<?php
/**
 * 读书（v24 第 14 批 用户第 5 条）：像 calibre 那样管自己的书。
 *
 * 用户原话：「增加读书模块，就像 calibre 一样管理自己的图书，可以导入图书，
 *            可以上传图书，可以解析各种格式的图书，可以点开图书进行查看、阅读，
 *            可以标记为读完，有统计功能，有笔记功能，可以导入微信读书等
 *            各种读书软件的读书笔记等功能，在导航条上进行展示。」
 *
 * 三张表（见 Schema v20）：
 *   books         书本身（元数据 + 文件 + 读到哪 + 读完没读完）
 *   book_chapters 解析出来的正文
 *   book_notes    笔记 / 划线 / 书评（**按人**记）
 *
 * ⚠️ 与观影/旅程不同，读书**不走统一事件原语**：
 *    一次观影、一趟旅行都是"某一天发生的事"（有时间、有人、要上日历），
 *    而一本书是"一段持续几个月的状态"（哪天读到第几章才勉强算事件）。
 *    硬塞进 events 会让日历上挂一堆"在读《活着》"的日常噪音。
 *    真要上日历的那天是"读完的那天"—— 将来要做的话，也是从 finished_at 派生。
 *
 * 状态机（wish → reading → done，另有 paused 搁置）：
 *   · 标成 done 时记 finished_at；退回非 done 时**清空**它（不然统计口径会漂：
 *     "读完的书"里混着一本其实还在读的）。
 */

declare(strict_types=1);

namespace App;

final class Book
{
    /** 状态：想读 / 在读 / 读完 / 搁置 */
    public const STATUS = [
        'wish'    => '想读',
        'reading' => '在读',
        'done'    => '读完',
        'paused'  => '搁置',
    ];

    /** 笔记种类 */
    public const NOTE_KINDS = [
        'quote'  => '划线',
        'note'   => '笔记',
        'review' => '书评',
    ];

    /** 笔记来源 */
    public const NOTE_SOURCES = [
        'manual' => '本站',
        'weread' => '微信读书',
        'douban' => '豆瓣',
        'other'  => '其它',
    ];

    /** 上传图书允许的格式（解析能力见 BookParser） */
    public const FILE_EXT = ['epub', 'txt', 'pdf', 'mobi', 'azw3', 'azw', 'doc', 'docx'];

    // ---------------- 读 ----------------

    /**
     * 书架。
     *
     * @param array $f 过滤：status / category / q（书名作者标签）/ owner（谁的书）
     */
    public static function all(int $familyId, array $f = []): array
    {
        $sql = 'SELECT b.*, p.name AS owner_name, p.avatar AS owner_avatar,
                       p.avatar_color AS owner_color,
                       (SELECT COUNT(*) FROM book_notes n WHERE n.book_id = b.id) AS note_count
                  FROM books b
                  LEFT JOIN persons p ON p.id = b.owner_id
                 WHERE b.family_id = ?';
        $args = [$familyId];
        $st = (string)($f['status'] ?? '');
        if ($st !== '' && isset(self::STATUS[$st])) {
            $sql .= ' AND b.status = ?';
            $args[] = $st;
        }
        $cat = trim((string)($f['category'] ?? ''));
        if ($cat !== '') {
            $sql .= ' AND b.category = ?';
            $args[] = $cat;
        }
        $owner = (int)($f['owner'] ?? 0);
        if ($owner > 0) {
            $sql .= ' AND b.owner_id = ?';
            $args[] = $owner;
        }
        $q = trim((string)($f['q'] ?? ''));
        if ($q !== '') {
            $like = '%' . $q . '%';
            $sql .= ' AND (b.title LIKE ? OR b.author LIKE ? OR b.subtitle LIKE ?
                           OR b.publisher LIKE ? OR b.tags LIKE ? OR b.isbn LIKE ?)';
            array_push($args, $like, $like, $like, $like, $like, $like);
        }
        // 在读的排最前（那是"手头正在看什么"），其次是最近更新过的
        $sql .= ' ORDER BY FIELD(b.status, "reading", "wish", "paused", "done"), b.updated_at DESC, b.id DESC';
        $st2 = Database::get()->prepare($sql);
        $st2->execute($args);
        return $st2->fetchAll();
    }

    /**
     * 各状态的数量（书架页的筛选条用；'_all' 是总数）。
     *
     * ⚠️ 与筛选条件**无关**：这里要的是"这个状态一共有几本"，
     *    不是"当前筛选下有几本"（否则点进"在读"后，其它状态的数字全变 0，
     *    筛选条就成了自我实现的死路 —— 再也点不回去）。
     */
    public static function statusCounts(int $familyId): array
    {
        $out = ['_all' => 0];
        foreach (self::STATUS as $k => $v) {
            $out[$k] = 0;
        }
        $st = Database::get()->prepare(
            'SELECT status, COUNT(*) AS n FROM books WHERE family_id = ? GROUP BY status'
        );
        $st->execute([$familyId]);
        foreach ($st->fetchAll() as $r) {
            $out['_all'] += (int)$r['n'];
            $k = (string)$r['status'];
            if (isset($out[$k])) {
                $out[$k] = (int)$r['n'];
            }
        }
        return $out;
    }

    /** 用过的分类（筛选用） */
    public static function categories(int $familyId): array
    {
        $st = Database::get()->prepare(
            'SELECT category AS name, COUNT(*) AS n FROM books
              WHERE family_id = ? AND category IS NOT NULL AND category <> ""
              GROUP BY category ORDER BY n DESC, category'
        );
        $st->execute([$familyId]);
        return $st->fetchAll();
    }

    public static function find(int $familyId, int $id): ?array
    {
        $st = Database::get()->prepare(
            'SELECT b.*, p.name AS owner_name, p.avatar AS owner_avatar, p.avatar_color AS owner_color
               FROM books b LEFT JOIN persons p ON p.id = b.owner_id
              WHERE b.family_id = ? AND b.id = ?'
        );
        $st->execute([$familyId, $id]);
        $r = $st->fetch();
        return $r ?: null;
    }

    /**
     * 章节目录（**不取正文** —— 一本书的正文有几 MB，列表页取它就是自杀）。
     */
    public static function chapters(int $bookId): array
    {
        $st = Database::get()->prepare(
            'SELECT id, seq, title, words FROM book_chapters WHERE book_id = ? ORDER BY seq'
        );
        $st->execute([$bookId]);
        return $st->fetchAll();
    }

    /** 一章（含正文） */
    public static function chapter(int $bookId, int $seq): ?array
    {
        $st = Database::get()->prepare(
            'SELECT * FROM book_chapters WHERE book_id = ? AND seq = ?'
        );
        $st->execute([$bookId, $seq]);
        $r = $st->fetch();
        return $r ?: null;
    }

    /** 整本正文（导出/统计字数用；量很大，只在必要时调） */
    public static function chapterCount(int $bookId): int
    {
        $st = Database::get()->prepare('SELECT COUNT(*) FROM book_chapters WHERE book_id = ?');
        $st->execute([$bookId]);
        return (int)$st->fetchColumn();
    }

    // ---------------- 写 ----------------

    /** @return int 新书 id */
    public static function create(int $familyId, ?int $creatorId, array $d): int
    {
        $db = Database::get();
        $db->prepare(
            'INSERT INTO books (family_id, owner_id, creator_id, title, subtitle, author, translator,
                                publisher, published, isbn, language, category, tags, summary,
                                cover_key, file_key, file_name, file_format, file_size,
                                pages, words, status, rating, started_at, finished_at)
             VALUES (?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?)'
        )->execute([
            $familyId,
            self::ownerId($familyId, (int)($d['owner_id'] ?? 0)),
            $creatorId ?: null,
            self::title($d['title'] ?? ''),
            self::txt($d['subtitle'] ?? ''),
            self::txt($d['author'] ?? ''),
            self::txt($d['translator'] ?? ''),
            self::txt($d['publisher'] ?? ''),
            self::txt($d['published'] ?? ''),
            self::txt($d['isbn'] ?? ''),
            self::txt($d['language'] ?? ''),
            self::txt($d['category'] ?? ''),
            self::txt($d['tags'] ?? ''),
            self::longText($d['summary'] ?? ''),
            self::key($d['cover_key'] ?? ''),
            self::key($d['file_key'] ?? ''),
            self::txt($d['file_name'] ?? ''),
            self::fmt($d['file_format'] ?? ''),
            self::intOrNull($d['file_size'] ?? 0),
            self::intOrNull($d['pages'] ?? 0),
            self::intOrNull($d['words'] ?? 0),
            self::status($d['status'] ?? ''),
            self::rating($d['rating'] ?? null),
            self::dateOrNull($d['started_at'] ?? ''),
            self::dateOrNull($d['finished_at'] ?? ''),
        ]);
        return (int)$db->lastInsertId();
    }

    public static function update(int $familyId, int $id, array $d): void
    {
        $old = self::find($familyId, $id);
        if (!$old) {
            return;
        }
        $status = self::status($d['status'] ?? '');
        // ⚠️ 状态与"读完那天"必须一起维护：
        //    · 变成 done 且还没记过 → 记今天；
        //    · 从 done 退回来 → **清空**（留着会让"今年读完几本"一直虚高）。
        $fin = self::dateOrNull($d['finished_at'] ?? '') ?? ((string)$old['finished_at'] ?: null);
        if ($status === 'done' && $fin === null) {
            $fin = date('Y-m-d');
        } elseif ($status !== 'done') {
            $fin = null;
        }
        $db = Database::get();
        $db->prepare(
            'UPDATE books SET owner_id=?, title=?, subtitle=?, author=?, translator=?, publisher=?,
                    published=?, isbn=?, language=?, category=?, tags=?, summary=?, cover_key=?,
                    file_key=?, file_name=?, file_format=?, file_size=?, pages=?, words=?,
                    status=?, rating=?, started_at=?, finished_at=?
              WHERE id=? AND family_id=?'
        )->execute([
            self::ownerId($familyId, (int)($d['owner_id'] ?? 0)),
            self::title($d['title'] ?? ''),
            self::txt($d['subtitle'] ?? ''),
            self::txt($d['author'] ?? ''),
            self::txt($d['translator'] ?? ''),
            self::txt($d['publisher'] ?? ''),
            self::txt($d['published'] ?? ''),
            self::txt($d['isbn'] ?? ''),
            self::txt($d['language'] ?? ''),
            self::txt($d['category'] ?? ''),
            self::txt($d['tags'] ?? ''),
            self::longText($d['summary'] ?? ''),
            self::key($d['cover_key'] ?? ''),
            self::key($d['file_key'] ?? ''),
            self::txt($d['file_name'] ?? ''),
            self::fmt($d['file_format'] ?? ''),
            self::intOrNull($d['file_size'] ?? 0),
            self::intOrNull($d['pages'] ?? 0),
            self::intOrNull($d['words'] ?? 0),
            $status,
            self::rating($d['rating'] ?? null),
            self::dateOrNull($d['started_at'] ?? ''),
            $fin,
            $id, $familyId,
        ]);
    }

    /**
     * 改状态（列表上的一键：想读 → 在读 → 读完）。
     *
     * @return string 改完之后的状态
     */
    public static function setStatus(int $familyId, int $id, string $status): string
    {
        $old = self::find($familyId, $id);
        if (!$old) {
            return '';
        }
        $status = self::status($status);
        $db = Database::get();
        if ($status === 'done') {
            $db->prepare(
                'UPDATE books SET status=?, finished_at=COALESCE(finished_at, ?),
                        started_at=COALESCE(started_at, ?) WHERE id=? AND family_id=?'
            )->execute([$status, date('Y-m-d'), date('Y-m-d'), $id, $familyId]);
        } elseif ($status === 'reading') {
            $db->prepare(
                'UPDATE books SET status=?, finished_at=NULL, started_at=COALESCE(started_at, ?)
                  WHERE id=? AND family_id=?'
            )->execute([$status, date('Y-m-d'), $id, $familyId]);
        } else {
            $db->prepare('UPDATE books SET status=?, finished_at=NULL WHERE id=? AND family_id=?')
               ->execute([$status, $id, $familyId]);
        }
        return $status;
    }

    /** 读到第几章（阅读器翻页时记） */
    public static function setProgress(int $familyId, int $id, int $seq): void
    {
        Database::get()->prepare(
            'UPDATE books SET progress = ? WHERE id = ? AND family_id = ?'
        )->execute([max(0, $seq), $id, $familyId]);
    }

    public static function destroy(int $familyId, int $id): void
    {
        $b = self::find($familyId, $id);
        if (!$b) {
            return;
        }
        // 文件与封面是自己存的，数据库级联删不掉存储对象
        if (!empty($b['file_key'])) {
            \App\Storage\Storage::delete($familyId, (string)$b['file_key']);
        }
        if (!empty($b['cover_key'])) {
            \App\Storage\Storage::delete($familyId, (string)$b['cover_key']);
        }
        Database::get()->prepare('DELETE FROM books WHERE id = ? AND family_id = ?')->execute([$id, $familyId]);
    }

    /** 整组替换章节（重新解析 / 重新上传文件时用） */
    public static function replaceChapters(int $bookId, array $chapters): int
    {
        $db = Database::get();
        $db->prepare('DELETE FROM book_chapters WHERE book_id = ?')->execute([$bookId]);
        $st = $db->prepare(
            'INSERT INTO book_chapters (book_id, seq, title, content, words) VALUES (?,?,?,?,?)'
        );
        $seq = 0;
        $words = 0;
        foreach ($chapters as $c) {
            $seq++;
            $body = (string)($c['content'] ?? '');
            $w = self::countWords($body);
            $words += $w;
            $st->execute([$bookId, $seq, self::txt($c['title'] ?? ''), $body, $w]);
        }
        $db->prepare('UPDATE books SET chapter_count = ?, words = ? WHERE id = ?')
           ->execute([$seq, $words > 0 ? $words : null, $bookId]);
        return $seq;
    }

    // ---------------- 笔记 ----------------

    /**
     * 一本书的笔记（按时间正序，**全部人**的都给）。
     *
     * ⚠️ 昵称必须按**看的人**（$viewerId）取，不能写成 `nk.viewer_id = n.person_id`
     *    —— 那是"这人对自己的称呼"，页面上会冒出一个跟谁都不对应的名字。
     *    （nicknames 是 (viewer_id, target_id) 二元组，缺了 viewer 就取错人。）
     *
     * 笔记不按人过滤：笔记是"读的人留下的字"，家庭里没必要互相藏。
     *
     * @param int $viewerId 谁在看（决定"我怎么称呼这条笔记的作者"）
     */
    public static function notes(int $bookId, int $viewerId = 0): array
    {
        $st = Database::get()->prepare(
            'SELECT n.*, p.name AS person_name, p.avatar, p.avatar_color,
                    nk.nickname AS my_nickname
               FROM book_notes n
               LEFT JOIN persons p ON p.id = n.person_id
               LEFT JOIN nicknames nk ON nk.target_id = n.person_id AND nk.viewer_id = ?
              WHERE n.book_id = ? ORDER BY n.created_at, n.id'
        );
        $st->execute([$viewerId, $bookId]);
        return $st->fetchAll();
    }

    /** @return int 笔记 id */
    public static function addNote(int $familyId, int $bookId, ?int $personId, array $d): int
    {
        $content = trim((string)($d['content'] ?? ''));
        if ($content === '') {
            return 0;
        }
        $db = Database::get();
        $db->prepare(
            'INSERT INTO book_notes (book_id, person_id, kind, chapter, loc, content, source)
             VALUES (?,?,?,?,?,?,?)'
        )->execute([
            $bookId,
            $personId > 0 ? $personId : null,
            isset(self::NOTE_KINDS[(string)($d['kind'] ?? '')]) ? (string)$d['kind'] : 'note',
            self::txt($d['chapter'] ?? ''),
            self::txt($d['loc'] ?? ''),
            mb_substr($content, 0, 8000, 'UTF-8'),
            self::source($d['source'] ?? ''),
        ]);
        return (int)$db->lastInsertId();
    }

    public static function deleteNote(int $familyId, int $noteId, int $personId): void
    {
        // 只能删自己写的（导入的无主笔记谁都能删 —— 不然它永远留在那儿）
        $st = Database::get()->prepare(
            'SELECT n.id FROM book_notes n JOIN books b ON b.id = n.book_id
              WHERE n.id = ? AND b.family_id = ? AND (n.person_id IS NULL OR n.person_id = ?)'
        );
        $st->execute([$noteId, $familyId, $personId]);
        if ($st->fetchColumn() === false) {
            return;
        }
        Database::get()->prepare('DELETE FROM book_notes WHERE id = ?')->execute([$noteId]);
    }

    // ---------------- 统计 ----------------

    /**
     * 书架的整体数字。
     *
     * ⚠️ 读完的书按 **finished_at 的年份**分桶（不是 created_at）：
     *    "今年读完了几本"问的是读完的时间，加进书架的时间没有意义
     *    （很多人是年底一次性把看过的书补进去的）。
     */
    public static function stats(int $familyId): array
    {
        $db = Database::get();
        $byStatus = [];
        foreach (self::STATUS as $k => $v) {
            $byStatus[$k] = 0;
        }
        $st = $db->prepare('SELECT status, COUNT(*) AS n FROM books WHERE family_id = ? GROUP BY status');
        $st->execute([$familyId]);
        foreach ($st->fetchAll() as $r) {
            $byStatus[(string)$r['status']] = (int)$r['n'];
        }
        $one = static function (string $sql) use ($db, $familyId): int {
            $s = $db->prepare($sql);
            $s->execute([$familyId]);
            return (int)$s->fetchColumn();
        };
        $out = [
            'total'   => array_sum($byStatus),
            'status'  => $byStatus,
            'pages'   => $one('SELECT COALESCE(SUM(pages),0) FROM books WHERE family_id = ? AND status = "done"'),
            'words'   => $one('SELECT COALESCE(SUM(words),0) FROM books WHERE family_id = ? AND status = "done"'),
            'rated'   => $one('SELECT COUNT(*) FROM books WHERE family_id = ? AND rating IS NOT NULL'),
            'avgRate' => 0.0,
            'notes'   => $one('SELECT COUNT(*) FROM book_notes n JOIN books b ON b.id = n.book_id
                                WHERE b.family_id = ?'),
        ];
        $sum = $one('SELECT COALESCE(SUM(rating),0) FROM books WHERE family_id = ? AND rating IS NOT NULL');
        $out['avgRate'] = $out['rated'] > 0 ? round($sum / $out['rated'], 1) : 0.0;

        // 按年读完（近 8 年）
        $st = $db->prepare(
            'SELECT YEAR(finished_at) AS y, COUNT(*) AS n FROM books
              WHERE family_id = ? AND status = "done" AND finished_at IS NOT NULL
              GROUP BY YEAR(finished_at) ORDER BY y'
        );
        $st->execute([$familyId]);
        $out['byYear'] = $st->fetchAll();

        // 评分分布（0-10）
        $dist = array_fill(0, 11, 0);
        $st = $db->prepare(
            'SELECT rating, COUNT(*) AS n FROM books
              WHERE family_id = ? AND rating IS NOT NULL GROUP BY rating'
        );
        $st->execute([$familyId]);
        foreach ($st->fetchAll() as $r) {
            $dist[max(0, min(10, (int)$r['rating']))] = (int)$r['n'];
        }
        $out['ratingDist'] = $dist;

        // 读得最多的作者 / 分类
        $st = $db->prepare(
            'SELECT author AS name, COUNT(*) AS n FROM books
              WHERE family_id = ? AND author IS NOT NULL AND author <> ""
              GROUP BY author ORDER BY n DESC, author LIMIT 8'
        );
        $st->execute([$familyId]);
        $out['topAuthors'] = $st->fetchAll();

        $st = $db->prepare(
            'SELECT category AS name, COUNT(*) AS n FROM books
              WHERE family_id = ? AND category IS NOT NULL AND category <> ""
              GROUP BY category ORDER BY n DESC, category LIMIT 8'
        );
        $st->execute([$familyId]);
        $out['topCategories'] = $st->fetchAll();

        return $out;
    }

    // ---------------- 展示 ----------------

    public static function statusWord(string $k): string
    {
        return self::STATUS[$k] ?? '想读';
    }

    public static function normalizeStatus(string $v): string
    {
        return self::status($v);
    }

    public static function kindWord(string $k): string
    {
        return self::NOTE_KINDS[$k] ?? '笔记';
    }

    public static function sourceWord(string $k): string
    {
        return self::NOTE_SOURCES[$k] ?? (string)$k;
    }

    /** 文件大小的"人话" */
    public static function sizeWord($bytes): string
    {
        $b = (int)$bytes;
        if ($b <= 0) {
            return '';
        }
        if ($b < 1024) {
            return $b . ' B';
        }
        if ($b < 1024 * 1024) {
            return round($b / 1024, 1) . ' KB';
        }
        return round($b / 1024 / 1024, 1) . ' MB';
    }

    /** 字数的"人话"（按中文习惯说"万字"） */
    public static function wordsWord($words): string
    {
        $w = (int)$words;
        if ($w <= 0) {
            return '';
        }
        if ($w < 10000) {
            return number_format($w) . ' 字';
        }
        return round($w / 10000, 1) . ' 万字';
    }

    /** 中英混排的字数（中文按字、西文按词）—— 与 BookParser 同一口径 */
    public static function countWords(string $s): int
    {
        $s = trim($s);
        if ($s === '') {
            return 0;
        }
        $cn = preg_match_all('/[\x{4e00}-\x{9fff}]/u', $s);
        $noCn = preg_replace('/[\x{4e00}-\x{9fff}]/u', ' ', $s);
        $en = preg_match_all('/[A-Za-z0-9]+/u', $noCn);
        return (int)$cn + (int)$en;
    }

    // ---------------- 内部 ----------------

    private static function ownerId(int $familyId, int $id): ?int
    {
        if ($id <= 0) {
            return null;
        }
        $st = Database::get()->prepare('SELECT id FROM persons WHERE id = ? AND family_id = ?');
        $st->execute([$id, $familyId]);
        return $st->fetchColumn() === false ? null : $id;
    }

    private static function status(string $v): string
    {
        return isset(self::STATUS[$v]) ? $v : 'wish';
    }

    private static function source(string $v): string
    {
        $v = trim($v);
        return $v !== '' ? mb_substr($v, 0, 40, 'UTF-8') : 'manual';
    }

    private static function title(string $v): string
    {
        return mb_substr(trim($v), 0, 300, 'UTF-8');
    }

    private static function txt(string $v): ?string
    {
        $v = trim($v);
        return $v !== '' ? $v : null;
    }

    private static function longText(string $v): ?string
    {
        $v = trim($v);
        return $v !== '' ? mb_substr($v, 0, 20000, 'UTF-8') : null;
    }

    private static function key(string $v): ?string
    {
        $v = ltrim(trim($v), '/');
        if ($v === '' || strpos($v, '..') !== false || strpos($v, "\0") !== false) {
            return null;
        }
        return $v;
    }

    private static function fmt(string $v): ?string
    {
        $v = strtolower(trim($v));
        $v = preg_replace('/[^a-z0-9]/', '', $v) ?? '';
        return $v !== '' ? mb_substr($v, 0, 20, 'UTF-8') : null;
    }

    private static function rating($v): ?int
    {
        if ($v === null || $v === '') {
            return null;
        }
        $n = (int)$v;
        return ($n >= 0 && $n <= 10) ? $n : null;
    }

    private static function intOrNull($v): ?int
    {
        $n = (int)$v;
        return $n > 0 ? $n : null;
    }

    private static function dateOrNull(string $v): ?string
    {
        $v = trim($v);
        return preg_match('/^\d{4}-\d{2}-\d{2}$/', $v) ? $v : null;
    }
}