<?php
/**
 * 渠道效能分析接口  GET /api/channel/analysis.php?year=2025
 * v1.0.18 渠道管理 - 渠道效能分析：
 * - 企业/人员两个维度，分别按 source_channel（渠道字段）分组计数、按数量降序、计算百分比
 * - 每个渠道附带 source_detail TOP10 排名（来源/数量）
 * - year 为空 = 全部年份；否则按创建年份过滤
 * 返回：{ years, company: [{channel, count, percent, details:[{source,count}]}], person: [...] }
 */
require_once __DIR__ . '/../common/Api.php';

Api::boot(['module' => 'channel']);

$year = trim($_REQUEST['year'] ?? '');
if ($year !== '' && (!ctype_digit($year) || (int)$year < 2000 || (int)$year > 2100)) {
    $year = '';
}

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

// 可选年份（企业/人员创建年份并集）
$years = $pdo->query(
    "SELECT DISTINCT y FROM (
        SELECT YEAR(created_at) AS y FROM companies WHERE is_active = 1 AND created_at IS NOT NULL
        UNION
        SELECT YEAR(created_at) AS y FROM persons WHERE is_active = 1 AND created_at IS NOT NULL
     ) t ORDER BY y DESC"
)->fetchAll(PDO::FETCH_COLUMN);

/** 单维度渠道分析 */
function channelAnalysis($pdo, $table, $year)
{
    // REV-9：表名白名单，杜绝 SQL 插值
    if (!in_array($table, ['companies', 'persons'], true)) {
        Response::error('参数错误', 400);
    }
    $where = 'is_active = 1 AND source_channel IS NOT NULL AND source_channel <> \'\'';
    $params = [];
    if ($year !== '') {
        $where .= ' AND YEAR(created_at) = ?';
        $params[] = (int)$year;
    }

    $stmt = $pdo->prepare(
        "SELECT source_channel AS channel, COUNT(*) AS cnt
         FROM $table WHERE $where
         GROUP BY source_channel ORDER BY cnt DESC"
    );
    $stmt->execute($params);
    $rows = $stmt->fetchAll();

    $total = 0;
    foreach ($rows as $r) {
        $total += (int)$r['cnt'];
    }

    $result = [];
    foreach ($rows as $r) {
        $channel = $r['channel'];
        // 该渠道 source_detail TOP10
        $detailStmt = $pdo->prepare(
            "SELECT COALESCE(NULLIF(TRIM(source_detail), ''), '（未填写）') AS source, COUNT(*) AS cnt
             FROM $table
             WHERE is_active = 1 AND source_channel = ?" . ($year !== '' ? ' AND YEAR(created_at) = ?' : '') . "
             GROUP BY source ORDER BY cnt DESC LIMIT 10"
        );
        $dParams = [$channel];
        if ($year !== '') {
            $dParams[] = (int)$year;
        }
        $detailStmt->execute($dParams);

        $result[] = [
            'channel' => $channel,
            'count'   => (int)$r['cnt'],
            'percent' => $total > 0 ? round(((int)$r['cnt'] / $total) * 100, 1) : 0,
            'details' => $detailStmt->fetchAll(),
        ];
    }
    return $result;
}

Response::success([
    'years'   => $years,
    'company' => channelAnalysis($pdo, 'companies', $year),
    'person'  => channelAnalysis($pdo, 'persons', $year),
]);