// ==UserScript==
// @name         gemini 代码底部增加复制按钮
// @namespace    http://tampermonkey.net/
// @version      0.2
// @description  gemini Adds a "Copy Code" button to the bottom of specified code block structures. 
// @author       Your Name
// @match        https://gemini.google.com/app/*
// @grant        GM_addStyle

// @grant        GM_setClipboard
// @license MIT
// @downloadURL none
// ==/UserScript==

(function() {
    'use strict';

    const CUSTOM_BUTTON_CLASS = 'custom-bottom-copy-button';
    const FOOTER_CLASS = 'custom-code-block-footer';
    const PROCESSED_MARKER_CLASS = 'custom-bottom-copy-added';

    function createAndAddButton(codeBlockElement) {
        // Check if already processed
        if (codeBlockElement.classList.contains(PROCESSED_MARKER_CLASS)) {
            return;
        }

        // Try to find the code content element
        // Prioritize the specific data-test-id if available, then fall back to pre code
        const codeContentElement = codeBlockElement.querySelector('code[data-test-id="code-content"], pre code');

        if (!codeContentElement) {
            // console.warn('[Custom Copy Button] Code content element not found in:', codeBlockElement);
            return;
        }

        // Create the button
        const copyButton = document.createElement('button');
        copyButton.textContent = '复制代码'; // "Copy Code"
        copyButton.className = CUSTOM_BUTTON_CLASS;
        copyButton.setAttribute('aria-label', '复制代码');

        copyButton.addEventListener('click', async (event) => {
            event.stopPropagation(); // Prevent event bubbling

            const codeText = codeContentElement.innerText; // Use innerText to get the rendered text
            const originalButtonText = copyButton.textContent;

            try {
                await navigator.clipboard.writeText(codeText);
                copyButton.textContent = '已复制!';
                // console.log('[Custom Copy Button] Code copied via navigator.clipboard.');
            } catch (err) {
                // console.error('[Custom Copy Button] Navigator.clipboard failed:', err);
                try {
                    GM_setClipboard(codeText); // Fallback to GM_setClipboard
                    copyButton.textContent = '已复制 (GM)!';
                    // console.log('[Custom Copy Button] Code copied via GM_setClipboard.');
                } catch (gmErr) {
                    // console.error('[Custom Copy Button] GM_setClipboard failed:', gmErr);
                    copyButton.textContent = '复制失败';
                    alert('无法复制代码到剪贴板。请手动复制。');
                }
            }

            setTimeout(() => {
                copyButton.textContent = originalButtonText;
            }, 2500);
        });

        // Create a footer element to hold the button
        let footerDiv = codeBlockElement.querySelector('.' + FOOTER_CLASS);
        if (!footerDiv) {
            footerDiv = document.createElement('div');
            footerDiv.className = FOOTER_CLASS;
            codeBlockElement.appendChild(footerDiv); // Append footer to the code block
        }
        footerDiv.appendChild(copyButton);

        codeBlockElement.classList.add(PROCESSED_MARKER_CLASS);
    }

    function processAllCodeBlocks() {
        const codeBlocks = document.querySelectorAll('div.code-block');
        codeBlocks.forEach(block => {
            createAndAddButton(block);
        });
    }

    // Add styles for the new button and footer
    GM_addStyle(`
        .${FOOTER_CLASS} {
            display: flex;
            justify-content: flex-end; /* Aligns button to the right */
            padding: 8px;
            margin-top: 5px; /* Space between code and footer */
            border-top: 1px solid #e0e0e0; /* Optional separator */
            background-color: #f9f9f9; /* Slight background for the footer */
        }
        .${CUSTOM_BUTTON_CLASS} {
            background-color: #4CAF50; /* Green */
            color: white;
            border: none;
            padding: 8px 16px;
            text-align: center;
            text-decoration: none;
            display: inline-block;
            font-size: 13px;
            border-radius: 4px;
            cursor: pointer;
            transition: background-color 0.3s ease;
        }
        .${CUSTOM_BUTTON_CLASS}:hover {
            background-color: #45a049; /* Darker Green */
        }
        .${CUSTOM_BUTTON_CLASS}:active {
            background-color: #3e8e41;
        }
    `);

    // Initial run
    processAllCodeBlocks();

    // Use MutationObserver to handle dynamically loaded code blocks
    const observer = new MutationObserver((mutationsList) => {
        for (const mutation of mutationsList) {
            if (mutation.type === 'childList' && mutation.addedNodes.length > 0) {
                mutation.addedNodes.forEach(node => {
                    if (node.nodeType === Node.ELEMENT_NODE) {
                        // Check if the added node is a code block itself
                        if (node.matches && node.matches('div.code-block')) {
                            createAndAddButton(node);
                        }
                        // Check if the added node contains code blocks
                        node.querySelectorAll('div.code-block').forEach(createAndAddButton);
                    }
                });
            }
        }
    });

    observer.observe(document.body, { childList: true, subtree: true });

    // You can expose the function for debugging if needed:
    // window.customProcessCodeBlocks = processAllCodeBlocks;

})();