split code into more modules, fixes #8

modules/config.js

@@ -0,0 +1,8 @@
+var config = {
+  min_size: 0,             // < 0 will (obviously) cause crash
+  max_size: 512,           // too big values might lead to slow response time or DoS
+  default_size: 180,       // size to be used when no size given
+  browser_cache_time: 3600 // seconds until browser will request image again
+};
+
+module.exports = config;

modules/helpers.js

@@ -0,0 +1,72 @@
+var networking = require('./networking');
+var config = require('./config');
+var skins = require('./skins');
+var fs = require('fs');
+
+var valid_uuid = /^[0-9a-f]{32}$/;
+var skins_dir = config.skins_dir;
+
+var exp = {};
+
+// exracts the skin url of a +profile+ object
+// returns null when no url found
+exp.skin_url = function(profile) {
+  var url = null;
+  if (profile && profile.properties) {
+    profile.properties.forEach(function(prop) {
+      if (prop.name == 'textures') {
+        var json = Buffer(prop.value, 'base64').toString();
+        var props = JSON.parse(json);
+        url = props && props.textures && props.textures.SKIN && props.textures.SKIN.url;
+      }
+    });
+  }
+  return url;
+};
+
+
+// returns true if the +uuid+ is a valid uuid
+// the uuid may be not exist, however
+exp.uuid_valid = function(uuid) {
+  return valid_uuid.test(uuid);
+};
+
+// handles requests for +uuid+ images with +size+
+//
+// callback is a function with 3 parameters:
+//   error, status, image buffer
+//
+// the status gives information about how the image was received
+//  -1: profile requested, but it was not found
+//   1: found on disk
+//   2: profile requested/found, skin downloaded from mojang servers
+//   3: profile requested/found, but it has no skin
+exp.get_avatar = function(uuid, size, callback) {
+  var filepath = skins_dir + uuid + ".png";
+  if (fs.existsSync(filepath)) {
+    skins.resize_img(filepath, size, function(result) {
+      callback(null, 1, result);
+    });
+  } else {
+    networking.get_profile(uuid, function(err, profile) {
+      if (err) {
+        callback(err, -1, profile);
+      }
+      var skinurl = exp.skin_url(profile);
+
+      if (skinurl) {
+        networking.skin_file(skinurl, filepath, function() {
+          console.log('got skin');
+          skins.resize_img(filepath, size, function(result) {
+            callback(null, 2, result);
+          });
+        });
+      } else {
+        // profile found, but has no skin
+        callback(null, 3, null);
+      }
+    });
+  }
+};
+
+module.exports = exp;

modules/networking.js

@@ -0,0 +1,65 @@
+var request = require('request');
+var skins = require('./skins');
+
+var session_url = "https://sessionserver.mojang.com/session/minecraft/profile/";
+
+var exp = {};
+
+exp.get_profile = function(uuid, callback) {
+  request.get({
+    url: session_url + uuid,
+    timeout: 1000 // ms
+  }, function (error, response, body) {
+    if (!error && response.statusCode == 200) {
+      callback(null, JSON.parse(body));
+    } else {
+      if (error) {
+        callback(error, null);
+        return;
+      } else if (response.statusCode == 204 || response.statusCode == 404) {
+        // we get 204 No Content when UUID doesn't exist (including 404 in case they change that)
+      } else if (response.statusCode == 429) {
+        // Too Many Requests
+        console.warn("Too many requests for " + uuid);
+        console.warn(body);
+      } else {
+        console.error("Unknown error:");
+        console.error(response);
+        console.error(body);
+      }
+      callback(null, null);
+    }
+  });
+};
+
+exp.skin_file = function(url, outname, callback) {
+  request.get({
+    url: url,
+    encoding: null, // encoding must be null so we get a buffer
+    timeout: 1000 // ms
+  }, function (error, response, body) {
+    if (!error && response.statusCode == 200) {
+      skins.extract_face(body, outname, function() {
+        callback();
+      });
+    } else {
+      if (error) {
+        console.error(error);
+      } else if (response.statusCode == 404) {
+        console.warn("Texture not found: " + url);
+      } else if (response.statusCode == 429) {
+        // Too Many Requests
+        // Never got this, seems like textures aren't limited
+        console.warn("Too many requests for " + url);
+        console.warn(body);
+      } else {
+        console.error("Unknown error:");
+        console.error(response);
+        console.error(body);
+      }
+      callback(null);
+    }
+  });
+};
+
+module.exports = exp;

modules/skins.js

@@ -0,0 +1,32 @@
+var lwip = require('lwip');
+
+var exp = {};
+
+// extracts the face from an image +buffer+
+// save it to a file called +outname+
+exp.extract_face = function(buffer, outname, callback) {
+  lwip.open(buffer, "png", function(err, image) {
+    if (err) throw err;
+    image.batch()
+    .crop(8, 8, 15, 15)
+    .writeFile(outname, function(err) {
+      if (err) throw err;
+      callback();
+    });
+  });
+};
+
+// resizes the image file +inname+ to +size+ by +size+ pixels
+// +callback+ is a buffer of the resized image
+exp.resize_img = function(inname, size, callback) {
+  lwip.open(inname, function(err, image) {
+    if (err) throw err;
+    image.batch()
+    .resize(size, size, "nearest-neighbor") // nearest-neighbor doesn't blur
+    .toBuffer('png', function(err, buffer) {
+      callback(buffer);
+    });
+  });
+};
+
+module.exports = exp;