<?php

declare(strict_types=1);

namespace App\Services\FormBuilder;

use App\Enums\FormBuilder\FormFieldType;
use App\Enums\FormBuilder\FormSchemaSnapshotMode;
use App\Enums\FormBuilder\FormSubmissionReviewStatus;
use App\Enums\FormBuilder\FormSubmissionStatus;
use App\Events\FormBuilder\FormSubmissionCreated;
use App\Events\FormBuilder\FormSubmissionDeleted;
use App\Events\FormBuilder\FormSubmissionDraftUpdated;
use App\Events\FormBuilder\FormSubmissionReviewed;
use App\Events\FormBuilder\FormSubmissionSubmitted;
use App\Exceptions\FormBuilder\FrozenSchemaException;
use App\Models\FormBuilder\FormSchema;
use App\Models\FormBuilder\FormSubmission;
use App\Models\FormBuilder\FormSubmissionDelegation;
use App\Models\FormBuilder\FormValue;
use App\Models\User;
use App\Support\Json\JsonCanonicalizer;
use Illuminate\Database\Eloquent\Model;
use Illuminate\Support\Facades\DB;

/**
 * Submission lifecycle: draft → submitted → reviewed per ARCH §4.3, §15.
 * Fires domain events so webhooks / listeners / activity attach without
 * tight coupling (ARCH §18.5).
 */
final class FormSubmissionService
{
    public function __construct(
        private readonly FormLocaleResolver $localeResolver,
        private readonly FormValueService $valueService,
        private readonly FormFieldBindingService $bindingService,
        private readonly FormFieldValidationRuleService $validationRuleService,
        private readonly FormFieldConfigService $configService,
        private readonly FormFieldConditionalLogicService $conditionalLogicService,
        private readonly FormFieldOptionService $optionService,
    ) {}

    /**
     * @param  array<string, mixed>  $context  opened_at / public_submitter_* / is_test / idempotency_key / event_id
     *
     * `event_id` may be supplied for flows where the schema is org-owned (not
     * event-owned) and the route has no `{event}` parameter for the
     * FormSubmissionObserver fallback to pick up — e.g. the artist-advance
     * portal where the engagement is the source of truth per WS-4
     * (ARCH-FORM-BUILDER §17.3 footnote).
     */
    public function createDraft(FormSchema $schema, ?Model $subject, ?User $submitter, array $context = []): FormSubmission
    {
        if (isset($context['idempotency_key'])) {
            $existing = FormSubmission::query()
                ->where('form_schema_id', $schema->id)
                ->where('idempotency_key', $context['idempotency_key'])
                ->first();
            if ($existing !== null) {
                return $existing;
            }
        }

        return DB::transaction(function () use ($schema, $subject, $submitter, $context): FormSubmission {
            $submission = new FormSubmission;
            $submission->form_schema_id = $schema->id;
            if ($subject !== null) {
                $submission->subject_type = $this->morphKeyFor($subject);
                $submission->subject_id = (string) $subject->getKey();
            }
            if (isset($context['event_id']) && is_string($context['event_id']) && $context['event_id'] !== '') {
                $submission->event_id = $context['event_id'];
            }
            $submission->submitted_by_user_id = $submitter?->id;
            $submission->status = FormSubmissionStatus::DRAFT->value;
            $submission->is_test = (bool) ($context['is_test'] ?? false);
            $submission->opened_at = $context['opened_at'] ?? now();
            $submission->schema_version_at_open = (int) $schema->version;
            $submission->idempotency_key = $context['idempotency_key'] ?? null;
            $submission->public_submitter_name = $context['public_submitter_name'] ?? null;
            $submission->public_submitter_email = $context['public_submitter_email'] ?? null;
            $submission->public_submitter_ip = $context['public_submitter_ip'] ?? null;
            $submission->submitted_in_locale = $this->localeResolver->resolve($schema, $submitter);
            $submission->save();

            FormSubmissionCreated::dispatch($submission);

            return $submission->refresh();
        });
    }

    /**
     * @param  array<string, mixed>  $values  slug → value
     */
    public function saveDraft(FormSubmission $submission, array $values, ?User $actor): FormSubmission
    {
        $this->assertWritable($submission);

        DB::transaction(function () use ($submission, $values, $actor): void {
            $this->valueService->upsertMany($submission, $values, $actor);
            $submission->first_interacted_at ??= now();
            $submission->auto_save_count = (int) $submission->auto_save_count + 1;
            $submission->save();
        });

        FormSubmissionDraftUpdated::dispatch($submission);

        return $submission->refresh();
    }

    public function submit(FormSubmission $submission, ?User $actor): FormSubmission
    {
        $this->assertWritable($submission);

        $result = DB::transaction(function () use ($submission): FormSubmission {
            $schema = $submission->schema;

            $submission->status = FormSubmissionStatus::SUBMITTED->value;
            $submission->submitted_at = now();
            $submission->schema_version_at_submit = $schema->version;

            if ($schema->snapshot_mode !== FormSchemaSnapshotMode::NEVER) {
                // RFC-WS-6 session 2.7: schema_snapshot is audit-immutable;
                // canonicalize before storage so MySQL JSON-column round-trip
                // can never corrupt audit-replay diffs or webhook signing.
                $submission->schema_snapshot = JsonCanonicalizer::canonicalize(
                    $this->buildSnapshot($schema),
                );
            }

            if ($submission->opened_at !== null) {
                // abs + int cast: Carbon's diffInSeconds returns signed fractional
                // seconds, and the column is unsignedInteger.
                $submission->submission_duration_seconds = (int) abs(now()->diffInSeconds($submission->opened_at));
            }

            $submission->save();

            // Compute SIGNATURE hashes on submit (ARCH §9). One query, scalar-safe.
            $this->finaliseSignatureValues($submission);

            return $submission;
        });

        // RFC-WS-6 §5 (O2) — fire AFTER commit. Pre-commit dispatch let
        // queued listeners (tag sync, shifts, webhooks, mailables) enqueue
        // with state that may never persist on rollback. The new
        // ApplyBindings two-transaction pattern (RFC Q4) requires the
        // outer commit to land before any listener observes the submission.
        FormSubmissionSubmitted::dispatch($result->refresh());

        return $result->refresh();
    }

    public function review(FormSubmission $submission, FormSubmissionReviewStatus $status, ?string $notes, User $reviewer): FormSubmission
    {
        return DB::transaction(function () use ($submission, $status, $notes, $reviewer): FormSubmission {
            $submission->review_status = $status->value;
            $submission->review_notes = $notes;
            $submission->reviewed_by_user_id = $reviewer->id;
            $submission->reviewed_at = now();
            $submission->save();

            FormSubmissionReviewed::dispatch($submission, $reviewer);

            return $submission->refresh();
        });
    }

    public function delegate(FormSubmission $submission, User $delegatee, User $delegator, ?string $message = null): FormSubmissionDelegation
    {
        /** @var FormSubmissionDelegation $delegation */
        $delegation = FormSubmissionDelegation::create([
            'form_submission_id' => $submission->id,
            'delegated_to_user_id' => $delegatee->id,
            'delegated_by_user_id' => $delegator->id,
            'granted_at' => now(),
            'message' => $message,
        ]);

        activity()
            ->performedOn($submission)
            ->causedBy($delegator)
            ->withProperties(['delegated_to_user_id' => $delegatee->id])
            ->log('submission.delegated');

        return $delegation;
    }

    public function revokeDelegation(FormSubmissionDelegation $delegation, User $actor): FormSubmissionDelegation
    {
        $delegation->revoked_at = now();
        $delegation->save();

        activity()
            ->performedOn($delegation->submission ?? $delegation)
            ->causedBy($actor)
            ->log('submission.delegation_revoked');

        return $delegation->refresh();
    }

    public function delete(FormSubmission $submission, User $actor): void
    {
        DB::transaction(function () use ($submission, $actor): void {
            $submission->delete();
            FormSubmissionDeleted::dispatch($submission);
            activity()->performedOn($submission)->causedBy($actor)->log('submission.deleted');
        });
    }

    private function assertWritable(FormSubmission $submission): void
    {
        $schema = $submission->schema;
        if (
            $submission->status === FormSubmissionStatus::SUBMITTED
            && $schema->freeze_on_submit
        ) {
            throw FrozenSchemaException::forSchema($schema->id);
        }
    }

    /**
     * @return array<string, mixed>
     */
    private function buildSnapshot(FormSchema $schema): array
    {
        $schema->loadMissing(['fields.bindings', 'fields.validationRules', 'fields.configs', 'fields.options', 'sections']);

        return [
            'schema_version' => $schema->version,
            'snapshot_created_at' => now()->toIso8601String(),
            'schema' => [
                'name' => $schema->name,
                'slug' => $schema->slug,
                'purpose' => $schema->purpose instanceof \BackedEnum ? $schema->purpose->value : $schema->purpose,
                'description' => $schema->description,
                'locale' => $schema->locale,
                'freeze_on_submit' => (bool) $schema->freeze_on_submit,
                'section_level_submit' => (bool) $schema->section_level_submit,
                'consent_version' => $schema->consent_version,
                'settings' => $schema->settings,
            ],
            'sections' => $schema->sections->map(fn ($s) => [
                'id' => $s->id,
                'slug' => $s->slug,
                'name' => $s->name,
                'sort_order' => $s->sort_order,
                'depends_on_section_slug' => $this->sectionSlug($schema, $s->depends_on_section_id),
                'required_for_schema_submit' => (bool) $s->required_for_schema_submit,
            ])->toArray(),
            'fields' => $schema->fields->map(fn ($f) => [
                'id' => $f->id,
                'slug' => $f->slug,
                'field_type' => $f->field_type,
                'label' => $f->label,
                'help_text' => $f->help_text,
                'section_slug' => $this->sectionSlug($schema, $f->form_schema_section_id),
                'options' => $f->options->isNotEmpty()
                    ? $this->optionService->toJsonShape($f->options)
                    : null,
                'validation_rules' => $this->validationRuleService->toJsonShape($f->validationRules),
                'configs' => $this->configService->toJsonShape($f->configs),
                'is_required' => (bool) $f->is_required,
                'is_filterable' => (bool) $f->is_filterable,
                'is_pii' => (bool) $f->is_pii,
                // WS-6 RFC Q6 — singular 'binding' kept for legacy webhook /
                // GDPR readers; plural 'bindings' carries every binding on
                // the field with id, merge_strategy, trust_level,
                // is_identity_key for PersonProvisioner / BindingConflictResolver
                // / FormBindingApplicator. Single helper to avoid duplicated
                // dynamic-property access inside this lambda.
                ...$this->bindingService->snapshotShapesFor($f->bindings),
                'conditional_logic' => $this->conditionalLogicService->toJsonShape($f->rootConditionalLogicGroup()),
                'translations' => $this->stripOptionsFromTranslations($f->translations),
                'value_storage_hint' => $f->value_storage_hint instanceof \BackedEnum ? $f->value_storage_hint->value : $f->value_storage_hint,
                'sort_order' => $f->sort_order,
            ])->toArray(),
        ];
    }

    /**
     * Per-locale `options[]` parallel arrays moved onto each
     * form_field_options.translations row in WS-5d. The field's own
     * translations bag retains only label/help_text per locale; strip
     * any residual options key defensively (commit 2 backfill should
     * already have done so on existing rows).
     *
     * @return array<string, mixed>|null
     */
    private function stripOptionsFromTranslations(mixed $translations): ?array
    {
        if (! is_array($translations) || $translations === []) {
            return null;
        }
        $clean = [];
        foreach ($translations as $locale => $bag) {
            if (is_array($bag)) {
                unset($bag['options']);
                if ($bag !== []) {
                    $clean[$locale] = $bag;
                }
            } else {
                $clean[$locale] = $bag;
            }
        }

        return $clean === [] ? null : $clean;
    }

    private function sectionSlug(FormSchema $schema, ?string $sectionId): ?string
    {
        if ($sectionId === null) {
            return null;
        }

        return $schema->sections->firstWhere('id', $sectionId)?->slug;
    }

    private function finaliseSignatureValues(FormSubmission $submission): void
    {
        $signatureValues = FormValue::query()
            ->with('field')
            ->where('form_submission_id', $submission->id)
            ->get()
            ->filter(fn ($v) => $v->field?->field_type === FormFieldType::SIGNATURE->value);

        foreach ($signatureValues as $value) {
            $raw = $value->value ?? [];
            if (! is_array($raw) || ! isset($raw['file_path'])) {
                continue;
            }

            $payload = array_merge([
                'signed_at' => now()->toIso8601String(),
                'signer_name' => $submission->public_submitter_name ?? optional($submission->submittedBy)->name,
                'signer_ip' => $submission->public_submitter_ip ?? request()?->ip(),
            ], $raw);

            $disk = $raw['disk'] ?? config('filesystems.default');
            $bytes = '';
            try {
                if (\Illuminate\Support\Facades\Storage::disk($disk)->exists($raw['file_path'])) {
                    $bytes = (string) \Illuminate\Support\Facades\Storage::disk($disk)->get($raw['file_path']);
                }
            } catch (\Throwable) {
                $bytes = '';
            }

            $hashInput = $bytes.($payload['signed_at'] ?? '').($payload['signer_name'] ?? '').($payload['signer_ip'] ?? '');
            $payload['hash'] = 'sha256:'.hash('sha256', $hashInput);
            $payload['disk'] = $disk;

            $value->value = $payload;
            $value->save();
        }
    }

    private function morphKeyFor(Model $model): string
    {
        $alias = $model->getMorphClass();

        return (string) $alias;
    }
}