finished world wrapper

1 files changed, 67 insertions, 0 deletions

diff --git a/socket.js b/socket.js
new file mode 100644
index 0000000..4a030f5
--- /dev/null
+++ b/socket.js
@@ -0,0 +1,67 @@
+/* socket.js, a simple wrapper for a YWOT websocket connection */
+
+class retryws extends EventEmitter{ // a wrapper on ws that retries on failure
+  constructor(addr) {
+    let sock;
+    this.sockdown = true; 
+    this.send = (message) => {
+      if (sockdown){
+        throw "Socket is down!";
+      }
+      sock.send(message);
+    }
+    function sockinit(){ // addr is not expected to change, so not handed as input; similarly, sock is not passed in a chain because behavior is expected to be serial (either initializing or retrying)
+      sock = new ws(addr);
+      sock.on('open', () => { this.emit('open'); sockdown = false; });
+      sock.on('close', (err) => { setTimeout(sockinit,1000); sockdown = true; this.emit('close'); });
+      sock.on('error', (err) => { sock.close(); });
+      sock.on('message', (message) => { this.emit('message',message); });
+    }
+  }
+}
+
+
+class Socket extends retryws {
+  constructor(world='') { // Takes the name of the world, which can be an empty string.
+    let loc = (name = '') ? '' : `/${name}`;
+    let addr = `wss://www.yourworldoftext.com/${loc}ws`;
+    super(addr);
+    this.on('message', (msg)=>{
+      msg = JSON.parse(msg);
+      switch (message.kind){
+        case 'write':
+          this.emit('write', message.accepted, message.rejected); break; // A confirmation message for writes (accepted/rejected updates)
+        case 'cursor':
+          this.emit('cursor', message.positions, message.sender); break; // Must be used for self-identification
+        case 'tileUpdate':
+          this.emit('tileUpdate', message.sender, message.source, message.tiles); break; // Any change by another user or possibly oneself
+        case 'fetch':
+          this.emit('fetch', message.tiles); break; // The response to a fetch request
+      }
+    }
+
+    this.fetch = function(coords){ //coords is a list of quadruplets, each a min/max pair of y/x coordinate pairs which describes at most 1000 tiles
+    //Unchecked for speed
+      for (var i=0; i<coords.length; i++){
+        coords[i] = {"minY":coords[i][0], "minX":coords[i][1], "maxY":coords[i][2], "maxX":coords[i][3]};
+      }
+      this.send(`{"fetchRectangles":${JSON.stringify(coords)},"kind":"fetch","v":"3"}`);
+    }
+
+    this.write = function(chars){ //chars is an list of triplets [ tile coordinate (y/x), pixel coordinate (y/x < 16), char ]
+      if (chars.length > 200){
+        throw "Too many characters to write";
+      }
+      for (var i=0; i<chars.length; i++){
+        chars[i].splice(4,0,0); //
+        chars[i].push(i);
+      }
+      this.send(`{"edits":${JSON.stringify(chars)},"kind":"write"}`;
+    }
+    
+    this.cursor = function(coords){ //coords is just one quadruplet analagous to fetch; I think the api could handle more, but it's unnecessary for now.
+      this.send(`"kind":"cursor","positions":[${JSON.stringify(coords)}]}`;
+    }
+
+  }
+}