routes.js

var fs = require('fs'),
    Map = require('./projector'),
    Projector = require('./projector');

/**
 * Map tile routing
 * :zoom/:col/:row.png routing
 */
module.exports.tilePng = function tilePng(options){
  var options = options || {},
      map = options.map;

  if (!options.map) {
    throw new Error("You must set options.map equal to your map");
  }

  return function tilePng(req, res, next){
    var tileCoordinate, bounds;
    // verify arguments
    tileCoordinate = req.path.match(/(\d+)\/(\d+)\/(\d+)\.png$/);
    if (!tileCoordinate) {
      return next();
    }
    // slice the regexp down to usable size
    tileCoordinate = tileCoordinate.slice(1,4).map(Number);

    // set the bounds and render
    bounds = Projector.util.tileToMeters(tileCoordinate[1], tileCoordinate[2], tileCoordinate[0]);
    map.render({
      bounds: {minX: bounds[0], minY: bounds[1], maxX: bounds[2], maxY: bounds[3]},
      width: 256,
      height: 256,
      zoom: tileCoordinate[0],
      callback: function(err, canvas) {
        // TODO: catche the error
        var stream = canvas.createPNGStream();
        stream.pipe(res);
      }
    });
  };
};

 /**
 * UTFGrid routing
 * :zoom/:col/:row.jsonp routing
 */
module.exports.utfGrid = function utfGrid(options){
  var options = options || {},
      map = options.map,
      format;

  if (!options.map) {
    throw new Error("You must set options.map equal to your map");
  }


  return function tilePng(req, res, next){
    var tileCoordinate, format, bounds;

    // verify arguments (don't forget jsonp!)
    tileCoordinate = req.path.match(/(\d+)\/(\d+)\/(\d+)\.(png|json|jsonp)$/);
    if (!tileCoordinate) {
      return next();
    }

    // slice the regexp down to usable size
    console.log(tileCoordinate[4]);
    format = tileCoordinate[4];
    tileCoordinate = tileCoordinate.slice(1,4).map(Number);

    // Show the rasterized utfgrid for debugging
    respondWithImage = format === 'png';
    if (respondWithImage) {
      renderHandler = function(err, canvas) {
        var stream = canvas.createPNGStream();
        stream.pipe(res);
      };
    }
    else {
      renderHandler = function(err, grid) {
        res.jsonp(grid);
      };
    }
    bounds = Projector.util.tileToMeters(tileCoordinate[1], tileCoordinate[2], tileCoordinate[0], 64);
    map.renderGrid({
      bounds: {minX: bounds[0], minY: bounds[1], maxX: bounds[2], maxY: bounds[3]},
      width: 64,
      height: 64,
      zoom: tileCoordinate[0],
      drawImage: respondWithImage,
      callback: renderHandler
    });
  };
};

module.exports.tileJson = function tileJson(options) {
  var options = options || {},
      path = options.path;

  if (!options.path) {
    throw new Error("You must set options.path to point to your tile.json file");
  }

  return function tileJson(req, res, next){
    fs.readFile(path, 'utf8', function(err, file){
      if (err) return next(err);
      var tileJson;

      // don't let JSON.parse barf all over everything
      try {
        tileJson = JSON.parse(file);
      }
      catch(err) {
        return next(err);
      }

      return res.jsonp(tileJson);
    });
  }
};