<?php
/**
 * 观影统计 / 高级搜索 / 年度报告的聚合查询 —— v11 从 MovieLog 迁入。
 *
 * MovieLog 那三个页面（stats.php / search.php / annual_report.php）原本直接写 SQL，
 * 而且用的是 **SQLite 方言**（strftime('%Y', ...)）。迁进家书时做了两件事：
 *   1. 方言换 MySQL：strftime('%Y', x) → YEAR(x)，'%Y-%m' → DATE_FORMAT(x, '%Y-%m')；
 *      LIMIT 的绑定值不能用 execute([$n])（非模拟预处理下会被当字符串，
 *      MySQL 直接报 `LIMIT '12'` 语法错），一律 (int) 内联。
 *   2. 表结构换家书的统一事件原语：movies → events(kind='movie')，
 *      viewers → event_attendees，remark → note，watch_date → starts_at，
 *      cinema_id 挂在 movie_details 上。
 *
 * 「我」的口径：观影人是同行的人（event_attendees）。年度报告以**登录者**为中心，
 * 只统计他参与过的场次 —— 与 MovieLog 的 self_person_id 一致。
 */

declare(strict_types=1);

namespace App;

use PDO;

final class MovieStats
{
    /** 顶部四张总览卡 + 观影跨度 */
    public static function overview(int $familyId): array
    {
        $db = Database::get();
        $one = static function (string $sql, array $a = []) use ($db): string {
            $st = $db->prepare($sql);
            $st->execute($a);
            $v = $st->fetchColumn();
            return $v === false || $v === null ? '' : (string)$v;
        };
        $span = $db->prepare(
            "SELECT MIN(e.starts_at) AS f, MAX(e.starts_at) AS l
             FROM events e WHERE e.family_id = ? AND e.kind = 'movie' AND e.starts_at IS NOT NULL"
        );
        $span->execute([$familyId]);
        $row = $span->fetch() ?: ['f' => null, 'l' => null];

        return [
            'movies'      => (int)$one("SELECT COUNT(*) FROM events WHERE family_id = ? AND kind = 'movie'", [$familyId]),
            'cinemas'     => (int)$one('SELECT COUNT(*) FROM cinemas WHERE family_id = ?', [$familyId]),
            'persons'     => (int)$one(
                "SELECT COUNT(DISTINCT a.person_id) FROM event_attendees a
                   JOIN events e ON e.id = a.event_id AND e.kind = 'movie'
                  WHERE e.family_id = ?", [$familyId]),
            'viewership'  => (int)$one(
                "SELECT COUNT(*) FROM event_attendees a
                   JOIN events e ON e.id = a.event_id AND e.kind = 'movie'
                  WHERE e.family_id = ?", [$familyId]),
            'first_date'  => $row['f'] !== null ? substr((string)$row['f'], 0, 10) : null,
            'last_date'   => $row['l'] !== null ? substr((string)$row['l'], 0, 10) : null,
        ];
    }

    /** 按影院：每家看过多少部（0 部的也列出来，便于发现重复建的影院） */
    public static function byCinema(int $familyId): array
    {
        $st = Database::get()->prepare(
            "SELECT c.id, c.name, c.place, c.color, COUNT(e.id) AS cnt
               FROM cinemas c
               LEFT JOIN movie_details d ON d.cinema_id = c.id
               LEFT JOIN events e ON e.id = d.event_id AND e.kind = 'movie' AND e.family_id = c.family_id
              WHERE c.family_id = ?
              GROUP BY c.id, c.name, c.place, c.color
              ORDER BY cnt DESC, c.name"
        );
        $st->execute([$familyId]);
        return $st->fetchAll();
    }

    /** 按观影人：参与了多少场（带头像，供统计页画条；名称按「我叫他什么」显示） */
    public static function byPerson(int $familyId, int $viewerId = 0): array
    {
        $st = Database::get()->prepare(
            "SELECT p.id, p.name, p.avatar, n.nickname AS my_nickname, COUNT(e.id) AS cnt
               FROM persons p
               LEFT JOIN event_attendees a ON a.person_id = p.id
               LEFT JOIN events e ON e.id = a.event_id AND e.kind = 'movie' AND e.family_id = ?
               LEFT JOIN nicknames n ON n.target_id = p.id AND n.viewer_id = ?
              WHERE p.family_id = ? AND p.kind = 'member'
              GROUP BY p.id, p.name, p.avatar, n.nickname
              ORDER BY cnt DESC, p.id"
        );
        $st->execute([$familyId, $viewerId, $familyId]);
        return $st->fetchAll();
    }

    /** 最近 n 个月（只列有记录的月份，按时间倒序） */
    public static function byMonth(int $familyId, int $limit = 12): array
    {
        // ⚠️ LIMIT 不能走绑定参数：非模拟预处理下 PDO 会把它当字符串送过去，
        //    MySQL 报 `LIMIT '12'` 语法错。已 (int) 转，无注入面。
        $st = Database::get()->prepare(
            "SELECT DATE_FORMAT(e.starts_at, '%Y-%m') AS ym, COUNT(*) AS cnt
               FROM events e
              WHERE e.family_id = ? AND e.kind = 'movie' AND e.starts_at IS NOT NULL
              GROUP BY ym
              ORDER BY ym DESC
              LIMIT " . (int)$limit
        );
        $st->execute([$familyId]);
        return $st->fetchAll();
    }

    /** 按年 */
    public static function byYear(int $familyId): array
    {
        $st = Database::get()->prepare(
            "SELECT YEAR(e.starts_at) AS y, COUNT(*) AS cnt
               FROM events e
              WHERE e.family_id = ? AND e.kind = 'movie' AND e.starts_at IS NOT NULL
              GROUP BY y
              ORDER BY y DESC"
        );
        $st->execute([$familyId]);
        return $st->fetchAll();
    }

    /** 有观影记录的年份（倒序），年度报告的年份下拉用 */
    public static function years(int $familyId): array
    {
        $st = Database::get()->prepare(
            "SELECT DISTINCT YEAR(e.starts_at) AS y
               FROM events e
              WHERE e.family_id = ? AND e.kind = 'movie' AND e.starts_at IS NOT NULL
              ORDER BY y DESC"
        );
        $st->execute([$familyId]);
        return array_map('intval', $st->fetchAll(PDO::FETCH_COLUMN));
    }

    /**
     * 高级搜索：片名 / 影院 / 观影人 / 日期范围 组合过滤。
     * 条件全空时返回 []（页面据此提示「先设置条件」）。
     */
    public static function search(int $familyId, array $p, int $viewerId = 0): array
    {
        $title = trim((string)($p['title'] ?? ''));
        $cid   = (int)($p['cinema_id'] ?? 0);
        $pid   = (int)($p['person_id'] ?? 0);
        $from  = self::dateOrNull((string)($p['date_from'] ?? ''));
        $to    = self::dateOrNull((string)($p['date_to'] ?? ''));
        if ($title === '' && $cid <= 0 && $pid <= 0 && $from === null && $to === null) {
            return [];
        }

        $sql =
            "SELECT e.id, e.title, e.starts_at, e.ends_at,
                    d.poster_key, c.name AS cinema_name, c.color AS cinema_color,
                    (SELECT GROUP_CONCAT(p2.name ORDER BY a2.position, p2.id SEPARATOR '、')
                       FROM event_attendees a2 JOIN persons p2 ON p2.id = a2.person_id
                      WHERE a2.event_id = e.id) AS attendee_names
               FROM events e
               LEFT JOIN movie_details d ON d.event_id = e.id
               LEFT JOIN cinemas c ON c.id = d.cinema_id
              WHERE e.family_id = ? AND e.kind = 'movie'";
        $bind = [$familyId];
        if ($title !== '') {
            $sql .= ' AND e.title LIKE ?';
            $bind[] = '%' . $title . '%';
        }
        if ($cid > 0) {
            $sql .= ' AND d.cinema_id = ?';
            $bind[] = $cid;
        }
        if ($pid > 0) {
            $sql .= ' AND EXISTS (SELECT 1 FROM event_attendees a3
                                  WHERE a3.event_id = e.id AND a3.person_id = ?)';
            $bind[] = $pid;
        }
        if ($from !== null) {
            $sql .= ' AND e.starts_at >= ?';
            $bind[] = $from . ' 00:00:00';
        }
        if ($to !== null) {
            $sql .= ' AND e.starts_at <= ?';
            $bind[] = $to . ' 23:59:59';
        }
        $sql .= ' ORDER BY e.starts_at DESC, e.id DESC';

        $st = Database::get()->prepare($sql);
        $st->execute($bind);
        $rows = $st->fetchAll();
        MovieReview::attachStats($rows);
        Movie::attachAttendees($rows, $viewerId);
        return $rows;
    }

    /**
     * 年度报告：以**登录者**为中心，只统计他参与过的场次。
     * 结构与 MovieLog::getAnnualStats 一致 —— 页面模板按同样的键取用。
     */
    public static function annual(int $familyId, int $personId, int $year): array
    {
        $db = Database::get();
        $y  = (int)$year;
        $blank = [
            'total' => 0, 'days' => 0,
            'top_cinema' => '无', 'top_cinema_count' => 0,
            'top_person' => '无', 'top_person_count' => 0,
            'first_date' => null, 'last_date' => null,
            'most_viewers_movie' => '无', 'most_viewers_count' => 0,
            'month_distribution' => array_fill(1, 12, 0),
            'weekday_distribution' => ['日' => 0, '一' => 0, '二' => 0, '三' => 0, '四' => 0, '五' => 0, '六' => 0],
            'avg_per_month' => 0, 'avg_days_between' => 0,
            'keywords' => [], 'recent_movies' => [], 'my_movies' => [], 'common_viewers' => [],
        ];
        if ($personId <= 0) {
            return $blank;
        }
        // 「我参与过的场次」这个子查询被下面反复用 —— 写成 EXISTS 而不是 IN 大列表
        $mine = "EXISTS (SELECT 1 FROM event_attendees am
                          WHERE am.event_id = e.id AND am.person_id = ?)";
        $base = "FROM events e WHERE e.family_id = ? AND e.kind = 'movie' AND YEAR(e.starts_at) = ? AND {$mine}";
        $args = static fn(array $extra = []): array => array_merge([$familyId, $y, $personId], $extra);

        $one = static function (string $sql, array $a) use ($db): string {
            $st = $db->prepare($sql);
            $st->execute($a);
            $v = $st->fetchColumn();
            return $v === false || $v === null ? '' : (string)$v;
        };

        $out = $blank;
        $out['total'] = (int)$one("SELECT COUNT(*) {$base}", $args());
        $out['days']  = (int)$one(
            "SELECT COUNT(DISTINCT DATE(e.starts_at)) {$base} AND e.starts_at IS NOT NULL", $args());

        // 最常去的影院
        $st = $db->prepare(
            "SELECT c.name AS n, COUNT(*) AS c
               FROM events e
               JOIN movie_details d ON d.event_id = e.id
               JOIN cinemas c ON c.id = d.cinema_id
              WHERE e.family_id = ? AND e.kind = 'movie' AND YEAR(e.starts_at) = ? AND {$mine}
              GROUP BY c.id, c.name ORDER BY c DESC LIMIT 1"
        );
        $st->execute($args());
        if ($r = $st->fetch()) {
            $out['top_cinema'] = (string)$r['n'];
            $out['top_cinema_count'] = (int)$r['c'];
        }

        // 一起看过最多场的人
        $st = $db->prepare(
            "SELECT p.id, p.name, p.avatar, COUNT(*) AS c
               FROM event_attendees a
               JOIN persons p ON p.id = a.person_id
              WHERE a.event_id IN (
                      SELECT e2.id FROM events e2
                       WHERE e2.family_id = ? AND e2.kind = 'movie' AND YEAR(e2.starts_at) = ?
                         AND EXISTS (SELECT 1 FROM event_attendees am
                                     WHERE am.event_id = e2.id AND am.person_id = ?))
                AND a.person_id <> ?
              GROUP BY p.id, p.name, p.avatar ORDER BY c DESC"
        );
        $st->execute([$familyId, $y, $personId, $personId]);
        $out['common_viewers'] = $st->fetchAll();
        if ($out['common_viewers']) {
            $out['top_person'] = (string)$out['common_viewers'][0]['name'];
            $out['top_person_count'] = (int)$out['common_viewers'][0]['c'];
        }

        // 时间跨度
        $st = $db->prepare("SELECT MIN(e.starts_at) AS f, MAX(e.starts_at) AS l {$base} AND e.starts_at IS NOT NULL");
        $st->execute($args());
        if ($r = $st->fetch()) {
            $out['first_date'] = $r['f'] !== null ? substr((string)$r['f'], 0, 10) : null;
            $out['last_date']  = $r['l'] !== null ? substr((string)$r['l'], 0, 10) : null;
        }

        // 同场人最多的一部
        $st = $db->prepare(
            "SELECT e.title AS t, (SELECT COUNT(*) FROM event_attendees a WHERE a.event_id = e.id) AS c
               {$base}
              ORDER BY c DESC, e.id DESC LIMIT 1"
        );
        $st->execute($args());
        if ($r = $st->fetch()) {
            $out['most_viewers_movie'] = (string)$r['t'];
            $out['most_viewers_count'] = (int)$r['c'];
        }

        // 月份 / 星期分布
        $st = $db->prepare(
            "SELECT MONTH(e.starts_at) AS m, COUNT(*) AS c {$base} AND e.starts_at IS NOT NULL GROUP BY m"
        );
        $st->execute($args());
        foreach ($st->fetchAll() as $r) {
            $out['month_distribution'][(int)$r['m']] = (int)$r['c'];
        }
        $st = $db->prepare(
            "SELECT DAYOFWEEK(e.starts_at) AS w, COUNT(*) AS c {$base} AND e.starts_at IS NOT NULL GROUP BY w"
        );
        $st->execute($args());
        $wmap = [1 => '日', 2 => '一', 3 => '二', 4 => '三', 5 => '四', 6 => '五', 7 => '六'];
        foreach ($st->fetchAll() as $r) {
            $k = $wmap[(int)$r['w']] ?? null;
            if ($k !== null) {
                $out['weekday_distribution'][$k] = (int)$r['c'];
            }
        }

        // 频率
        $out['avg_per_month']    = $out['total'] > 0 ? round($out['total'] / 12, 1) : 0;
        $out['avg_days_between'] = $out['total'] > 0 ? round(365 / $out['total'], 1) : 0;

        // 关键词（从备注里分词，取前 5）
        $st = $db->prepare("SELECT e.note {$base} AND e.note IS NOT NULL AND e.note <> ''");
        $st->execute($args());
        $wc = [];
        foreach ($st->fetchAll(PDO::FETCH_COLUMN) as $text) {
            $words = preg_split('/[\s，,。.！!？?、；;：:]+/u', (string)$text, -1, PREG_SPLIT_NO_EMPTY);
            foreach ($words as $w) {
                $w = trim($w);
                if (mb_strlen($w, 'UTF-8') >= 2) {
                    $wc[$w] = ($wc[$w] ?? 0) + 1;
                }
            }
        }
        arsort($wc);
        $out['keywords'] = array_slice(array_keys($wc), 0, 5);

        // 最近 5 部（只要片名）
        $st = $db->prepare("SELECT e.title {$base} ORDER BY e.starts_at DESC, e.id DESC LIMIT 5");
        $st->execute($args());
        $out['recent_movies'] = array_map('strval', $st->fetchAll(PDO::FETCH_COLUMN));

        // 我的观影清单（含海报 + 同场的人）
        $st = $db->prepare(
            "SELECT e.id, e.title, e.starts_at, d.poster_key
               FROM events e LEFT JOIN movie_details d ON d.event_id = e.id
              WHERE e.family_id = ? AND e.kind = 'movie' AND YEAR(e.starts_at) = ? AND {$mine}
              ORDER BY e.starts_at DESC, e.id DESC"
        );
        $st->execute($args());
        $list = $st->fetchAll();
        $co = $db->prepare(
            "SELECT p.id, p.name, p.avatar, p.avatar_color, n.nickname AS my_nickname
               FROM event_attendees a JOIN persons p ON p.id = a.person_id
               LEFT JOIN nicknames n ON n.target_id = p.id AND n.viewer_id = ?
              WHERE a.event_id = ? AND a.person_id <> ?
              ORDER BY a.position, p.id"
        );
        foreach ($list as &$mv) {
            $co->execute([$personId, (int)$mv['id'], $personId]);
            $mv['viewers'] = $co->fetchAll();
        }
        unset($mv);
        $out['my_movies'] = $list;

        return $out;
    }

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