<?php
/**
 * 渠道年度统计接口  GET /api/channel/stats.php?year=2025
 * 返回：指定年度（默认今年）各渠道效率统计 + 年度汇总
 */
require_once __DIR__ . '/../common/db.php';
require_once __DIR__ . '/../common/response.php';
require_once __DIR__ . '/../common/auth.php';

checkPermission('channel');

$year = (int)($_REQUEST['year'] ?? date('Y'));
if ($year < 2000 || $year > 2100) {
    $year = (int)date('Y');
}

$pdo = DB::getInstance()->getPdo();

$rows = $pdo->prepare(
    "SELECT id, channel_name, channel_type, efficiency_score, created_at
     FROM channels
     WHERE is_active = 1 AND YEAR(created_at) = ?
     ORDER BY efficiency_score DESC"
);
$rows->execute([$year]);
$list = $rows->fetchAll();

$summary = [
    'channel_count' => count($list),
    'avg_score'     => 0,
    'max_score'     => 0,
    'min_score'     => 0,
];
if ($list) {
    $scores = array_column($list, 'efficiency_score');
    $summary['avg_score'] = round(array_sum($scores) / count($scores), 2);
    $summary['max_score'] = (float)max($scores);
    $summary['min_score'] = (float)min($scores);
}

// 可用年度（用于前端下拉）
$years = $pdo->query("SELECT DISTINCT YEAR(created_at) AS y FROM channels WHERE is_active = 1 ORDER BY y DESC")->fetchAll(PDO::FETCH_COLUMN);

Response::success(['year' => $year, 'list' => $list, 'summary' => $summary, 'years' => $years]);