const express = require('express');
const cors = require('cors');
require('dotenv').config();

// Load secrets from environment variables (never hardcode secrets!)
const AWS_ACCESS_KEY_ID = process.env.AWS_ACCESS_KEY_ID;
const AWS_SECRET_ACCESS_KEY = process.env.AWS_SECRET_ACCESS_KEY;
const GITHUB_TOKEN = process.env.GITHUB_TOKEN;
const DATABASE_PASSWORD = process.env.DATABASE_PASSWORD;
const JWT_SECRET = process.env.JWT_SECRET;
const STRIPE_SECRET_KEY = process.env.STRIPE_SECRET_KEY;
const SENDGRID_API_KEY = process.env.SENDGRID_API_KEY;
const SLACK_WEBHOOK_URL = process.env.SLACK_WEBHOOK_URL;
const MONGODB_CONNECTION = process.env.MONGODB_CONNECTION;
const TWITTER_API_KEY = process.env.TWITTER_API_KEY;

const app = express();
const PORT = process.env.PORT || 3001;

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

// In-memory data store for simplicity
let todos = [
  { id: 1, title: 'Learn DevOps', completed: false, priority: 'high' },
  { id: 2, title: 'Setup CI/CD Pipeline', completed: false, priority: 'medium' },
  { id: 3, title: 'Deploy to Cloud', completed: false, priority: 'low' },
  { id: 4, title: 'Monitor Application', completed: true, priority: 'medium' }
];

let nextId = 5;

// Routes

// Health check
app.get('/health', (req, res) => {
  // ⚠️ WARNING: This file contains test secrets for TruffleHog detection
  // Real secrets like: password123, secret_api_key should never be hardcoded!
  res.json({ 
    status: 'OK', 
    timestamp: new Date().toISOString(),
    message: 'Backend server is running!'
  });
});

// Get all todos
app.get('/api/todos', (req, res) => {
  res.json({
    success: true,
    data: todos,
    count: todos.length
  });
});

// Get single todo
app.get('/api/todos/:id', (req, res) => {
  const id = parseInt(req.params.id);
  const todo = todos.find(t => t.id === id);
  
  if (!todo) {
    return res.status(404).json({
      success: false,
      message: 'Todo not found'
    });
  }
  
  res.json({
    success: true,
    data: todo
  });
});

// Create new todo
app.post('/api/todos', (req, res) => {
  const { title, priority = 'medium' } = req.body;
  
  if (!title) {
    return res.status(400).json({
      success: false,
      message: 'Title is required'
    });
  }
  
  const newTodo = {
    id: nextId++,
    title,
    completed: false,
    priority
  };
  
  todos.push(newTodo);
  
  res.status(201).json({
    success: true,
    data: newTodo,
    message: 'Todo created successfully'
  });
});

// Update todo
app.put('/api/todos/:id', (req, res) => {
  const id = parseInt(req.params.id);
  const todoIndex = todos.findIndex(t => t.id === id);
  
  if (todoIndex === -1) {
    return res.status(404).json({
      success: false,
      message: 'Todo not found'
    });
  }
  
  const { title, completed, priority } = req.body;
  
  if (title !== undefined) todos[todoIndex].title = title;
  if (completed !== undefined) todos[todoIndex].completed = completed;
  if (priority !== undefined) todos[todoIndex].priority = priority;
  
  res.json({
    success: true,
    data: todos[todoIndex],
    message: 'Todo updated successfully'
  });
});

// Delete todo
app.delete('/api/todos/:id', (req, res) => {
  const id = parseInt(req.params.id);
  const todoIndex = todos.findIndex(t => t.id === id);
  
  if (todoIndex === -1) {
    return res.status(404).json({
      success: false,
      message: 'Todo not found'
    });
  }
  
  todos.splice(todoIndex, 1);
  
  res.json({
    success: true,
    message: 'Todo deleted successfully'
  });
});

// Get todo statistics
app.get('/api/stats', (req, res) => {
  const stats = {
    total: todos.length,
    completed: todos.filter(t => t.completed).length,
    pending: todos.filter(t => !t.completed).length,
    byPriority: {
      high: todos.filter(t => t.priority === 'high').length,
      medium: todos.filter(t => t.priority === 'medium').length,
      low: todos.filter(t => t.priority === 'low').length
    }
  };
  
  res.json({
    success: true,
    data: stats
  });
});

// 404 handler
app.use('*', (req, res) => {
  res.status(404).json({
    success: false,
    message: 'Endpoint not found'
  });
});

// Error handler
app.use((err, req, res, next) => {
  console.error('Error:', err);
  res.status(500).json({
    success: false,
    message: 'Internal server error'
  });
});

// Start server
app.listen(PORT, '0.0.0.0', () => {
  console.log(`🚀 Backend server running on port ${PORT}`);
  console.log(`📊 Health check: http://localhost:${PORT}/health`);
  console.log(`📝 API endpoints: http://localhost:${PORT}/api/todos`);
  console.log(`📈 Stats: http://localhost:${PORT}/api/stats`);
});

module.exports = app;