// ==UserScript==
// @name        Trigger full page load for Jira Cloud and Confluence Cloud
// @namespace   https://greasyfork.org/users/1047370
// @description Trigger the page to load parts that are normally (since August 2025) lazily loaded, when that part of the page this shown.  Works on Jira Cloud and Confluence Cloud as of August 2025.
// @include     https://*.atlassian.net/*
// @include     https://*.jira.com/*
// @match       https://*.atlassian.net/*
// @match       https://*.jira.com/*
// @version     0.2
// @author      Marnix Klooster <marnix.klooster@gmail.com>
// @copyright   public domain
// @license     public domain
// @homepage    https://greasyfork.org/scripts/546394
// @grant       none
// @run-at      document-start
// @downloadURL none
// ==/UserScript==

(function() {
    'use strict';
    
    const processedElements = new WeakSet();
    let isProcessing = false;
    
    const waitForPageLoad = () => {
        return new Promise(resolve => {
            if (document.readyState === 'complete') {
                resolve();
            } else {
                window.addEventListener('load', resolve);
            }
        });
    };
    
    const createGlassPane = () => {
        // Capture current scroll position
        const scrollTop = window.scrollY;
        const scrollLeft = window.scrollX;
        
        // Create the overlay container
        const pane = document.createElement('div');
        pane.style.cssText = `
            position: fixed;
            top: 0;
            left: 0;
            width: 100vw;
            height: 100vh;
            background: white;
            z-index: 999999;
            overflow: hidden;
        `;
        
        // Create viewport snapshot
        const snapshot = document.createElement('div');
        snapshot.style.cssText = `
            position: absolute;
            top: -${scrollTop}px;
            left: -${scrollLeft}px;
            width: ${document.documentElement.scrollWidth}px;
            height: ${document.documentElement.scrollHeight}px;
            pointer-events: none;
            transform-origin: 0 0;
        `;
        
        // Clone the current page content
        try {
            const bodyClone = document.body.cloneNode(true);
            
            // Remove any existing glass panes from the clone to avoid recursion
            const existingPanes = bodyClone.querySelectorAll('[style*="z-index: 999999"]');
            existingPanes.forEach(pane => pane.remove());
            
            // Remove scripts from clone to prevent execution
            const scripts = bodyClone.querySelectorAll('script');
            scripts.forEach(script => script.remove());
            
            snapshot.appendChild(bodyClone);
        } catch (e) {
            // Fallback to white background if cloning fails
            snapshot.style.background = 'white';
        }
        
        pane.appendChild(snapshot);
        
        // Create progress overlay on top of screenshot
        const progressOverlay = document.createElement('div');
        progressOverlay.style.cssText = `
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: rgba(255, 255, 255, 0.9);
            display: flex;
            align-items: center;
            justify-content: center;
            opacity: 0;
            transition: opacity 0.3s ease;
        `;
        
        const progressContainer = document.createElement('div');
        progressContainer.style.cssText = `
            background: white;
            border-radius: 8px;
            padding: 24px;
            box-shadow: 0 8px 32px rgba(0, 0, 0, 0.12);
            min-width: 300px;
            text-align: center;
        `;
        
        const progressText = document.createElement('div');
        progressText.textContent = 'Loading content...';
        progressText.style.cssText = `
            font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', sans-serif;
            font-size: 14px;
            color: #172B4D;
            margin-bottom: 16px;
            font-weight: 500;
        `;
        
        const progressTrack = document.createElement('div');
        progressTrack.style.cssText = `
            width: 100%;
            height: 4px;
            background: #DFE1E6;
            border-radius: 2px;
            overflow: hidden;
        `;
        
        const progressBar = document.createElement('div');
        progressBar.style.cssText = `
            width: 0%;
            height: 100%;
            background: #0052CC;
            border-radius: 2px;
            transition: width 0.3s ease;
        `;
        
        progressTrack.appendChild(progressBar);
        progressContainer.appendChild(progressText);
        progressContainer.appendChild(progressTrack);
        progressOverlay.appendChild(progressContainer);
        pane.appendChild(progressOverlay);
        
        document.body.appendChild(pane);
        
        const showProgress = () => {
            progressOverlay.style.opacity = '1';
        };
        
        return { pane, progressBar, showProgress };
    };
    
    const findEmptyDivs = () => {
        return Array.from(document.querySelectorAll('div'))
            .filter(div => 
                div.textContent.trim() === '' && 
                div.attributes.length === 0 &&
                !processedElements.has(div)
            );
    };
    
    const waitForStability = (element, timeout = 50) => {
        return new Promise(resolve => {
            let timer;
            const observer = new MutationObserver(() => {
                clearTimeout(timer);
                timer = setTimeout(() => {
                    observer.disconnect();
                    resolve();
                }, timeout);
            });
            
            observer.observe(element, {
                childList: true,
                subtree: true,
                attributes: true,
                characterData: true
            });
            
            // Start initial timer in case no mutations occur
            timer = setTimeout(() => {
                observer.disconnect();
                resolve();
            }, timeout);
        });
    };
    
    const triggerByMinimalScroll = async (element) => {
        const originalScrollY = window.scrollY;
        const rect = element.getBoundingClientRect();
        
        // Only scroll if element is not already in viewport
        if (rect.top > window.innerHeight || rect.bottom < 0) {
            // Calculate minimal scroll to bring element just into intersection margin
            // Scroll just enough to trigger intersection observer (usually has rootMargin)
            const targetY = originalScrollY + rect.top - window.innerHeight + 100; // 100px margin
            
            // Use instant scrolling to minimize visual disruption
            window.scrollTo({ top: targetY, behavior: 'auto' });
            
            // Wait briefly for intersection observers to trigger
            await new Promise(resolve => setTimeout(resolve, 50));
            
            // Immediately scroll back to original position
            window.scrollTo({ top: originalScrollY, behavior: 'auto' });
        }
        
        // Wait for any content loading to complete
        await waitForStability(element);
        processedElements.add(element);
    };
    
    const processLazyElements = async () => {
        if (isProcessing) return;
        isProcessing = true;
        
        const emptyDivs = findEmptyDivs();
        
        if (emptyDivs.length === 0) {
            isProcessing = false;
            return;
        }
        
        console.log(`Processing ${emptyDivs.length} lazy-loaded elements`);
        const { pane: glassPane, progressBar, showProgress } = createGlassPane();
        
        // Wait 200ms before showing progress to prevent flashing for quick operations
        const showTimer = setTimeout(showProgress, 200);
        
        try {
            for (let i = 0; i < emptyDivs.length; i++) {
                const progress = ((i + 1) / emptyDivs.length) * 100;
                progressBar.style.width = `${progress}%`;
                
                await triggerByMinimalScroll(emptyDivs[i]);
            }
        } finally {
            clearTimeout(showTimer);
            glassPane.remove();
            isProcessing = false;
        }
    };
    
    const observePageChanges = () => {
        const observer = new MutationObserver(() => {
            // Debounce to avoid excessive processing
            clearTimeout(observer.timer);
            observer.timer = setTimeout(processLazyElements, 100);
        });
        
        observer.observe(document.body, {
            childList: true,
            subtree: true
        });
    };
    
    const init = async () => {
        await waitForPageLoad();
        console.log('Page fully loaded, starting lazy element processing');
        
        await processLazyElements();
        observePageChanges();
    };
    
    init();
    
})();