class PortScanner {
    constructor() {
        this.isScanning = false;
        this.progressInterval = null;
        this.initializeEventListeners();
    }

    initializeEventListeners() {
        // Form elements
        this.targetIpInput = document.getElementById('target-ip');
        this.startPortInput = document.getElementById('start-port');
        this.endPortInput = document.getElementById('end-port');
        this.timeoutInput = document.getElementById('timeout');
        this.threadsInput = document.getElementById('threads');
        
        // Buttons
        this.scanBtn = document.getElementById('scan-btn');
        this.pingBtn = document.getElementById('ping-btn');
        this.exportBtn = document.getElementById('export-btn');
        this.clearBtn = document.getElementById('clear-btn');
        
        // Sections
        this.progressSection = document.getElementById('progress-section');
        this.resultsSection = document.getElementById('results-section');
        
        // Event listeners
        this.scanBtn.addEventListener('click', () => this.startScan());
        this.pingBtn.addEventListener('click', () => this.pingHost());
        this.exportBtn.addEventListener('click', () => this.exportResults());
        this.clearBtn.addEventListener('click', () => this.clearResults());
        
        // Preset buttons
        document.querySelectorAll('.preset-btn').forEach(btn => {
            btn.addEventListener('click', (e) => {
                const start = e.target.dataset.start;
                const end = e.target.dataset.end;
                this.startPortInput.value = start;
                this.endPortInput.value = end;
            });
        });
        
        // Form validation
        this.targetIpInput.addEventListener('input', () => this.validateForm());
        this.startPortInput.addEventListener('input', () => this.validateForm());
        this.endPortInput.addEventListener('input', () => this.validateForm());
    }

    validateForm() {
        const ip = this.targetIpInput.value.trim();
        const startPort = parseInt(this.startPortInput.value);
        const endPort = parseInt(this.endPortInput.value);
        
        let isValid = true;
        
        // IP validation
        if (!ip || !this.isValidIP(ip)) {
            isValid = false;
        }
        
        // Port validation
        if (startPort < 1 || endPort > 65535 || startPort > endPort) {
            isValid = false;
        }
        
        this.scanBtn.disabled = !isValid || this.isScanning;
        return isValid;
    }

    isValidIP(ip) {
        const ipRegex = /^(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$/;
        return ipRegex.test(ip);
    }

    async pingHost() {
        const ip = this.targetIpInput.value.trim();
        
        if (!ip || !this.isValidIP(ip)) {
            this.showNotification('Please enter a valid IP address', 'error');
            return;
        }
        
        this.pingBtn.disabled = true;
        this.pingBtn.innerHTML = '<i class="fas fa-spinner fa-spin"></i> Pinging...';
        
        try {
            const response = await fetch('/api/ping', {
                method: 'POST',
                headers: {
                    'Content-Type': 'application/json',
                },
                body: JSON.stringify({ ip: ip })
            });
            
            const data = await response.json();
            
            if (response.ok) {
                const status = data.status === 'reachable' ? 'Host is reachable' : 'Host appears unreachable';
                const type = data.status === 'reachable' ? 'success' : 'error';
                this.showNotification(status, type);
            } else {
                this.showNotification(data.error || 'Ping failed', 'error');
            }
        } catch (error) {
            this.showNotification('Network error during ping', 'error');
        } finally {
            this.pingBtn.disabled = false;
            this.pingBtn.innerHTML = '<i class="fas fa-satellite-dish"></i> Ping';
        }
    }

    async startScan() {
        if (!this.validateForm()) {
            this.showNotification('Please check your input values', 'error');
            return;
        }
        
        const scanData = {
            ip: this.targetIpInput.value.trim(),
            start_port: parseInt(this.startPortInput.value),
            end_port: parseInt(this.endPortInput.value),
            timeout: parseFloat(this.timeoutInput.value),
            threads: parseInt(this.threadsInput.value)
        };
        
        // Check port range limit
        const portRange = scanData.end_port - scanData.start_port + 1;
        if (portRange > 10000) {
            this.showNotification('Port range too large (max 10000 ports)', 'error');
            return;
        }
        
        this.isScanning = true;
        this.scanBtn.disabled = true;
        this.scanBtn.innerHTML = '<i class="fas fa-spinner fa-spin"></i> Scanning...';
        
        // Show progress section
        this.progressSection.style.display = 'block';
        this.resultsSection.style.display = 'none';
        
        // Start progress monitoring
        this.startProgressMonitoring();
        
        try {
            const response = await fetch('/api/scan', {
                method: 'POST',
                headers: {
                    'Content-Type': 'application/json',
                },
                body: JSON.stringify(scanData)
            });
            
            const data = await response.json();
            
            if (response.ok) {
                this.displayResults(data);
                this.showNotification(`Scan completed! Found ${data.total_open} open ports`, 'success');
            } else {
                this.showNotification(data.error || 'Scan failed', 'error');
            }
        } catch (error) {
            this.showNotification('Network error during scan', 'error');
        } finally {
            this.stopProgressMonitoring();
            this.isScanning = false;
            this.scanBtn.disabled = false;
            this.scanBtn.innerHTML = '<i class="fas fa-search"></i> Start Scan';
            this.progressSection.style.display = 'none';
        }
    }

    startProgressMonitoring() {
        this.progressInterval = setInterval(async () => {
            try {
                const response = await fetch('/api/progress');
                const data = await response.json();
                
                const progressFill = document.getElementById('progress-fill');
                const progressText = document.getElementById('progress-text');
                
                progressFill.style.width = `${data.percentage}%`;
                progressText.textContent = `Scanning... ${data.progress}/${data.total} ports (${data.percentage}%)`;
            } catch (error) {
                console.error('Error fetching progress:', error);
            }
        }, 500);
    }

    stopProgressMonitoring() {
        if (this.progressInterval) {
            clearInterval(this.progressInterval);
            this.progressInterval = null;
        }
    }

    displayResults(data) {
        const resultsSection = document.getElementById('results-section');
        const resultsSummary = document.getElementById('results-summary');
        const resultsTableBody = document.getElementById('results-tbody');
        
        // Update summary
        resultsSummary.innerHTML = `
            <strong>Target:</strong> ${data.target_ip} | 
            <strong>Range:</strong> ${data.scan_range} | 
            <strong>Open Ports:</strong> ${data.total_open}/${data.total_scanned} | 
            <strong>Duration:</strong> ${data.scan_duration}s
        `;
        
        // Clear previous results
        resultsTableBody.innerHTML = '';
        
        // Add results to table
        if (data.open_ports && data.open_ports.length > 0) {
            data.open_ports.forEach(port => {
                const row = document.createElement('tr');
                row.innerHTML = `
                    <td><strong>${port.port}</strong></td>
                    <td><span class="status-${port.status}">${port.status.toUpperCase()}</span></td>
                    <td>${port.service || 'unknown'}</td>
                    <td>TCP</td>
                `;
                resultsTableBody.appendChild(row);
            });
        } else {
            const row = document.createElement('tr');
            row.innerHTML = '<td colspan="4" style="text-align: center; color: #666;">No open ports found</td>';
            resultsTableBody.appendChild(row);
        }
        
        // Show results section
        resultsSection.style.display = 'block';
        
        // Store results for export
        this.lastScanResults = data;
    }

    exportResults() {
        if (!this.lastScanResults) {
            this.showNotification('No results to export', 'error');
            return;
        }
        
        const data = this.lastScanResults;
        let csvContent = 'Port,Status,Service,Protocol\n';
        
        if (data.open_ports && data.open_ports.length > 0) {
            data.open_ports.forEach(port => {
                csvContent += `${port.port},${port.status},${port.service || 'unknown'},TCP\n`;
            });
        }
        
        // Create and download file
        const blob = new Blob([csvContent], { type: 'text/csv' });
        const url = window.URL.createObjectURL(blob);
        const a = document.createElement('a');
        a.href = url;
        a.download = `port_scan_${data.target_ip}_${new Date().toISOString().slice(0, 19).replace(/:/g, '-')}.csv`;
        document.body.appendChild(a);
        a.click();
        document.body.removeChild(a);
        window.URL.revokeObjectURL(url);
        
        this.showNotification('Results exported successfully', 'success');
    }

    clearResults() {
        this.resultsSection.style.display = 'none';
        this.lastScanResults = null;
        this.showNotification('Results cleared', 'info');
    }

    showNotification(message, type = 'info') {
        const notification = document.getElementById('notification');
        notification.textContent = message;
        notification.className = `notification ${type}`;
        notification.classList.add('show');
        
        setTimeout(() => {
            notification.classList.remove('show');
        }, 4000);
    }
}

// Initialize the application when DOM is loaded
document.addEventListener('DOMContentLoaded', () => {
    new PortScanner();
});

// Add some utility functions for better UX
document.addEventListener('keydown', (e) => {
    if (e.key === 'Enter' && e.target.tagName === 'INPUT') {
        const scanner = new PortScanner();
        if (scanner.validateForm()) {
            scanner.startScan();
        }
    }
});

// Auto-focus on IP input when page loads
window.addEventListener('load', () => {
    document.getElementById('target-ip').focus();
});