<?php
declare(strict_types=1);

require_once __DIR__ . '/common.php';
require_once dirname(__DIR__) . '/db_conn.php';

api_header_json();

$user = api_require_login();
$method = strtoupper((string)($_SERVER['REQUEST_METHOD'] ?? 'GET'));

/**
 * Normalize keyword for storage (trim + max 50 chars).
 */
function normalize_keyword(string $value): string {
    $keyword = trim($value);
    if ($keyword === '') {
        return '';
    }

    if (function_exists('mb_substr')) {
        return mb_substr($keyword, 0, 50, 'UTF-8');
    }

    return substr($keyword, 0, 50);
}

/**
 * Insert one search log row using per-user seq and short retry on PK conflicts.
 */
function insert_search_log(PDO $pdo, string $memberId, string $sysCompCode, string $keyword): array {
    $maxAttempts = 3;

    for ($attempt = 1; $attempt <= $maxAttempts; $attempt++) {
        try {
            $pdo->beginTransaction();

            $stmtSeq = $pdo->prepare(
                'SELECT COALESCE(MAX(seq), 0) + 1 AS next_seq
                   FROM edu_search_logs
                  WHERE member_id = ?
                    AND sys_comp_code = ?'
            );
            $stmtSeq->execute([$memberId, $sysCompCode]);
            $nextSeq = (int)($stmtSeq->fetchColumn() ?: 1);

            $stmtInsert = $pdo->prepare(
                'INSERT INTO edu_search_logs
                    (member_id, sys_comp_code, seq, keyword, searched_at)
                 VALUES
                    (?, ?, ?, ?, NOW())'
            );
            $stmtInsert->execute([$memberId, $sysCompCode, $nextSeq, $keyword]);

            $pdo->commit();

            return [
                'seq' => $nextSeq,
                'keyword' => $keyword,
                'searched_at' => date('Y-m-d H:i:s'),
                'retry_count' => $attempt - 1,
            ];
        } catch (Throwable $e) {
            if ($pdo->inTransaction()) {
                $pdo->rollBack();
            }

            $sqlState = '';
            if ($e instanceof PDOException && isset($e->errorInfo[0])) {
                $sqlState = (string)$e->errorInfo[0];
            }

            $isDuplicateKey = ($sqlState === '23000');
            if (!$isDuplicateKey || $attempt >= $maxAttempts) {
                throw $e;
            }
        }
    }

    throw new RuntimeException('search_log_insert_retry_exceeded');
}

if ($method === 'GET') {
    $windowDays = 7;
    $limit = (int)($_GET['limit'] ?? 20);
    if ($limit < 1) {
        $limit = 1;
    } elseif ($limit > 50) {
        $limit = 50;
    }

    try {
        $pdo = db_conn();

        $stmt = $pdo->prepare(
            'SELECT seq, keyword, searched_at
               FROM edu_search_logs
              WHERE member_id = ?
                AND sys_comp_code = ?
                AND searched_at >= (NOW() - INTERVAL 7 DAY)
              ORDER BY searched_at DESC, seq DESC
              LIMIT ' . $limit
        );
        $stmt->execute([(string)$user['member_id'], (string)$user['sys_comp_code']]);
        $rows = $stmt->fetchAll(PDO::FETCH_ASSOC) ?: [];

        $logs = array_map(static function (array $row): array {
            return [
                'seq' => (int)($row['seq'] ?? 0),
                'keyword' => (string)($row['keyword'] ?? ''),
                'searched_at' => (string)($row['searched_at'] ?? ''),
            ];
        }, $rows);

        echo json_encode([
            'success' => true,
            'data' => [
                'logs' => $logs,
                'window_days' => $windowDays,
                'limit' => $limit,
                'member_id' => (string)$user['member_id'],
                'sys_comp_code' => (string)$user['sys_comp_code'],
            ],
            'meta' => [
                'api' => 'search_logs',
                'version' => 1,
                'status' => 'ok',
            ],
        ], JSON_UNESCAPED_UNICODE);
        exit;
    } catch (Throwable $e) {
        error_log('[search_logs][GET] ' . $e->getMessage());
        api_error(500, 'search_logs_fetch_failed');
    }
}

if ($method === 'POST') {
    $input = api_get_input();
    $keyword = normalize_keyword((string)($input['keyword'] ?? ''));

    if ($keyword === '') {
        api_error(400, 'keyword_required');
    }

    try {
        $pdo = db_conn();
        $inserted = insert_search_log(
            $pdo,
            (string)$user['member_id'],
            (string)$user['sys_comp_code'],
            $keyword
        );

        echo json_encode([
            'success' => true,
            'data' => [
                'accepted' => true,
                'keyword' => $inserted['keyword'],
                'seq' => (int)$inserted['seq'],
                'searched_at' => (string)$inserted['searched_at'],
                'member_id' => (string)$user['member_id'],
                'sys_comp_code' => (string)$user['sys_comp_code'],
            ],
            'meta' => [
                'api' => 'search_logs',
                'version' => 1,
                'status' => 'ok',
                'retry_count' => (int)$inserted['retry_count'],
            ],
        ], JSON_UNESCAPED_UNICODE);
        exit;
    } catch (Throwable $e) {
        error_log('[search_logs][POST] ' . $e->getMessage());
        api_error(500, 'search_log_insert_failed');
    }
}

api_error(405, 'method_not_allowed', [
    'allowed_methods' => ['GET', 'POST'],
]);