From 644f08a447f26ce526bfb1df8d55d57ecc2c2d42 Mon Sep 17 00:00:00 2001
From: Ilya Shurumov <ishurumov@gmail.com>
Date: Fri, 9 Jul 2021 21:19:00 +0600
Subject: [PATCH] - added local storage FS for saved games

---
 src_rebuild/platform/Emscripten/lsfs.js    | 147 +++++++++++++++++++++
 src_rebuild/platform/Emscripten/shell.html |  13 +-
 src_rebuild/premake5.lua                   |   3 +-
 3 files changed, 161 insertions(+), 2 deletions(-)
 create mode 100644 src_rebuild/platform/Emscripten/lsfs.js

diff --git a/src_rebuild/platform/Emscripten/lsfs.js b/src_rebuild/platform/Emscripten/lsfs.js
new file mode 100644
index 00000000..2884409d
--- /dev/null
+++ b/src_rebuild/platform/Emscripten/lsfs.js
@@ -0,0 +1,147 @@
+// Reusing all MEMFS functionality
+// additionaly read data at mount
+// and save data at some operations.
+// Intended to use only for small files (like game settings),
+// because LocalStorage is very limited
+// and data saved as text in JSON format.
+
+function LSFS() {
+  if (LSFS.mount) {
+    return LSFS;
+  }
+
+  var wrapCreateNode = wrapNode(MEMFS.createNode);
+
+  var wrap_node_ops = {
+    setattr: wrapSave(MEMFS.node_ops.setattr),
+    mknod: wrapNode(MEMFS.node_ops.mknod),
+    rename: wrapSave(MEMFS.node_ops.rename),
+    unlink: wrapSave(MEMFS.node_ops.unlink),
+    rmdir: wrapSave(MEMFS.node_ops.rmdir),
+    symlink: wrapNode(MEMFS.node_ops.symlink)
+  };
+
+  var wrap_stream_ops = {
+    write: wrapSave(MEMFS.stream_ops.write),
+    msync: wrapSave(MEMFS.stream_ops.msync)
+  };
+
+  var props = [ 'name', 'mode', 'rdev', 'link', 'usedBytes', 'timestamp' ];
+
+  LSFS.mount = mount;
+
+  return LSFS;
+
+  function wrapNode(fn) {
+    return function() {
+      var node = fn.apply(null, arguments);
+      setupNode(node);
+      return node;
+    }
+  }
+
+  function wrapSave(fn) {
+    return function(node) {
+      var res = fn.apply(null, arguments);
+      save(node);
+      return res;
+    }
+  }
+
+  function setupNode(node) {
+    var node_ops = {};
+    for (var op in node.node_ops) {
+      node_ops[op] = wrap_node_ops[op] || node.node_ops[op];
+    }
+    node.node_ops = node_ops;
+
+    var stream_ops = {};
+    for (var op in node.stream_ops) {
+      stream_ops[op] = wrap_stream_ops[op] || node.stream_ops[op];
+    }
+    node.stream_ops = stream_ops;
+  }
+
+  function filter(node) {
+    var result = {};
+    for (var key in node) {
+      if (props.indexOf(key) !== -1) {
+        result[key] = node[key];
+      }
+    }
+
+    if (node.contents) {
+      if (node.contents.length) {
+        result.contents = Array.apply([], node.contents);
+      } else {
+        result.contents = {};
+        for (var name in node.contents) {
+          result.contents[name] = filter(node.contents[name]);
+        }
+      }
+    }
+
+    return result;
+  }
+
+  function save(node) {
+    if (node.node) {
+      node = node.node;
+    }
+
+    var mount = node.mount;
+    if (!mount || !mount.opts || !mount.opts.key) {
+      return;
+    }
+
+    try {
+      localStorage.setItem(mount.opts.key, JSON.stringify(filter(mount.root)));
+    } catch (err) {}
+  }
+
+  function mount(mount) {
+    if (!mount.opts || !mount.opts.key) {
+      return;
+    }
+
+    var data;
+    try {
+      data = localStorage.getItem(mount.opts.key);
+    } catch (err) {}
+    if (data) {
+      try {
+        data = JSON.parse(data);
+      } catch (err) {}
+    }
+
+    var node = MEMFS.mount(mount);
+    setupNode(node);
+    load(node, mount, data);
+
+    return node;
+  }
+
+  function load(node, mount, data) {
+    node.mount = mount;
+    if (!data) {
+      return;
+    }
+    for (var key in data) {
+      if (props.indexOf(key) !== -1) {
+        node[key] = data[key];
+      }
+    }
+    if (data.contents) {
+      if (data.contents.length) {
+        node.contents = data.contents;
+      } else {
+        node.contents = {};
+        for (var name in data.contents) {
+          var childData = data.contents[name];
+          var childNode = wrapCreateNode(node, name, childData.mode, childData.rdev);
+          load(childNode, mount, childData);
+        }
+      }
+    }
+  }
+}
\ No newline at end of file
diff --git a/src_rebuild/platform/Emscripten/shell.html b/src_rebuild/platform/Emscripten/shell.html
index 18699d7b..b224f8b2 100644
--- a/src_rebuild/platform/Emscripten/shell.html
+++ b/src_rebuild/platform/Emscripten/shell.html
@@ -7,7 +7,6 @@
     <link rel="stylesheet" href="style.css">
     <link href="https://fonts.googleapis.com/css?family=Oswald&display=swap" rel="stylesheet">
     <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css" integrity="sha384-ggOyR0iXCbMQv3Xipma34MD+dH/1fQ784/j6cY/iJTQUOhcWr7x9JvoRxT2MZw1T" crossorigin="anonymous">
-
     <style>
         .emscripten {
             padding-right: 0;
@@ -173,10 +172,21 @@
                 Module.setStatus(left ? 'Preparing... (' + (this.totalDependencies - left) + '/' + this.totalDependencies + ')' : 'All downloads complete.');
             }
         };
+		
         Module.setStatus('Downloading...');
 		
+		// don't immediately run the game
 		Module['noInitialRun'] = true
 		
+		// for save data
+		Module.preRun.push(function() {
+		    ENV.HOME = "/userstorage";
+			
+			// create LSFS and mount 'data' local storage item into '/data' directory
+		    FS.mkdir('/userstorage'); // for old versions use: FS.createFolder(FS.root, 'data', true, true);
+		    FS.mount(LSFS(), { key: 'userstorage' }, '/userstorage');
+		})
+		
         window.onerror = function () {
             Module.setStatus('Exception thrown, see JavaScript console');
             spinnerElement.style.display = 'none';
@@ -202,6 +212,7 @@
 			callMain(["-ini", "demo_config.ini"]);
 		}
     </script>
+	<script src="lsfs.js"></script> 
     {{{ SCRIPT }}}
 </body>
 </html>
\ No newline at end of file
diff --git a/src_rebuild/premake5.lua b/src_rebuild/premake5.lua
index 1bf9d67d..0fb28796 100644
--- a/src_rebuild/premake5.lua
+++ b/src_rebuild/premake5.lua
@@ -76,7 +76,8 @@ workspace "REDRIVER2"
 			targetextension ".html"
 			
 		postbuildcommands {
-			"{COPY} " .. WEBSHELL_PATH .. "/style.css %{cfg.buildtarget.directory}"
+			"{COPY} " .. WEBSHELL_PATH .. "/style.css %{cfg.buildtarget.directory}",
+			"{COPY} " .. WEBSHELL_PATH .. "/lsfs.js %{cfg.buildtarget.directory}"
 		}
 
 	else