// ==UserScript==
// @name         IndexedDB KeyVal Store导出、导入为JSON
// @namespace    http://tampermonkey.net/
// @version      0.1
// @description  将IndexedDB keyval-store存储桶中的全部数据导出下载为JSON，从JSON文件导入数据到IndexedDB keyval-store
// @author       WorldDev
// @match        *://*/*
// @grant        none
// ==/UserScript==

(function() {
    'use strict';

    // 延迟一秒执行
    setTimeout(() => {
        // 创建一个容器来放置按钮
        const buttonContainer = document.createElement('div');
        buttonContainer.style.position = 'fixed';
        buttonContainer.style.top = '100px';
        buttonContainer.style.left = '100px';
        buttonContainer.style.zIndex = '9999';
        buttonContainer.style.display = 'flex';
        buttonContainer.style.flexDirection = 'column';
        buttonContainer.style.gap = '0'; // 设置按钮无间隔
        document.body.appendChild(buttonContainer);

        // 创建导出按钮
        const exportButton = document.createElement('button');
        exportButton.id = 'exportButton';
        exportButton.textContent = '导出数据为JSON';
        buttonContainer.appendChild(exportButton);

        // 创建导入按钮
        const importButton = document.createElement('button');
        importButton.id = 'importButton';
        importButton.textContent = '从JSON导入数据';
        buttonContainer.appendChild(importButton);

        // 创建隐藏的文件输入元素用于导入
        const fileInput = document.createElement('input');
        fileInput.type = 'file';
        fileInput.accept = '.json';
        fileInput.style.display = 'none';
        document.body.appendChild(fileInput);

        // 绑定事件监听器
        document.getElementById('exportButton').addEventListener('click', exportDataToJson);
        document.getElementById('importButton').addEventListener('click', () => fileInput.click());
        fileInput.addEventListener('change', handleFileSelect);

        function openDatabase() {
            return new Promise((resolve, reject) => {
                const request = indexedDB.open('keyval-store');
                request.onerror = event => reject(event.target.error);
                request.onsuccess = event => resolve(event.target.result);
                request.onupgradeneeded = event => {
                    const db = event.target.result;
                    if (!db.objectStoreNames.contains('keyval')) {
                        db.createObjectStore('keyval');
                    }
                };
            });
        }

        async function getAllData(db) {
            const transaction = db.transaction(['keyval'], 'readonly');
            const objectStore = transaction.objectStore('keyval');
            const data = await getAllFromObjectStore(objectStore);
            return data;
        }

        function getAllFromObjectStore(objectStore) {
            return new Promise((resolve, reject) => {
                const allItems = [];
                const request = objectStore.openCursor();
                request.onsuccess = event => {
                    const cursor = event.target.result;
                    if (cursor) {
                        allItems.push({ key: cursor.key, value: cursor.value });
                        cursor.continue();
                    } else {
                        resolve(allItems);
                    }
                };
                request.onerror = event => reject(event.target.error);
            });
        }

        async function exportDataToJson() {
            try {
                const db = await openDatabase();
                const data = await getAllData(db);
                const jsonContent = JSON.stringify(data, null, 2);
                downloadJson(jsonContent, 'indexeddb_data.json');
            } catch (error) {
                console.error('导出数据时出错:', error);
                alert('导出数据失败，请检查控制台错误信息。');
            }
        }

        function downloadJson(content, filename) {
            const blob = new Blob([content], { type: 'application/json' });
            const url = URL.createObjectURL(blob);
            const a = document.createElement('a');
            a.href = url;
            a.download = filename;
            document.body.appendChild(a);
            a.click();
            document.body.removeChild(a);
            URL.revokeObjectURL(url);
        }

        function handleFileSelect(event) {
            const file = event.target.files[0];
            if (file) {
                const reader = new FileReader();
                reader.readAsText(file);
                reader.onload = async e => {
                    try {
                        const jsonData = JSON.parse(e.target.result);
                        const db = await openDatabase();
                        await importDataToDb(db, jsonData);
                        alert('数据导入成功！');
                    } catch (error) {
                        console.error('导入数据时出错:', error);
                        alert('导入数据失败，请检查控制台错误信息。');
                    }
                };
            }
        }

        async function importDataToDb(db, data) {
            const transaction = db.transaction(['keyval'], 'readwrite');
            const objectStore = transaction.objectStore('keyval');

            for (const item of data) {
                objectStore.put(item.value, item.key);
            }

            return new Promise((resolve, reject) => {
                transaction.oncomplete = () => resolve();
                transaction.onerror = event => reject(event.target.error);
            });
        }
    }, 1000); // 延迟1秒执行
})();