<?php
// ============================================
// 文件: lib/movies.php
// 说明: 电影 / 影院读取与搜索，以及表单提交时的关联数据处理
// ============================================

// ===== 电影列表 =====
function getMovies() {
    $db = getDB();
    $stmt = $db->query("
        SELECT m.*, c.place, c.name as cinema_name, c.address as cinema_address, c.color as cinema_color
        FROM movies m
        LEFT JOIN cinemas c ON m.cinema_id = c.id
        ORDER BY m.watch_date DESC, m.created_at DESC
    ");
    $movies = $stmt->fetchAll();
    attachViewersToMovies($movies);
    return $movies;
}

function getMovie($id) {
    $db = getDB();
    $stmt = $db->prepare("
        SELECT m.*, c.place, c.name as cinema_name, c.address as cinema_address, c.color as cinema_color
        FROM movies m
        LEFT JOIN cinemas c ON m.cinema_id = c.id
        WHERE m.id = ?
    ");
    $stmt->execute([$id]);
    $movie = $stmt->fetch();
    if ($movie) {
        $stmt2 = $db->prepare("
            SELECT v.id, v.movie_id, v.person_id,
                   COALESCE(p.name, v.name) as name, 
                   p.color as person_color,
                   p.avatar as person_avatar
            FROM viewers v
            LEFT JOIN persons p ON v.person_id = p.id
            WHERE v.movie_id = ?
            ORDER BY v.id
        ");
        $stmt2->execute([$id]);
        $movie['viewers'] = $stmt2->fetchAll();

        $stmt3 = $db->prepare("SELECT * FROM movie_photos WHERE movie_id = ? ORDER BY id");
        $stmt3->execute([$id]);
        $movie['photos'] = $stmt3->fetchAll();
    }
    return $movie;
}

function attachViewersToMovies(&$movies) {
    if (empty($movies)) return;
    $db = getDB();
    $movie_ids = array_column($movies, 'id');
    if (empty($movie_ids)) return;
    $placeholders = implode(',', array_fill(0, count($movie_ids), '?'));
    $stmt = $db->prepare("
        SELECT v.movie_id, p.id as person_id, p.name, p.color, p.avatar
        FROM viewers v
        LEFT JOIN persons p ON v.person_id = p.id
        WHERE v.movie_id IN ($placeholders)
        ORDER BY v.id
    ");
    $stmt->execute($movie_ids);
    $rows = $stmt->fetchAll();
    $viewers_map = [];
    foreach ($rows as $row) {
        $movie_id = $row['movie_id'];
        if (!isset($viewers_map[$movie_id])) $viewers_map[$movie_id] = [];
        $viewers_map[$movie_id][] = [
            'person_id' => $row['person_id'],
            'name'      => $row['name'] ?? '未知',
            'color'     => $row['color'] ?? '#888888',
            'avatar'    => $row['avatar']
        ];
    }
    foreach ($movies as &$movie) {
        $movie['viewers'] = $viewers_map[$movie['id']] ?? [];
    }
}

// ===== 影院 =====
function getCinemas() {
    $db = getDB();
    $stmt = $db->query("SELECT * FROM cinemas ORDER BY place, name");
    return $stmt->fetchAll();
}

// ===== 搜索 =====
function searchMovies($keyword) {
    return advancedSearch(['title' => $keyword]);
}

function advancedSearch($params) {
    $db = getDB();
    $sql = "
        SELECT DISTINCT m.*, 
               c.place, c.name as cinema_name, c.address as cinema_address, c.color as cinema_color
        FROM movies m
        LEFT JOIN cinemas c ON m.cinema_id = c.id
        LEFT JOIN viewers v ON m.id = v.movie_id
        LEFT JOIN persons p ON v.person_id = p.id
        WHERE 1=1
    ";
    $bind = [];
    if (!empty($params['title'])) {
        $sql .= " AND m.title LIKE :title";
        $bind[':title'] = '%' . $params['title'] . '%';
    }
    if (!empty($params['cinema_id']) && is_numeric($params['cinema_id'])) {
        $sql .= " AND m.cinema_id = :cinema_id";
        $bind[':cinema_id'] = (int)$params['cinema_id'];
    }
    if (!empty($params['person_id']) && is_numeric($params['person_id'])) {
        $sql .= " AND v.person_id = :person_id";
        $bind[':person_id'] = (int)$params['person_id'];
    }
    if (!empty($params['date_from'])) {
        $sql .= " AND m.watch_date >= :date_from";
        $bind[':date_from'] = $params['date_from'];
    }
    if (!empty($params['date_to'])) {
        $sql .= " AND m.watch_date <= :date_to";
        $bind[':date_to'] = $params['date_to'];
    }
    $sql .= " ORDER BY m.watch_date DESC, m.created_at DESC";
    $stmt = $db->prepare($sql);
    $stmt->execute($bind);
    $movies = $stmt->fetchAll();
    attachViewersToMovies($movies);
    return $movies;
}

// ===== 表单提交时的关联数据处理 =====

/**
 * 解析表单提交的电影院选择。
 * 选择「新建」且填了名称时创建影院并返回新 id；未选择或信息不足时返回 null。
 */
function resolveCinemaId($cinema_id, $new_place, $new_name, $new_address) {
    $db = getDB();

    if ($cinema_id === 'new' && !empty($new_name)) {
        $stmt = $db->prepare("INSERT INTO cinemas (place, name, address) VALUES (?, ?, ?)");
        $stmt->execute([$new_place, $new_name, $new_address]);
        $cinema_id = $db->lastInsertId();
    } elseif ($cinema_id === 'new') {
        $cinema_id = null;
    } elseif (!empty($cinema_id) && is_numeric($cinema_id)) {
        $cinema_id = (int)$cinema_id;
    } else {
        $cinema_id = null;
    }

    return $cinema_id;
}

/**
 * 解析「一起看的人」表单行：已有观影人取 id，选择「新增」则按姓名建库或复用。
 * 返回去重后的观影人 id 列表。
 */
function resolvePersonIds($viewer_selects, $viewer_news) {
    $db = getDB();
    $person_ids = [];
    foreach ($viewer_selects as $idx => $val) {
        if ($val === 'new') {
            $new_name = trim($viewer_news[$idx] ?? '');
            if (!empty($new_name)) {
                $chk = $db->prepare("SELECT id FROM persons WHERE name = ?");
                $chk->execute([$new_name]);
                $existing = $chk->fetch();
                if ($existing) {
                    $person_ids[] = $existing['id'];
                } else {
                    $ins = $db->prepare("INSERT INTO persons (name) VALUES (?)");
                    $ins->execute([$new_name]);
                    $person_ids[] = $db->lastInsertId();
                }
            }
        } elseif (is_numeric($val) && $val > 0) {
            $person_ids[] = (int)$val;
        }
    }
    return array_unique($person_ids);
}

// 把观影人写入电影关联表
function linkViewers($movie_id, $person_ids) {
    if (empty($person_ids)) return;
    $db = getDB();
    $stmt = $db->prepare("INSERT INTO viewers (movie_id, person_id, name) VALUES (?, ?, ?)");
    foreach ($person_ids as $pid) {
        $stmt->execute([$movie_id, $pid, '']);
    }
}