved', 'restored'], true)) {
            if ($action === 'saved') {
                $state['draft'] = $this->validateDraft($input['draft'], $cluster->id);
                $restoredContributors = [];
            } else {
                $event = $this->events($cluster->id)->where('after_data->version', $input['revision'])->first();
                abort_unless($event !== null, 404);
                $restored = $this->decode($event);
                $state['draft'] = $restored['draft'];
                $restoredContributors = $restored['workflow']['contributors'] ?? [$event->actor_user_id];
            }
            $state['approved'] = null;
            $state['workflow'] = ['state' => 'draft', 'edition' => $state['version'] + 1,
                'contributors' => array_values(array_unique([...($workflow['state'] === 'published' ? [] : $workflow['contributors']), ...$restoredContributors, $actorId])),
                'hash' => $this->editionHash($cluster, $state['draft']), 'approval' => null,
                'independent_required' => $this->independentRequired($workflow)];

            return $state;
        }
        validator($input, ['reason' => 'required|string|min:10|max:3000'])->validate();
        $allowed = ['submitted' => ['draft', 'returned'], 'review_started' => ['submitted'], 'returned' => ['in_review'], 'rejected' => ['in_review'],
            'approved' => ['in_review'], 'published' => ['approved'], 'archived' => ['draft', 'submitted', 'in_review', 'returned', 'rejected', 'approved', 'published'], 'withdrawn' => ['draft', 'submitted', 'in_review', 'returned', 'rejected', 'approved', 'published', 'archived']];
        abort_unless(isset($allowed[$action]) && in_array($workflow['state'], $allowed[$action], true), 409, 'Transição incompatível com o estado da edição.');
        if (in_array($action, ['submitted', 'approved', 'published'], true)) {
            abort_unless(hash_equals($workflow['hash'], $this->editionHash($cluster, $state['draft'])), 409, 'O contexto do cluster mudou. Guarde nova edição e volte a conferir.');
        }
        if ($action === 'submitted' || $action === 'approved') {
            $this->assertComplete($state['draft']);
        }
        if ($action === 'approved') {
            abort_if($this->independentRequired($workflow) && in_array($actorId, $workflow['contributors'], true), 403, 'Aprovação independente necessária para esta edição.');
            $workflow['approval'] = ['actor' => $actorId, 'edition' => $workflow['edition'], 'hash' => $workflow['hash'], 'at' => now()->toISOString(), 'reason' => $input['reason']];
            $state['approved'] = ['draft' => $state['draft'], 'at' => now()->toISOString(), 'actor' => $actorId, 'version' => $state['version'] + 1, 'evidence' => $input['reason']];
        }
        if ($action === 'published') {
            $decision = $workflow['approval'];
            abort_unless($decision && $decision['edition'] === $workflow['edition'] && hash_equals($decision['hash'], $workflow['hash']), 422, 'Aprovação desta edição necessária.');
            $reviewer = User::whereKey($decision['actor'])->first();
            abort_unless($reviewer && $reviewer->can('manage-portal') && ! app(PortalProfileAccess::class)->has($reviewer, 'auditor'), 403, 'Autoridade da aprovação revogada.');
            abort_if($this->independentRequired($workflow) && in_array($reviewer->id, $workflow['contributors'], true), 403, 'Aprovação independente necessária.');
            $state['published'] = [...$state['approved'], 'at' => now()->toISOString(), 'version' => $state['version'] + 1];
        }
        if ($action === 'withdrawn' || ($action === 'archived' && $workflow['state'] === 'published')) {
            $state['published'] = null;
        }
        $workflow['state'] = match ($action) {
            'submitted' => 'submitted', 'review_started' => 'in_review', 'returned' => 'returned', 'rejected' => 'rejected',
            'approved' => 'approved', 'published' => 'published', 'archived' => 'archived', 'withdrawn' => $workflow['state'] === 'published' ? 'archived' : $workflow['state'],
        };
        $state['workflow'] = $workflow;

        return $state;
    }

    /** @param array<array-key,mixed> $workflow */
    private function independentRequired(array $workflow): bool
    {
        return ($workflow['independent_required'] ?? false) || in_array('cluster_competitiveness', config('editorial_workflow.independent_approval.kinds', []), true);
    }
}