276 lines
12 KiB
PHP
276 lines
12 KiB
PHP
<?php
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/**
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* LLM Chat API - AI聊天接口（带对话管理）
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* 支持：创建/删除/切换对话，消息历史持久化
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*/
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require_once('./include/db_info.inc.php');
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require_once('./include/setlang.php');
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require_once('./include/const.inc.php');
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// ---- SSE 辅助函数 ----
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function sse_send($event, $data) {
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echo "event: $event\ndata: " . json_encode($data, JSON_UNESCAPED_UNICODE) . "\n\n";
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@ob_flush();
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@flush();
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}
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function sse_error($msg) {
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sse_send("error", ["message" => $msg]);
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}
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// ---- 基础校验 ----
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if (!isset($OJ_LLM_ENABLED) || !$OJ_LLM_ENABLED) {
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header("Content-Type: application/json; charset=utf-8");
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echo json_encode(["error" => "AI聊天功能未开启"], JSON_UNESCAPED_UNICODE);
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exit;
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}
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session_start();
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if (!isset($_SESSION[$OJ_NAME . '_user_id'])) {
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header("Content-Type: application/json; charset=utf-8");
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echo json_encode(["error" => "请先登录"], JSON_UNESCAPED_UNICODE);
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exit;
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}
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$user_id = $_SESSION[$OJ_NAME . '_user_id'];
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// ---- 自动建表 ----
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pdo_query("CREATE TABLE IF NOT EXISTS `llm_chat_session` (
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`session_id` INT AUTO_INCREMENT PRIMARY KEY,
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`user_id` VARCHAR(48) NOT NULL,
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`title` VARCHAR(200) NOT NULL DEFAULT '新对话',
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`create_time` DATETIME NOT NULL,
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`update_time` DATETIME NOT NULL,
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INDEX `idx_user` (`user_id`)
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) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;");
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pdo_query("CREATE TABLE IF NOT EXISTS `llm_chat_message` (
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`id` INT AUTO_INCREMENT PRIMARY KEY,
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`session_id` INT NOT NULL,
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`role` VARCHAR(20) NOT NULL,
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`content` TEXT NOT NULL,
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`create_time` DATETIME NOT NULL,
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INDEX `idx_session` (`session_id`),
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INDEX `idx_session_role` (`session_id`, `id`)
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) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;");
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// ---- GET 请求 ----
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if ($_SERVER['REQUEST_METHOD'] === 'GET') {
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header("Content-Type: application/json; charset=utf-8");
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$action = isset($_GET['action']) ? $_GET['action'] : '';
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if ($action === 'sessions') {
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$sessions = pdo_query(
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"SELECT `session_id`, `title`, `create_time`, `update_time` FROM `llm_chat_session` WHERE `user_id`=? ORDER BY `update_time` DESC",
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$user_id
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);
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echo json_encode(["sessions" => $sessions !== -1 ? $sessions : []], JSON_UNESCAPED_UNICODE);
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} elseif ($action === 'messages') {
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$session_id = isset($_GET['session_id']) ? intval($_GET['session_id']) : 0;
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if ($session_id <= 0) { echo json_encode(["error" => "无效的会话ID"]); exit; }
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$check = pdo_query("SELECT 1 FROM `llm_chat_session` WHERE `session_id`=? AND `user_id`=?", $session_id, $user_id);
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if (empty($check) || $check === -1) { echo json_encode(["error" => "无权访问"]); exit; }
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$messages = pdo_query("SELECT `role`, `content` FROM `llm_chat_message` WHERE `session_id`=? ORDER BY `id` ASC", $session_id);
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echo json_encode(["messages" => $messages !== -1 ? $messages : []], JSON_UNESCAPED_UNICODE);
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} elseif ($action === 'last_session') {
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$last = pdo_query("SELECT `session_id` FROM `llm_chat_session` WHERE `user_id`=? ORDER BY `update_time` DESC LIMIT 1", $user_id);
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echo json_encode(["session_id" => (!empty($last) && $last !== -1) ? intval($last[0]['session_id']) : 0], JSON_UNESCAPED_UNICODE);
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}
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exit;
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}
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// ---- DELETE 请求 ----
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if ($_SERVER['REQUEST_METHOD'] === 'DELETE') {
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header("Content-Type: application/json; charset=utf-8");
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$input = json_decode(file_get_contents('php://input'), true);
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$session_id = isset($input['session_id']) ? intval($input['session_id']) : 0;
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if ($session_id <= 0) { echo json_encode(["error" => "无效的会话ID"]); exit; }
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$check = pdo_query("SELECT 1 FROM `llm_chat_session` WHERE `session_id`=? AND `user_id`=?", $session_id, $user_id);
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if (empty($check) || $check === -1) { echo json_encode(["error" => "无权删除"]); exit; }
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pdo_query("DELETE FROM `llm_chat_message` WHERE `session_id`=?", $session_id);
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pdo_query("DELETE FROM `llm_chat_session` WHERE `session_id`=?", $session_id);
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echo json_encode(["success" => true], JSON_UNESCAPED_UNICODE);
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exit;
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}
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// ---- POST 请求 ----
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$input = json_decode(file_get_contents('php://input'), true);
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if (!$input) { header("Content-Type: application/json; charset=utf-8"); echo json_encode(["error" => "无效请求"]); exit; }
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$action = isset($input['action']) ? $input['action'] : 'chat';
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// 创建新会话
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if ($action === 'create_session') {
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header("Content-Type: application/json; charset=utf-8");
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$title = isset($input['title']) ? trim($input['title']) : '新对话';
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$now = date('Y-m-d H:i:s');
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$session_id = pdo_query("INSERT INTO `llm_chat_session` (`user_id`, `title`, `create_time`, `update_time`) VALUES (?, ?, ?, ?)", $user_id, $title, $now, $now);
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echo json_encode(["session_id" => $session_id, "title" => $title], JSON_UNESCAPED_UNICODE);
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exit;
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}
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// 重命名会话
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if ($action === 'rename_session') {
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header("Content-Type: application/json; charset=utf-8");
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$session_id = isset($input['session_id']) ? intval($input['session_id']) : 0;
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$title = isset($input['title']) ? trim($input['title']) : '';
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if ($session_id <= 0 || empty($title)) { echo json_encode(["error" => "参数错误"]); exit; }
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pdo_query("UPDATE `llm_chat_session` SET `title`=? WHERE `session_id`=? AND `user_id`=?", $title, $session_id, $user_id);
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echo json_encode(["success" => true], JSON_UNESCAPED_UNICODE);
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exit;
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}
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// ---- 聊天（流式SSE） ----
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$message = isset($input['message']) ? trim($input['message']) : '';
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$session_id = isset($input['session_id']) ? intval($input['session_id']) : 0;
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if (empty($message)) { header("Content-Type: application/json; charset=utf-8"); echo json_encode(["error" => "消息不能为空"]); exit; }
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// 自动创建会话
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if ($session_id <= 0) {
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$now = date('Y-m-d H:i:s');
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$auto_title = mb_substr($message, 0, 20, 'UTF-8');
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if (mb_strlen($message, 'UTF-8') > 20) $auto_title .= '...';
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$session_id = pdo_query("INSERT INTO `llm_chat_session` (`user_id`, `title`, `create_time`, `update_time`) VALUES (?, ?, ?, ?)", $user_id, $auto_title, $now, $now);
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}
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// 验证归属
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$check = pdo_query("SELECT 1 FROM `llm_chat_session` WHERE `session_id`=? AND `user_id`=?", $session_id, $user_id);
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if (empty($check) || $check === -1) { header("Content-Type: application/json; charset=utf-8"); echo json_encode(["error" => "无权访问"]); exit; }
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// 保存用户消息
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$now = date('Y-m-d H:i:s');
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pdo_query("INSERT INTO `llm_chat_message` (`session_id`, `role`, `content`, `create_time`) VALUES (?, 'user', ?, ?)", $session_id, $message, $now);
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pdo_query("UPDATE `llm_chat_session` SET `update_time`=? WHERE `session_id`=?", $now, $session_id);
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// 获取历史（最近10条上下文）
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$history = pdo_query("SELECT `role`, `content` FROM `llm_chat_message` WHERE `session_id`=? ORDER BY `id` DESC LIMIT 11", $session_id);
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$messages = [];
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if ($history !== -1 && !empty($history)) {
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$history = array_reverse($history);
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$recent = array_slice($history, 0, -1);
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$recent = array_slice($recent, -10);
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foreach ($recent as $msg) {
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$messages[] = ['role' => $msg['role'], 'content' => $msg['content']];
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}
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}
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$messages[] = ['role' => 'user', 'content' => $message];
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// ---- SSE 响应头 ----
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header("Content-Type: text/event-stream; charset=utf-8");
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header("Cache-Control: no-cache");
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header("X-Accel-Buffering: no");
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if (function_exists('apache_setenv')) @apache_setenv('no-gzip', '1');
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@ini_set('zlib.output_compression', 0);
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@ini_set('implicit_flush', 1);
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while (ob_get_level()) ob_end_flush();
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sse_send("session", ["session_id" => $session_id]);
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// ---- 系统提示词 ----
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$system_prompt = <<<'EOP'
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你是一位名叫"MiniMax老师"的AI助教，正在与学生进行日常对话。
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你的职责：
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1. 用亲切、友好的语气和学生交流
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2. 回答学生的各种问题，包括但不限于学习、生活、编程概念等
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3. 提供有帮助的信息和建议
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4. 使用中文回答
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严格禁止的行为：
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1. 绝对不要帮助学生解答任何编程题目、算法题、数据结构题等OJ题目
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2. 绝对不要提供任何题目的解题思路、代码实现或算法分析
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3. 如果学生询问关于具体OJ题目的问题，请礼貌地拒绝并解释你需要自己思考来完成题目
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4. 不要帮助学生完成任何看起来像是作业或考试的编程任务
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你可以做的事情：
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- 解释编程概念和原理（不针对具体题目）
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- 讨论学习方法和技巧
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- 回答日常生活问题
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- 聊天闲谈
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- 其他与做题无关的问题
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EOP;
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$api_url = isset($OJ_LLM_API_URL) ? $OJ_LLM_API_URL : "https://api.minimaxi.com/anthropic/v1/messages";
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$api_key = isset($OJ_LLM_API_KEY) ? $OJ_LLM_API_KEY : "";
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$model = isset($OJ_LLM_MODEL) ? $OJ_LLM_MODEL : "MiniMax-M2.7";
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$max_tokens = isset($OJ_LLM_MAX_TOKENS) ? intval($OJ_LLM_MAX_TOKENS) : 2048;
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$timeout = isset($OJ_LLM_TIMEOUT) ? intval($OJ_LLM_TIMEOUT) : 120;
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if (empty($api_key)) { sse_error("API Key未配置"); exit; }
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$request_body = json_encode([
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"model" => $model, "max_tokens" => $max_tokens, "system" => $system_prompt,
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"temperature" => 0.8, "stream" => true, "messages" => $messages
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]);
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// ---- 流式转发 ----
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$GLOBALS['_llm_alive'] = true;
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$GLOBALS['_llm_full_text'] = "";
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$GLOBALS['_llm_buffer'] = "";
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register_shutdown_function(function() { $GLOBALS['_llm_alive'] = false; });
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$ch = curl_init($api_url);
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curl_setopt_array($ch, [
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CURLOPT_POST => true, CURLOPT_POSTFIELDS => $request_body,
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CURLOPT_HTTPHEADER => ["Content-Type: application/json", "x-api-key: " . $api_key, "anthropic-version: 2023-06-01"],
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CURLOPT_RETURNTRANSFER => false, CURLOPT_TIMEOUT => $timeout, CURLOPT_CONNECTTIMEOUT => 10,
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CURLOPT_SSL_VERIFYPEER => true,
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CURLOPT_WRITEFUNCTION => function($ch, $chunk) use (&$_llm_alive, &$_llm_full_text, &$_llm_buffer) {
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if (!$_llm_alive) return 0;
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$_llm_buffer .= $chunk;
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while (($pos = strpos($_llm_buffer, "\n")) !== false) {
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$line = substr($_llm_buffer, 0, $pos);
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$_llm_buffer = substr($_llm_buffer, $pos + 1);
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$line = trim($line);
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if (empty($line)) continue;
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if (strncmp($line, "data: ", 6) === 0) {
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$json_str = substr($line, 6);
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if ($json_str === "[DONE]") continue;
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$data = json_decode($json_str, true);
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if (!$data) continue;
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$type = isset($data['type']) ? $data['type'] : '';
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if ($type === 'content_block_delta' && isset($data['delta']['text'])) {
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$_llm_full_text .= $data['delta']['text'];
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sse_send("chunk", ["text" => $data['delta']['text']]);
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} elseif ($type === 'message_delta' && isset($data['delta']['stop_reason'])) {
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if (in_array($data['delta']['stop_reason'], ['end_turn', 'max_tokens'])) {
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sse_send("done", []);
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return 0;
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}
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} elseif (in_array($type, ['message_start', 'ping', 'content_block_start', 'content_block_stop'])) {
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continue;
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} elseif ($type === 'error') {
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sse_send("error", ["message" => "API错误: " . (isset($data['error']['message']) ? $data['error']['message'] : '未知')]);
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return 0;
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}
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}
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}
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return strlen($chunk);
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}
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]);
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$result = curl_exec($ch);
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$http_code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
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$curl_error = curl_error($ch);
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curl_close($ch);
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// 保存AI回复
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if (!empty($_llm_full_text)) {
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$save_now = date('Y-m-d H:i:s');
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pdo_query("INSERT INTO `llm_chat_message` (`session_id`, `role`, `content`, `create_time`) VALUES (?, 'assistant', ?, ?)", $session_id, $_llm_full_text, $save_now);
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}
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if (!$_llm_alive) exit;
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if ($result === false && empty($_llm_full_text)) { sse_error("网络请求失败: " . ($curl_error ?: "未知")); exit; }
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if (empty($_llm_full_text) && $http_code !== 200) { sse_error("API请求失败 (HTTP $http_code)"); exit; }
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if (empty($_llm_full_text)) { sse_error("API返回为空"); exit; }
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?>
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