import express from 'express';
import { AuditLog } from '../models/AuditLog.js';
import { AuditService } from '../services/auditService.js';
import { auth } from '../utils/auth.js';
import { metrics } from '../utils/metrics.js';
import { logger } from '../utils/logger.js';

const router = express.Router();
const auditService = new AuditService();

/**
 * Search audit logs
 */
router.get('/audit-logs', auth(), async (req, res) => {
    try {
        const {
            accountId,
            userId,
            category,
            action,
            resource,
            startDate,
            endDate,
            page = 1,
            limit = 50
        } = req.query;

        const criteria = {
            accountId: accountId || req.user.accountId,
            userId,
            category,
            action,
            resource,
            startDate: startDate ? new Date(startDate) : undefined,
            endDate: endDate ? new Date(endDate) : undefined,
            page: parseInt(page),
            limit: parseInt(limit)
        };

        const logs = await auditService.searchLogs(criteria);

        res.json({
            success: true,
            data: logs,
            pagination: {
                page: parseInt(page),
                limit: parseInt(limit),
                hasMore: logs.length === parseInt(limit)
            }
        });

        metrics.recordApiCall('audit.search', 'success');
    } catch (error) {
        logger.error('Failed to search audit logs:', error);
        metrics.recordApiCall('audit.search', 'error');
        res.status(500).json({
            success: false,
            error: 'Failed to search audit logs'
        });
    }
});

/**
 * Get audit trail for a resource
 */
router.get('/audit-trail/:resourceType/:resourceId', auth(), async (req, res) => {
    try {
        const { resourceType, resourceId } = req.params;

        const trail = await auditService.getAuditTrail(resourceId, resourceType);

        res.json({
            success: true,
            data: trail,
            count: trail.length
        });

        metrics.recordApiCall('audit.trail', 'success');
    } catch (error) {
        logger.error('Failed to get audit trail:', error);
        metrics.recordApiCall('audit.trail', 'error');
        res.status(500).json({
            success: false,
            error: 'Failed to get audit trail'
        });
    }
});

/**
 * Generate compliance report
 */
router.post('/audit-reports/compliance', auth(), async (req, res) => {
    try {
        const { startDate, endDate } = req.body;

        if (!startDate || !endDate) {
            return res.status(400).json({
                success: false,
                error: 'Start date and end date are required'
            });
        }

        const report = await auditService.generateComplianceReport(
            req.user.accountId,
            new Date(startDate),
            new Date(endDate)
        );

        res.json({
            success: true,
            data: report
        });

        metrics.recordApiCall('audit.compliance_report', 'success');
    } catch (error) {
        logger.error('Failed to generate compliance report:', error);
        metrics.recordApiCall('audit.compliance_report', 'error');
        res.status(500).json({
            success: false,
            error: 'Failed to generate compliance report'
        });
    }
});

/**
 * Detect anomalies
 */
router.get('/audit-anomalies', auth(), async (req, res) => {
    try {
        const { window = 3600000 } = req.query; // Default 1 hour

        const anomalies = await auditService.detectAnomalies(
            req.user.accountId,
            parseInt(window)
        );

        res.json({
            success: true,
            data: anomalies,
            count: anomalies.length,
            window: parseInt(window)
        });

        metrics.recordApiCall('audit.anomalies', 'success');
    } catch (error) {
        logger.error('Failed to detect anomalies:', error);
        metrics.recordApiCall('audit.anomalies', 'error');
        res.status(500).json({
            success: false,
            error: 'Failed to detect anomalies'
        });
    }
});

/**
 * Get activity summary
 */
router.get('/audit-summary', auth(), async (req, res) => {
    try {
        const { days = 7 } = req.query;

        const summary = await AuditLog.getActivitySummary(
            req.user.accountId,
            parseInt(days)
        );

        res.json({
            success: true,
            data: summary,
            period: {
                days: parseInt(days),
                startDate: new Date(Date.now() - parseInt(days) * 24 * 60 * 60 * 1000),
                endDate: new Date()
            }
        });

        metrics.recordApiCall('audit.summary', 'success');
    } catch (error) {
        logger.error('Failed to get activity summary:', error);
        metrics.recordApiCall('audit.summary', 'error');
        res.status(500).json({
            success: false,
            error: 'Failed to get activity summary'
        });
    }
});

/**
 * Get audit log by ID
 */
router.get('/audit-logs/:auditId', auth(), async (req, res) => {
    try {
        const { auditId } = req.params;

        const log = await AuditLog.findOne({ auditId });
        if (!log) {
            return res.status(404).json({
                success: false,
                error: 'Audit log not found'
            });
        }

        // Check access permissions
        if (log.accountId !== req.user.accountId) {
            return res.status(403).json({
                success: false,
                error: 'Access denied'
            });
        }

        res.json({
            success: true,
            data: log
        });

        metrics.recordApiCall('audit.get', 'success');
    } catch (error) {
        logger.error('Failed to get audit log:', error);
        metrics.recordApiCall('audit.get', 'error');
        res.status(500).json({
            success: false,
            error: 'Failed to get audit log'
        });
    }
});

/**
 * Export audit logs
 */
router.post('/audit-export', auth(), async (req, res) => {
    try {
        const {
            format = 'json',
            startDate,
            endDate,
            category,
            compress = false
        } = req.body;

        const criteria = {
            accountId: req.user.accountId,
            startDate: startDate ? new Date(startDate) : new Date(Date.now() - 30 * 24 * 60 * 60 * 1000),
            endDate: endDate ? new Date(endDate) : new Date(),
            category
        };

        const logs = await auditService.searchLogs(criteria);

        let exportData;
        let contentType;
        let filename = `audit_export_${Date.now()}`;

        switch (format) {
            case 'csv':
                exportData = convertToCSV(logs);
                contentType = 'text/csv';
                filename += '.csv';
                break;
            case 'json':
            default:
                exportData = JSON.stringify(logs, null, 2);
                contentType = 'application/json';
                filename += '.json';
                break;
        }

        if (compress) {
            // In production, implement compression
            filename += '.gz';
            contentType = 'application/gzip';
        }

        res.setHeader('Content-Type', contentType);
        res.setHeader('Content-Disposition', `attachment; filename="${filename}"`);
        res.send(exportData);

        metrics.recordApiCall('audit.export', 'success');
    } catch (error) {
        logger.error('Failed to export audit logs:', error);
        metrics.recordApiCall('audit.export', 'error');
        res.status(500).json({
            success: false,
            error: 'Failed to export audit logs'
        });
    }
});

/**
 * Create manual audit log entry
 */
router.post('/audit-logs', auth(), async (req, res) => {
    try {
        const eventData = {
            ...req.body,
            accountId: req.user.accountId,
            actor: {
                type: 'user',
                id: req.user.id,
                ip: req.ip,
                userAgent: req.get('user-agent')
            }
        };

        const auditLog = await auditService.logEvent(eventData);

        res.status(201).json({
            success: true,
            data: auditLog
        });

        metrics.recordApiCall('audit.create', 'success');
    } catch (error) {
        logger.error('Failed to create audit log:', error);
        metrics.recordApiCall('audit.create', 'error');
        res.status(500).json({
            success: false,
            error: 'Failed to create audit log'
        });
    }
});

/**
 * Helper function to convert to CSV
 */
function convertToCSV(logs) {
    if (logs.length === 0) return '';

    const headers = [
        'Timestamp',
        'Audit ID',
        'Action',
        'Category',
        'Resource',
        'Resource ID',
        'Actor Type',
        'Actor ID',
        'Result',
        'IP Address'
    ];

    const rows = logs.map(log => [
        log.timestamp,
        log.auditId,
        log.action,
        log.category,
        log.resource || '',
        log.resourceId || '',
        log.actor.type,
        log.actor.id,
        log.result.status,
        log.actor.ip || ''
    ]);

    const csvContent = [
        headers.join(','),
        ...rows.map(row => row.map(cell => 
            typeof cell === 'string' && cell.includes(',') ? `"${cell}"` : cell
        ).join(','))
    ].join('\n');

    return csvContent;
}

export default router;