package com.mes.core;

import com.alibaba.fastjson2.JSON;
import com.alibaba.fastjson2.JSONObject;
import com.alibaba.fastjson2.JSONWriter;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.HashSet;
import java.util.Set;

/**
 * 本机 UI 偏好 - 管理“始终显示”的菜单白名单
 *
 * 存储位置：config/ui_prefs.json
 * 结构：
 * {
 *   "alwaysShow": ["manual_submit"]
 * }
 */
public class UiPrefs {
    private static final Logger log = LoggerFactory.getLogger(UiPrefs.class);
    private static final String CONFIG_FILE = "config/ui_prefs.json";

    /** 菜单 key：手动提交子菜单 */
    public static final String KEY_MANUAL_SUBMIT = "manual_submit";

    private static UiPrefs INSTANCE;

    private final Path configPath;
    private final Set<String> alwaysShow = new HashSet<>();

    private UiPrefs() {
        this.configPath = Paths.get(CONFIG_FILE);
        load();
    }

    public static synchronized UiPrefs getInstance() {
        if (INSTANCE == null) {
            INSTANCE = new UiPrefs();
        }
        return INSTANCE;
    }

    /** 是否勾选了“始终显示” */
    public boolean isAlwaysShow(String key) {
        return alwaysShow.contains(key);
    }

    /** 设置“始终显示”状态，立即落盘 */
    public void setAlwaysShow(String key, boolean always) {
        boolean changed;
        if (always) {
            changed = alwaysShow.add(key);
        } else {
            changed = alwaysShow.remove(key);
        }
        if (changed) {
            save();
        }
    }

    private void load() {
        try {
            if (!Files.exists(configPath)) {
                log.info("UI偏好文件不存在，使用默认值: {}", configPath);
                return;
            }
            String content = new String(Files.readAllBytes(configPath), StandardCharsets.UTF_8);
            JSONObject json = JSON.parseObject(content);
            if (json == null) return;

            alwaysShow.clear();
            java.util.List<Object> list = json.getJSONArray("alwaysShow");
            if (list != null) {
                for (Object o : list) {
                    if (o != null) alwaysShow.add(o.toString());
                }
            }
            log.info("UI偏好加载成功: alwaysShow={}", alwaysShow);
        } catch (Exception e) {
            log.error("加载UI偏好失败: {}", e.getMessage(), e);
        }
    }

    private void save() {
        try {
            if (configPath.getParent() != null && !Files.exists(configPath.getParent())) {
                Files.createDirectories(configPath.getParent());
            }
            JSONObject root = new JSONObject();
            root.put("alwaysShow", new java.util.ArrayList<>(alwaysShow));
            String content = JSON.toJSONString(root, JSONWriter.Feature.PrettyFormat);
            Files.write(configPath, content.getBytes(StandardCharsets.UTF_8));
            log.info("UI偏好已保存: {}", alwaysShow);
        } catch (IOException e) {
            log.error("保存UI偏好失败: {}", e.getMessage(), e);
        }
    }
}