const API_BASE_URL = '/api';
let currentUser = null;
let resetToken = null;

// Theme management
function initializeTheme() {
    const savedTheme = localStorage.getItem('theme') || 'light';
    document.documentElement.setAttribute('data-theme', savedTheme);
}

function toggleTheme() {
    const currentTheme = document.documentElement.getAttribute('data-theme') || 'light';
    const newTheme = currentTheme === 'light' ? 'dark' : 'light';

    document.documentElement.setAttribute('data-theme', newTheme);
    localStorage.setItem('theme', newTheme);
}

function parseURLParams() {
    const urlParams = new URLSearchParams(window.location.search);
    const hasResetFlag = urlParams.has('reset-password');
    const token = urlParams.get('token');

    return {
        isResetMode: hasResetFlag && token,
        resetToken: token
    };
}

document.addEventListener('DOMContentLoaded', function() {
    // Initialize theme before anything else
    initializeTheme();

    // Ensure user section is hidden by default
    const userSection = document.getElementById('userSection');
    if (userSection) {
        userSection.classList.remove('active');
        userSection.style.display = 'none';
    }

    const urlInfo = parseURLParams();

    if (urlInfo.isResetMode) {
        resetToken = urlInfo.resetToken;
        showResetPasswordSection();
        return;
    }

    const token = localStorage.getItem('authToken');
    const userData = localStorage.getItem('userData');

    if (token && userData) {
        try {
            currentUser = JSON.parse(userData);
            // Only show user section if we have valid user data
            if (currentUser && currentUser.username) {
                showUserSection();
            } else {
                throw new Error('Invalid user data structure');
            }
        } catch (e) {
            console.error('Invalid user data in localStorage', e);
            localStorage.removeItem('authToken');
            localStorage.removeItem('userData');
            currentUser = null;
            // Make sure user section stays hidden
            if (userSection) {
                userSection.classList.remove('active');
                userSection.style.display = 'none';
            }
        }
    } else {
        // No auth data, make sure user section is hidden
        currentUser = null;
        if (userSection) {
            userSection.classList.remove('active');
            userSection.style.display = 'none';
        }
    }

    const forgotPasswordLink = document.getElementById('forgotPasswordLink');
    if (forgotPasswordLink) {
        forgotPasswordLink.addEventListener('click', handleForgotPassword);
    }
});

function switchTab(tab) {
    document.querySelectorAll('.tab').forEach(t => t.classList.remove('active'));
    document.querySelector(`.tab:nth-child(${tab === 'login' ? '1' : '2'})`).classList.add('active');

    document.querySelectorAll('.form').forEach(f => f.classList.remove('active'));
    document.getElementById(tab + 'Form').classList.add('active');

    clearMessages();
}

function clearMessages() {
    document.querySelectorAll('.message').forEach(msg => {
        msg.style.display = 'none';
        msg.textContent = '';
    });
}

function showMessage(elementId, message, type) {
    const element = document.getElementById(elementId);
    element.textContent = message;
    element.className = `message ${type}`;
    element.style.display = 'block';
}

function setButtonLoading(buttonId, loading) {
    const button = document.getElementById(buttonId);
    if (loading) {
        button.innerHTML = '<span class="loading"></span>Processing...';
        button.disabled = true;
    } else {
        if (buttonId.includes('login')) {
            button.innerHTML = 'Sign In';
        } else if (buttonId.includes('register')) {
            button.innerHTML = 'Create Account';
        } else if (buttonId.includes('editProfile')) {
            button.innerHTML = 'Update Profile';
        } else if (buttonId.includes('resetPassword')) {
            button.innerHTML = 'Reset Password';
        }
        button.disabled = false;
    }
}

// Only add event listeners if elements exist (for index.html)
const loginForm = document.getElementById('loginForm');
if (loginForm) {
    loginForm.addEventListener('submit', async function(e) {
    e.preventDefault();

    const username = document.getElementById('loginUsername').value;
    const password = document.getElementById('loginPassword').value;

    setButtonLoading('loginBtn', true);
    clearMessages();

    try {
        const response = await fetch(`${API_BASE_URL}/authenticate`, {
            method: 'POST',
            headers: {
                'Content-Type': 'application/json'
            },
            body: JSON.stringify({ username, password })
        });

        if (response.ok) {
            const data = await response.json();

            localStorage.setItem('authToken', data.token);
            localStorage.setItem('userData', JSON.stringify(data));

            currentUser = data;
            setButtonLoading('loginBtn', false);
            showUserSection();
        } else {
            try {
                const errorData = await response.json();
                const errorMessage = errorData.message || 'Login failed. Please check your credentials.';
                showMessage('loginMessage', errorMessage, 'error');
            } catch (parseError) {
                // If response is not JSON, fall back to text
                const errorText = await response.text();
                showMessage('loginMessage', errorText || 'Login failed. Please check your credentials.', 'error');
            }
        }
    } catch (error) {
        console.error('Login error:', error);
        showMessage('loginMessage', 'Network error. Please check if the auth service is running.', 'error');
    } finally {
        setButtonLoading('loginBtn', false);
    }
});
}

const registerForm = document.getElementById('registerForm');
if (registerForm) {
    registerForm.addEventListener('submit', async function(e) {
    e.preventDefault();

    const username = document.getElementById('registerUsername').value;
    const password = document.getElementById('registerPassword').value;
    const email = document.getElementById('registerEmail').value;

    if (username.length < 4) {
        showMessage('registerMessage', "Username must be at least 4 characters long.", 'error');
        return;
    }

    if (password.length < 4) {
        showMessage('registerMessage', "Password must be at least 4 characters long.", 'error');
        return;
    }

    setButtonLoading('registerBtn', true);
    clearMessages();

    try {
        const response = await fetch(`${API_BASE_URL}/register`, {
            method: 'POST',
            headers: {
                'Content-Type': 'application/json'
            },
            body: JSON.stringify({ username, email, password })
        });

        if (response.ok) {
            const data = await response.json();

            localStorage.setItem('authToken', data.token);
            localStorage.setItem('userData', JSON.stringify(data));

            currentUser = data;
            setButtonLoading('registerBtn', false);
            showUserSection();
        } else {
            try {
                const errorData = await response.json();
                const errorMessage = errorData.message || 'Registration failed. Please try again.';
                showMessage('registerMessage', errorMessage, 'error');
            } catch (parseError) {
                const errorText = await response.text();
                showMessage('registerMessage', errorText || 'Registration failed. Please try again.', 'error');
            }
        }
    } catch (error) {
        console.error('Registration error:', error);
        showMessage('registerMessage', 'Network error. Please check if the auth service is running.', 'error');
    } finally {
        setButtonLoading('registerBtn', false);
    }
});
}

const resetPasswordForm = document.getElementById('resetPasswordForm');
if (resetPasswordForm) {
    resetPasswordForm.addEventListener('submit', async function(e) {
    e.preventDefault();

    const newPassword = document.getElementById('resetNewPassword').value;
    const confirmPassword = document.getElementById('resetConfirmPassword').value;

    if (newPassword !== confirmPassword) {
        showMessage('resetPasswordMessage', 'New passwords do not match.', 'error');
        return;
    }

    if (newPassword.length < 4) {
        showMessage('resetPasswordMessage', 'New password must be at least 4 characters long.', 'error');
        return;
    }

    setButtonLoading('resetPasswordBtn', true);
    clearResetPasswordMessages();

    try {
        const response = await fetch(`${API_BASE_URL}/users/reset-password`, {
            method: 'POST',
            headers: {
                'Content-Type': 'application/json',
                'Authorization': 'Bearer ' + resetToken
            },
            body: JSON.stringify({
                newPassword: newPassword
            })
        });

        if (response.ok) {
            showMessage('resetPasswordMessage', 'Password reset successfully!', 'success');

            document.getElementById('resetPasswordForm').reset();
            setTimeout(() => {
                window.location.href = window.location.pathname;
            }, 1000);
        } else {
            try {
                const errorData = await response.json();
                const errorMessage = errorData.message || 'Failed to reset password. Please try again.';
                showMessage('resetPasswordMessage', errorMessage, 'error');
            } catch (parseError) {
                // If response is not JSON, fall back to text
                const errorText = await response.text();
                showMessage('resetPasswordMessage', errorText || 'Failed to reset password. Please try again.', 'error');
            }
        }
    } catch (error) {
        console.error('Reset password error:', error);
        showMessage('resetPasswordMessage', 'Network error. Please check if the auth service is running.', 'error');
    } finally {
        setButtonLoading('resetPasswordBtn', false);
    }
});
}

const editProfileForm = document.getElementById('editProfileForm');
if (editProfileForm) {
    editProfileForm.addEventListener('submit', async function(e) {
    e.preventDefault();

    const currentPassword = document.getElementById('currentPassword').value;
    const newPassword = document.getElementById('newPassword').value;
    const confirmPassword = document.getElementById('confirmPassword').value;
    const email = document.getElementById('editEmail').value;

    // Validate that at least one field is being updated
    const isPasswordChange = newPassword.trim() !== '';
    const currentEmail = currentUser.email || '';
    const newEmail = email.trim();
    const isEmailChange = newEmail !== currentEmail;

    if (!isPasswordChange && !isEmailChange) {
        showMessage('editProfileMessage', 'Please make at least one change: update your email address or change your password.', 'error');
        return;
    }

    if (isPasswordChange && newPassword !== confirmPassword) {
        showMessage('editProfileMessage', 'New passwords do not match.', 'error');
        return;
    }

    if (isPasswordChange && newPassword.length < 4) {
        showMessage('editProfileMessage', 'New password must be at least 4 characters long.', 'error');
        return;
    }

    setButtonLoading('editProfileBtn', true);
    clearEditProfileMessages();

    try {
        const requestBody = { currentPassword };

        if (isPasswordChange) {
            requestBody.newPassword = newPassword;
        }

        if (isEmailChange) {
            requestBody.email = newEmail;
        }

        const response = await fetch(`${API_BASE_URL}/users/update-profile`, {
            method: 'POST',
            headers: {
                'Content-Type': 'application/json',
                'Authorization': `Bearer ${localStorage.getItem('authToken')}`
            },
            body: JSON.stringify(requestBody)
        });

        if (response.ok) {
            const data = await response.json();

            let message = '';
            if (isPasswordChange && isEmailChange) {
                message = 'Email and password updated successfully! Please log in with your new password.';
                document.getElementById('editProfileForm').reset();
                setTimeout(() => logout(), 1500);
            } else if (isPasswordChange) {
                message = 'Password updated successfully! Please log in with your new password.';
                document.getElementById('editProfileForm').reset();
                setTimeout(() => logout(), 1500);
            } else if (isEmailChange) {
                message = 'Email updated successfully!';
                // Update the stored user data with new email
                currentUser.email = newEmail;
                localStorage.setItem('userData', JSON.stringify(currentUser));
                updateUserDisplay(); // Refresh the displayed email
                document.getElementById('editProfileForm').reset();
                setTimeout(() => hideEditProfileForm(), 1000);
            }

            showMessage('editProfileMessage', message, 'success');
        } else {
            try {
                const errorData = await response.json();
                const errorMessage = errorData.message || 'Failed to update profile. Please try again.';
                showMessage('editProfileMessage', errorMessage, 'error');
            } catch (parseError) {
                // If response is not JSON, fall back to text
                const errorText = await response.text();
                showMessage('editProfileMessage', errorText || 'Failed to update profile. Please try again.', 'error');
            }
        }
    } catch (error) {
        console.error('Update profile error:', error);
        showMessage('editProfileMessage', 'Network error. Please check if the auth service is running.', 'error');
    } finally {
        setButtonLoading('editProfileBtn', false);
    }
});
}

function clearEditProfileMessages() {
    const messageElement = document.getElementById('editProfileMessage');
    messageElement.style.display = 'none';
    messageElement.textContent = '';
}

function clearResetPasswordMessages() {
    const messageElement = document.getElementById('resetPasswordMessage');
    messageElement.style.display = 'none';
    messageElement.textContent = '';
}

function updateUserDisplay() {
    if (!currentUser) {
        console.log('updateUserDisplay called but no currentUser');
        return;
    }

    const usernameEl = document.getElementById('currentUsername');
    const emailEl = document.getElementById('currentEmail');
    const userIdEl = document.getElementById('currentUserId');
    const rolesEl = document.getElementById('currentRoles');

    if (usernameEl) usernameEl.textContent = currentUser.username || '';
    if (emailEl) emailEl.textContent = maskUserEmail(currentUser.email) || '-';
    if (userIdEl) userIdEl.textContent = maskUserId(currentUser.id) || '';
    if (rolesEl) rolesEl.textContent = (currentUser.roles || []).join(', ');

    // Show/hide admin panel button based on user role
    updateAdminPanelVisibility();
}

function showUserSection() {
    const authSection = document.getElementById('authSection');
    const userSection = document.getElementById('userSection');
    const header = document.querySelector('.header');

    if (authSection) authSection.style.display = 'none';
    if (userSection) {
        userSection.classList.add('active');
        userSection.style.display = 'block';
    }
    if (header) header.style.display = 'block';

    updateUserDisplay();
}

function showResetPasswordSection() {
    document.getElementById('authSection').style.display = 'none';
    document.getElementById('userSection').classList.remove('active');
    document.getElementById('resetPasswordSection').style.display = 'block';
    document.querySelector('.header').style.display = 'none';
    document.getElementById('resetNewPassword').focus();
}

function maskUserId(id) {
    const parts = id.split("-");
    return parts[0] + "-****-" + parts[4];
}

function maskUserEmail(email) {
    if (!email.includes("@")) {
        return email;
    }

    const [user, domain] = email.split("@");

    if (user.length <= 2) {
        return user[0] + "*@" + domain;
    }

    const first = user[0];
    const last = user[user.length - 1];
    const maskedPart = "*".repeat(user.length - 2);

    return `${first}${maskedPart}${last}@${domain}`;
}

function logout() {
    localStorage.removeItem('authToken');
    localStorage.removeItem('userData');
    currentUser = null;

    const userSection = document.getElementById('userSection');
    const authSection = document.getElementById('authSection');
    const header = document.querySelector('.header');
    const loginForm = document.getElementById('loginForm');
    const registerForm = document.getElementById('registerForm');

    if (userSection) {
        userSection.classList.remove('active');
        userSection.style.display = 'none';
    }
    if (authSection) authSection.style.display = 'block';
    if (header) header.style.display = 'block';
    if (loginForm) loginForm.reset();
    if (registerForm) registerForm.reset();

    hideEditProfileForm();
    clearMessages();
    switchTab('login');
}

function toggleEditProfileForm() {
    const formSection = document.getElementById('editProfileSection');
    const isVisible = formSection.style.display === 'block';

    if (isVisible) {
        hideEditProfileForm();
    } else {
        showEditProfileForm();
    }
}

function showEditProfileForm() {
    const formSection = document.getElementById('editProfileSection');
    const actionBtn = document.getElementById('showEditProfileBtn');

    if (formSection) formSection.style.display = 'block';

    // Add active styling to button
    if (actionBtn) actionBtn.classList.add('active');

    // Clear any previous messages
    clearEditProfileMessages();

    // Pre-populate email field with current user's email
    if (currentUser) {
        const editEmail = document.getElementById('editEmail');
        if (editEmail) editEmail.value = currentUser.email || '';
    }

    // Focus on email input first since that's the most common change
    setTimeout(() => {
        const editEmail = document.getElementById('editEmail');
        if (editEmail) editEmail.focus();
    }, 100);
}

function hideEditProfileForm() {
    const formSection = document.getElementById('editProfileSection');
    const actionBtn = document.getElementById('showEditProfileBtn');

    if (formSection) formSection.style.display = 'none';

    // Remove active styling from button
    if (actionBtn) actionBtn.classList.remove('active');

    // Clear form and messages
    const editForm = document.getElementById('editProfileForm');
    if (editForm) editForm.reset();
    clearEditProfileMessages();
}

// Admin panel functions
function hasAdminRole() {
    return currentUser && Array.isArray(currentUser.roles) && currentUser.roles.includes('ADMIN');
}

function updateAdminPanelVisibility() {
    const adminBtn = document.getElementById('adminPanelBtn');
    if (adminBtn) {
        adminBtn.style.display = hasAdminRole() ? 'block' : 'none';
    }
}

function openAdminPanel() {
    if (!hasAdminRole()) {
        alert('Access denied. Admin privileges required.');
        return;
    }
    window.location.href = 'admin.html';
}

async function handleForgotPassword(e) {
    e.preventDefault();

    const username = document.getElementById('loginUsername').value.trim();

    if (!username) {
        showMessage('loginMessage', 'Please enter your username above and then click "Forgot password" again.', 'error');
        document.getElementById('loginUsername').focus();
        return;
    }

    clearMessages();

    const link = document.getElementById('forgotPasswordLink');
    const originalText = link.textContent;
    link.textContent = 'Sending email...';
    link.style.pointerEvents = 'none';

    try {
        const response = await fetch(`${API_BASE_URL}/forgot-password?username=${encodeURIComponent(username)}`, {
            method: 'POST',
            headers: {
                'Content-Type': 'application/json'
            }
        });

        if (response.ok) {
            showMessage('loginMessage', 'Password reset email sent! Please check your inbox.', 'success');
            document.getElementById('loginUsername').value = '';
        } else {
            try {
                const errorData = await response.json();
                const errorMessage = errorData.message || 'Failed to send reset email. Please try again.';
                showMessage('loginMessage', errorMessage, 'error');
            } catch (parseError) {
                const errorText = await response.text();
                showMessage('loginMessage', errorText || 'Failed to send reset email. Please try again.', 'error');
            }
        }
    } catch (error) {
        console.error('Forgot password error:', error);
        showMessage('loginMessage', 'Network error. Please check if the auth service is running.', 'error');
    } finally {
        link.textContent = originalText;
        link.style.pointerEvents = 'auto';
    }
}