<?php

declare(strict_types=1);

if (!defined('ABSPATH')) {
    exit;
}

final class TheDotDevAgenticBridge_Fix_Engine
{
    private const MAX_AUDIT_LOG = 50;

    /** @return array<string, string> */
    public static function finding_to_resolver_map(): array
    {
        return TheDotDevAgenticBridge_Resolver_Registry::engine_finding_map();
    }

    /** @return array<string, mixed>|null */
    public static function coverage_for_finding(string $finding_id): ?array
    {
        return TheDotDevAgenticBridge_Resolver_Registry::coverage_for_finding($finding_id);
    }

    public static function apply_available_for_finding(string $finding_id): bool
    {
        $coverage = self::coverage_for_finding($finding_id);
        return self::is_enabled() && is_array($coverage) && !empty($coverage['applyAvailable']);
    }

    public static function register_runtime_hooks(): void
    {
        add_action('wp_head', [self::class, 'render_schema_head'], 2);
    }

    public static function is_enabled(): bool
    {
        return class_exists('TheDotDevAgenticBridge_Entitlements') && TheDotDevAgenticBridge_Entitlements::can_suggested_fixes();
    }

    /** @return array{ok: bool, error: string, preview: array<string, mixed>} */
    public static function preview_for_finding(string $finding_id): array
    {
        if (!self::is_enabled()) {
            return ['ok' => false, 'error' => 'engine_disabled', 'preview' => []];
        }

        $resolver_id = self::finding_to_resolver_map()[$finding_id] ?? '';
        if ($resolver_id === '') {
            return ['ok' => false, 'error' => 'unsupported_finding', 'preview' => []];
        }

        $preview = match ($resolver_id) {
            'publish_artifacts' => self::preview_publish_artifacts($finding_id),
            'add_home_schema' => self::preview_home_schema($finding_id),
            default => ['ok' => false, 'error' => 'unsupported_resolver'],
        };

        if (empty($preview['ok'])) {
            return ['ok' => false, 'error' => (string) ($preview['error'] ?? 'preview_failed'), 'preview' => []];
        }

        $id = function_exists('wp_generate_uuid4') ? wp_generate_uuid4() : ('preview-' . gmdate('YmdHis'));
        $body = wp_json_encode($preview['changes'] ?? [], JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE);
        $fingerprint = hash('sha256', is_string($body) ? $body : '');
        $record = [
            'id' => $id,
            'state' => 'ready',
            'fingerprint' => $fingerprint,
            'findingId' => $finding_id,
            'resolverId' => $resolver_id,
            'generatedAt' => gmdate('c'),
            'summary' => (string) ($preview['summary'] ?? ''),
            'changes' => $preview['changes'] ?? [],
            'deferred' => !empty($preview['deferred']),
            'deferReason' => (string) ($preview['deferReason'] ?? ''),
            'currentFingerprint' => self::snapshot_fingerprint(self::capture_undo_snapshot()),
        ];

        TheDotDevAgenticBridge_Storage::update(['fix_engine_pending_preview' => $record]);

        return ['ok' => true, 'error' => '', 'preview' => $record];
    }

    /** @return array{ok: bool, error: string} */
    public static function approve_preview(string $preview_id, string $fingerprint, int $actor_id): array
    {
        $settings = TheDotDevAgenticBridge_Storage::get();
        $preview = is_array($settings['fix_engine_pending_preview'] ?? null) ? $settings['fix_engine_pending_preview'] : null;
        if (!is_array($preview) || !hash_equals((string) ($preview['id'] ?? ''), $preview_id) || !hash_equals((string) ($preview['fingerprint'] ?? ''), $fingerprint)) {
            return ['ok' => false, 'error' => 'preview_mismatch'];
        }
        if (!hash_equals((string) ($preview['currentFingerprint'] ?? ''), self::snapshot_fingerprint(self::capture_undo_snapshot()))) {
            return ['ok' => false, 'error' => 'stale_preview'];
        }
        if (!empty($preview['deferred'])) {
            return ['ok' => false, 'error' => 'deferred'];
        }
        if (($preview['state'] ?? 'ready') === 'approved') {
            return ['ok' => false, 'error' => 'already_approved'];
        }
        $preview['state'] = 'approved';
        $preview['approvedBy'] = $actor_id;
        $preview['approvedAt'] = gmdate('c');
        TheDotDevAgenticBridge_Storage::update(['fix_engine_pending_preview' => $preview]);
        return ['ok' => true, 'error' => ''];
    }

    /** @return array{ok: bool, error: string} */
    public static function apply_preview(string $preview_id, string $fingerprint): array
    {
        if (!self::is_enabled()) {
            return ['ok' => false, 'error' => 'engine_disabled'];
        }
        $settings = TheDotDevAgenticBridge_Storage::get();
        $preview = is_array($settings['fix_engine_pending_preview'] ?? null) ? $settings['fix_engine_pending_preview'] : null;
        if (!is_array($preview)) {
            return ['ok' => false, 'error' => 'missing_preview'];
        }
        if (!hash_equals((string) ($preview['id'] ?? ''), $preview_id)) {
            return ['ok' => false, 'error' => 'preview_mismatch'];
        }
        if (!hash_equals((string) ($preview['fingerprint'] ?? ''), $fingerprint)) {
            return ['ok' => false, 'error' => 'preview_mismatch'];
        }
        if (!empty($preview['deferred'])) {
            return ['ok' => false, 'error' => 'deferred'];
        }
        if (($preview['state'] ?? 'ready') !== 'approved' || empty($preview['approvedAt'])) {
            return ['ok' => false, 'error' => 'approval_required'];
        }

        if (!hash_equals((string) ($preview['currentFingerprint'] ?? ''), self::snapshot_fingerprint(self::capture_undo_snapshot()))) {
            return ['ok' => false, 'error' => 'stale_preview'];
        }

        $resolver_id = (string) ($preview['resolverId'] ?? '');
        $snapshot = self::capture_undo_snapshot();
        $result = match ($resolver_id) {
            'publish_artifacts' => self::apply_publish_artifacts(),
            'add_home_schema' => self::apply_home_schema(),
            default => ['ok' => false, 'error' => 'unsupported_resolver'],
        };

        if (empty($result['ok'])) {
            return ['ok' => false, 'error' => (string) ($result['error'] ?? 'apply_failed')];
        }

        $verification = self::rescan((string) ($preview['findingId'] ?? ''));
        $audit = self::append_audit([
            'findingId' => (string) ($preview['findingId'] ?? ''),
            'resolverId' => $resolver_id,
            'summary' => (string) ($preview['summary'] ?? ''),
            'changes' => is_array($preview['changes'] ?? null) ? $preview['changes'] : [],
            'undoSnapshot' => $snapshot,
            'actorId' => get_current_user_id(),
            'approvedBy' => (int) ($preview['approvedBy'] ?? 0),
            'approvedAt' => (string) ($preview['approvedAt'] ?? ''),
            'appliedFingerprint' => self::snapshot_fingerprint(self::capture_undo_snapshot()),
            'verification' => $verification,
        ]);

        TheDotDevAgenticBridge_Storage::update(['fix_engine_pending_preview' => null]);
        return ['ok' => true, 'error' => '', 'auditId' => $audit];
    }

    /** @return array{ok: bool, error: string} */
    public static function undo(string $audit_id): array
    {
        $settings = TheDotDevAgenticBridge_Storage::get();
        $log = is_array($settings['fix_engine_audit_log'] ?? null) ? $settings['fix_engine_audit_log'] : [];
        foreach ($log as $idx => $entry) {
            if (!is_array($entry)) {
                continue;
            }
            if (!hash_equals((string) ($entry['id'] ?? ''), $audit_id)) {
                continue;
            }
            if (!empty($entry['undoneAt'])) {
                return ['ok' => false, 'error' => 'already_undone'];
            }
            $snapshot = is_array($entry['undoSnapshot'] ?? null) ? $entry['undoSnapshot'] : [];
            if (!hash_equals((string) ($entry['appliedFingerprint'] ?? ''), self::snapshot_fingerprint(self::capture_undo_snapshot()))) {
                return ['ok' => false, 'error' => 'restore_refused'];
            }
            self::restore_undo_snapshot($snapshot);
            $log[$idx]['undoneAt'] = gmdate('c');
            TheDotDevAgenticBridge_Storage::update(['fix_engine_audit_log' => $log]);
            self::rescan((string) ($entry['findingId'] ?? ''));
            return ['ok' => true, 'error' => ''];
        }

        return ['ok' => false, 'error' => 'audit_not_found'];
    }

    /** @return list<array<string, mixed>> */
    public static function audit_log(): array
    {
        $log = TheDotDevAgenticBridge_Storage::get()['fix_engine_audit_log'] ?? [];
        return is_array($log) ? $log : [];
    }

    /** @param array<string, mixed> $entry */
    public static function restore_available(array $entry): bool
    {
        if (!empty($entry['undoneAt']) || empty($entry['id'])) {
            return false;
        }
        return hash_equals((string) ($entry['appliedFingerprint'] ?? ''), self::snapshot_fingerprint(self::capture_undo_snapshot()));
    }

    /** @return array<string, mixed>|null */
    public static function pending_preview(): ?array
    {
        $preview = TheDotDevAgenticBridge_Storage::get()['fix_engine_pending_preview'] ?? null;
        return is_array($preview) ? $preview : null;
    }

    public static function render_schema_head(): void
    {
        $settings = TheDotDevAgenticBridge_Storage::get();
        if (empty($settings['fix_engine_schema_enabled'])) {
            return;
        }
        $nodes = is_array($settings['fix_engine_schema_nodes'] ?? null) ? $settings['fix_engine_schema_nodes'] : [];
        if ($nodes === []) {
            return;
        }
        $graph = ['@context' => 'https://schema.org', '@graph' => array_values($nodes)];
        $json = wp_json_encode($graph, JSON_HEX_TAG | JSON_HEX_AMP | JSON_HEX_APOS | JSON_HEX_QUOT | JSON_INVALID_UTF8_SUBSTITUTE);
        if (!is_string($json) || $json === '') {
            return;
        }
        // wp_get_inline_script_tag retains valid JSON-LD while its JSON_HEX payload cannot terminate the script element.
        echo wp_get_inline_script_tag($json, ['type' => 'application/ld+json']); // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped -- WordPress-generated script element with JSON_HEX payload.
    }

    /** @return array<string, mixed> */
    private static function preview_publish_artifacts(string $finding_id): array
    {
        $draft = TheDotDevAgenticBridge_Artifacts::generate_preview_draft();
        if (!$draft['ok']) {
            return ['ok' => false, 'error' => 'artifact_preview_failed'];
        }
        $payload = is_array($draft['draft'] ?? null) ? $draft['draft'] : [];
        return [
            'ok' => true,
            'summary' => __('Publish local /llms.txt and /agent-map.json from reviewed content metadata.', 'agentic-bridge'),
            'changes' => [
                'findingId' => $finding_id,
                'llmsPreviewBytes' => strlen((string) ($payload['llms_txt'] ?? '')),
                'agentMapEntryCount' => count(is_array($payload['agent_map']['entries'] ?? null) ? $payload['agent_map']['entries'] : []),
                'routes' => ['/llms.txt', '/agent-map.json'],
            ],
        ];
    }

    /** @return array<string, mixed> */
    private static function preview_home_schema(string $finding_id): array
    {
        $owner = TheDotDevAgenticBridge_Resolver_Registry::detect_seo_owner_vocabulary();
        if (($owner['owner'] ?? 'none') !== 'none') {
            return ['ok' => true, 'summary' => __('Homepage schema is deferred because another SEO plugin owns this output.', 'agentic-bridge'), 'changes' => ['findingId' => $finding_id, 'seoOwner' => $owner['owner']], 'deferred' => true, 'deferReason' => 'seo_plugin_owner'];
        }
        $analysis = self::homepage_schema_analysis();
        $types = is_array($analysis['types'] ?? null) ? $analysis['types'] : [];
        $normalized = array_map(static fn($item): string => strtolower((string) $item), $types);
        $missing = [];
        if (!in_array('organization', $normalized, true)) {
            $missing[] = 'Organization';
        }
        if (!in_array('website', $normalized, true)) {
            $missing[] = 'WebSite';
        }

        if ($missing === []) {
            return ['ok' => false, 'error' => 'schema_already_present'];
        }

        return [
            'ok' => true,
            'summary' => __('Add missing homepage Organization/WebSite JSON-LD without changing existing SEO plugin schema.', 'agentic-bridge'),
            'changes' => [
                'findingId' => $finding_id,
                'missingTypes' => $missing,
                'seoOwner' => (string) ($owner['owner'] ?? 'none'),
                'coexistOnly' => true,
            ],
        ];
    }

    /** @return array{ok: bool, error: string} */
    private static function apply_publish_artifacts(): array
    {
        $result = TheDotDevAgenticBridge_Artifacts::publish_from_preview();
        if (!$result['ok']) {
            return ['ok' => false, 'error' => (string) ($result['error'] ?? 'publish_failed')];
        }
        flush_rewrite_rules();
        return ['ok' => true, 'error' => ''];
    }

    /** @return array{ok: bool, error: string} */
    private static function apply_home_schema(): array
    {
        $analysis = self::homepage_schema_analysis();
        $types = is_array($analysis['types'] ?? null) ? $analysis['types'] : [];
        $normalized = array_map(static fn($item): string => strtolower((string) $item), $types);
        $nodes = [];

        if (!in_array('organization', $normalized, true)) {
            $nodes[] = [
                '@type' => 'Organization',
                '@id' => untrailingslashit(home_url('/')) . '#organization',
                'name' => get_bloginfo('name'),
                'url' => home_url('/'),
            ];
        }
        if (!in_array('website', $normalized, true)) {
            $nodes[] = [
                '@type' => 'WebSite',
                '@id' => untrailingslashit(home_url('/')) . '#website',
                'name' => get_bloginfo('name'),
                'url' => home_url('/'),
            ];
        }
        if ($nodes === []) {
            return ['ok' => false, 'error' => 'schema_already_present'];
        }
        TheDotDevAgenticBridge_Storage::update([
            'fix_engine_schema_enabled' => true,
            'fix_engine_schema_nodes' => $nodes,
        ]);
        return ['ok' => true, 'error' => ''];
    }

    /** @return array<string, mixed> */
    private static function capture_undo_snapshot(): array
    {
        $settings = TheDotDevAgenticBridge_Storage::get();
        return [
            'artifacts_published' => !empty($settings['artifacts_published']),
            'last_known_good' => is_array($settings['last_known_good'] ?? null) ? $settings['last_known_good'] : [],
            'artifact_preview_draft' => $settings['artifact_preview_draft'] ?? null,
            'artifact_revisions' => is_array($settings['artifact_revisions'] ?? null) ? $settings['artifact_revisions'] : [],
            'fix_engine_schema_enabled' => !empty($settings['fix_engine_schema_enabled']),
            'fix_engine_schema_nodes' => is_array($settings['fix_engine_schema_nodes'] ?? null) ? $settings['fix_engine_schema_nodes'] : [],
        ];
    }

    /** @param array<string, mixed> $snapshot */
    private static function restore_undo_snapshot(array $snapshot): void
    {
        TheDotDevAgenticBridge_Storage::update([
            'artifacts_published' => !empty($snapshot['artifacts_published']),
            'last_known_good' => is_array($snapshot['last_known_good'] ?? null) ? $snapshot['last_known_good'] : [],
            'artifact_preview_draft' => $snapshot['artifact_preview_draft'] ?? null,
            'artifact_revisions' => is_array($snapshot['artifact_revisions'] ?? null) ? $snapshot['artifact_revisions'] : [],
            'fix_engine_schema_enabled' => !empty($snapshot['fix_engine_schema_enabled']),
            'fix_engine_schema_nodes' => is_array($snapshot['fix_engine_schema_nodes'] ?? null) ? $snapshot['fix_engine_schema_nodes'] : [],
        ]);
    }

    /** @param array<string, mixed> $entry */
    private static function append_audit(array $entry): string
    {
        $settings = TheDotDevAgenticBridge_Storage::get();
        $log = is_array($settings['fix_engine_audit_log'] ?? null) ? $settings['fix_engine_audit_log'] : [];
        $id = function_exists('wp_generate_uuid4') ? wp_generate_uuid4() : ('audit-' . gmdate('YmdHis'));
        array_unshift($log, [
            'id' => $id,
            'appliedAt' => gmdate('c'),
            'findingId' => (string) ($entry['findingId'] ?? ''),
            'resolverId' => (string) ($entry['resolverId'] ?? ''),
            'summary' => (string) ($entry['summary'] ?? ''),
            'changes' => $entry['changes'] ?? [],
            'undoSnapshot' => $entry['undoSnapshot'] ?? [],
            'undoneAt' => '',
            'actorId' => (int) ($entry['actorId'] ?? 0),
            'approvedBy' => (int) ($entry['approvedBy'] ?? 0),
            'approvedAt' => (string) ($entry['approvedAt'] ?? ''),
            'appliedFingerprint' => (string) ($entry['appliedFingerprint'] ?? ''),
            'verification' => is_array($entry['verification'] ?? null) ? $entry['verification'] : ['result' => 'unknown', 'checkedAt' => ''],
        ]);
        TheDotDevAgenticBridge_Storage::update(['fix_engine_audit_log' => array_slice($log, 0, self::MAX_AUDIT_LOG)]);
        return $id;
    }

    /** @return array{result: string, checkedAt: string} */
    private static function rescan(string $finding_id): array
    {
        $scanner = new TheDotDevAgenticBridge_Readiness_Scanner();
        $result = $scanner->run_all();
        TheDotDevAgenticBridge_Readiness_Store::save_result($result);
        foreach (($result['findings'] ?? []) as $finding) {
            if (is_array($finding) && ($finding['id'] ?? '') === $finding_id) {
                $status = (string) ($finding['status'] ?? '');
                return ['result' => $status === 'pass' ? 'passed' : ($status === 'fail' ? 'failed' : 'unknown'), 'checkedAt' => (string) ($finding['lastChecked'] ?? $result['scannedAt'] ?? '')];
            }
        }
        return ['result' => 'unknown', 'checkedAt' => (string) ($result['scannedAt'] ?? '')];
    }

    /** @param array<string, mixed> $snapshot */
    private static function snapshot_fingerprint(array $snapshot): string
    {
        $encoded = wp_json_encode($snapshot, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE);
        return hash('sha256', is_string($encoded) ? $encoded : '');
    }

    /** @return array<string, mixed> */
    private static function homepage_schema_analysis(): array
    {
        $fetch = TheDotDevAgenticBridge_Same_Origin_Observer::fetch('/');
        if (empty($fetch['ok'])) {
            return ['status' => 'absent', 'types' => []];
        }
        return TheDotDevAgenticBridge_Readiness_Schema::analyze_html((string) ($fetch['body_sample'] ?? ''));
    }

}