<?php
/**
 * Export and erase the signed-in person's MazeGraph data.
 *
 * @package MazeAi
 * @since   1.0.0
 */

declare(strict_types=1);

namespace MazeAi\Privacy;

defined('ABSPATH') || exit;

use MazeAi\Chat\ConversationStore;
use MazeAi\Chat\Transcript;
use MazeAi\Engines\Events\EventLog;
use MazeAi\Http\Resources\SessionResource;
use MazeAi\Jobs\Pipelines\UsageRollup;
use MazeAi\Kernel\Contracts\MemoryStore;
use MazeAi\Kernel\Support\Event;
use MazeAi\Memory\OptionsMemoryStore;
use MazeAi\Sessions\SessionRepository;
use MazeAi\Support\Redactor;
use MazeAi\Support\UserPreferences;

/**
 * Shares bounded export and erasure behavior between the app and WordPress's privacy-request workflow.
 *
 * @since 1.0.0
 */
class PersonalData
{
    public const EXPORT_PAGE = 20;

    public const EXPORT_METADATA_PAGE = 100;

    public const SELF_SERVICE_EXPORT_MAX_PAGE = 10000;

    public function __construct(
        protected SessionRepository $sessions,
        protected ConversationStore $store,
        protected EventLog $events,
        protected UsageRollup $usage,
        protected MemoryStore $memory,
        protected OptionsMemoryStore $notes,
        protected UserPreferences $preferences
    ) {
    }

    /**
     * One bounded page of a person's retained MazeGraph data.
     *
     * @return array{data: list<array<string, mixed>>, done: bool}
     */
    public function exportUser(int $userId, int $page = 1): array
    {
        if ($userId <= 0) {
            return ['data' => [], 'done' => true];
        }

        $page = max(1, min(100000, $page));
        $rows = $this->sessions->forExport($userId, $page, self::EXPORT_PAGE);
        $metadataOffset = ($page - 1) * self::EXPORT_METADATA_PAGE;
        $events = $this->events->recent($userId, self::EXPORT_METADATA_PAGE, $metadataOffset);
        $usage = $this->usage->exportHistory($userId, self::EXPORT_METADATA_PAGE, $metadataOffset);
        $data = [];

        if ($page === 1) {
            $instructions = $this->preferences->instructions($userId);
            if ($instructions !== '') {
                $data[] = [
                    'group_id'    => 'maze-graph-preferences',
                    'group_label' => __('MazeGraph preferences', 'maze-graph'),
                    'item_id'     => 'maze-graph-preferences-' . $userId,
                    'data'        => [['name' => __('Your instructions', 'maze-graph'), 'value' => $instructions]],
                ];
            }
            $consentVersion = $this->preferences->consentVersion($userId);
            if ($consentVersion > 0) {
                $data[] = [
                    'group_id'    => 'maze-graph-preferences',
                    'group_label' => __('MazeGraph preferences', 'maze-graph'),
                    'item_id'     => 'maze-graph-consent-' . $userId,
                    'data'        => [
                        ['name' => __('Accepted data notice', 'maze-graph'), 'value' => __('Yes', 'maze-graph')],
                        ['name' => __('Data notice version', 'maze-graph'), 'value' => (string) $consentVersion],
                    ],
                ];
            }
            if ($this->preferences->onboardingChecklistCompleted($userId)) {
                $data[] = [
                    'group_id'    => 'maze-graph-preferences',
                    'group_label' => __('MazeGraph preferences', 'maze-graph'),
                    'item_id'     => 'maze-graph-onboarding-checklist-' . $userId,
                    'data'        => [['name' => __('Getting-started checklist completed', 'maze-graph'), 'value' => __('Yes', 'maze-graph')]],
                ];
            }
            if ($this->preferences->onboardingTourCompleted($userId)) {
                $data[] = [
                    'group_id'    => 'maze-graph-preferences',
                    'group_label' => __('MazeGraph preferences', 'maze-graph'),
                    'item_id'     => 'maze-graph-onboarding-tour-' . $userId,
                    'data'        => [['name' => __('Interface tour completed', 'maze-graph'), 'value' => __('Yes', 'maze-graph')]],
                ];
            }
            if ($this->preferences->legacyOnboardingChecklistDismissed($userId)) {
                $data[] = [
                    'group_id'    => 'maze-graph-preferences',
                    'group_label' => __('MazeGraph preferences', 'maze-graph'),
                    'item_id'     => 'maze-graph-onboarding-legacy-' . $userId,
                    'data'        => [['name' => __('Prior getting-started checklist hidden setting', 'maze-graph'), 'value' => __('Yes', 'maze-graph')]],
                ];
            }
            foreach ($this->notes->ofUser($userId) as $note) {
                $data[] = [
                    'group_id'    => 'maze-graph-notes',
                    'group_label' => __('MazeGraph notes', 'maze-graph'),
                    'item_id'     => 'maze-graph-note-' . $note['id'],
                    'data'        => [['name' => __('Note', 'maze-graph'), 'value' => $note['content']], ['name' => __('Saved', 'maze-graph'), 'value' => $note['created_at']]],
                ];
            }
        }

        foreach ($rows as $row) {
            $lines = [];
            foreach (Transcript::visible($this->store->entries((int) $row['id'])) as $entry) {
                if (($entry['type'] ?? '') === 'message' && in_array($entry['role'] ?? '', ['user', 'assistant'], true)) {
                    $text = Transcript::text($entry);
                    if ($text !== '') {
                        $lines[] = ($entry['role'] === 'user' ? __('You', 'maze-graph') : 'MazeGraph') . ': ' . $text;
                    }
                }
            }

            $data[] = [
                'group_id'    => 'maze-graph-sessions',
                'group_label' => __('MazeGraph sessions', 'maze-graph'),
                'item_id'     => 'maze-graph-session-' . $row['uuid'],
                'data'        => [
                    ['name' => __('Title', 'maze-graph'), 'value' => Redactor::mask((string) $row['title'])],
                    ['name' => __('Started', 'maze-graph'), 'value' => (string) SessionResource::time($row['created_at'] ?? null)],
                    ['name' => __('Messages', 'maze-graph'), 'value' => implode("\n\n", $lines)],
                ],
            ];
        }

        foreach ($events as $event) {
            $payload = json_decode((string) ($event['payload'] ?? ''), true);
            $eventName = (string) ($event['event_name'] ?? '');
            if (!in_array($eventName, Event::NAMES, true)) {
                $eventName = '';
            }
            $data[] = [
                'group_id'    => 'maze-graph-activity',
                'group_label' => __('MazeGraph activity', 'maze-graph'),
                'item_id'     => 'maze-graph-event-' . (int) ($event['id'] ?? 0),
                'data'        => [
                    ['name' => __('Event', 'maze-graph'), 'value' => $eventName],
                    ['name' => __('Date', 'maze-graph'), 'value' => (string) ($event['created_at'] ?? '')],
                    ['name' => __('Recorded details', 'maze-graph'), 'value' => is_array($payload) ? (string) wp_json_encode($payload, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE) : '{}'],
                ],
            ];
        }

        foreach ($usage as $record) {
            $data[] = [
                'group_id'    => 'maze-graph-usage',
                'group_label' => __('MazeGraph usage', 'maze-graph'),
                'item_id'     => 'maze-graph-usage-' . $userId . '-' . $record['day'] . '-' . md5($record['model']),
                'data'        => [
                    ['name' => __('Day (UTC)', 'maze-graph'), 'value' => $record['day']],
                    ['name' => __('Model', 'maze-graph'), 'value' => $record['model']],
                    ['name' => __('Input tokens', 'maze-graph'), 'value' => (string) $record['tokens_in']],
                    ['name' => __('Output tokens', 'maze-graph'), 'value' => (string) $record['tokens_out']],
                    ['name' => __('Messages', 'maze-graph'), 'value' => (string) $record['messages']],
                ],
            ];
        }

        return [
            'data' => $data,
            'done' => count($rows) < self::EXPORT_PAGE
                && count($events) < self::EXPORT_METADATA_PAGE
                && count($usage) < self::EXPORT_METADATA_PAGE,
        ];
    }

    /** Erase the person's MazeGraph records; site settings and other users' records are unaffected. */
    public function eraseUser(int $userId): int
    {
        if ($userId <= 0) {
            return 0;
        }

        $eventCount = $this->events->countRecent($userId);
        $removed = $this->sessions->eraseUser($userId);
        $removed += $eventCount > 0 ? 1 : 0;
        $removed += $this->usage->forgetUser($userId);
        $removed += $this->memory->forgetUser($userId);
        $removed += $this->preferences->forget($userId) ? 1 : 0;

        return $removed;
    }
}