msr-download-button.user.js

// ==UserScript==
// @name         Monster Siren Record Download Button
// @namespace    Nep
// @version      0.3
// @description  Adds a download button to Monster Siren music pages to download song records directly.
// @author       Nep
// @match        https://monster-siren.hypergryph.com/*
// @connect      res01.hycdn.cn
// @grant        GM_xmlhttpRequest
// @grant        GM_addStyle
// ==/UserScript==

(function() {
    'use strict';

    const BUTTON_ID = 'custom-download-btn';
    let currentSong = null;

    function sanitizeFilename(filename) {
        return filename.replace(/[<>:"/\\|?*]/g, '').trim();
    }

    function handleDownloadClick() {
        const button = document.getElementById(BUTTON_ID);
        const originalText = button.textContent;

        button.textContent = 'Downloading...';
        button.disabled = true;

        const filename = sanitizeFilename(currentSong.name) + '.wav';

        GM_xmlhttpRequest({
            method: 'GET',
            url: currentSong.sourceUrl,
            headers: {
                'Cache-Control': 'no-cache',
                'Pragma': 'no-cache'
            },
            responseType: 'blob',
            onprogress: function(response) {
                button.textContent = `Downloading... ${Math.round((response.loaded / response.total) * 100)}%`;
            },
            onload: function(response) {
                try {
                    const blob = new Blob([response.response], { type: 'application/octet-stream' });
                    const objectUrl = URL.createObjectURL(blob);
                    
                    const link = document.createElement('a');
                    link.href = objectUrl;
                    link.download = filename || 'download';
                    link.style.display = 'none';
                    
                    document.body.appendChild(link);
                    link.click();
                    document.body.removeChild(link);

                    setTimeout(() => URL.revokeObjectURL(objectUrl), 1000);
                    button.textContent = `Downloaded ${filename}!`;

                    setTimeout(() => {
                        button.textContent = originalText;
                        button.disabled = false;
                    }, 2000);
                    
                } 
                catch (error) {
                    console.error('Error creating download:', error);
                    button.textContent = `Error downloading ${filename}`;

                    setTimeout(() => {
                        button.textContent = originalText;
                        button.disabled = false;
                    }, 2000);
                }
            },
            onerror: function(error) {
                console.error('Download request failed:', error);
                button.textContent = `Error downloading ${filename}`;
                setTimeout(() => {
                    button.textContent = originalText;
                    button.disabled = false;
                }, 2000);
            }
        });
        return false;
    }

    function injectDownloadButton() {
        if (document.getElementById(BUTTON_ID)) {
            return;
        }

        const controlContainer = document.querySelector('.infoAndControl___32k-O');
        if (!controlContainer) {
            return;
        }

        const downloadButton = document.createElement('button');
        downloadButton.id = BUTTON_ID;
        downloadButton.textContent = 'Download';
        downloadButton.className = 'custom-download-button';
        downloadButton.addEventListener('click', handleDownloadClick);

        const currentUrl = window.location.href;
        GM_xmlhttpRequest({
            method: 'GET',
            url: "https://monster-siren.hypergryph.com/api/song/" + currentUrl.split('/').pop(),
            headers: {
                'Content-Type': 'application/json'
            },
            onload: function(response) {
                try {
                    const data = JSON.parse(response.responseText);
                    currentSong = data.data;
                    downloadButton.textContent = `Download ${sanitizeFilename(currentSong.name)}.wav`;
                } 
                catch (error) {
                    console.error('Error fetching song:', error);
                    downloadButton.textContent = 'Error';
                }
            },
            onerror: function(error) {
                console.error('API request failed:', error);
                downloadButton.textContent = 'Error';
            }
        });

        downloadButton.style.position = 'fixed';
        downloadButton.style.top = '20px';
        downloadButton.style.right = '20px';
        downloadButton.style.zIndex = '9999';

        controlContainer.appendChild(downloadButton);
    }

    GM_addStyle(`
        .custom-download-button {
            background: #007bff;
            color: white;
            border: none;
            padding: 10px 20px;
            border-radius: 5px;
            cursor: pointer;
            font-size: 14px;
            font-weight: bold;
            transition: background-color 0.3s ease;
            box-shadow: 0 2px 4px rgba(0,0,0,0.2);
        }

        .custom-download-button:hover:not(:disabled) {
            background: #0056b3;
        }

        .custom-download-button:disabled {
            background: #6c757d;
            cursor: not-allowed;
        }

        .custom-download-button:active {
            transform: translateY(1px);
        }
    `);

    let currentUrl = window.location.href;

    function handleUrlChange() {
        const newUrl = window.location.href;
        if (newUrl !== currentUrl) {
            currentUrl = newUrl;
            console.log('URL changed to:', newUrl);

            const existingButton = document.getElementById(BUTTON_ID);
            if (existingButton) {
                existingButton.remove();
            }

            setTimeout(injectDownloadButton, 100);
        }
    }

    const originalPushState = history.pushState;
    const originalReplaceState = history.replaceState;

    history.pushState = function() {
        originalPushState.apply(history, arguments);
        setTimeout(handleUrlChange, 0);
    };

    history.replaceState = function() {
        originalReplaceState.apply(history, arguments);
        setTimeout(handleUrlChange, 0);
    };

    window.addEventListener('popstate', handleUrlChange);

    setInterval(handleUrlChange, 1000);

    const observer = new MutationObserver(function(mutations) {
        handleUrlChange();

        if (!document.getElementById(BUTTON_ID)) {
            injectDownloadButton();
        }
    });

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

    if (document.readyState === 'loading') {
        document.addEventListener('DOMContentLoaded', injectDownloadButton);
    } else {
        injectDownloadButton();
    }

})();