/**
 * Admin Panel - User Management Logic (Premium Edition)
 */

let allMgmtUsers = [];
let filteredMgmtUsers = [];
let deleteTargetId = null;
let activeExpandedId = null;

async function loadUserManagement() {
    const grid = document.getElementById('users-mgmt-grid');
    if (!grid) return;

    grid.innerHTML = '<div class="loading-state" style="padding:60px;"><i class="fa-solid fa-spinner fa-spin"></i><span>Fetching user directory...</span></div>';

    try {
        const res = await fetch('/api/admin/users');
        allMgmtUsers = await res.json();
        
        updateUserMgmtStats(allMgmtUsers);
        applyUserMgmtFilters();
    } catch (err) {
        grid.innerHTML = '<div class="error-state">Error loading user management data.</div>';
    }
}

function updateUserMgmtStats(users) {
    const totalEl = document.getElementById('total-users-val');
    const activeEl = document.getElementById('active-users-val');
    const disabledEl = document.getElementById('disabled-users-val');

    if (totalEl) totalEl.innerText = users.length;
    if (activeEl) activeEl.innerText = users.filter(u => u.is_active).length;
    if (disabledEl) disabledEl.innerText = users.filter(u => !u.is_active).length;
}

function applyUserMgmtFilters() {
    const searchInput = document.getElementById('user-mgmt-search');
    const searchTerm = searchInput ? searchInput.value.trim().toLowerCase() : '';
    
    // We'll also use a global 'currentMgmtFilter' set by the tabs
    const activeTab = document.querySelector('.u-tab-m.active');
    const filterRole = activeTab ? activeTab.getAttribute('onclick').match(/'([^']+)'/)[1] : 'all';

    filteredMgmtUsers = allMgmtUsers.filter(u => {
        const searchable = `${u.id} ${u.name} ${u.phone} ${u.email}`.toLowerCase();
        const matchesSearch = searchTerm === '' || searchable.includes(searchTerm);
        const matchesRole = filterRole === 'all' || u.role === filterRole;
        return matchesSearch && matchesRole;
    });

    renderUserMgmtGrid(filteredMgmtUsers);
}

function filterUserMgmt(role, btn) {
    document.querySelectorAll('.u-tab-m').forEach(b => b.classList.remove('active'));
    btn.classList.add('active');
    applyUserMgmtFilters();
}

function renderUserMgmtGrid(users) {
    const grid = document.getElementById('users-mgmt-grid');
    if (!grid) return;

    if (users.length === 0) {
        grid.innerHTML = '<div class="empty-state" style="padding:60px; grid-column: 1/-1;"><i class="fa-solid fa-user-slash"></i><span>No matching users found.</span></div>';
        return;
    }

    grid.innerHTML = users.map(u => {
        const initial = (u.name || 'U').charAt(0).toUpperCase();
        const status = u.is_active ? 'active' : 'disabled';
        const isExpanded = activeExpandedId === u.id;
        
        // Role-Based Styling
        let crystalClass = 'crystal-user';
        let roleLabel = 'General User';
        let roleIcon = 'fa-user-shield';
        
        if (u.role === 'admin') {
            crystalClass = 'crystal-admin';
            roleLabel = 'System Admin';
            roleIcon = 'fa-lock';
        } else if (u.role === 'admin-user') {
            crystalClass = 'crystal-agent';
            roleLabel = 'Agent / Moderator';
            roleIcon = 'fa-user-tie';
        }

        return `
        <div class="card-u-standard ${!u.is_active ? 'is-disabled' : ''} ${isExpanded ? 'expanded' : ''}" id="user-m-card-${u.id}">
            <!-- Header -->
            <div class="card-u-header">
                <div class="card-u-avatar ${crystalClass}">${initial}</div>
                <div class="card-u-info">
                    <div class="card-u-name">${escapeHtml(u.name)}</div>
                    <div class="card-u-phone"><i class="fa-solid fa-phone"></i> ${escapeHtml(u.phone)}</div>
                </div>
                <div class="status-pill-u ${status}">${status}</div>
            </div>

            <!-- Body Swap Zone -->
            <div class="card-u-body-wrap">
                <div class="card-u-meta animate-scale" id="user-meta-${u.id}">
                    <span><i class="fa-solid fa-fingerprint"></i> ${u.id.slice(0, 10)}...</span>
                    <span><i class="fa-solid fa-clock-rotate-left"></i> ${escapeHtml(u.joined_at.split(' ')[0])}</span>
                </div>
                <div class="card-u-expansion animate-scale" id="user-expansion-${u.id}" style="display: none;"></div>
            </div>

            <!-- Actions -->
            <div class="card-u-actions" id="user-actions-${u.id}">
                <button class="btn-u-action" id="user-manage-btn-${u.id}" onclick="toggleUserCardExpansion('${u.id}')">
                    <i class="fa-solid fa-gears"></i> Manage Access
                </button>
                ${u.role !== 'admin' ? `
                    <button class="btn-u-action ${u.is_active ? 'warning' : 'success'}" onclick="toggleUserMgmtStatus('${u.id}')">
                        <i class="fa-solid ${u.is_active ? 'fa-ban' : 'fa-check'}"></i> 
                        ${u.is_active ? 'Disable' : 'Enable'}
                    </button>
                ` : `
                    <button class="btn-u-action disabled" disabled title="Admin users cannot be disabled">
                        <i class="fa-solid fa-shield-halved"></i> Protected
                    </button>
                `}
            </div>
        </div>`;
    }).join('');
}

function toggleUserCardExpansion(userId) {
    console.log('toggleUserCardExpansion called for:', userId);
    const card = document.getElementById(`user-m-card-${userId}`);
    const metaDiv = document.getElementById(`user-meta-${userId}`);
    const expansionDiv = document.getElementById(`user-expansion-${userId}`);
    const manageBtn = document.getElementById(`user-manage-btn-${userId}`);
    const actionsDiv = document.getElementById(`user-actions-${userId}`);
    
    console.log('Elements found:', { card: !!card, metaDiv: !!metaDiv, expansionDiv: !!expansionDiv, manageBtn: !!manageBtn, actionsDiv: !!actionsDiv });
    
    if (!card || !metaDiv || !expansionDiv) {
        console.error('Required elements not found!');
        return;
    }
    
    const isExpanded = card.classList.contains('expanded');
    console.log('Is expanded:', isExpanded);
    
    if (!isExpanded) {
        // Expand this card
        console.log('Expanding card...');
        card.classList.add('expanded');
        metaDiv.style.display = 'none';
        expansionDiv.style.display = 'flex';
        
        // Find user data
        const user = allMgmtUsers.find(u => u.id === userId) || filteredMgmtUsers.find(u => u.id === userId);
        console.log('User data:', user);
        if (!user) return;
        
        // Build expansion content
        const isAdmin = user.role === 'admin';
        
        expansionDiv.innerHTML = `
            <div class="u-tool-section">
                <h5>Security Override</h5>
                <div class="u-input-row">
                    <input type="password" id="new-pass-${userId}" class="u-input-premium" placeholder="Set New Password">
                </div>
            </div>
            <div class="u-tool-section">
                <div style="display: flex; gap: 10px;">
                    <button class="btn-u-action primary" onclick="openChangePasswordModal('${userId}')" style="flex: 1;">
                        <i class="fa-solid fa-key"></i> Change Password
                    </button>
                    ${!isAdmin ? `
                        <button class="btn-u-action danger" onclick="openDeleteUserModal('${userId}', '${escapeHtml(user.name)}')" style="flex: 1;">
                            <i class="fa-solid fa-trash-can"></i> Delete User
                        </button>
                    ` : `
                        <button class="btn-u-action disabled" disabled title="Admin users cannot be deleted" style="flex: 1;">
                            <i class="fa-solid fa-shield-halved"></i> Protected
                        </button>
                    `}
                </div>
            </div>
        `;
        
        // Update button to Cancel
        if (manageBtn) manageBtn.innerHTML = '<i class="fa-solid fa-xmark"></i> Cancel';
        
        // Hide Enable/Disable button in expanded mode
        const enableDisableBtn = actionsDiv ? actionsDiv.querySelector('[onclick^="toggleUserMgmtStatus"]') : null;
        if (enableDisableBtn) enableDisableBtn.style.display = 'none';
        
        activeExpandedId = userId;
    } else {
        // Collapse this card
        console.log('Collapsing card...');
        card.classList.remove('expanded');
        metaDiv.style.display = 'flex';
        expansionDiv.style.display = 'none';
        expansionDiv.innerHTML = '';
        
        // Update button back to Manage Access
        if (manageBtn) manageBtn.innerHTML = '<i class="fa-solid fa-gears"></i> Manage Access';
        
        // Show Enable/Disable button again
        const enableDisableBtn = actionsDiv ? actionsDiv.querySelector('[onclick^="toggleUserMgmtStatus"]') : null;
        if (enableDisableBtn) enableDisableBtn.style.display = 'flex';
        
        activeExpandedId = null;
    }
}

async function toggleUserMgmtStatus(userId) {
    try {
        const res = await fetch(`/api/admin/users/${userId}/toggle-status`, { method: 'POST' });
        const data = await res.json();
        
        if (res.ok) {
            // Collapse any expanded card and refresh list
            activeExpandedId = null;
            loadUserManagement();
            if (typeof showToast === 'function') showToast('success', 'Status Updated', 'User access level has been modified.');
        } else {
            if (typeof showToast === 'function') showToast('error', 'Action Denied', data.error || 'Failed to update status.');
        }
    } catch (e) {
        if (typeof showToast === 'function') showToast('error', 'Network Error', 'Failed to connect to server.');
    }
}

async function updateUserMgmtPassword(userId) {
    const passInput = document.getElementById(`new-pass-${userId}`);
    const newPass = passInput ? passInput.value.trim() : '';
    
    if (!newPass) {
        alert('Please enter a password.');
        return;
    }

    try {
        const res = await fetch(`/api/admin/users/${userId}/change-password`, {
            method: 'POST',
            headers: { 'Content-Type': 'application/json' },
            body: JSON.stringify({ new_password: newPass })
        });
        
        if (res.ok) {
            passInput.value = '';
            if (typeof showToast === 'function') showToast('success', 'Security Update', 'User password has been manually overridden.');
        }
    } catch (e) {}
}

/* ─────────────────────────────────────────────────────
   CHANGE PASSWORD MODAL LOGIC
   ───────────────────────────────────────────────────── */

let changePassTargetId = null;

function openChangePasswordModal(userId) {
    changePassTargetId = userId;
    const modal = document.getElementById('user-change-pass-modal');
    const newPassEl = document.getElementById('change-pass-new');
    const errorEl = document.getElementById('change-pass-error');
    
    // Get the password from the input field
    const passInput = document.getElementById(`new-pass-${userId}`);
    const newPassword = passInput ? passInput.value : '';
    
    if (!newPassword) {
        if (typeof showToast === 'function') showToast('error', 'Error', 'Please enter a new password first.');
        return;
    }
    
    if (newPassEl) newPassEl.value = newPassword;
    if (errorEl) errorEl.innerText = '';
    
    if (modal) modal.style.display = 'flex';
    
    // Set up the confirm button
    const finalBtn = document.getElementById('final-change-pass-btn');
    if (finalBtn) {
        finalBtn.onclick = confirmChangePassword;
    }
}

function closeChangePasswordModal() {
    const modal = document.getElementById('user-change-pass-modal');
    if (modal) modal.style.display = 'none';
    changePassTargetId = null;
}

async function confirmChangePassword() {
    if (!changePassTargetId) return;
    
    const newPassEl = document.getElementById('change-pass-new');
    const errorEl = document.getElementById('change-pass-error');
    
    const newPassword = newPassEl ? newPassEl.value : '';
    
    if (errorEl) errorEl.innerText = 'Updating password...';
    
    try {
        const res = await fetch(`/api/admin/users/${changePassTargetId}/change-password`, {
            method: 'POST',
            headers: { 'Content-Type': 'application/json' },
            body: JSON.stringify({ new_password: newPassword })
        });
        const data = await res.json();
        
        if (res.ok) {
            closeChangePasswordModal();
            // Clear the password input
            const passInput = document.getElementById(`new-pass-${changePassTargetId}`);
            if (passInput) passInput.value = '';
            if (typeof showToast === 'function') showToast('success', 'Success', 'User password has been changed.');
        } else {
            if (errorEl) errorEl.innerText = data.error || 'Failed to change password.';
        }
    } catch (e) {
        if (errorEl) errorEl.innerText = 'Network error occurred.';
    }
}

/* ─────────────────────────────────────────────────────
   SECURE DELETION LOGIC
   ───────────────────────────────────────────────────── */

function openDeleteUserModal(id, name) {
    deleteTargetId = id;
    const modal = document.getElementById('user-delete-modal');
    const nameEl = document.getElementById('delete-target-name');
    const errorEl = document.getElementById('delete-error');
    const passInput = document.getElementById('admin-auth-pass');

    if (nameEl) nameEl.innerText = name;
    if (errorEl) errorEl.innerText = '';
    if (passInput) passInput.value = '';

    if (modal) modal.style.display = 'flex';

    // Set up the final button
    const finalBtn = document.getElementById('final-delete-btn');
    if (finalBtn) {
        finalBtn.onclick = confirmDeleteUser;
    }
}

function closeDeleteModal() {
    const modal = document.getElementById('user-delete-modal');
    if (modal) modal.style.display = 'none';
    deleteTargetId = null;
}

async function confirmDeleteUser() {
    if (!deleteTargetId) return;

    const passInput = document.getElementById('admin-auth-pass');
    const adminPass = passInput ? passInput.value : '';
    const errorEl = document.getElementById('delete-error');

    if (!adminPass) {
        if (errorEl) errorEl.innerText = 'Authorization required.';
        return;
    }

    if (errorEl) errorEl.innerText = 'Deleting account...';

    try {
        const res = await fetch(`/api/admin/users/${deleteTargetId}/delete`, {
            method: 'POST',
            headers: { 'Content-Type': 'application/json' },
            body: JSON.stringify({ admin_password: adminPass })
        });
        const data = await res.json();

        if (res.ok) {
            // Show success toast first
            if (typeof showToast === 'function') showToast('success', 'Success', 'User deleted successfully.');
            
            // Wait 1 second before closing modal and refreshing
            setTimeout(() => {
                closeDeleteModal();
                loadUserManagement();
            }, 1000);
        } else {
            if (errorEl) errorEl.innerText = data.error || 'Authorization failed.';
            if (typeof showToast === 'function') showToast('error', 'Error', data.error || 'Failed to delete user.');
        }
    } catch (e) {
        if (errorEl) errorEl.innerText = 'Network error occurred.';
    }
}

// Helper: Escape HTML
function escapeHtml(value) {
    return String(value)
        .replaceAll('&', '&amp;')
        .replaceAll('<', '&lt;')
        .replaceAll('>', '&gt;')
        .replaceAll('"', '&quot;')
        .replaceAll("'", '&#39;');
}