<?php
// ============================================
// 文件: lib/stats.php
// 说明: 统计仪表板与年度报告的查询逻辑
// ============================================

// ===== 统计 =====
function getStatsOverview() {
    $db = getDB();
    $stats = [];
    $stmt = $db->query("SELECT COUNT(*) FROM movies");
    $stats['total_movies'] = $stmt->fetchColumn();
    $stmt = $db->query("SELECT COUNT(*) FROM cinemas");
    $stats['total_cinemas'] = $stmt->fetchColumn();
    $stmt = $db->query("SELECT COUNT(*) FROM persons");
    $stats['total_persons'] = $stmt->fetchColumn();
    $stmt = $db->query("SELECT COUNT(*) FROM viewers");
    $stats['total_viewership'] = $stmt->fetchColumn();
    $stmt = $db->query("SELECT MIN(watch_date) as first, MAX(watch_date) as last FROM movies WHERE watch_date IS NOT NULL");
    $row = $stmt->fetch();
    $stats['first_date'] = $row['first'];
    $stats['last_date'] = $row['last'];
    return $stats;
}

function statsByCinema() {
    $db = getDB();
    $stmt = $db->query("
        SELECT c.id, c.name, c.color, COUNT(m.id) as count
        FROM cinemas c
        LEFT JOIN movies m ON c.id = m.cinema_id
        GROUP BY c.id
        ORDER BY count DESC
    ");
    return $stmt->fetchAll();
}

function statsByPerson() {
    $db = getDB();
    $stmt = $db->query("
        SELECT p.id, p.name, p.color, p.avatar, COUNT(v.movie_id) as count
        FROM persons p
        LEFT JOIN viewers v ON p.id = v.person_id
        GROUP BY p.id
        ORDER BY count DESC
    ");
    return $stmt->fetchAll();
}

function statsByMonth($limit = 12) {
    $db = getDB();
    $stmt = $db->prepare("
        SELECT strftime('%Y-%m', watch_date) as month, COUNT(*) as count
        FROM movies
        WHERE watch_date IS NOT NULL
        GROUP BY month
        ORDER BY month DESC
        LIMIT ?
    ");
    $stmt->execute([$limit]);
    return $stmt->fetchAll();
}

function statsByYear() {
    $db = getDB();
    $stmt = $db->query("
        SELECT strftime('%Y', watch_date) as year, COUNT(*) as count
        FROM movies
        WHERE watch_date IS NOT NULL
        GROUP BY year
        ORDER BY year DESC
    ");
    return $stmt->fetchAll();
}

// ===== 年度报告 =====
function getAnnualStats($year) {
    $db = getDB();
    $stats = [];

    // 获取当前管理员
    $admin = getCurrentAdmin();
    $self_person_id = $admin['person_id'] ?? null;
    $stats['self_person_name'] = $admin['person_name'] ?? null;
    $stats['self_person_avatar'] = $admin['person_avatar'] ?? null;

    if (!$self_person_id) {
        // 未关联观影人，返回空数据
        $stats['total'] = 0;
        $stats['days'] = 0;
        $stats['top_cinema'] = '无';
        $stats['top_cinema_count'] = 0;
        $stats['top_person'] = '无';
        $stats['top_person_count'] = 0;
        $stats['first_date'] = null;
        $stats['last_date'] = null;
        $stats['most_viewers_movie'] = '无';
        $stats['most_viewers_count'] = 0;
        $stats['month_distribution'] = array_fill(1, 12, 0);
        $stats['weekday_distribution'] = ['日'=>0,'一'=>0,'二'=>0,'三'=>0,'四'=>0,'五'=>0,'六'=>0];
        $stats['avg_per_month'] = 0;
        $stats['avg_days_between'] = 0;
        $stats['keywords'] = [];
        $stats['recent_movies'] = [];
        $stats['my_movies'] = [];
        $stats['common_viewers'] = [];
        return $stats;
    }

    // 1. 总观影数（当前用户参与的电影）
    $stmt = $db->prepare("
        SELECT COUNT(DISTINCT m.id)
        FROM movies m
        JOIN viewers v ON m.id = v.movie_id
        WHERE strftime('%Y', m.watch_date) = ?
          AND v.person_id = ?
    ");
    $stmt->execute([$year, $self_person_id]);
    $stats['total'] = (int)$stmt->fetchColumn();

    // 2. 观影天数
    $stmt = $db->prepare("
        SELECT COUNT(DISTINCT m.watch_date)
        FROM movies m
        JOIN viewers v ON m.id = v.movie_id
        WHERE strftime('%Y', m.watch_date) = ?
          AND v.person_id = ?
          AND m.watch_date IS NOT NULL
    ");
    $stmt->execute([$year, $self_person_id]);
    $stats['days'] = (int)$stmt->fetchColumn();

    // 3. 最常去的影院
    $stmt = $db->prepare("
        SELECT c.name, COUNT(m.id) as count
        FROM movies m
        JOIN viewers v ON m.id = v.movie_id
        LEFT JOIN cinemas c ON m.cinema_id = c.id
        WHERE strftime('%Y', m.watch_date) = ?
          AND v.person_id = ?
          AND m.cinema_id IS NOT NULL
        GROUP BY m.cinema_id
        ORDER BY count DESC LIMIT 1
    ");
    $stmt->execute([$year, $self_person_id]);
    $top_cinema = $stmt->fetch();
    $stats['top_cinema'] = $top_cinema ? $top_cinema['name'] : '无';
    $stats['top_cinema_count'] = $top_cinema ? (int)$top_cinema['count'] : 0;

    // 4. 最常一起观影的人（与当前用户同场最多的人）
    // 先获取当前用户看过的所有电影ID
    $stmt = $db->prepare("
        SELECT DISTINCT m.id
        FROM movies m
        JOIN viewers v ON m.id = v.movie_id
        WHERE strftime('%Y', m.watch_date) = ?
          AND v.person_id = ?
    ");
    $stmt->execute([$year, $self_person_id]);
    $movie_ids = $stmt->fetchAll(PDO::FETCH_COLUMN);

    // 共同观影人统计
    $common_viewers = [];
    if (!empty($movie_ids)) {
        $placeholders = implode(',', array_fill(0, count($movie_ids), '?'));
        $params = array_merge($movie_ids, [$self_person_id]);
        $stmt = $db->prepare("
            SELECT p.id, p.name, p.avatar, COUNT(*) as count
            FROM viewers v
            JOIN persons p ON v.person_id = p.id
            WHERE v.movie_id IN ($placeholders)
              AND v.person_id != ?
            GROUP BY v.person_id
            ORDER BY count DESC
        ");
        $stmt->execute($params);
        $common_viewers = $stmt->fetchAll();
    }
    $stats['common_viewers'] = $common_viewers;

    // 最常一起观影的人（取第一个）
    $stats['top_person'] = !empty($common_viewers) ? $common_viewers[0]['name'] : '无';
    $stats['top_person_count'] = !empty($common_viewers) ? (int)$common_viewers[0]['count'] : 0;

    // 5. 最早和最晚日期
    $stmt = $db->prepare("
        SELECT MIN(m.watch_date) as first, MAX(m.watch_date) as last
        FROM movies m
        JOIN viewers v ON m.id = v.movie_id
        WHERE strftime('%Y', m.watch_date) = ?
          AND v.person_id = ?
          AND m.watch_date IS NOT NULL
    ");
    $stmt->execute([$year, $self_person_id]);
    $row = $stmt->fetch();
    $stats['first_date'] = $row['first'];
    $stats['last_date'] = $row['last'];

    // 6. 单次最多人的电影（当前用户参与的电影中）
    $stmt = $db->prepare("
        SELECT m.id, m.title, COUNT(v.id) as viewer_count
        FROM movies m
        JOIN viewers v ON m.id = v.movie_id
        WHERE strftime('%Y', m.watch_date) = ?
          AND m.id IN (SELECT movie_id FROM viewers WHERE person_id = ?)
        GROUP BY m.id
        ORDER BY viewer_count DESC LIMIT 1
    ");
    $stmt->execute([$year, $self_person_id]);
    $most_viewers = $stmt->fetch();
    $stats['most_viewers_movie'] = $most_viewers ? $most_viewers['title'] : '无';
    $stats['most_viewers_count'] = $most_viewers ? (int)$most_viewers['viewer_count'] : 0;

    // 7. 月份分布
    $stmt = $db->prepare("
        SELECT strftime('%m', m.watch_date) as month, COUNT(*) as count
        FROM movies m
        JOIN viewers v ON m.id = v.movie_id
        WHERE strftime('%Y', m.watch_date) = ?
          AND v.person_id = ?
          AND m.watch_date IS NOT NULL
        GROUP BY month
        ORDER BY month
    ");
    $stmt->execute([$year, $self_person_id]);
    $month_data = $stmt->fetchAll(PDO::FETCH_KEY_PAIR);
    $stats['month_distribution'] = [];
    for ($m=1; $m<=12; $m++) {
        $key = str_pad($m, 2, '0', STR_PAD_LEFT);
        $stats['month_distribution'][$m] = isset($month_data[$key]) ? (int)$month_data[$key] : 0;
    }

    // 8. 星期分布
    $stmt = $db->prepare("
        SELECT strftime('%w', m.watch_date) as wday, COUNT(*) as count
        FROM movies m
        JOIN viewers v ON m.id = v.movie_id
        WHERE strftime('%Y', m.watch_date) = ?
          AND v.person_id = ?
          AND m.watch_date IS NOT NULL
        GROUP BY wday
        ORDER BY wday
    ");
    $stmt->execute([$year, $self_person_id]);
    $wday_data = $stmt->fetchAll(PDO::FETCH_KEY_PAIR);
    $weekdays = ['日','一','二','三','四','五','六'];
    $stats['weekday_distribution'] = [];
    foreach ($weekdays as $idx => $name) {
        $stats['weekday_distribution'][$name] = isset($wday_data[$idx]) ? (int)$wday_data[$idx] : 0;
    }

    // 9. 月均和频率
    $stats['avg_per_month'] = $stats['total'] > 0 ? round($stats['total'] / 12, 1) : 0;
    $stats['avg_days_between'] = $stats['total'] > 0 ? round(365 / $stats['total'], 1) : 0;

    // 10. 关键词（基于当前用户电影的备注）
    $stmt = $db->prepare("
        SELECT m.remark
        FROM movies m
        JOIN viewers v ON m.id = v.movie_id
        WHERE strftime('%Y', m.watch_date) = ?
          AND v.person_id = ?
          AND m.remark IS NOT NULL
          AND m.remark != ''
    ");
    $stmt->execute([$year, $self_person_id]);
    $remarks = $stmt->fetchAll(PDO::FETCH_COLUMN);
    $word_count = [];
    foreach ($remarks as $text) {
        $words = preg_split('/[\s，,。.！!？?、；;：:]+/', $text, -1, PREG_SPLIT_NO_EMPTY);
        foreach ($words as $w) {
            $w = trim($w);
            if (mb_strlen($w) >= 2) {
                if (!isset($word_count[$w])) $word_count[$w] = 0;
                $word_count[$w]++;
            }
        }
    }
    arsort($word_count);
    $stats['keywords'] = array_slice(array_keys($word_count), 0, 5);

    // 11. 最近5部（当前用户参与的）
    $stmt = $db->prepare("
        SELECT DISTINCT m.title
        FROM movies m
        JOIN viewers v ON m.id = v.movie_id
        WHERE strftime('%Y', m.watch_date) = ?
          AND v.person_id = ?
        ORDER BY m.watch_date DESC
        LIMIT 5
    ");
    $stmt->execute([$year, $self_person_id]);
    $stats['recent_movies'] = $stmt->fetchAll(PDO::FETCH_COLUMN);

    // 12. 我的观影记录（含海报）
    $stmt = $db->prepare("
        SELECT m.id, m.title, m.watch_date, m.poster_path
        FROM movies m
        JOIN viewers v ON m.id = v.movie_id
        WHERE strftime('%Y', m.watch_date) = ?
          AND v.person_id = ?
        GROUP BY m.id
        ORDER BY m.watch_date DESC
    ");
    $stmt->execute([$year, $self_person_id]);
    $movie_list = $stmt->fetchAll();

    // 对每个电影查询一起观影的人（含头像）
    foreach ($movie_list as &$movie) {
        $stmt2 = $db->prepare("
            SELECT p.id, p.name, p.avatar
            FROM viewers v
            LEFT JOIN persons p ON v.person_id = p.id
            WHERE v.movie_id = ?
              AND v.person_id != ?
        ");
        $stmt2->execute([$movie['id'], $self_person_id]);
        $movie['viewers'] = $stmt2->fetchAll();
    }
    $stats['my_movies'] = $movie_list;

    return $stats;
}

function getYearsWithData() {
    $db = getDB();
    $stmt = $db->query("SELECT DISTINCT strftime('%Y', watch_date) as year FROM movies WHERE watch_date IS NOT NULL ORDER BY year DESC");
    return $stmt->fetchAll(PDO::FETCH_COLUMN);
}