require('dotenv').config();
const express = require('express');
const AWS = require('aws-sdk');
const cors = require('cors');
const path = require('path');

const app = express();
const port = 3001;

app.use(cors());
app.use(express.json());

// Serve static files from the React app
app.use(express.static(path.join(__dirname, 'public')));

// Configure AWS S3
const s3 = new AWS.S3({
    endpoint: 'https://storage.yandexcloud.net',
    region: process.env.AWS_REGION,
    credentials: {
        accessKeyId: process.env.AWS_ACCESS_KEY_ID,
        secretAccessKey: process.env.AWS_SECRET_ACCESS_KEY,
    }
});

const BUCKET_NAME = process.env.S3_BUCKET_NAME;
const FILE_KEY = 'domains.txt';

// Get domains from S3
app.get('/api/domains', async (req, res) => {
    const params = {
        Bucket: BUCKET_NAME,
        Key: FILE_KEY,
    };

    try {
        const data = await s3.getObject(params).promise();
        const fileContent = data.Body.toString('utf-8');
        const domains = fileContent.split('\n').filter(line => line).map(line => {
            // Trim the line to remove any leading/trailing whitespace, including \r
            // And split by any whitespace to be more robust
            const parts = line.trim().split(/\s+/);
            const domain = parts[0] || '';
            const type = parts[1] || '';
            return { domain, type };
        });
        res.json(domains);
    } catch (error) {
        if (error.code === 'NoSuchKey') {
            res.json([]); // Return empty array if file does not exist
        } else {
            console.error(error);
            res.status(500).send('Error reading from S3');
        }
    }
});

// Update domains in S3
app.post('/api/domains', async (req, res) => {
    const { domains } = req.body;
    const fileContent = domains.map(d => `${d.domain} ${d.type}`).join('\n');

    const params = {
        Bucket: BUCKET_NAME,
        Key: FILE_KEY,
        Body: fileContent,
        ContentType: 'text/plain',
    };

    try {
        await s3.putObject(params).promise();
        res.send('File updated successfully');
    } catch (error) {
        console.error(error);
        res.status(500).send('Error writing to S3');
    }
});

// --- ASNs Routes ---

// Get ASNs from S3
app.get('/api/asns', async (req, res) => {
    const params = {
        Bucket: BUCKET_NAME,
        Key: 'asns.txt',
    };

    try {
        const data = await s3.getObject(params).promise();
        const fileContent = data.Body.toString('utf-8');
        const asns = fileContent.split('\n').filter(line => line).map(line => {
            const parts = line.trim().split(/\s+/);
            const domain = parts[0] || ''; // Keep name 'domain' for consistency in component
            const type = parts[1] || '';
            return { domain, type };
        });
        res.json(asns);
    } catch (error) {
        if (error.code === 'NoSuchKey') {
            res.json([]);
        } else {
            console.error(error);
            res.status(500).send('Error reading from S3');
        }
    }
});

// Update ASNs in S3
app.post('/api/asns', async (req, res) => {
    const { domains: asns } = req.body; // Keep name 'domains' for consistency
    const fileContent = asns.map(a => `${a.domain} ${a.type}`).join('\n');

    const params = {
        Bucket: BUCKET_NAME,
        Key: 'asns.txt',
        Body: fileContent,
        ContentType: 'text/plain',
    };

    try {
        await s3.putObject(params).promise();
        res.send('File updated successfully');
    } catch (error) {
        console.error(error);
        res.status(500).send('Error writing to S3');
    }
});

// --- Servers Routes (JSON format) ---

// Get servers from S3
app.get('/api/servers', async (req, res) => {
    const params = {
        Bucket: BUCKET_NAME,
        Key: 'servers.json',
    };

    try {
        const data = await s3.getObject(params).promise();
        const fileContent = data.Body.toString('utf-8');
        let servers = [];
        
        try {
            servers = JSON.parse(fileContent);
            // Ensure it's an array
            if (!Array.isArray(servers)) {
                servers = [];
            }
        } catch (parseError) {
            console.error('Error parsing servers.json:', parseError);
            servers = [];
        }
        
        res.json(servers);
    } catch (error) {
        if (error.code === 'NoSuchKey') {
            res.json([]); // Return empty array if file does not exist
        } else {
            console.error(error);
            res.status(500).send('Error reading from S3');
        }
    }
});

// Update servers in S3
app.post('/api/servers', async (req, res) => {
    const { domains: servers } = req.body; // Keep name 'domains' for consistency
    
    // Validate servers structure
    if (!Array.isArray(servers)) {
        return res.status(400).send('Servers must be an array');
    }
    
    // Validate each server has required fields
    for (let i = 0; i < servers.length; i++) {
        const server = servers[i];
        if (!server.ip || !server.dns || !server.country || !server.provider || !server.tunnel) {
            return res.status(400).send(`Server at index ${i} is missing required fields`);
        }
    }

    const params = {
        Bucket: BUCKET_NAME,
        Key: 'servers.json',
        Body: JSON.stringify(servers, null, 2), // Pretty print JSON
        ContentType: 'application/json',
    };

    try {
        await s3.putObject(params).promise();
        res.send('File updated successfully');
    } catch (error) {
        console.error(error);
        res.status(500).send('Error writing to S3');
    }
});

// --- Filters Routes (JSON format) ---

// Get filters from S3
app.get('/api/filters', async (req, res) => {
    const params = {
        Bucket: BUCKET_NAME,
        Key: 'filters.json',
    };

    try {
        const data = await s3.getObject(params).promise();
        const fileContent = data.Body.toString('utf-8');
        let filters = [];
        
        try {
            filters = JSON.parse(fileContent);
            // Ensure it's an array
            if (!Array.isArray(filters)) {
                filters = [];
            }
        } catch (parseError) {
            console.error('Error parsing filters.json:', parseError);
            filters = [];
        }
        
        res.json(filters);
    } catch (error) {
        if (error.code === 'NoSuchKey') {
            res.json([]); // Return empty array if file does not exist
        } else {
            console.error(error);
            res.status(500).send('Error reading from S3');
        }
    }
});

// Update filters in S3
app.post('/api/filters', async (req, res) => {
    const { domains: filters } = req.body; // Keep name 'domains' for consistency
    
    // Validate filters structure
    if (!Array.isArray(filters)) {
        return res.status(400).send('Filters must be an array');
    }
    
    // Validate each filter has required fields
    for (let i = 0; i < filters.length; i++) {
        const filter = filters[i];
        if (!filter.community || !filter.gateway) {
            return res.status(400).send(`Filter at index ${i} is missing required fields`);
        }
    }

    const params = {
        Bucket: BUCKET_NAME,
        Key: 'filters.json',
        Body: JSON.stringify(filters, null, 2), // Pretty print JSON
        ContentType: 'application/json',
    };

    try {
        await s3.putObject(params).promise();
        res.send('File updated successfully');
    } catch (error) {
        console.error(error);
        res.status(500).send('Error writing to S3');
    }
});

// Новый эндпоинт для получения дат последнего изменения файлов S3
app.get('/api/s3/last-modified', async (req, res) => {
    try {
        const [domainsHead, asnsHead, serversHead, filtersHead] = await Promise.all([
            s3.headObject({ Bucket: BUCKET_NAME, Key: 'domains.txt' }).promise(),
            s3.headObject({ Bucket: BUCKET_NAME, Key: 'asns.txt' }).promise(),
            s3.headObject({ Bucket: BUCKET_NAME, Key: 'servers.json' }).promise(),
            s3.headObject({ Bucket: BUCKET_NAME, Key: 'filters.json' }).promise()
        ]);
        res.json({
            domainsLastModified: domainsHead.LastModified ? domainsHead.LastModified.toISOString() : null,
            asnsLastModified: asnsHead.LastModified ? asnsHead.LastModified.toISOString() : null,
            serversLastModified: serversHead.LastModified ? serversHead.LastModified.toISOString() : null,
            filtersLastModified: filtersHead.LastModified ? filtersHead.LastModified.toISOString() : null
        });
    } catch (error) {
        console.error(error);
        res.status(500).send('Error fetching last modified dates from S3');
    }
});

// Generate MikroTik configuration from filters
app.get('/api/filters/generate-config', async (req, res) => {
    const params = {
        Bucket: BUCKET_NAME,
        Key: 'filters.json',
    };

    try {
        const data = await s3.getObject(params).promise();
        const fileContent = data.Body.toString('utf-8');
        let filters = [];
        
        try {
            filters = JSON.parse(fileContent);
            if (!Array.isArray(filters)) {
                filters = [];
            }
        } catch (parseError) {
            console.error('Error parsing filters.json:', parseError);
            filters = [];
        }

        if (filters.length === 0) {
            return res.json({ config: '// No filters to generate configuration' });
        }

        // Group filters by gateway
        const gatewayGroups = {};
        filters.forEach(filter => {
            if (!gatewayGroups[filter.gateway]) {
                gatewayGroups[filter.gateway] = [];
            }
            gatewayGroups[filter.gateway].push(filter.community);
        });

        let config = '// Frouting filter configuration for MikroTik 7.14+\n';
        config += '// Generated automatically\n';
        config += `// Date: ${new Date().toISOString()}\n\n`;

        // Если есть только один gateway, создаем простую конфигурацию
        if (Object.keys(gatewayGroups).length === 1) {
            const [gateway, communities] = Object.entries(gatewayGroups)[0];
            config += `if (\n`;
            communities.forEach((community, index) => {
                config += `(bgp-communities includes ${community})`;
                if (index < communities.length - 1) {
                    config += ` \nor `;
                }
            });
            config += `\n)\n{\n    set gw ${gateway}; accept;\n}\nelse\n{\n reject;\n}\n`;
        } else {
            // Если несколько gateway, создаем каскадную структуру
            const gatewayEntries = Object.entries(gatewayGroups);
            gatewayEntries.forEach(([gateway, communities], gatewayIndex) => {
                if (gatewayIndex === 0) {
                    config += `if (\n`;
                } else {
                    config += `else if (\n`;
                }
                
                communities.forEach((community, index) => {
                    config += `(bgp-communities includes ${community})`;
                    if (index < communities.length - 1) {
                        config += ` \nor `;
                    }
                });
                config += `\n)\n{\n    set gw ${gateway}; accept;\n}`;
                
                if (gatewayIndex === gatewayEntries.length - 1) {
                    config += `\nelse\n{\n reject;\n}\n`;
                } else {
                    config += `\n`;
                }
            });
        }

        res.json({ config });
    } catch (error) {
        if (error.code === 'NoSuchKey') {
            res.json({ config: '// filters.json file not found' });
        } else {
            console.error(error);
            res.status(500).send('Error generating configuration');
        }
    }
});

// Export MikroTik configuration to S3
app.post('/api/filters/export-config', async (req, res) => {
    const params = {
        Bucket: BUCKET_NAME,
        Key: 'filters.json',
    };

    try {
        const data = await s3.getObject(params).promise();
        const fileContent = data.Body.toString('utf-8');
        let filters = [];
        
        try {
            filters = JSON.parse(fileContent);
            if (!Array.isArray(filters)) {
                filters = [];
            }
        } catch (parseError) {
            console.error('Error parsing filters.json:', parseError);
            filters = [];
        }

        if (filters.length === 0) {
            return res.json({ success: false, message: 'Нет фильтров для экспорта' });
        }

        // Group filters by gateway
        const gatewayGroups = {};
        filters.forEach(filter => {
            if (!gatewayGroups[filter.gateway]) {
                gatewayGroups[filter.gateway] = [];
            }
            gatewayGroups[filter.gateway].push(filter.community);
        });

        let config = '// Frouting filter configuration for MikroTik 7.14+\n';
        config += '// Generated automatically\n';
        config += `// Date: ${new Date().toISOString()}\n\n`;

        // Если есть только один gateway, создаем простую конфигурацию
        if (Object.keys(gatewayGroups).length === 1) {
            const [gateway, communities] = Object.entries(gatewayGroups)[0];
            config += `if (\n`;
            communities.forEach((community, index) => {
                config += `(bgp-communities includes ${community})`;
                if (index < communities.length - 1) {
                    config += ` \nor `;
                }
            });
            config += `\n)\n{\n    set gw ${gateway}; accept;\n}\nelse\n{\n reject;\n}\n`;
        } else {
            // Если несколько gateway, создаем каскадную структуру
            const gatewayEntries = Object.entries(gatewayGroups);
            gatewayEntries.forEach(([gateway, communities], gatewayIndex) => {
                if (gatewayIndex === 0) {
                    config += `if (\n`;
                } else {
                    config += `else if (\n`;
                }
                
                communities.forEach((community, index) => {
                    config += `(bgp-communities includes ${community})`;
                    if (index < communities.length - 1) {
                        config += ` \nor `;
                    }
                });
                config += `\n)\n{\n    set gw ${gateway}; accept;\n}`;
                
                if (gatewayIndex === gatewayEntries.length - 1) {
                    config += `\nelse\n{\n reject;\n}\n`;
                } else {
                    config += `\n`;
                }
            });
        }

        // Save configuration to S3
        const exportParams = {
            Bucket: BUCKET_NAME,
            Key: 'mikrotik-frouting-config.txt',
            Body: config,
            ContentType: 'text/plain',
        };

        await s3.putObject(exportParams).promise();
        res.json({ success: true, message: 'Конфигурация экспортирована в S3' });
    } catch (error) {
        console.error(error);
        res.status(500).send('Error exporting configuration');
    }
});

// The "catchall" handler: for any request that doesn't
// match one above, send back React's index.html file.
app.get('*', (req, res) => {
  res.sendFile(path.join(__dirname, 'public', 'index.html'));
});

app.listen(port, () => {
    console.log(`Server is running on http://localhost:${port}`);
});