Fills embark logs tabs with existing embark logs

A logfile is now generated by default, in the format `.embark/embark-log__YYYY-MM-DD_HH-mm-ss.log`.

When the home tab is loaded, the process logs are fetched for all the processes. The list of processes returned now includes `embark`, and when `/embark-api/process-logs/embark` is fetched, the logFile is parsed and an array of log messages are returned.

embark-ui/src/components/Console.js

@@ -33,23 +33,18 @@ class Console extends Component {
 
   renderTabs() {
     const {processLogs, processes, commands} = this.props;
-    return [
-      (<Tab title="Embark" key="Embark">
-        <Logs>
-          {commands.map((command, index) => <CommandResult key={index} result={command.result}/>)}
-        </Logs>
-      </Tab>)
-    ].concat(processes.map(process => (
-      <Tab title={process.name} key={process.name}>
+    return processes.map(process => (
+      <Tab title={process.name} key={process.name} onClick={(e, x) => this.clickTab(e, x)}>
         <Logs>
           {
             processLogs.reverse().filter((item) => item.name === process.name)
               .map((item, i) => <p key={i} className={item.logLevel}
                                    dangerouslySetInnerHTML={{__html: convert.toHtml(item.msg)}}></p>)
           }
+          {process.name === "embark" && commands.map((command, index) => <CommandResult key={index} result={command.result}/>)}
         </Logs>
       </Tab>
-    )));
+    ));
   }
 
   render() {

lib/core/engine.js

@@ -38,6 +38,9 @@ class Engine {
     if (this.interceptLogs || this.interceptLogs === undefined) {
       utils.interceptLogs(console, this.logger);
     }
+    
+    // register API calls for the logger
+    this.logger.registerAPICall(this.plugins);
 
     this.ipc = new IPC({logger: this.logger, ipcRole: this.ipcRole});
     if (this.ipc.isClient()) {

lib/core/logger.js

@@ -1,5 +1,6 @@
 require('colors');
 let fs = require('./fs.js');
+const date = require('date-and-time');
 
 class Logger {
   constructor(options) {
@@ -8,6 +9,17 @@ class Logger {
     this.logLevel = options.logLevel || 'info';
     this.logFunction = options.logFunction || console.log;
     this.logFile = options.logFile;
+    this.dateFormat = 'YYYY-MM-DD HH:mm:ss';
+    this.logRegex = /\[(?<date>\d\d\d\d-\d\d-\d\d \d\d:\d\d:\d\d)\] (?:\[(?<logLevel>\w*)\]:?)?\s?\s?(?<msg>.*)/gmi;
+
+    // Use a default logFile if none is specified in the cli,
+    // in the format .embark/embark-log__YYYY-MM-DD_HH-mm-ss.log.
+    // This logFile is needed so that when the backend tab starts,
+    // the initial logs of Embark can be displayed.
+    if (!this.logFile) {
+      const now = new Date();
+      this.logFile = fs.dappPath(`.embark/embark-log__${date.format(now, 'YYYY-MM-DD_HH-mm-ss')}.log`);
+    }
   }
 }
 
@@ -27,19 +39,59 @@ Logger.prototype.registerAPICall = function (plugins) {
     'ws',
     '/embark-api/logs',
     (ws, _req) => {
-      self.events.on("log", function(logLevel, logMsg) {
+      self.events.on("log", function (logLevel, logMsg) {
         ws.send(JSON.stringify({msg: logMsg, msg_clear: logMsg.stripColors, logLevel: logLevel}), () => {});
       });
     }
   );
+  plugin.registerAPICall(
+    'get',
+    '/embark-api/process-logs/embark',
+    (req, res) => {
+      res.send(this.parseLogFile());
+    }
+  );
+};
+
+/**
+ * Parses the logFile, returning an array of JSON objects containing the
+ * log messages.
+ *
+ * @returns {Array} array containing
+ *  - msg: the log message
+ *  - logLevel: log level (ie 'info', 'debug')
+ *  - name: process name (always "embark")
+ *  - timestamp: timestamp of log message (milliseconds since 1/1/1970)
+ */
+Logger.prototype.parseLogFile = function () {
+  let matches;
+  let logs = [];
+  const logFile = fs.readFileSync(this.logFile, 'utf8');
+  while ((matches = this.logRegex.exec(logFile)) !== null) {
+    // This is necessary to avoid infinite loops with zero-width matches
+    if (matches.index === this.logRegex.lastIndex) {
+      this.logRegex.lastIndex++;
+    }
+
+    if(matches && matches.groups){
+      logs.push({
+        msg: [matches.groups.msg],
+        logLevel: matches.groups.logLevel,
+        name: 'embark',
+        timestamp: date.parse(matches.groups.date, this.dateFormat).getTime()
+      });
+    }
+  }
+
+  return logs;
 };
 
 Logger.prototype.writeToFile = function (_txt) {
-  if (!this.logfile) {
+  if (!this.logFile) {
     return;
   }
-
-  fs.appendFileSync(this.logFile, "\n" + Array.from(arguments).join(' '));
+  const formattedDate = [`[${date.format(new Date(), this.dateFormat)}]`]; // adds a timestamp to the logs in the logFile
+  fs.appendFileSync(this.logFile, "\n" + formattedDate.concat(Array.from(arguments)).join(' '));
 };
 
 Logger.prototype.error = function () {
@@ -93,8 +145,7 @@ Logger.prototype.dir = function (txt) {
   }
   this.events.emit("log", "dir", txt);
   this.logFunction(txt);
-  this.writeToFile("[dir]: ");
-  this.writeToFile(txt);
+  this.writeToFile("[dir]: ", ...arguments);
 };
 
 Logger.prototype.shouldLog = function (level) {

lib/core/processes/processManager.js

@@ -21,7 +21,8 @@ class ProcessManager {
           acc.push({state: self.processes[processName].state, name: processName});
           return acc;
         };
-        res.send(Object.keys(self.processes).reduce(formatter, []));
+        // add "embark" process to list of running processes
+        res.send(Object.keys(self.processes).reduce(formatter, []).concat({ state: "running", name: "embark" }));
       }
     );
   }