From 75d1c1f2f43e72643fdabd045cdc1a28fe69e5ef Mon Sep 17 00:00:00 2001
From: Kagami Hiiragi <kagami@genshiken.org>
Date: Thu, 15 Jan 2015 21:11:33 +0300
Subject: [PATCH] Implement messages.addr

---
 README.md       |  4 ++--
 lib/messages.js | 49 ++++++++++++++++++++++++++++++++++++++++++++-----
 test.js         | 20 ++++++++++++++++++++
 3 files changed, 66 insertions(+), 7 deletions(-)

diff --git a/README.md b/README.md
index 9c268cf..e8667a2 100644
--- a/README.md
+++ b/README.md
@@ -37,8 +37,8 @@ API documentation is available [here](https://bitchan.github.io/bitmessage/docs/
   - [x] pubkey features
 - [ ] Message types
   - [x] version
-  - [ ] verack
-  - [ ] addr
+  - [x] verack
+  - [x] addr
   - [ ] inv
   - [ ] getdata
   - [ ] error
diff --git a/lib/messages.js b/lib/messages.js
index caaa920..0909560 100644
--- a/lib/messages.js
+++ b/lib/messages.js
@@ -21,11 +21,11 @@ exports.version = {
   NONCE: new Buffer("20bde0a3355dad78", "hex"),
 
   /**
-   * Decode version payload.
+   * Decode `version` payload.
    * NOTE: `nonce` is copied.
-   * @param {Buffer} buf - Buffer that starts with encoded version
+   * @param {Buffer} buf - Buffer that starts with encoded `version`
    * payload
-   * @return {Object} Decoded version structure.
+   * @return {Object} Decoded `version` structure.
    */
   decode: function(payload) {
     // 4 + 8 + 8 + 26 + 26 + 8 + (1+) + (1+)
@@ -59,9 +59,9 @@ exports.version = {
   },
 
   /**
-   * Encode version payload.
+   * Encode `version` payload.
    * @param {Object} opts - Version options
-   * @return {Buffer} Encoded version payload.
+   * @return {Buffer} Encoded `version` payload.
    */
   encode: function(opts) {
     // Deal with default options.
@@ -97,3 +97,42 @@ exports.version = {
     ]);
   },
 };
+
+/**
+ * Addresses message. Provide information on known nodes of the network.
+ * @see {@link https://bitmessage.org/wiki/Protocol_specification#addr}
+ * @namespace
+ */
+exports.addr = {
+  /**
+   * Decode `addr` payload.
+   * @param {Buffer} buf - Buffer that starts with encoded `addr` payload
+   * @return {Object} Decoded `addr` structure.
+   */
+  decode: function(buf) {
+    var decoded = structs.var_int.decode(buf);
+    var listLength = decoded.value;
+    var length = decoded.length + listLength * 38;
+    assert(buf.length >= length, "Buffer is too small");
+    var rest = decoded.rest;
+    var addrs = new Array(listLength);
+    for (var i = 0; i < listLength; i++) {
+      addrs[i] = structs.net_addr.decode(rest.slice(i*38, (i+1)*38));
+    }
+    return {
+      addrs: addrs,
+      // Real data length.
+      length: length,
+    };
+  },
+
+  /**
+   * Encode `addr` payload.
+   * @param {Object[]} addrs - Network addresses
+   * @return {Buffer} Encoded `addr` payload.
+   */
+  encode: function(addrs) {
+    var addrsBuf = Buffer.concat(addrs.map(structs.net_addr.encode));
+    return Buffer.concat([structs.var_int.encode(addrs.length), addrsBuf]);
+  },
+};
diff --git a/test.js b/test.js
index e6ac178..971dc58 100644
--- a/test.js
+++ b/test.js
@@ -18,6 +18,7 @@ var serviceFeatures = structs.serviceFeatures;
 var pubkeyFeatures = structs.pubkeyFeatures;
 var messages = bitmessage.messages;
 var version = messages.version;
+var addr = messages.addr;
 var WIF = bitmessage.WIF;
 var POW = bitmessage.POW;
 var Address = bitmessage.Address;
@@ -301,6 +302,25 @@ describe("Message types", function() {
       expect(res.length).to.equal(101);
     });
   });
+
+  describe("addr", function() {
+    it("should encode and decode", function() {
+      var res = addr.decode(addr.encode([]));
+      expect(res.length).to.equal(1);
+      expect(res.addrs).to.deep.equal([]);
+
+      res = addr.decode(addr.encode([
+        {host: "1.2.3.4", port: 8444},
+        {host: "ff::1", port: 18444},
+      ]));
+      expect(res.length).to.equal(77);
+      expect(res.addrs.length).to.equal(2);
+      expect(res.addrs[0].host).to.equal("1.2.3.4");
+      expect(res.addrs[0].port).to.equal(8444);
+      expect(res.addrs[1].host).to.equal("ff:0:0:0:0:0:0:1");
+      expect(res.addrs[1].port).to.equal(18444);
+    });
+  });
 });
 
 describe("WIF", function() {