<?php
/**
 * SPDX-FileCopyrightText: 2024 Sascha Nitsch (grumpydeveloper) https://contentnation.net/@grumpydevelop
 * SPDX-License-Identifier: GPL-3.0-or-later
 *
 * @author Sascha Nitsch (grumpydeveloper)
 **/

namespace Federator\DIO;

/**
 * IO functions related to users
 */
class Posts
{
    /**
     * get posts by user
     *
     * @param \mysqli $dbh @unused-param
     *          database handle
     * @param string $userid
     *          user id
     * @param \Federator\Connector\Connector $connector
     *          connector to fetch use with
     * @param \Federator\Cache\Cache|null $cache
     *          optional caching service
     * @param string $min
     *          minimum date
     * @param string $max
     *          maximum date
     * @return \Federator\Data\ActivityPub\Common\Activity[]
     */
    public static function getPostsByUser($dbh, $userid, $connector, $cache, $min, $max)
    {
        // ask cache
        if ($cache !== null) {
            $posts = $cache->getRemotePostsByUser($userid, $min, $max);
            if ($posts !== false) {
                return $posts;
            }
        }
        $posts = self::getPostsFromDb($dbh, $userid, $min, $max);
        if ($posts === false) {
            $posts = [];
        }

        // Only override $min if we found posts in our DB
        $remoteMin = $min;
        if (!empty($posts)) {
            // Find the latest published date in the DB posts
            $latestPublished = null;
            foreach ($posts as $post) {
                $published = $post->getPublished();
                if ($published != null) {
                    $publishedStr = gmdate('Y-m-d H:i:s', $published);
                    if ($latestPublished === null || $publishedStr > $latestPublished) {
                        $latestPublished = $publishedStr;
                    }
                }
            }
            if ($latestPublished !== null) {
                $remoteMin = $latestPublished;
            }
        }

        // Always fetch newer posts from connector (if any)
        $newPosts = $connector->getRemotePostsByUser($userid, $remoteMin, $max);
        if ($newPosts !== false && is_array($newPosts)) {
            // Merge new posts with DB posts, avoiding duplicates by ID
            $existingIds = [];
            foreach ($posts as $post) {
                $existingIds[$post->getID()] = true;
            }
            foreach ($newPosts as $newPost) {
                if (!isset($existingIds[$newPost->getID()])) {
                    $posts[] = $newPost;
                }
            }
        }

        // save posts to DB
        foreach ($posts as $post) {
            if ($post->getID() !== "") {
                self::savePost($dbh, $userid, $post);
            }
        }

        if ($cache !== null) {
            $cache->saveRemotePostsByUser($userid, $posts);
        }
        return $posts;
    }

    /**
     * Get posts for a user from the DB (optionally by date)
     *
     * @param \mysqli $dbh
     * @param string $userId
     * @param string|null $min
     * @param string|null $max
     * @return \Federator\Data\ActivityPub\Common\Activity[]|false
     */
    public static function getPostsFromDb($dbh, $userId, $min = null, $max = null)
    {
        $sql = 'SELECT id, user_id, type, object, published FROM posts WHERE user_id = ?';
        $params = [$userId];
        $types = 's';
        if ($min !== null) {
            $sql .= ' AND published >= ?';
            $params[] = $min;
            $types .= 's';
        }
        if ($max !== null) {
            $sql .= ' AND published <= ?';
            $params[] = $max;
            $types .= 's';
        }
        $sql .= ' ORDER BY published DESC';

        $stmt = $dbh->prepare($sql);
        if ($stmt === false) {
            throw new \Federator\Exceptions\ServerError();
        }
        $stmt->bind_param($types, ...$params);
        $stmt->execute();
        $result = $stmt->get_result();
        if (!($result instanceof \mysqli_result)) {
            $stmt->close();
            return false;
        }
        $posts = [];
        while ($row = $result->fetch_assoc()) {
            if (!empty($row['object'])) {
                $objectData = json_decode($row['object'], true);
                if (is_array($objectData)) {
                    // Use the ActivityPub factory to create the APObject
                    $object = \Federator\Data\ActivityPub\Factory::newActivityFromJson($objectData);
                    if ($object !== false) {
                        $posts[] = $object;
                    }
                }
            }
        }
        $stmt->close();
        return $posts;
    }

    /**
     * Save a post (insert or update)
     *
     * @param \mysqli $dbh
     * @param string $userId
     * @param \Federator\Data\ActivityPub\Common\Activity $post
     * @return bool
     */
    public static function savePost($dbh, $userId, $post)
    {
        $sql = 'INSERT INTO posts (
                `id`, `url`, `user_id`, `actor`, `type`, `object`, `to`, `cc`, `published`
            ) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)
            ON DUPLICATE KEY UPDATE
                `url` = VALUES(`url`),
                `user_id` = VALUES(`user_id`),
                `actor` = VALUES(`actor`),
                `type` = VALUES(`type`),
                `object` = VALUES(`object`),
                `to` = VALUES(`to`),
                `cc` = VALUES(`cc`),
                `published` = VALUES(`published`)';
        $stmt = $dbh->prepare($sql);
        if ($stmt === false) {
            throw new \Federator\Exceptions\ServerError();
        }

        $id = $post->getID();
        $url = $post->getUrl();
        $actor = $post->getAActor();
        $type = $post->getType();
        $object = $post->getObject();
        $objectJson = ($object instanceof \Federator\Data\ActivityPub\Common\APObject)
            ? json_encode($object)
            : $object;
        if ($objectJson === false) {
            $objectJson = null;
        }
        $to = $post->getTo();
        $cc = $post->getCC();
        $toJson = is_array($to) ? json_encode($to) : (is_string($to) ? json_encode([$to]) : null);
        $ccJson = is_array($cc) ? json_encode($cc) : (is_string($cc) ? json_encode([$cc]) : null);
        $published = $post->getPublished();
        $publishedStr = $published ? gmdate('Y-m-d H:i:s', $published) : gmdate('Y-m-d H:i:s');

        $stmt->bind_param(
            "sssssssss",
            $id,
            $url,
            $userId,
            $actor,
            $type,
            $objectJson,
            $toJson,
            $ccJson,
            $publishedStr
        );
        $result = $stmt->execute();
        $stmt->close();
        return $result;
    }

    /**
     * Delete a post
     *
     * @param \mysqli $dbh
     * @param string $id   The post ID
     * @return bool
     */
    public static function deletePost($dbh, $id)
    {
        $sql = 'delete from posts where id = ?';
        $stmt = $dbh->prepare($sql);
        if ($stmt === false) {
            throw new \Federator\Exceptions\ServerError();
        }
        $stmt->bind_param("s", $id);
        $stmt->execute();
        $affectedRows = $stmt->affected_rows;
        $stmt->close();
        return $affectedRows > 0;
    }
}