First working whiteboard

4 files changed, 147 insertions, 174 deletions

diff --git a/Makefile b/Makefile
index 2d14170..640a081 100755
--- a/Makefile
+++ b/Makefile
@@ -36,9 +36,15 @@ ifeq ($(CXXFLAGS),)
 CXXFLAGS=-g -O2
 endif
 
-CXXFLAGS+=-Wall -fPIE -std=c++20 -Wpedantic -gdwarf-4
+CXXFLAGS+=-Wall -fPIE -Wpedantic -gdwarf-4
 LDFLAGS+=-pie
 
+ifeq ($(CXX),g++-9)
+CXXFLAGS+=-std=c++17
+else
+CXXFLAGS+=-std=c++20
+endif
+
 ifeq ($(CXX),clang++-10)
 LIBS+= \
 -fuse-ld=lld-10 \
diff --git a/html/index.html b/html/index.html
index 780660a..64eae90 100644
--- a/html/index.html
+++ b/html/index.html
@@ -14,12 +14,7 @@
                         <textarea rows="30" cols="80" id="board" name="board"></textarea>
 			<br/>
 			<br/>
-			<h2>Contact</h2>
-			Roland Reichwein<br/>
-			Hauptstr. 101a<br/>
-			82008 Unterhaching<br/>
-			<a href="mailto:mail@reichwein.it">mail@reichwein.it</a><br/>
-			<a href="https://www.reichwein.it">https://www.reichwein.it</a><br/>
+			Reichwein.IT Whiteboard by <a href="https://www.reichwein.it">https://www.reichwein.it</a><br/>
 		</div>
 
 		<a id="download-a" hidden></a>
diff --git a/html/whiteboard.js b/html/whiteboard.js
index dd81ff0..2b35180 100644
--- a/html/whiteboard.js
+++ b/html/whiteboard.js
@@ -1,40 +1,81 @@
 // started on main page load
 function init() {
-
-	// Connect "Enter" in text field with Button click
-	var url = document.getElementById("url");
-	url.addEventListener("keyup", function(event) {
-  		if (event.keyCode === 13) {
-   			event.preventDefault();
-   			on_start();
-  		}
-	});
+	init_board();
 }
 
-function set_status(message) {
-	if (message == "")
-		message = "&nbsp;";
+function init_board() {
+	var xhr = new XMLHttpRequest();
+	
+	// run on data received back
+	xhr.onreadystatechange = function() {
+				if (this.readyState == 3) {
+					//set_status("Please wait while downloading " + filename + " ...");
+					return;
+				}
+                                if (this.readyState != 4) {
+					return;
+				}
+				if (this.status != 200) {
+					//set_status("Server Error while retrieving " + filename + ", status: " + this.status + " " + this.statusText);
+                                        return;
+                                }
+
+                                var file = new Blob([this.response]);
+				reader = new FileReader();
+				reader.onload = function() {
+					var board = document.getElementById("board");
+					board.innerHTML = reader.result;
+
+					// Initialization done. Now we can start modifying.
+					board.addEventListener("input", function() {on_modify(); });
+
+					setInterval(function() {checkupdate();}, 2000);
+				}
+				
+			        reader.readAsBinaryString(file);
+
+				//set_status(""); // OK
+	}
+
+	var parser = new DOMParser();
+	var xmlDocument = parser.parseFromString("<request></request>", "text/xml");
+	
+	var requestElement = xmlDocument.getElementsByTagName("request")[0];
+
+	var commandElement = xmlDocument.createElement("command");
+	commandElement.appendChild(document.createTextNode("getfile"));
+	requestElement.appendChild(commandElement);
+
+	var idElement = xmlDocument.createElement("id");
+	idElement.appendChild(document.createTextNode("id1"));
+	requestElement.appendChild(idElement);
+
+	xhr.open("POST", "whiteboard.fcgi", true);
+	xhr.setRequestHeader("Content-type", "text/xml");
+	xhr.responseType = 'blob';
+	xhr.send(xmlDocument);
 
-	document.getElementById("status").innerHTML = message;
+	//set_status("Please wait while server prepares " + filename + " ...");
 }
 
-// started on button click: get filename
-function on_start() {
+function on_modify() {
 	var xhr = new XMLHttpRequest();
-
+	
 	// run on data received back
 	xhr.onreadystatechange = function() {
+				if (this.readyState == 3) {
+					//set_status("Please wait while downloading " + filename + " ...");
+					return;
+				}
                                 if (this.readyState != 4) {
 					return;
 				}
 				if (this.status != 200) {
-					set_status("Server Error while retrieving filename, " + filename + ", status: " + this.status + " " + this.statusText);
+					//set_status("Server Error while retrieving " + filename + ", status: " + this.status + " " + this.statusText);
                                         return;
                                 }
 
-				var filename = this.responseText;
-
-				get_file(filename);
+				//set_status(""); // OK
 	}
 
 	var parser = new DOMParser();
@@ -43,50 +84,65 @@ function on_start() {
 	var requestElement = xmlDocument.getElementsByTagName("request")[0];
 
 	var commandElement = xmlDocument.createElement("command");
-	commandElement.appendChild(document.createTextNode("getfilename"));
+	commandElement.appendChild(document.createTextNode("modify"));
 	requestElement.appendChild(commandElement);
 
-	var urlElement = xmlDocument.createElement("url");
-	urlElement.appendChild(document.createTextNode(document.getElementById("url").value));
-	requestElement.appendChild(urlElement);
+	var idElement = xmlDocument.createElement("id");
+	idElement.appendChild(document.createTextNode("id1"));
+	requestElement.appendChild(idElement);
+
+	var dataElement = xmlDocument.createElement("data");
+	dataElement.appendChild(document.createTextNode(document.getElementById("board").value));
+	requestElement.appendChild(dataElement);
 
-	var formatElement = xmlDocument.createElement("format");
-	formatElement.appendChild(document.createTextNode(document.getElementById("mp3").checked ? "mp3" : "mp4"));
-	requestElement.appendChild(formatElement);
-	
 	xhr.open("POST", "whiteboard.fcgi", true);
 	xhr.setRequestHeader("Content-type", "text/xml");
-	xhr.responseType = 'text';
+	xhr.responseType = 'blob';
 	xhr.send(xmlDocument);
 
-	set_status("Please wait while retrieving filename...");
+	//set_status("Please wait while server prepares " + filename + " ...");
 }
 
-// started on button click: get file
-function get_file(filename) {
-	var xhr = new XMLHttpRequest();
+// checksum of string
+function checksum32(s) {
+	var result = 0;
+	for (var i = 0; i < s.length; i++) {
+		result = ((((result >>> 1) | ((result & 1) << 31)) | 0) ^ (s.charCodeAt(i) & 0xFF)) | 0;
+	}
+	return (result & 0x7FFFFFFF) | 0;
+}
 
+// gets called by regular polling
+function checkupdate() {
+	var xhr = new XMLHttpRequest();
+	
 	// run on data received back
 	xhr.onreadystatechange = function() {
 				if (this.readyState == 3) {
-					set_status("Please wait while downloading " + filename + " ...");
+					//set_status("Please wait while downloading " + filename + " ...");
 					return;
 				}
                                 if (this.readyState != 4) {
 					return;
 				}
 				if (this.status != 200) {
-					set_status("Server Error while retrieving " + filename + ", status: " + this.status + " " + this.statusText);
+					//set_status("Server Error while retrieving " + filename + ", status: " + this.status + " " + this.statusText);
                                         return;
                                 }
 
-                                var a = document.getElementById("download-a");
-                                a.setAttribute("download", filename);
-                                var file = new Blob([this.response]);
-                                a.href = window.URL.createObjectURL(file);
-                                a.click();
-				
-				set_status(""); // OK
+				// no change if response is text/plain
+				if (this.getResponseHeader("Content-Type") == "application/octet-stream") {
+					var file = new Blob([this.response]);
+					reader = new FileReader();
+					reader.onload = function() {
+						var board = document.getElementById("board");
+						board.value = reader.result;
+					}
+					
+					reader.readAsBinaryString(file);
+				}
+
+				//set_status(""); // OK
 	}
 
 	var parser = new DOMParser();
@@ -95,22 +151,22 @@ function get_file(filename) {
 	var requestElement = xmlDocument.getElementsByTagName("request")[0];
 
 	var commandElement = xmlDocument.createElement("command");
-	commandElement.appendChild(document.createTextNode("getfile"));
+	commandElement.appendChild(document.createTextNode("checkupdate"));
 	requestElement.appendChild(commandElement);
 
-	var urlElement = xmlDocument.createElement("url");
-	urlElement.appendChild(document.createTextNode(document.getElementById("url").value));
-	requestElement.appendChild(urlElement);
+	var idElement = xmlDocument.createElement("id");
+	idElement.appendChild(document.createTextNode("id1"));
+	requestElement.appendChild(idElement);
+
+	var checksumElement = xmlDocument.createElement("checksum");
+	checksumElement.appendChild(document.createTextNode(checksum32(document.getElementById("board").value)));
+	requestElement.appendChild(checksumElement);
 
-	var formatElement = xmlDocument.createElement("format");
-	formatElement.appendChild(document.createTextNode(document.getElementById("mp3").checked ? "mp3" : "mp4"));
-	requestElement.appendChild(formatElement);
-	
 	xhr.open("POST", "whiteboard.fcgi", true);
 	xhr.setRequestHeader("Content-type", "text/xml");
 	xhr.responseType = 'blob';
 	xhr.send(xmlDocument);
 
-	set_status("Please wait while server prepares " + filename + " ...");
+	//set_status("Please wait while server prepares " + filename + " ...");
 }
 
diff --git a/whiteboard.cpp b/whiteboard.cpp
index cecee9e..b6b3a8d 100644
--- a/whiteboard.cpp
+++ b/whiteboard.cpp
@@ -25,38 +25,15 @@ using namespace std::string_literals;
 namespace fs = std::filesystem;
 
 namespace {
- 
- class TempDir
- {
- private:
-  fs::path m_path;
-  fs::path m_oldpath;
- public:
-  TempDir()
-  {
-   char templ[] = "/tmp/downtubeXXXXXX";
-   char *temp = mkdtemp(templ);
-   if (temp == nullptr) {
-    throw std::runtime_error("Can't create temporary directory.");
-   }
-
-   m_path = temp;
-   m_oldpath = fs::current_path();
-   fs::current_path(m_path);
-  }
 
-  ~TempDir()
-  {
-   fs::current_path(m_oldpath);
-   fs::remove_all(m_path);
+ uint32_t checksum32(const std::string& s) {
+  uint32_t result{0};
+  for (int i = 0; i < s.size(); i++) {
+   result = ((result >> 1) | ((result & 1) << 31)) ^ (s[i] & 0xFF);
   }
-
-  const fs::path& getPath() const {return m_path;}
- };
-
- std::regex re{"https?://(www\\.youtube\\.com/watch\\?v=|youtu\\.be/)[[:alnum:]_&=-]+", std::regex::extended}; // www.youtube.com/watch?v=ItjMIxS3-rI or https://youtu.be/ItjMIxS3-rI
-
-} // anonymous namespace
+  return result & 0x7FFFFFFF;
+ }
+}
 
 int main(void)
 {
@@ -81,6 +58,8 @@ int main(void)
   return 1;
  }
 
+ std::string filedata {""}; // initial content
+
  while (FCGX_Accept_r(&request) >= 0) {
   try {
    char* method = FCGX_GetParam("REQUEST_METHOD", request.envp);
@@ -99,107 +78,44 @@ int main(void)
 
     pt::ptree xml;
     std::istringstream ss{xmlData};
-    pt::xml_parser::read_xml(ss, xml, pt::xml_parser::no_comments | pt::xml_parser::trim_whitespace);
+    pt::xml_parser::read_xml(ss, xml);
 
-    std::string url {xml.get<std::string>("request.url")};
-    std::string format {xml.get<std::string>("request.format")};
     std::string command {xml.get<std::string>("request.command")};
+    std::string id {xml.get<std::string>("request.id")};
 
-    //FCGX_PutS("Content-Type: text/plain\r\n\r\n", request.out);
-    //FCGX_FPrintF(request.out, "url: %s\r\n", url.c_str());
-    //FCGX_FPrintF(request.out, "format: %s\r\n", format.c_str()); // mp3, mp4
-
-    if (format != "mp3" && format != "mp4") {
-     throw std::runtime_error("Bad format: "s + format);
-    }
-
-    if (!std::regex_match(url, re)) {
-     throw std::runtime_error("Bad URL");
-    }
-
-    // remove trailing "&..."
-    size_t and_pos {url.find('&')};
-    if (and_pos != std::string::npos)
-     url = url.substr(0, and_pos);
-
-    //FCGX_FPrintF(request.out, "command: %s\r\n", command.c_str());
-
-    TempDir tempDir;
-
-    //FCGX_FPrintF(request.out, "path: %s\r\n", tempDir.getPath().string().c_str());
-
-    if (command == "getfilename") {
-     //std::string cmd{"youtube-dl -o '%(title)s."s + format + "' --get-filename --no-call-home --restrict-filenames "s + url + " > filename.txt"};
-     // Recoding to MP4 is too slow currently. So keep original format for now
-     std::string cmd{"xyoutube-dl -o '%(title)s.%(ext)s' --get-filename --no-call-home --restrict-filenames "s + url + " > filename.txt"};
-     if (system(cmd.c_str()))
-      throw std::runtime_error("Can't guess filename");
-      
-     std::string filename {File::getFile("filename.txt")};
-     boost::algorithm::trim(filename);
-
-     if (format == "mp3")
-      filename = fs::path{filename}.stem().string() + ".mp3";
-   
+    if (command == "modify") {
+     std::string data {xml.get<std::string>("request.data")};
+     filedata = data;
      FCGX_PutS("Content-Type: text/plain\r\n\r\n", request.out);
-     FCGX_FPrintF(request.out, "%s", filename.c_str());
     } else if (command == "getfile") {
-     if (format == "mp3") {
-      std::string cmd{"xyoutube-dl --no-warnings --no-call-home --no-progress -x --audio-format mp3 -o 'audio.%(ext)s' --restrict-filenames "s + url};
-      system(cmd.c_str()); // Ignore error - "ERROR:   Stream #1:0 -> #0:1 (copy)" - seems to be ok
-
-      std::string filedata {File::getFile("audio.mp3")}; // may throw
 
-      if (filedata.size() > 30000000)
-       throw std::runtime_error("File too big");
-   
-      FCGX_PutS("Content-Type: application/octet-stream\r\n", request.out);
-      FCGX_FPrintF(request.out, "Content-Length: %d\r\n\r\n", filedata.size());
-      FCGX_PutStr(filedata.c_str(), filedata.size(), request.out);
-     } else if (format == "mp4") {
-      //std::string cmd{"youtube-dl --no-warnings --no-call-home --no-progress --recode-video mp4 -o video.mp4 --restrict-filenames "s + url};
-      // Recoding to MP4 is too slow currently. So keep original format for now
-      std::string cmd{"xyoutube-dl --no-warnings --no-call-home --no-progress -o video.mp4 --restrict-filenames "s + url};
-      system(cmd.c_str()); // Ignore error
-
-      // youtube-dl gets it wrong and creates, e.g. video.mkv.
-      // So find it and load it
-      fs::directory_iterator di{fs::current_path()};
-      fs::path filename;
-      for (const auto& i: di) {
-       if (boost::algorithm::starts_with(i.path().filename().string(), "video."s)) {
-        filename = i.path().filename().string();
-        break;
-       }
-      }
-     
-      if (filename.empty()) {
-       throw std::runtime_error("No video file found.");
-      }
-
-      std::string filedata {File::getFile(filename)}; // may throw
-   
-      if (filedata.size() > 300000000)
-       throw std::runtime_error("File too big");
-   
+     if (filedata.size() > 30000000)
+      throw std::runtime_error("File too big");
+  
+     FCGX_PutS("Content-Type: application/octet-stream\r\n", request.out);
+     FCGX_FPrintF(request.out, "Content-Length: %d\r\n\r\n", filedata.size());
+     FCGX_PutStr(filedata.c_str(), filedata.size(), request.out);
+    } else if (command == "checkupdate") {
+     std::string checksum_s {xml.get<std::string>("request.checksum")};
+     uint32_t checksum{static_cast<uint32_t>(stoul(checksum_s))};
+
+     //std::cout << "Checksum JS: " << checksum_s << std::endl;
+     //std::cout << "Checksum C++: " << checksum32(filedata) << std::endl;
+
+     if (checksum != checksum32(filedata)) {
+      //std::cout << "Sending change..." << std::endl;
       FCGX_PutS("Content-Type: application/octet-stream\r\n", request.out);
       FCGX_FPrintF(request.out, "Content-Length: %d\r\n\r\n", filedata.size());
       FCGX_PutStr(filedata.c_str(), filedata.size(), request.out);
      } else {
-      throw std::runtime_error("Bad format for unknown reason: "s + format); // should have been caught above already!
+      //std::cout << "No change..." << std::endl;
+      FCGX_PutS("Content-Type: text/plain\r\n\r\n", request.out);
+      FCGX_PutS("No change.\r\n", request.out);
      }
     } else {
      throw std::runtime_error("Bad command: "s + command);
     }
 
-    // Name:
-    // youtube-dl -o "%(title)s.mp3" --get-filename --no-call-home --restrict-filenames $SOURCE > filename.txt
-    //
-    // MP3:
-    // youtube-dl --no-warnings --no-call-home --no-progress -x --audio-format mp3 --embed-thumbnail -o "%(title)s.(ext)s" --restrict-filenames $SOURCE
-    //
-    // MP4:
-    // youtube-dl --no-warnings --no-call-home --no-progress --recode-video mp4 -o "%(title)s.(ext)s" --restrict-filenames $SOURCE
    } else {
     throw std::runtime_error("Unsupported method.\r\n");
    }