From 373e967082bc170c1822eb82ef9f046ae9cb3ac0 Mon Sep 17 00:00:00 2001
From: Gordon Williams <gw@pur3.co.uk>
Date: Thu, 24 Mar 2022 15:52:19 +0000
Subject: [PATCH] first hack at support for running the App Loader inside
 Gadgetbridge

---
 gadgetbridge.js | 162 ++++++++++++++++++++++++++++++++++++++++++++++++
 index.html      |   1 +
 2 files changed, 163 insertions(+)
 create mode 100644 gadgetbridge.js

diff --git a/gadgetbridge.js b/gadgetbridge.js
new file mode 100644
index 000000000..679fffc60
--- /dev/null
+++ b/gadgetbridge.js
@@ -0,0 +1,162 @@
+/* Detects if we're running under Gadgetbridge in a WebView, and if
+so it overwrites the 'Puck' library with a special one that calls back
+into Gadgetbridge to handle watch communications */
+
+/*// test code
+Android = {
+  bangleTx : function(data) {
+    console.log("TX : "+JSON.stringify(data));
+  }
+};*/
+
+if (typeof Android!=="undefined") {
+  console.log("Running under Gadgetbridge, overwrite Puck library");
+
+  var isBusy = false;
+  var queue = [];
+  var connection = {
+    cb : function(data) {},
+    write : function(data, writecb) {
+      Android.bangleTx(data);  
+      Puck.writeProgress(data.length, data.length);
+      if (writecb) setTimeout(writecb,10);
+    },
+    close : function() {},
+    received : "", 
+    hadData : false
+  }
+
+  function bangleRx(data) { 
+//    document.getElementById("status").innerText = "RX:"+data;
+    connection.received += data;
+    connection.hadData = true;
+    if (connection.cb)  connection.cb(data);
+  } 
+
+  function log(level, s) {
+    if (Puck.log) Puck.log(level, s);
+  }
+
+  function handleQueue() {
+    if (!queue.length) return;
+    var q = queue.shift();
+    log(3,"Executing "+JSON.stringify(q)+" from queue");
+    if (q.type == "write") Puck.write(q.data, q.callback, q.callbackNewline);
+    else log(1,"Unknown queue item "+JSON.stringify(q));
+  }
+
+ /* convenience function... Write data, call the callback with data:
+       callbackNewline = false => if no new data received for ~0.2 sec
+       callbackNewline = true => after a newline */
+  function write(data, callback, callbackNewline) {
+    let result;
+    /// If there wasn't a callback function, then promisify
+    if (typeof callback !== 'function') {
+      callbackNewline = callback;
+
+      result = new Promise((resolve, reject) => callback = (value, err) => {
+        if (err) reject(err);
+        else resolve(value);
+      });
+    }
+
+    if (isBusy) {
+      log(3, "Busy - adding Puck.write to queue");
+      queue.push({type:"write", data:data, callback:callback, callbackNewline:callbackNewline});
+      return result;
+    }
+
+    var cbTimeout;
+    function onWritten() {
+      if (callbackNewline) {
+        connection.cb = function(d) {
+          var newLineIdx = connection.received.indexOf("\n");
+          if (newLineIdx>=0) {
+            var l = connection.received.substr(0,newLineIdx);
+            connection.received = connection.received.substr(newLineIdx+1);
+            connection.cb = undefined;
+            if (cbTimeout) clearTimeout(cbTimeout);
+            cbTimeout = undefined;
+            if (callback)
+              callback(l);
+            isBusy = false;
+            handleQueue();
+          }
+        };
+      }
+      // wait for any received data if we have a callback...
+      var maxTime = 300; // 30 sec - Max time we wait in total, even if getting data
+      var dataWaitTime = callbackNewline ? 100/*10 sec if waiting for newline*/ : 3/*300ms*/;
+      var maxDataTime = dataWaitTime; // max time we wait after having received data
+      cbTimeout = setTimeout(function timeout() {
+        cbTimeout = undefined;
+        if (maxTime) maxTime--;
+        if (maxDataTime) maxDataTime--;
+        if (connection.hadData) maxDataTime=dataWaitTime;
+        if (maxDataTime && maxTime) {
+          cbTimeout = setTimeout(timeout, 100);
+        } else {
+          connection.cb = undefined;
+          if (callback)
+            callback(connection.received);
+          isBusy = false;
+          handleQueue();
+          connection.received = "";
+        }
+        connection.hadData = false;
+      }, 100);
+    }
+
+    if (!connection.txInProgress) connection.received = "";
+    isBusy = true;
+    connection.write(data, onWritten);
+    return result
+  }
+
+  // ----------------------------------------------------------
+
+  Puck = {
+    /// Are we writing debug information? 0 is no, 1 is some, 2 is more, 3 is all.
+    debug : Puck.debug,
+    /// Should we use flow control? Default is true
+    flowControl : true,
+    /// Used internally to write log information - you can replace this with your own function
+    log : function(level, s) { if (level <= this.debug) console.log("<BLE> "+s)},
+    /// Called with the current send progress or undefined when done - you can replace this with your own function
+    writeProgress : Puck.writeProgress,
+    connect : function(callback) {
+      setTimeout(callback, 10);
+    },
+    write : write,
+    eval : function(expr, cb) {
+      const response = write('\x10Bluetooth.println(JSON.stringify(' + expr + '))\n', true)
+        .then(function (d) {
+          try {
+            return JSON.parse(d);
+          } catch (e) {
+            log(1, "Unable to decode " + JSON.stringify(d) + ", got " + e.toString());
+            return Promise.reject(d);
+          }
+        });
+      if (cb) {
+        return void response.then(cb, (err) => cb(null, err));
+      } else {
+        return response;
+      }
+    },
+    isConnected : function() { return true;  },
+    getConnection : function() {  return connection; },
+    close : function() {
+      if (connection)
+        connection.close();
+    },
+  };
+  // no need for header 
+  document.getElementsByTagName("header")[0].style="display:none";
+  // force connection attempt automatically
+  setTimeout(function() {
+   getInstalledApps(true).catch(err => {
+      showToast("Device connection failed, "+err,"error");
+    });
+  }, 100);
+}
diff --git a/index.html b/index.html
index a418b48eb..bd8ddea5a 100644
--- a/index.html
+++ b/index.html
@@ -179,5 +179,6 @@
     <script src="core/js/appinfo.js"></script>
     <script src="core/js/index.js"></script>
     <script src="core/js/pwa.js" defer></script>
+    <script src="gadgetbridge.js"></script>    
   </body>
 </html>