/* @file config_store.cpp
 * @brief ConfigStore implementation: TOML parsing, thread-safe get/set with thread-local safety.
 * ConfigStore 实现：TOML 解析、线程安全的 get/set（基于 thread-local 安全机制）。
 * Copyright (c) 2026 dstalk contributors. GPLv3.
 */

#include "config_store.hpp"
#include "../../plugins/config/include/toml_parse.h"

#include <cstdio>
#include <fstream>
#include <sstream>
#include <string>

namespace dstalk {

// 在互斥锁下加载并解析 TOML 文件到键值存储 / Load and parse a TOML file into the key-value store under mutex.
int ConfigStore::load_file(const char* path)
{
    if (!path) return -1;

    std::ifstream file(path);
    if (!file.is_open()) return -1;

    std::stringstream ss;
    ss << file.rdbuf();
    std::string data = ss.str();

    // W12.2: 使用共享 TOML 解析器（从 config_plugin.cpp 去重） / Use shared TOML parser (de-duplicated from config_plugin.cpp)
    toml::parse(data, [this](const std::string& key, const std::string& value) {
        std::lock_guard<std::mutex> lock(mutex_);
        data_[key] = value;
    });

    return 0;
}

// 检索配置值，返回线程本地副本以避免 c_str() 悬空 / Retrieve config value, returning a thread-local copy to avoid dangling c_str().
const char* ConfigStore::get(const char* key) const
{
    if (!key) return nullptr;
    std::lock_guard<std::mutex> lock(mutex_);
    auto it = data_.find(key);
    if (it == data_.end()) return nullptr;

    // W12.2: 在释放锁之前复制到线程本地缓冲区 /
    // Copy to thread-local buffer before releasing lock.
    // 防止当并发 set() 触发 std::string 重新分配时 c_str() 悬空 /
    // Prevents c_str() dangling when concurrent set() on the same key
    // triggers std::string reallocation (W11.2 audit Finding 3).
    thread_local std::string tls_cached;
    tls_cached = it->second;
    return tls_cached.c_str();
}

// 以 std::string 值类型检索配置（安全的值副本）/ Retrieve config value as an owned std::string (safe by-value copy).
std::string ConfigStore::get_copy(const char* key) const
{
    if (!key) return {};
    std::lock_guard<std::mutex> lock(mutex_);
    auto it = data_.find(key);
    if (it == data_.end()) return {};
    return it->second;  // 在锁下复制构造，始终安全 / copy-constructed under lock, always safe
}

// 在锁下设置配置键值对 / Set a config key-value pair under lock.
int ConfigStore::set(const char* key, const char* value)
{
    if (!key || !value) return -1;
    std::lock_guard<std::mutex> lock(mutex_);
    data_[key] = value;
    return 0;
}

} // namespace dstalk