// Dashboard JavaScript
class VPNDashboard {
    constructor() {
        this.token = localStorage.getItem('auth_token');
        this.currentUser = null;
        this.clients = [];
        this.serverStatus = {};
        this.protocols = [];
        
        this.init();
    }
     async init() {
        const token = localStorage.getItem("auth_token");
        if (!token) {
            window.location.href = 
            '/auth.html';
            return;
        }
        this.token = token;
        
        try {
            await this.loadUserInfo();
            await this.loadInitialData();
            this.setupEventListeners();
            this.startAutoRefresh();
        } catch (error) {
            console.error("Dashboard initialization failed:", error);
            this.showAlert("error", "Failed to load dashboard", error.message);
            // If loading fails, it might be due to an invalid token, redirect to login
            localStorage.removeItem("auth_token");
            localStorage.removeItem("refresh_token");
            localStorage.removeItem("user_data");
            window.location.href = "/auth.html";
        }
    } async loadUserInfo() {
        try {
            const response = await this.apiCall("/api/profile");
            this.currentUser = response.user;
            document.getElementById('userName').textContent = this.currentUser.username;
        } catch (error) {
            console.error('Failed to load user info:', error);
            throw error;
        }
    }
    
    async loadInitialData() {
        this.showLoading(true);
        
        try {
            await Promise.all([
                this.loadClients(),
                this.loadServerStatus(),
                this.loadProtocols(),
                this.loadServerStatistics()
            ]);
            
            this.updateOverviewStats();
            this.addActivity('Dashboard loaded successfully');
        } catch (error) {
            console.error('Failed to load initial data:', error);
            this.showAlert('error', 'Failed to load data', error.message);
        } finally {
            this.showLoading(false);
        }
    }
    
    async loadClients() {
        try {
            const response = await this.apiCall('/api/vpn-clients');
            this.clients = response.clients || [];
            this.renderClientsTable();
        } catch (error) {
            console.error('Failed to load clients:', error);
            this.clients = [];
        }
    }
    
    async loadServerStatus() {
        try {
            const response = await this.apiCall('/api/server/status');
            this.serverStatus = response.status || {};
            this.serverInfo = response.server_info || {};
            this.renderServerStatus();
        } catch (error) {
            console.error('Failed to load server status:', error);
            this.serverStatus = {};
        }
    }
    
    async loadProtocols() {
        try {
            const response = await fetch('/api/server/protocols');
            const data = await response.json();
            this.protocols = data.protocols || [];
            this.renderProtocols();
        } catch (error) {
            console.error('Failed to load protocols:', error);
            this.protocols = [];
        }
    }
    
    async loadServerStatistics() {
        try {
            const response = await this.apiCall('/api/server/statistics');
            this.statistics = response.statistics || {};
        } catch (error) {
            console.error('Failed to load server statistics:', error);
            this.statistics = {};
        }
    }
    
    updateOverviewStats() {
        const totalClients = this.clients.length;
        const runningServers = Object.values(this.serverStatus).filter(s => s.running).length;
        const serverLocation = this.serverInfo?.server_ip || 'Unknown';
        
        document.getElementById('totalClients').textContent = totalClients;
        document.getElementById('runningServers').textContent = runningServers;
        document.getElementById('serverLocation').textContent = serverLocation;
    }
    
    renderClientsTable() {
        const tbody = document.getElementById('clientsTableBody');
        
        if (this.clients.length === 0) {
            tbody.innerHTML = `
                <tr>
                    <td colspan="6" style="text-align: center; padding: 2rem; color: #666;">
                        <i class="fas fa-laptop" style="font-size: 2rem; margin-bottom: 1rem; display: block;"></i>
                        No VPN clients found. Create your first client to get started.
                    </td>
                </tr>
            `;
            return;
        }
        
        tbody.innerHTML = this.clients.map(client => `
            <tr>
                <td>
                    <strong>${this.escapeHtml(client.client_name)}</strong>
                    ${client.description ? `<br><small style="color: #666;">${this.escapeHtml(client.description)}</small>` : ''}
                </td>
                <td>
                    <span class="protocol-badge ${client.protocol}">
                        ${client.protocol.toUpperCase()}
                    </span>
                </td>
                <td>
                    <span class="status-badge ${client.status}">
                        ${client.status}
                    </span>
                </td>
                <td>${this.formatDate(client.created_at)}</td>
                <td>${client.last_connected ? this.formatDate(client.last_connected) : 'Never'}</td>
                <td>
                    <div class="client-actions">
                        <button class="btn small primary" onclick="dashboard.downloadClientConfig(${client.id})">
                            <i class="fas fa-download"></i>
                        </button>
                        <button class="btn small secondary" onclick="dashboard.viewClientDetails(${client.id})">
                            <i class="fas fa-eye"></i>
                        </button>
                        <button class="btn small danger" onclick="dashboard.revokeClient(${client.id})">
                            <i class="fas fa-ban"></i>
                        </button>
                    </div>
                </td>
            </tr>
        `).join('');
    }
    
    renderServerStatus() {
        const protocols = ['openvpn', 'ikev2', 'wireguard'];
        
        protocols.forEach(protocol => {
            const status = this.serverStatus[protocol] || { running: false, client_count: 0, port: 0 };
            const statusElement = document.getElementById(`${protocol}Status`);
            const clientsElement = document.getElementById(`${protocol}Clients`);
            const portElement = document.getElementById(`${protocol}Port`);
            
            if (statusElement) {
                statusElement.className = `server-status ${status.running ? 'online' : 'offline'}`;
                statusElement.innerHTML = `
                    <span class="status-dot"></span>
                    ${status.running ? 'Online' : 'Offline'}
                `;
            }
            
            if (clientsElement) {
                clientsElement.textContent = status.client_count || 0;
            }
            
            if (portElement) {
                portElement.textContent = status.port || 0;
            }
        });
    }
    
    renderProtocols() {
        const container = document.getElementById('protocolsGrid');
        
        container.innerHTML = this.protocols.map(protocol => `
            <div class="protocol-card">
                <div class="protocol-header">
                    <div class="protocol-icon">
                        <i class="fas fa-network-wired"></i>
                    </div>
                    <h3>${protocol.name}</h3>
                </div>
                <p class="protocol-description">${protocol.description}</p>
                <div class="protocol-details">
                    <div class="protocol-detail">
                        <span>Port:</span>
                        <span>${protocol.port}</span>
                    </div>
                    <div class="protocol-detail">
                        <span>Transport:</span>
                        <span>${protocol.transport}</span>
                    </div>
                </div>
                <div class="protocol-features">
                    <h4>Features:</h4>
                    <ul>
                        ${protocol.features.map(feature => `<li>${feature}</li>`).join('')}
                    </ul>
                </div>
                <button class="btn primary" onclick="dashboard.createClientWithProtocol('${protocol.key}')">
                    Create ${protocol.name} Client
                </button>
            </div>
        `).join('');
    }
    
    setupEventListeners() {
        // Close modals when clicking outside
        document.addEventListener('click', (e) => {
            if (e.target.classList.contains('modal')) {
                this.closeModal(e.target.id);
            }
        });
        
        // Close user dropdown when clicking outside
        document.addEventListener('click', (e) => {
            if (!e.target.closest('.user-menu')) {
                document.getElementById('userDropdown').classList.remove('show');
            }
        });
    }
    
    startAutoRefresh() {
        // Refresh server status every 30 seconds
        setInterval(() => {
            this.loadServerStatus();
        }, 30000);
        
        // Refresh clients every 60 seconds
        setInterval(() => {
            this.loadClients();
        }, 60000);
    }
    
    // API Helper
    async apiCall(endpoint, options = {}) {
        const defaultOptions = {
            headers: {
                'Authorization': `Bearer ${this.token}`,
                'Content-Type': 'application/json'
            }
        };
        
        const response = await fetch(endpoint, { ...defaultOptions, ...options });
        
        if (response.status === 401) {
            localStorage.removeItem('auth_token');
            window.location.href = '/auth.html';
            return;
        }
        
        if (!response.ok) {
            const error = await response.json().catch(() => ({ error: 'Network error' }));
            throw new Error(error.error || 'Request failed');
        }
        
        return await response.json();
    }
    
    // Navigation
    showSection(sectionId) {
        // Hide all sections
        document.querySelectorAll('.content-section').forEach(section => {
            section.classList.remove('active');
        });
        
        // Remove active class from nav items
        document.querySelectorAll('.nav-item').forEach(item => {
            item.classList.remove('active');
        });
        
        // Show selected section
        document.getElementById(sectionId).classList.add('active');
        
        // Add active class to nav item
        document.querySelector(`[data-section="${sectionId}"]`).classList.add('active');
        
        // Load section-specific data
        this.loadSectionData(sectionId);
    }
    
    async loadSectionData(sectionId) {
        switch (sectionId) {
            case 'server-status':
                await this.loadServerStatus();
                break;
            case 'vpn-clients':
                await this.loadClients();
                break;
            case 'protocols':
                await this.loadProtocols();
                break;
        }
    }
    
    // Client Management
    showCreateClientModal() {
        document.getElementById('createClientModal').classList.add('show');
        document.getElementById('createClientForm').reset();
    }
    
    createClientWithProtocol(protocol) {
        this.showCreateClientModal();
        document.getElementById('clientProtocol').value = protocol;
    }
    
    async createVPNClient(event) {
        event.preventDefault();
        
        const formData = new FormData(event.target);
        const clientData = {
            client_name: formData.get('clientName'),
            protocol: formData.get('protocol'),
            description: formData.get('description')
        };
        
        try {
            this.showLoading(true);
            
            const response = await this.apiCall('/api/vpn-clients', {
                method: 'POST',
                body: JSON.stringify(clientData)
            });
            
            this.showAlert('success', 'Client Created', 'VPN client created successfully');
            this.closeModal('createClientModal');
            await this.loadClients();
            this.addActivity(`Created VPN client: ${clientData.client_name}`);
            
        } catch (error) {
            console.error('Failed to create client:', error);
            this.showAlert('error', 'Creation Failed', error.message);
        } finally {
            this.showLoading(false);
        }
    }
    
    async downloadClientConfig(clientId) {
        try {
            const response = await fetch(`/api/vpn-clients/${clientId}/download`, {
                headers: {
                    'Authorization': `Bearer ${this.token}`
                }
            });
            
            if (!response.ok) {
                throw new Error('Download failed');
            }
            
            const blob = await response.blob();
            const url = window.URL.createObjectURL(blob);
            const a = document.createElement('a');
            a.href = url;
            a.download = `vpn-client-${clientId}.zip`;
            document.body.appendChild(a);
            a.click();
            window.URL.revokeObjectURL(url);
            document.body.removeChild(a);
            
            this.addActivity(`Downloaded configuration for client ${clientId}`);
            
        } catch (error) {
            console.error('Download failed:', error);
            this.showAlert('error', 'Download Failed', error.message);
        }
    }
    
    async revokeClient(clientId) {
        if (!confirm('Are you sure you want to revoke this client? This action cannot be undone.')) {
            return;
        }
        
        try {
            await this.apiCall(`/api/vpn-clients/${clientId}/revoke`, {
                method: 'POST'
            });
            
            this.showAlert('success', 'Client Revoked', 'Client access has been revoked');
            await this.loadClients();
            this.addActivity(`Revoked client ${clientId}`);
            
        } catch (error) {
            console.error('Failed to revoke client:', error);
            this.showAlert('error', 'Revocation Failed', error.message);
        }
    }
    
    // Server Management
    async startServer(protocol) {
        try {
            this.showLoading(true);
            
            const response = await this.apiCall(`/api/server/start/${protocol}`, {
                method: 'POST'
            });
            
            this.showAlert('success', 'Server Started', response.message);
            await this.loadServerStatus();
            this.addActivity(`Started ${protocol.toUpperCase()} server`);
            
        } catch (error) {
            console.error('Failed to start server:', error);
            this.showAlert('error', 'Start Failed', error.message);
        } finally {
            this.showLoading(false);
        }
    }
    
    async stopServer(protocol) {
        if (!confirm(`Are you sure you want to stop the ${protocol.toUpperCase()} server?`)) {
            return;
        }
        
        try {
            this.showLoading(true);
            
            const response = await this.apiCall(`/api/server/stop/${protocol}`, {
                method: 'POST'
            });
            
            this.showAlert('success', 'Server Stopped', response.message);
            await this.loadServerStatus();
            this.addActivity(`Stopped ${protocol.toUpperCase()} server`);
            
        } catch (error) {
            console.error('Failed to stop server:', error);
            this.showAlert('error', 'Stop Failed', error.message);
        } finally {
            this.showLoading(false);
        }
    }
    
    async restartServer(protocol) {
        if (!confirm(`Are you sure you want to restart the ${protocol.toUpperCase()} server?`)) {
            return;
        }
        
        try {
            this.showLoading(true);
            
            const response = await this.apiCall(`/api/server/restart/${protocol}`, {
                method: 'POST'
            });
            
            this.showAlert('success', 'Server Restarted', response.message);
            await this.loadServerStatus();
            this.addActivity(`Restarted ${protocol.toUpperCase()} server`);
            
        } catch (error) {
            console.error('Failed to restart server:', error);
            this.showAlert('error', 'Restart Failed', error.message);
        } finally {
            this.showLoading(false);
        }
    }
    
    async refreshServerStatus() {
        try {
            this.showLoading(true);
            await this.loadServerStatus();
            this.showAlert('success', 'Status Refreshed', 'Server status updated');
        } catch (error) {
            this.showAlert('error', 'Refresh Failed', error.message);
        } finally {
            this.showLoading(false);
        }
    }
    
    async loadServerLogs() {
        const protocol = document.getElementById('logProtocol').value;
        
        try {
            const response = await this.apiCall(`/api/server/logs/${protocol}?lines=100`);
            const logsContainer = document.getElementById('logsContainer');
            
            if (response.logs && response.logs.length > 0) {
                logsContainer.innerHTML = `
                    <div class="logs-content">
                        ${response.logs.join('\\n')}
                    </div>
                `;
            } else {
                logsContainer.innerHTML = `
                    <div class="logs-content">
                        No logs available for ${protocol.toUpperCase()}
                    </div>
                `;
            }
            
            // Scroll to bottom
            logsContainer.scrollTop = logsContainer.scrollHeight;
            
        } catch (error) {
            console.error('Failed to load logs:', error);
            this.showAlert('error', 'Logs Failed', error.message);
        }
    }
    
    // Filtering
    filterClients() {
        const protocolFilter = document.getElementById('protocolFilter').value;
        const statusFilter = document.getElementById('statusFilter').value;
        const searchFilter = document.getElementById('searchFilter').value.toLowerCase();
        
        let filteredClients = this.clients;
        
        if (protocolFilter) {
            filteredClients = filteredClients.filter(client => client.protocol === protocolFilter);
        }
        
        if (statusFilter) {
            filteredClients = filteredClients.filter(client => client.status === statusFilter);
        }
        
        if (searchFilter) {
            filteredClients = filteredClients.filter(client => 
                client.client_name.toLowerCase().includes(searchFilter) ||
                (client.description && client.description.toLowerCase().includes(searchFilter))
            );
        }
        
        // Temporarily store original clients and render filtered
        const originalClients = this.clients;
        this.clients = filteredClients;
        this.renderClientsTable();
        this.clients = originalClients;
    }
    
    // UI Helpers
    showModal(modalId) {
        document.getElementById(modalId).classList.add('show');
    }
    
    closeModal(modalId) {
        document.getElementById(modalId).classList.remove('show');
    }
    
    showLoading(show) {
        const overlay = document.getElementById('loadingOverlay');
        if (show) {
            overlay.classList.add('show');
        } else {
            overlay.classList.remove('show');
        }
    }
    
    showAlert(type, title, message) {
        const container = document.getElementById('alertContainer');
        const alertId = 'alert-' + Date.now();
        
        const alertHtml = `
            <div class="alert ${type}" id="${alertId}">
                <div class="alert-icon">
                    <i class="fas fa-${type === 'success' ? 'check-circle' : type === 'error' ? 'exclamation-circle' : 'info-circle'}"></i>
                </div>
                <div class="alert-content">
                    <div class="alert-title">${title}</div>
                    <div class="alert-message">${message}</div>
                </div>
                <button class="alert-close" onclick="dashboard.closeAlert('${alertId}')">
                    <i class="fas fa-times"></i>
                </button>
            </div>
        `;
        
        container.insertAdjacentHTML('beforeend', alertHtml);
        
        // Auto-remove after 5 seconds
        setTimeout(() => {
            this.closeAlert(alertId);
        }, 5000);
    }
    
    closeAlert(alertId) {
        const alert = document.getElementById(alertId);
        if (alert) {
            alert.remove();
        }
    }
    
    addActivity(message) {
        const activityList = document.getElementById('activityList');
        const activityHtml = `
            <div class="activity-item">
                <i class="fas fa-info-circle"></i>
                <span>${this.escapeHtml(message)}</span>
                <time>Just now</time>
            </div>
        `;
        
        activityList.insertAdjacentHTML('afterbegin', activityHtml);
        
        // Keep only last 10 activities
        const activities = activityList.querySelectorAll('.activity-item');
        if (activities.length > 10) {
            activities[activities.length - 1].remove();
        }
    }
    
    // Utility functions
    escapeHtml(text) {
        const div = document.createElement('div');
        div.textContent = text;
        return div.innerHTML;
    }
    
    formatDate(dateString) {
        if (!dateString) return 'Never';
        
        const date = new Date(dateString);
        const now = new Date();
        const diff = now - date;
        
        if (diff < 60000) return 'Just now';
        if (diff < 3600000) return `${Math.floor(diff / 60000)} minutes ago`;
        if (diff < 86400000) return `${Math.floor(diff / 3600000)} hours ago`;
        
        return date.toLocaleDateString();
    }
    
    // User menu
    toggleUserMenu() {
        document.getElementById('userDropdown').classList.toggle('show');
    }
    
    showProfile() {
        this.showAlert('info', 'Profile', 'Profile management coming soon');
    }
    
    showSettings() {
        this.showAlert('info', 'Settings', 'Settings management coming soon');
    }
    
    logout() {
        localStorage.removeItem('auth_token');
        window.location.href = '/auth.html';
    }
}

// Global functions for onclick handlers
let dashboard;

function showSection(sectionId) {
    dashboard.showSection(sectionId);
}

function showCreateClientModal() {
    dashboard.showCreateClientModal();
}

function createVPNClient(event) {
    dashboard.createVPNClient(event);
}

function closeModal(modalId) {
    dashboard.closeModal(modalId);
}

function toggleUserMenu() {
    dashboard.toggleUserMenu();
}

function showProfile() {
    dashboard.showProfile();
}

function showSettings() {
    dashboard.showSettings();
}

function logout() {
    dashboard.logout();
}

function startServer(protocol) {
    dashboard.startServer(protocol);
}

function stopServer(protocol) {
    dashboard.stopServer(protocol);
}

function restartServer(protocol) {
    dashboard.restartServer(protocol);
}

function refreshServerStatus() {
    dashboard.refreshServerStatus();
}

function loadServerLogs() {
    dashboard.loadServerLogs();
}

function filterClients() {
    dashboard.filterClients();
}

// Initialize dashboard when page loads
document.addEventListener('DOMContentLoaded', () => {
    dashboard = new VPNDashboard();
});