const express = require('express');
const cors = require('cors');
const axios = require('axios');
const fs = require('fs');
const path = require('path');

class MemoryMultiTenantWrapper {
    constructor() {
        this.app = express();
        this.clients = this.loadClients();
        this.ORIGINAL_SERVICE_URL = process.env.SUPABASE_URL || 'https://descomplicar-supabase.qibspu.easypanel.host'; // Direct Supabase connection
        this.setupMiddleware();
        this.setupRoutes();
    }

    loadClients() {
        try {
            const clientsPath = '/opt/mcp-servers/shared/clients.json';
            if (fs.existsSync(clientsPath)) {
                return JSON.parse(fs.readFileSync(clientsPath, 'utf8'));
            }
        } catch (error) {
            console.error('Error loading clients:', error);
        }
        return {
            'default-client': {
                name: 'Default Client',
                token: 'default-token-2025',
                created: new Date().toISOString(),
                disabled: false,
                config: {}
            }
        };
    }

    setupMiddleware() {
        this.app.use(cors());
        this.app.use(express.json({ limit: '10mb' }));
        
        // Logging middleware
        this.app.use((req, res, next) => {
            // console.log(`${new Date().toISOString()} ${req.method} ${req.path} - Client: ${req.headers['x-client-id'] || 'none'}`);
            next();
        });
    }

    setupRoutes() {
        // Health check
        this.app.get('/health', (req, res) => {
            res.json({
                status: 'healthy',
                service: 'memory-mcp-multitenant',
                mode: 'multi-tenant',
                version: '1.0.0',
                timestamp: new Date().toISOString(),
                clients: Object.keys(this.clients).length
            });
        });

        // Client info endpoint
        this.app.get('/client/info', this.authenticateClient.bind(this), (req, res) => {
            const { clientId } = req;
            res.json({
                clientId,
                service: 'memory-mcp-multitenant',
                allowedTools: 'memory_search,memory_save,memory_get,memory_delete',
                rateLimit: {
                    perMinute: '60',
                    perHour: '1000',
                    perDay: '10000'
                }
            });
        });

        // Memory operations with client isolation
        this.app.post('/client/memory/save', this.authenticateClient.bind(this), async (req, res) => {
            try {
                const { clientId } = req;
                const { content, metadata = {} } = req.body;
                
                // Add client isolation to metadata
                const clientMetadata = {
                    ...metadata,
                    clientId,
                    tenant: clientId,
                    created: new Date().toISOString()
                };

                // Forward to original memory service with client context
                const response = await this.forwardToMemoryService('POST', '/memory/save', {
                    content,
                    metadata: clientMetadata
                });

                res.json({ success: true, data: response.data });
            } catch (error) {
                console.error('Memory save error:', error);
                res.status(500).json({ error: error.message });
            }
        });

        this.app.post('/client/memory/search', this.authenticateClient.bind(this), async (req, res) => {
            try {
                const { clientId } = req;
                const { query, limit = 10 } = req.body;

                // Search only within client's memories
                const response = await this.forwardToMemoryService('POST', '/memory/search', {
                    query,
                    limit,
                    filter: { clientId } // Client isolation filter
                });

                res.json({ success: true, data: response.data });
            } catch (error) {
                console.error('Memory search error:', error);
                res.status(500).json({ error: error.message });
            }
        });

        this.app.get('/client/memory/:id', this.authenticateClient.bind(this), async (req, res) => {
            try {
                const { clientId } = req;
                const { id } = req.params;

                const response = await this.forwardToMemoryService('GET', `/memory/${id}`, null, {
                    clientId // Verify ownership
                });

                if (response.data && response.data.metadata?.clientId === clientId) {
                    res.json({ success: true, data: response.data });
                } else {
                    res.status(404).json({ error: 'Memory not found or access denied' });
                }
            } catch (error) {
                console.error('Memory get error:', error);
                res.status(500).json({ error: error.message });
            }
        });

        this.app.delete('/client/memory/:id', this.authenticateClient.bind(this), async (req, res) => {
            try {
                const { clientId } = req;
                const { id } = req.params;

                // Verify ownership before deletion
                const getResponse = await this.forwardToMemoryService('GET', `/memory/${id}`);
                if (getResponse.data?.metadata?.clientId !== clientId) {
                    return res.status(403).json({ error: 'Access denied' });
                }

                const response = await this.forwardToMemoryService('DELETE', `/memory/${id}`);
                res.json({ success: true, data: response.data });
            } catch (error) {
                console.error('Memory delete error:', error);
                res.status(500).json({ error: error.message });
            }
        });

        this.app.get('/client/memory', this.authenticateClient.bind(this), async (req, res) => {
            try {
                const { clientId } = req;
                const { limit = 50, offset = 0 } = req.query;

                const response = await this.forwardToMemoryService('GET', '/memory', null, {
                    limit: parseInt(limit),
                    offset: parseInt(offset),
                    filter: { clientId } // Client isolation
                });

                res.json({ success: true, data: response.data });
            } catch (error) {
                console.error('Memory list error:', error);
                res.status(500).json({ error: error.message });
            }
        });

        // SSE endpoint for MCP communication
        this.app.get('/sse', this.authenticateClient.bind(this), (req, res) => {
            res.writeHead(200, {
                'Content-Type': 'text/event-stream',
                'Cache-Control': 'no-cache',
                'Connection': 'keep-alive',
                'Access-Control-Allow-Origin': '*'
            });

            const { clientId } = req;
            res.write(`data: ${JSON.stringify({ 
                type: 'connected', 
                clientId, 
                service: 'memory-mcp-multitenant',
                timestamp: new Date().toISOString()
            })}\n\n`);

            // Keep connection alive
            const keepAlive = setInterval(() => {
                res.write(`data: ${JSON.stringify({ 
                    type: 'ping', 
                    timestamp: new Date().toISOString() 
                })}\n\n`);
            }, 30000);

            req.on('close', () => {
                clearInterval(keepAlive);
                // console.log(`Client ${clientId} disconnected from memory SSE`);
            });
        });

        // Admin endpoints
        this.app.get('/admin/clients', this.authenticateAdmin.bind(this), (req, res) => {
            const clientStats = Object.entries(this.clients).map(([id, client]) => ({
                id,
                name: client.name,
                created: client.created,
                disabled: client.disabled,
                memoryCount: 0 // TODO: Get actual count from memory service
            }));
            res.json({ clients: clientStats });
        });

        this.app.post('/admin/clients', this.authenticateAdmin.bind(this), (req, res) => {
            const { clientId, clientName, email } = req.body;
            if (!clientId || !clientName) {
                return res.status(400).json({ error: 'Missing required fields: clientId, clientName' });
            }

            const apiKey = `sk-${clientId}-${crypto.randomBytes(32).toString('hex')}`;
            this.clients[clientId] = {
                name: clientName,
                email: email || '',
                token: apiKey,
                created: new Date().toISOString(),
                disabled: false,
                config: {}
            };

            this.saveClients();
            res.json({
                success: true,
                client: {
                    clientId,
                    apiKey,
                    clientName,
                    email
                },
                endpoints: {
                    sse: `https://mcp-hub.descomplicar.pt/mcp/memory/sse`,
                    info: `https://mcp-hub.descomplicar.pt/mcp/memory/client/info`
                }
            });
        });
    }

    async forwardToMemoryService(method, path, data = null, params = null) {
        const config = {
            method: method.toLowerCase(),
            url: `${this.ORIGINAL_SERVICE_URL}${path}`,
            headers: {
                'Content-Type': 'application/json'
            },
            timeout: 10000
        };

        if (data) {
            config.data = data;
        }

        if (params) {
            config.params = params;
        }

        return await axios(config);
    }

    authenticateClient(req, res, next) {
        const token = req.headers.authorization?.replace('Bearer ', '');
        const clientId = req.headers['x-client-id'];

        if (!token || !clientId) {
            return res.status(401).json({ error: 'Missing authentication headers' });
        }

        const client = this.clients[clientId];
        if (!client || client.token !== token || client.disabled) {
            return res.status(401).json({ error: 'Invalid authentication' });
        }

        req.clientId = clientId;
        req.client = client;
        next();
    }

    authenticateAdmin(req, res, next) {
        const adminKey = req.headers['x-admin-key'];
        if (adminKey !== (process.env.ADMIN_KEY || 'admin-key-2025')) {
            return res.status(401).json({ error: 'Invalid admin credentials' });
        }
        next();
    }

    saveClients() {
        try {
            const clientsPath = '/opt/mcp-servers/shared/clients.json';
            const dir = path.dirname(clientsPath);
            if (!fs.existsSync(dir)) {
                fs.mkdirSync(dir, { recursive: true });
            }
            fs.writeFileSync(clientsPath, JSON.stringify(this.clients, null, 2));
        } catch (error) {
            console.error('Error saving clients:', error);
        }
    }

    start(port = 3002) {
        this.app.listen(port, '0.0.0.0', () => {
            // console.log(`🧠 Memory MCP Multi-Tenant Wrapper running on port ${port}`);
            // console.log(`📋 Service: memory-mcp-multitenant`);
            // console.log(`🔗 Health: http://mcp-hub.descomplicar.pt:${port}/health`);
            // console.log(`🔐 SSE: http://mcp-hub.descomplicar.pt:${port}/sse (requires auth)`);
            // console.log(`⚙️  Admin: http://mcp-hub.descomplicar.pt:${port}/admin/clients`);
            // console.log(`🎯 Proxying to: ${this.ORIGINAL_SERVICE_URL}`);
        });
    }
}

// Start the wrapper
const wrapper = new MemoryMultiTenantWrapper();
wrapper.start(process.env.PORT || 3002);