/**
 * ATM App - Vanilla JS Kiosk Implementation
 */

// --- 1. The "Library" Logic (Reused) ---

function h(tag, props = {}, ...children) {
    const el = document.createElement(tag);
    if (props) {
        Object.entries(props).forEach(([key, value]) => {
            if (key.startsWith('on') && typeof value === 'function') {
                el.addEventListener(key.substring(2).toLowerCase(), value);
            } else if (key === 'className') {
                el.className = value;
            } else if (key === 'style' && typeof value === 'object') {
                Object.assign(el.style, value);
            } else {
                el.setAttribute(key, value);
            }
        });
    }
    children.forEach(child => {
        if (typeof child === 'string' || typeof child === 'number') {
            el.appendChild(document.createTextNode(child));
        } else if (child instanceof Node) {
            el.appendChild(child);
        } else if (Array.isArray(child)) {
            child.forEach(c => el.appendChild(c));
        }
    });
    return el;
}

let _rootContainer = null;
let _rootComponent = null;

function render(component, container) {
    _rootContainer = container;
    _rootComponent = component;
    _render();
}

function _render() {
    _rootContainer.innerHTML = '';
    _rootContainer.appendChild(_rootComponent());
}

const createSignal = (initialValue) => {
    let _val = initialValue;
    const getValue = () => _val;
    const setValue = (newValue) => {
        _val = typeof newValue === 'function' ? newValue(_val) : newValue;
        _render();
    };
    return [getValue, setValue];
};

// --- 2. ATM Application Components ---

// Global State
const [getView, setView] = createSignal('pin'); // 'pin', 'menu', 'withdraw', 'custom_withdraw', 'balance'
const [getPin, setPin] = createSignal('');
const [getCustomAmount, setCustomAmount] = createSignal(''); // For custom withdrawal
const [getBalance, setBalance] = createSignal(1250000); // Shared mockup balance
const [getMessage, setMessage] = createSignal(''); // For feedback

// Header
function Header() {
    return h('div', { className: 'header', style: { marginBottom: '2rem' } },
        h('h1', null, 'ATM TERMINAL'),
        h('p', null, 'Global Financial Network')
    );
}

// PIN Entry View
function PinView() {
    const currentPin = getPin();

    const handleNumClick = (num) => {
        if (currentPin.length < 4) {
            setPin(prev => prev + num);
        }
    };

    const handleClear = () => setPin('');
    const handleEnter = () => {
        if (currentPin.length === 4) {
            // Mock auth success
            setView('menu');
        } else {
            setMessage('Invalid PIN Length');
            setTimeout(() => setMessage(''), 2000);
        }
    };

    return h('div', { className: 'card', style: { padding: '3rem 2rem' } },
        h('h2', null, 'Enter Security PIN'),
        h('div', { className: 'pin-display' },
            currentPin.replace(/./g, '•') || '----'
        ),
        h('p', { style: { color: 'red', height: '1.5rem' } }, getMessage()),
        h('div', { className: 'numpad' },
            ['1', '2', '3', '4', '5', '6', '7', '8', '9'].map(num =>
                h('button', { onClick: () => handleNumClick(num) }, num)
            ),
            h('button', { style: { background: '#ef4444', color: 'white' }, onClick: handleClear }, 'C'),
            h('button', { onClick: () => handleNumClick('0') }, '0'),
            h('button', { style: { background: '#10b981', color: 'white' }, onClick: handleEnter }, '↵')
        )
    );
}

// Main Menu View
function MenuView() {
    return h('div', { className: 'kiosk-content' },
        h('h2', { style: { textAlign: 'center', marginBottom: '1rem' } }, 'Select Transaction'),
        h('div', { className: 'kiosk-menu-stack' },
            h('button', { className: 'kiosk-btn', onClick: () => setView('withdraw') },
                'Withdraw Cash'
            ),
            h('button', { className: 'kiosk-btn', onClick: () => setView('balance') },
                'Check Balance'
            ),
            h('button', {
                className: 'kiosk-btn',
                style: { background: 'var(--bg-surface)', color: 'var(--text-main)', border: '1px solid var(--border)' },
                onClick: () => {
                    setPin('');
                    setView('pin');
                }
            }, 'Cancel Transaction')
        )
    );
}

// Withdraw View
function WithdrawView() {
    const handleWithdraw = (amount) => {
        if (getBalance() >= amount) {
            setBalance(prev => prev - amount);
            setMessage(`Please take your cash: $${amount}`);
            setTimeout(() => {
                setMessage('');
                setView('menu');
            }, 3000);
        } else {
            setMessage('Insufficient Funds');
            setTimeout(() => setMessage(''), 2000);
        }
    };

    if (getMessage()) {
        return h('div', { className: 'card', style: { padding: '4rem', textAlign: 'center' } },
            h('h2', { style: { color: 'var(--primary)' } }, getMessage())
        );
    }

    return h('div', { className: 'kiosk-content' },
        h('h2', { style: { textAlign: 'center', marginBottom: '1rem' } }, 'Select Amount'),
        h('div', { className: 'kiosk-grid' },
            h('button', { className: 'kiosk-btn', onClick: () => handleWithdraw(20) }, '$20'),
            h('button', { className: 'kiosk-btn', onClick: () => handleWithdraw(50) }, '$50'),
            h('button', { className: 'kiosk-btn', onClick: () => handleWithdraw(100) }, '$100'),
            h('button', {
                className: 'kiosk-btn',
                onClick: () => {
                    setCustomAmount('');
                    setView('custom_withdraw');
                }
            }, 'Other Amount'),
            h('button', { className: 'kiosk-btn', style: { gridColumn: 'span 2', background: 'var(--text-muted)' }, onClick: () => setView('menu') }, 'Cancel')
        )
    );
}

// Custom Withdraw View
function CustomWithdrawView() {
    const currentAmount = getCustomAmount();

    const handleNumClick = (num) => {
        if (currentAmount.length < 5) { // Limit to 5 digits for safety
            setCustomAmount(prev => prev + num);
        }
    };

    const handleClear = () => setCustomAmount('');

    const handleEnter = () => {
        const amount = parseInt(currentAmount, 10);
        if (amount > 0) {
            if (getBalance() >= amount) {
                setBalance(prev => prev - amount);
                setMessage(`Please take your cash: $${amount}`);
                setTimeout(() => {
                    setMessage('');
                    setView('menu');
                }, 3000);
            } else {
                setMessage('Insufficient Funds');
                setTimeout(() => setMessage(''), 2000);
            }
        } else {
            setMessage('Invalid Amount');
            setTimeout(() => setMessage(''), 2000);
        }
    };

    if (getMessage()) {
        return h('div', { className: 'card', style: { padding: '4rem', textAlign: 'center' } },
            h('h2', { style: { color: 'var(--primary)' } }, getMessage())
        );
    }

    return h('div', { className: 'card', style: { padding: '3rem 2rem' } },
        h('h2', null, 'Enter Amount'),
        h('div', { className: 'pin-display' },
            currentAmount ? `$${currentAmount}` : '$0'
        ),
        h('div', { className: 'numpad' },
            ['1', '2', '3', '4', '5', '6', '7', '8', '9'].map(num =>
                h('button', { onClick: () => handleNumClick(num) }, num)
            ),
            h('button', { style: { background: '#ef4444', color: 'white' }, onClick: handleClear }, 'C'),
            h('button', { onClick: () => handleNumClick('0') }, '0'),
            h('button', { style: { background: '#10b981', color: 'white' }, onClick: handleEnter }, '↵')
        ),
        h('button', {
            style: { width: '100%', marginTop: '2rem', padding: '1rem', background: 'var(--text-muted)' },
            onClick: () => setView('withdraw')
        }, 'Cancel')
    );
}

// Balance View
function BalanceView() {
    return h('div', { className: 'card', style: { textAlign: 'center', padding: '3rem' } },
        h('h2', { style: { color: 'var(--text-muted)' } }, 'Available Balance'),
        h('div', { style: { fontSize: '4rem', fontWeight: '800', margin: '2rem 0', color: 'var(--primary-hover)' } },
            '$' + getBalance().toLocaleString()
        ),
        h('button', { className: 'kiosk-btn', style: { width: '100%', maxWidth: '300px', margin: '0 auto' }, onClick: () => setView('menu') }, 'Return to Menu')
    );
}

// Main App
function App() {
    const view = getView();

    let mainContent;
    if (view === 'pin') {
        mainContent = PinView();
    } else if (view === 'menu') {
        mainContent = MenuView();
    } else if (view === 'withdraw') {
        mainContent = WithdrawView();
    } else if (view === 'custom_withdraw') {
        mainContent = CustomWithdrawView();
    } else if (view === 'balance') {
        mainContent = BalanceView();
    }

    return h('main', null,
        h('div', { className: 'container' },
            Header(),
            mainContent
        )
    );
}

// Mount
const root = document.getElementById('app');
render(App, root);