document.addEventListener('DOMContentLoaded', () => {
    const sidebar = document.getElementById('sidebar');
    const closeBtn = document.getElementById('close-sidebar');
    const trigger = document.getElementById('read-more-trigger');
    const body = document.body;
    let manualClose = false;

    // --- Shy Logo Logic ---
    const logo = document.querySelector('.header-logo img');
    const header = document.querySelector('.main-header');

    if (logo && header) {
        let offsetX = 0, offsetY = 0;
        let velX = 0, velY = 0;
        let mouseX = 0, mouseY = 0;
        let chaseStarted = false;
        let approaching = false;
        let stillTimer = null;
        let animating = false;

        const FLEE_RADIUS = 130;
        const FLEE_FORCE = 18;
        const FRICTION = 0.82;
        const APPROACH_SPEED = 0.035;
        const STILL_DELAY = 1000;

        function logoCenter() {
            const r = logo.getBoundingClientRect();
            return { x: r.left + r.width / 2, y: r.top + r.height / 2 };
        }

        function headerBounds() {
            const hr = header.getBoundingClientRect();
            const lr = logo.getBoundingClientRect();
            return {
                minX: -(lr.left - hr.left) + 8,
                maxX: (hr.right - lr.right) - 8,
                minY: -(lr.top - hr.top) + 8,
                maxY: (hr.bottom - lr.bottom) - 8
            };
        }

        function clamp(x, y) {
            const b = headerBounds();
            return {
                x: Math.max(b.minX, Math.min(b.maxX, x)),
                y: Math.max(b.minY, Math.min(b.maxY, y))
            };
        }

        function applyTransform() {
            logo.style.transform = `translate(${offsetX}px, ${offsetY}px)`;
        }

        function tick() {
            if (approaching) {
                // Gently approach where the mouse is
                const c = logoCenter();
                const targetX = mouseX - (c.x - offsetX);
                const targetY = mouseY - (c.y - offsetY);
                velX += (targetX - offsetX) * APPROACH_SPEED;
                velY += (targetY - offsetY) * APPROACH_SPEED;
                velX *= 0.85;
                velY *= 0.85;
            }

            velX *= FRICTION;
            velY *= FRICTION;
            offsetX += velX;
            offsetY += velY;

            const c = clamp(offsetX, offsetY);
            // Bounce off header edges
            if (c.x !== offsetX) velX *= -0.3;
            if (c.y !== offsetY) velY *= -0.3;
            offsetX = c.x;
            offsetY = c.y;

            applyTransform();

            const moving = Math.abs(velX) > 0.1 || Math.abs(velY) > 0.1;
            const farFromHome = Math.abs(offsetX) > 0.5 || Math.abs(offsetY) > 0.5;
            if (moving || approaching || farFromHome) {
                requestAnimationFrame(tick);
            } else {
                animating = false;
            }
        }

        function startAnim() {
            if (!animating) {
                animating = true;
                requestAnimationFrame(tick);
            }
        }

        header.addEventListener('mousemove', (e) => {
            mouseX = e.clientX;
            mouseY = e.clientY;

            const c = logoCenter();
            const dx = c.x - mouseX;
            const dy = c.y - mouseY;
            const dist = Math.sqrt(dx * dx + dy * dy);

            if (dist < FLEE_RADIUS) {
                chaseStarted = true;
                approaching = false;

                // Flee away from cursor
                const angle = Math.atan2(dy, dx);
                const force = ((FLEE_RADIUS - dist) / FLEE_RADIUS) * FLEE_FORCE;
                velX += Math.cos(angle) * force;
                velY += Math.sin(angle) * force;
                startAnim();
            }

            // Reset the "stopped chasing" timer
            clearTimeout(stillTimer);
            stillTimer = setTimeout(() => {
                if (chaseStarted) {
                    approaching = true;
                    startAnim();
                }
            }, STILL_DELAY);
        });

        header.addEventListener('mouseleave', () => {
            clearTimeout(stillTimer);
            approaching = false;
            chaseStarted = false;
            // Drift home
            velX += -offsetX * 0.08;
            velY += -offsetY * 0.08;
            startAnim();
        });
    }

    // --- Sidebar Logic ---

    function checkSidebarVisibility() {
        if (manualClose) return;

        const scrollTop = window.scrollY;
        const windowHeight = window.innerHeight;
        const docHeight = document.documentElement.scrollHeight;

        // "Sidebar fix": Check if page is short (content fits in window or close to it)
        // If content is short, sidebar should be visible immediately (if desktop)
        if (docHeight <= windowHeight * 1.2 && window.innerWidth > 900) {
            sidebar.classList.add('visible');
            sidebar.style.opacity = 1;
            sidebar.style.pointerEvents = 'auto';
            return;
        }

        // Scroll Logic for longer pages
        if (scrollTop + windowHeight > docHeight * 0.9) {
            sidebar.classList.add('visible');
            trigger.classList.add('visible');

            // Dynamic Opacity near bottom
            const remaining = docHeight - (scrollTop + windowHeight);
            const threshold = docHeight * 0.1;

            if (remaining < threshold) {
                const opacity = 1 - (remaining / threshold);
                sidebar.style.opacity = Math.min(Math.max(opacity, 0), 1);

                if (opacity > 0) {
                    sidebar.style.pointerEvents = 'auto';
                } else {
                    sidebar.style.pointerEvents = 'none';
                }
            } else {
                // Should be redundant with visibility check but safe
            }
        } else {
            // Hide if scrolled up? 
            // "It just is gone then... manual close... refresh if want it back"
            // But scroll behavior implies transient visibility.
            // We'll hide it if we scroll back up, unless it's short content.
            sidebar.style.opacity = 0;
            sidebar.style.pointerEvents = 'none';
        }
    }

    window.addEventListener('scroll', checkSidebarVisibility);
    window.addEventListener('resize', checkSidebarVisibility);

    // Initial check
    setTimeout(checkSidebarVisibility, 100); // Slight delay for rendering

    // Mobile Trigger
    trigger.addEventListener('click', () => {
        sidebar.classList.add('force-visible');
        sidebar.style.opacity = 1;
        sidebar.style.pointerEvents = 'auto';
    });

    // Close Button
    closeBtn.addEventListener('click', () => {
        sidebar.classList.remove('visible');
        sidebar.classList.remove('force-visible');
        sidebar.style.opacity = 0;
        sidebar.style.pointerEvents = 'none';
        manualClose = true;
        trigger.style.display = 'none';
    });

    // --- Font Tribute: Carter & Connare ---
    const TRIBUTE_FONTS = ['Georgia', 'Tahoma', 'Comic Sans MS', 'Trebuchet MS'];

    function tributeTextNodes() {
        const content = document.querySelector('.main-content');
        if (!content) return [];
        const nodes = [];
        const walker = document.createTreeWalker(content, NodeFilter.SHOW_TEXT, {
            acceptNode: (n) => {
                const el = n.parentElement;
                if (n.textContent.trim().length < 2) return NodeFilter.FILTER_REJECT;
                if (['SCRIPT','STYLE','CODE','PRE'].includes(el.tagName)) return NodeFilter.FILTER_REJECT;
                if (el.classList.contains('font-tribute')) return NodeFilter.FILTER_REJECT;
                return NodeFilter.FILTER_ACCEPT;
            }
        });
        while (walker.nextNode()) nodes.push(walker.currentNode);
        return nodes;
    }

    function sprinkleFont() {
        const nodes = tributeTextNodes();
        if (!nodes.length) return;

        const node = nodes[Math.floor(Math.random() * nodes.length)];
        const text = node.textContent;

        // Find a non-whitespace character
        let pos, tries = 0;
        do {
            pos = Math.floor(Math.random() * text.length);
        } while (text[pos].trim() === '' && ++tries < 20);
        if (text[pos].trim() === '') return;

        const font = TRIBUTE_FONTS[Math.floor(Math.random() * TRIBUTE_FONTS.length)];
        const span = document.createElement('span');
        span.textContent = text[pos];
        span.style.fontFamily = '"' + font + '"';
        span.className = 'font-tribute';

        const before = document.createTextNode(text.slice(0, pos));
        const after = document.createTextNode(text.slice(pos + 1));
        node.parentNode.insertBefore(before, node);
        node.parentNode.insertBefore(span, node);
        node.parentNode.insertBefore(after, node);
        node.parentNode.removeChild(node);
    }

    // Initial sprinkle: 3 letters
    for (let i = 0; i < 3; i++) sprinkleFont();

    // Occasionally, mid-read, one more letter quietly changes
    (function scheduleNext() {
        setTimeout(() => {
            sprinkleFont();
            scheduleNext();
        }, 12000 + Math.random() * 30000); // every 12-42 seconds
    })();

    // --- Dark Mode Logic ---

    // Create Toggle Button
    const sidebarContent = document.querySelector('.sidebar-content');
    const themeBtn = document.createElement('button');
    themeBtn.id = 'theme-toggle';
    themeBtn.textContent = 'Toggle Theme';
    sidebarContent.appendChild(themeBtn);

    function setDarkMode(enable) {
        if (enable) {
            body.classList.add('dark-mode');
            themeBtn.textContent = 'Switch to Light Mode';
        } else {
            body.classList.remove('dark-mode');
            themeBtn.textContent = 'Switch to Dark Mode';
        }
    }

    function getCookie(name) {
        const v = document.cookie.match('(^|;) ?' + name + '=([^;]*)(;|$)');
        return v ? v[2] : null;
    }

    function setCookie(name, value, hours) {
        const d = new Date();
        d.setTime(d.getTime() + (hours * 60 * 60 * 1000));
        document.cookie = name + "=" + value + ";path=/;expires=" + d.toUTCString();
    }

    // Init Dark Mode
    const cookieTheme = getCookie('theme');
    if (cookieTheme === 'dark') {
        setDarkMode(true);
    } else if (cookieTheme === 'light') {
        setDarkMode(false);
    } else {
        // Time based auto-detect
        const hour = new Date().getHours();
        if (hour < 6 || hour >= 18) {
            setDarkMode(true);
        } else {
            setDarkMode(false);
        }
    }

    themeBtn.addEventListener('click', () => {
        const isDark = body.classList.contains('dark-mode');
        setDarkMode(!isDark);
        setCookie('theme', !isDark ? 'dark' : 'light', 24);
    });
});