// ==UserScript==
// @name         Highlight to Anki by xxhk.org
// @namespace    http://tampermonkey.net/
// @version      20240608
// @description  Highlight selected text, save highlighted content to a .txt file on button click, and undo the last highlight action with debounce mechanism. Needed template of Anki : https://www.jianguoyun.com/p/DcgfQDIQ89bQBxiJsNQFIAA
// @match        https://*.com/*
// @grant        none
// ==/UserScript==

(function() {
    'use strict';

    const HIGHLIGHT_CLASS = 'user-highlight';
    const STORAGE_KEY = 'highlightedText';
    const HISTORY_KEY = 'highlightedTextHistory';
    let highlightTimeout = null;
    let isHighlightEnabled = true; // Default enabled
    let lastUndoTime = 0;

    // Function to extract and format the title
    function extractTitle() {
        let title = document.title.replace(/[\\/:*?"<>|]+/g, '-').replace(/\s+/g, '-').replace(/-+/g, '-');
        return title;  // Return the full formatted title
    }

    const Htitle = extractTitle();

    // Function to highlight selected text
    function highlightSelection() {
        if (!isHighlightEnabled) return;

        const selection = window.getSelection();
        if (!selection.rangeCount || selection.isCollapsed) return;

        const range = selection.getRangeAt(0);
        const fragment = range.cloneContents();
        const span = document.createElement('span');
        span.className = HIGHLIGHT_CLASS;
        span.setAttribute('style', 'background-color: yellow; color: inherit;');

        while (fragment.firstChild) {
            span.appendChild(fragment.firstChild);
        }

        range.deleteContents();
        range.insertNode(span);

        saveHighlights(true); // Save highlights and history
        selection.removeAllRanges(); // Clear the selection after highlighting
    }

    // Function to save highlighted text to localStorage
    function saveHighlights(saveHistory = false) {
        const highlights = [];
        document.querySelectorAll(`.${HIGHLIGHT_CLASS}`).forEach(span => {
            highlights.push({
                html: span.outerHTML,
                parentPath: getElementPath(span.parentNode)
            });
        });
        localStorage.setItem(STORAGE_KEY, JSON.stringify(highlights));

        if (saveHistory) {
            saveHistoryState();
        }
    }

    // Function to save the current state of highlighted text to localStorage
    function saveHistoryState() {
        const currentHighlights = localStorage.getItem(STORAGE_KEY);
        const highlightsHistory = JSON.parse(localStorage.getItem(HISTORY_KEY) || '[]');
        highlightsHistory.push(currentHighlights);
        localStorage.setItem(HISTORY_KEY, JSON.stringify(highlightsHistory));
    }

    // Function to undo the last highlight action
    function undoHighlight() {
        const currentTime = new Date().getTime();
        if (currentTime - lastUndoTime < 1000) {
            return; // If last undo was less than 1 second ago, ignore this undo request
        }
        lastUndoTime = currentTime;

        const highlights = document.querySelectorAll(`.${HIGHLIGHT_CLASS}`);
        if (highlights.length === 0) {
            alert('没有可以撤销的高亮操作。');
            return;
        }

        const lastHighlight = highlights[highlights.length - 1];
        const parent = lastHighlight.parentNode;
        parent.replaceChild(document.createTextNode(lastHighlight.textContent), lastHighlight);

        saveHighlights(true); // Update the saved highlights and history
    }

    // Function to get the unique path of an element in the DOM
    function getElementPath(element) {
        if (element.id) return `#${element.id}`;
        const path = [];
        while (element.parentNode) {
            let siblings = Array.from(element.parentNode.children).filter(e => e.tagName === element.tagName);
            path.unshift(`${element.tagName}:nth-of-type(${siblings.indexOf(element) + 1})`);
            element = element.parentNode;
        }
        return path.join(' > ');
    }

    // Function to restore highlighted text from localStorage
    function restoreHighlights() {
        const highlights = JSON.parse(localStorage.getItem(STORAGE_KEY) || '[]');
        highlights.forEach(item => {
            const parent = document.querySelector(item.parentPath);
            if (parent) {
                const tempDiv = document.createElement('div');
                tempDiv.innerHTML = item.html;
                const span = tempDiv.firstChild;
                parent.innerHTML = parent.innerHTML.replace(span.innerHTML, span.outerHTML);
            }
        });
    }

    // Function to prompt to save highlighted text to a .txt file
    function saveHighlightsToFile() {
        const highlights = [];
        const url = window.location.href;
        document.querySelectorAll(`.${HIGHLIGHT_CLASS}`).forEach(span => {
            let text = span.textContent.trim();
            if (text && text !== "🔗") {
                highlights.push(`${text} <a href="${url}">🔗</a>`); // Placeholder link
            }
        });

        // Merge paragraphs and handle empty lines correctly
        const mergedHighlights = [];
        let tempParagraph = [];

        highlights.forEach(line => {
            if (line.includes('🔗')) {
                tempParagraph.push(line);
                mergedHighlights.push(tempParagraph.join(' ').replace(/\s+/g, ' '));
                tempParagraph = [];
            } else if (line.trim() === '') {
                if (tempParagraph.length > 0) {
                    mergedHighlights.push(tempParagraph.join(' ').replace(/\s+/g, ' '));
                    tempParagraph = [];
                }
                mergedHighlights.push(''); // Keep the empty line
            } else {
                tempParagraph.push(line);
            }
        });

        if (tempParagraph.length > 0) {
            mergedHighlights.push(tempParagraph.join(' ').replace(/\s+/g, ' '));
        }

        const date = new Date().toISOString().slice(0, 10);
        const title = document.title.replace(/[\\/:*?"<>|]+/g, '_').replace(/\s+/g, '-').replace(/-+/g, '-');
        const content = `#方案支持：学习骇客（xxhk.org）\n#separator:Tab\n#html:true\n#tags:Highlight::${Htitle}\n\n${mergedHighlights.join('\n\n')}`;

        const blob = new Blob([content], { type: 'text/plain' });
        const blobUrl = URL.createObjectURL(blob);
        const a = document.createElement('a');
        a.href = blobUrl;
        a.download = `标注笔记：${date}_${title}.txt`;

        document.body.appendChild(a);
        a.click();
        document.body.removeChild(a);
        URL.revokeObjectURL(blobUrl);
    }

    // Function to handle close button click
    function handleCloseButtonClick() {
        isHighlightEnabled = false;
        const button = document.getElementById('highlight-button-container');
        button.style.display = 'none';
        alert('高亮标注功能已禁用。');
    }

    // Function to create and append a save button with close button
    function createSaveButton() {
        const buttonContainer = document.createElement('div');
        buttonContainer.id = 'highlight-button-container';
        buttonContainer.style.position = 'fixed';
        buttonContainer.style.top = '50%';
        buttonContainer.style.right = '10px';
        buttonContainer.style.transform = 'translateY(-50%)';
        buttonContainer.style.zIndex = '1000';
        buttonContainer.style.display = 'flex';
        buttonContainer.style.flexDirection = 'column';
        buttonContainer.style.alignItems = 'center';
        buttonContainer.style.backgroundColor = 'black';
        buttonContainer.style.color = '#fff';
        buttonContainer.style.borderRadius = '5px';
        buttonContainer.style.overflow = 'hidden';

        const downloadButton = document.createElement('button');
        downloadButton.textContent = '⬇️';
        downloadButton.style.width = '2em';
        downloadButton.style.height = '2em';
        downloadButton.style.backgroundColor = 'black';
        downloadButton.style.color = '#fff';
        downloadButton.style.border = 'none';
        downloadButton.style.cursor = 'pointer';

        const undoButton = document.createElement('button');
        undoButton.textContent = '↩️';
        undoButton.style.width = '2em';
        undoButton.style.height = '2em';
        undoButton.style.backgroundColor = 'black';
        undoButton.style.color = '#fff';
        undoButton.style.border = 'none';
        undoButton.style.cursor = 'pointer';

        const closeButton = document.createElement('button');
        closeButton.textContent = '✖';
        closeButton.style.width = '2em';
        closeButton.style.height = '2em';
        closeButton.style.backgroundColor = 'red';
        closeButton.style.color = '#fff';
        closeButton.style.border = 'none';
        closeButton.style.cursor = 'pointer';

        downloadButton.addEventListener('click', saveHighlightsToFile);
        undoButton.addEventListener('click', undoHighlight);
        closeButton.addEventListener('click', handleCloseButtonClick);

        buttonContainer.appendChild(downloadButton);
        buttonContainer.appendChild(undoButton);
        buttonContainer.appendChild(closeButton);
        document.body.appendChild(buttonContainer);
    }

    // Restore highlights on page load
    window.addEventListener('load', () => {


        restoreHighlights();
        createSaveButton();
    });

    // Function to handle text selection with a delay
    function handleSelectionChange() {
        if (highlightTimeout) clearTimeout(highlightTimeout);
        highlightTimeout = setTimeout(() => {
            const selection = window.getSelection();
            if (selection && selection.rangeCount > 0 && selection.toString().length > 0) {
                highlightSelection();
            }
        }, 500); // Adjust the delay as needed
    }

    // Add event listeners
    document.addEventListener('selectionchange', handleSelectionChange);
    document.addEventListener('touchend', handleSelectionChange);
    document.addEventListener('mouseup', handleSelectionChange);

})();