/**
 * Connections Routes
 * All routes related to connection management
 */

const express = require('express');
const router = express.Router();
const db = require('../db');

/**
 * GET /api/connections
 * Get all connections for a project
 */
router.get('/', (req, res, next) => {
  try {
    const projectId = req.query.projectId || 1;
    const connections = db.getAllConnections(projectId);
    res.json(connections);
  } catch (err) {
    next(err);
  }
});

/**
 * POST /api/connections
 * Create a new connection
 */
router.post('/', (req, res, next) => {
  try {
    const { sourceDeviceId, sourcePort, targetDeviceId, targetPort } = req.body;

    // Validation
    if (!sourceDeviceId) {
      return res.status(400).json({ error: 'Source device ID is required' });
    }
    if (typeof sourcePort !== 'number' || sourcePort < 1) {
      return res.status(400).json({ error: 'Valid source port number is required' });
    }
    if (!targetDeviceId) {
      return res.status(400).json({ error: 'Target device ID is required' });
    }
    if (typeof targetPort !== 'number' || targetPort < 1) {
      return res.status(400).json({ error: 'Valid target port number is required' });
    }
    if (sourceDeviceId === targetDeviceId) {
      return res.status(400).json({ error: 'Cannot connect device to itself' });
    }

    const connection = db.createConnection(
      sourceDeviceId,
      sourcePort,
      targetDeviceId,
      targetPort
    );
    res.status(201).json(connection);
  } catch (err) {
    // Handle unique constraint violations (port already in use)
    if (err.message && err.message.includes('UNIQUE constraint')) {
      return res.status(400).json({ error: 'One or both ports are already in use' });
    }
    next(err);
  }
});

/**
 * PUT /api/connections/:id
 * Update a connection
 */
router.put('/:id', (req, res, next) => {
  try {
    const { sourceDeviceId, sourcePort, targetDeviceId, targetPort } = req.body;

    // Validation
    if (!sourceDeviceId) {
      return res.status(400).json({ error: 'Source device ID is required' });
    }
    if (typeof sourcePort !== 'number' || sourcePort < 1) {
      return res.status(400).json({ error: 'Valid source port number is required' });
    }
    if (!targetDeviceId) {
      return res.status(400).json({ error: 'Target device ID is required' });
    }
    if (typeof targetPort !== 'number' || targetPort < 1) {
      return res.status(400).json({ error: 'Valid target port number is required' });
    }
    if (sourceDeviceId === targetDeviceId) {
      return res.status(400).json({ error: 'Cannot connect device to itself' });
    }

    db.updateConnection(
      req.params.id,
      sourceDeviceId,
      sourcePort,
      targetDeviceId,
      targetPort
    );
    res.json({ success: true });
  } catch (err) {
    if (err.message && err.message.includes('UNIQUE constraint')) {
      return res.status(400).json({ error: 'One or both ports are already in use' });
    }
    next(err);
  }
});

/**
 * PUT /api/connections/:id/waypoints
 * Update connection waypoints
 */
router.put('/:id/waypoints', (req, res, next) => {
  try {
    const { waypoints, view } = req.body;

    if (!waypoints || !Array.isArray(waypoints)) {
      return res.status(400).json({ error: 'Waypoints must be an array' });
    }

    // Validate waypoint structure
    for (const waypoint of waypoints) {
      if (typeof waypoint.x !== 'number' || typeof waypoint.y !== 'number') {
        return res.status(400).json({
          error: 'Each waypoint must have valid x and y coordinates'
        });
      }
    }

    db.updateConnectionWaypoints(req.params.id, waypoints, view);
    res.json({ success: true });
  } catch (err) {
    next(err);
  }
});

/**
 * DELETE /api/connections/:id
 * Delete a connection
 */
router.delete('/:id', (req, res, next) => {
  try {
    db.deleteConnection(req.params.id);
    res.json({ success: true });
  } catch (err) {
    next(err);
  }
});

module.exports = router;