script.js

document.addEventListener('DOMContentLoaded', () => {
    // DOM Element Selectors
    const loginCard = document.getElementById('loginCard');
    const registerCard = document.getElementById('registerCard');
    
    const goToRegisterBtn = document.getElementById('goToRegister');
    const goToLoginBtn = document.getElementById('goToLogin');

    const loginForm = document.getElementById('loginForm');
    const registerForm = document.getElementById('registerForm');

    // --- INTERFACE VIEW SWITCHING TOGGLES ---
    if (goToRegisterBtn && loginCard && registerCard) {
        goToRegisterBtn.addEventListener('click', () => {
            hideAlerts();
            loginCard.classList.add('hidden');
            registerCard.classList.remove('hidden');
        });
    }

    if (goToLoginBtn && loginCard && registerCard) {
        goToLoginBtn.addEventListener('click', () => {
            hideAlerts();
            registerCard.classList.add('hidden');
            loginCard.classList.remove('hidden');
        });
    }

    function hideAlerts() {
        document.querySelectorAll('.alert-box').forEach(box => box.style.display = 'none');
        document.querySelectorAll('.input-group').forEach(group => group.classList.remove('error'));
    }

    // --- LOCAL REGISTRATION REGISTRY HANDLER ---
    if (registerForm) {
        registerForm.addEventListener('submit', (e) => {
            e.preventDefault();
            hideAlerts();

            const emailEl = document.getElementById('regEmail');
            const passwordEl = document.getElementById('regPassword');
            
            if (!emailEl || !passwordEl) return;

            const email = emailEl.value.trim();
            const password = passwordEl.value;
            let valid = true;

            if (!email) {
                document.getElementById('regEmailGroup')?.classList.add('error');
                valid = false;
            }
            if (password.length < 8) {
                document.getElementById('regPasswordGroup')?.classList.add('error');
                valid = false;
            }

            if (!valid) return;

            const existingUser = localStorage.getItem(`user_${email}`);
            if (existingUser) {
                const registerAlert = document.getElementById('registerAlert');
                if (registerAlert) registerAlert.style.display = 'block';
                return;
            }

            const userData = { email: email, password: password };
            localStorage.setItem(`user_${email}`, JSON.stringify(userData));

            registerForm.reset();

            const loginAlertSuccess = document.getElementById('loginAlertSuccess');
            if (loginAlertSuccess) {
                loginAlertSuccess.textContent = "Registration successful! Please log in.";
                loginAlertSuccess.style.display = 'block';
            }

            registerCard?.classList.add('hidden');
            loginCard?.classList.remove('hidden');
        });
    }

    // --- LOCAL LOGIN HANDLER ---
    if (loginForm) {
        loginForm.addEventListener('submit', (e) => {
            // 1. Instantly stop form submission to prevent the page reload (?)
            e.preventDefault(); 
            hideAlerts();

            const emailEl = document.getElementById('loginEmail');
            const passwordEl = document.getElementById('loginPassword');

            // Fallback: If you forgot to put IDs directly on the inputs, try fetching by type
            const emailInput = emailEl || document.querySelector('input[type="email"]');
            const passwordInput = passwordEl || document.querySelector('input[type="password"]');

            if (!emailInput || !passwordInput) {
                console.error("Critical Error: Could not find email or password input fields in HTML.");
                return;
            }

            const email = emailInput.value.trim();
            const password = passwordInput.value;
            let valid = true;

            if (!email) {
                document.getElementById('loginEmailGroup')?.classList.add('error');
                valid = false;
            }
            if (!password) {
                document.getElementById('loginPasswordGroup')?.classList.add('error');
                valid = false;
            }

            if (!valid) return;

            // Fetch record from browser storage
            const storedUser = localStorage.getItem(`user_${email}`);

            if (storedUser) {
                const userData = JSON.parse(storedUser);
                
                if (userData.password === password) {
                    // Redirect to home page
                    window.location.href = '../indexes/index.html';
                } else {
                    const loginAlertError = document.getElementById('loginAlertError');
                    if (loginAlertError) loginAlertError.style.display = 'block';
                    else alert("Incorrect password!");
                }
            } else {
                const loginAlertError = document.getElementById('loginAlertError');
                if (loginAlertError) loginAlertError.style.display = 'block';
                else alert("Account not found. Please register first!");
            }
        });
    }
});