<!DOCTYPE html>
<!--
Copyright (c) 2013 The Chromium Authors. All rights reserved.
Use of this source code is governed by a BSD-style license that can be
found in the LICENSE file.
-->

<link rel="import"
      href="/ui/extras/about_tracing/tracing_controller_client.html">
<link rel="import" href="/ui/extras/about_tracing/inspector_connection.html">

<script>
'use strict';

tr.exportTo('tr.ui.e.about_tracing', function() {
  function createResolvedPromise(data) {
    var promise = new Promise(function(resolve, reject) {
      if (data)
        resolve(data);
      else
        resolve();
    });
    return promise;
  }

  function appendTraceChunksTo(chunks, messageString) {
    if (typeof messageString !== 'string')
      throw new Error('Invalid data');
    var re = /"params":\s*\{\s*"value":\s*\[([^]+)\]\s*\}\s*\}/;
    var m = re.exec(messageString);
    if (!m)
      throw new Error('Malformed response');

    if (chunks.length > 1)
      chunks.push(',');
    chunks.push(m[1]);
  }

  /**
   * Controls tracing using the inspector's FrontendAgentHost APIs.
   *
   * @constructor
   */
  function InspectorTracingControllerClient() {
    this.recording_ = false;
    this.bufferUsage_ = 0;
    this.conn_ = tr.ui.e.about_tracing.InspectorConnection.instance;
    this.currentTraceTextChunks_ = undefined;
  }

  InspectorTracingControllerClient.prototype = {
    __proto__: tr.ui.e.about_tracing.TracingControllerClient.prototype,

    beginMonitoring: function(monitoringOptions) {
      throw new Error('Not implemented');
    },

    endMonitoring: function() {
      throw new Error('Not implemented');
    },

    captureMonitoring: function() {
      throw new Error('Not implemented');
    },

    getMonitoringStatus: function() {
      return createResolvedPromise({
        isMonitoring: false,
        categoryFilter: '',
        useSystemTracing: false,
        useContinuousTracing: false,
        useSampling: false
      });
    },

    getCategories: function() {
      var res = this.conn_.req('Tracing.getCategories', {});
      return res.then(function(result) {
        return result.categories;
      }, function(err) {
        return [];
      });
    },

    beginRecording: function(recordingOptions) {
      if (this.recording_)
        throw new Error('Already recording');
      this.recording_ = 'starting';
      var res = this.conn_.req(
          'Tracing.start',
          {
            categories: recordingOptions.categoryFilter,
            options:
                [recordingOptions.tracingRecordMode,
                  (recordingOptions.useSampling ? 'enable-sampling' : '')
                ].join(','),
            bufferUsageReportingInterval: 1000
          });
      res = res.then(
          function ok() {
            this.conn_.setNotificationListener(
                'Tracing.bufferUsage',
                this.onBufferUsageUpdateFromInspector_.bind(this));
            this.recording_ = true;
          }.bind(this),
          function error() {
            this.recording_ = false;
          }.bind(this));
      return res;
    },

    onBufferUsageUpdateFromInspector_: function(params) {
      this.bufferUsage_ = params.value || params.percentFull;
    },

    beginGetBufferPercentFull: function() {
      var that = this;
      return new Promise(function(resolve, reject) {
        setTimeout(function() {
          resolve(that.bufferUsage_);
        }, 100);
      });
    },

    onDataCollected_: function(messageString) {
      appendTraceChunksTo(this.currentTraceTextChunks_, messageString);
    },

    endRecording: function() {
      if (this.recording_ === false)
        return createResolvedPromise();

      if (this.recording_ !== true)
        throw new Error('Cannot end');

      this.currentTraceTextChunks_ = ['['];
      this.conn_.setNotificationListener(
          'Tracing.dataCollected', this.onDataCollected_.bind(this));

      var clearListeners = function() {
        this.conn_.setNotificationListener(
            'Tracing.bufferUsage', undefined);
        this.conn_.setNotificationListener(
            'Tracing.tracingComplete', undefined);
        this.conn_.setNotificationListener(
            'Tracing.dataCollected', undefined);
      }.bind(this);

      this.recording_ = 'stopping';
      return new Promise(function(resolve, reject) {
        function tracingComplete() {
          clearListeners();
          this.recording_ = false;
          this.currentTraceTextChunks_.push(']');
          var traceText = this.currentTraceTextChunks_.join('');
          this.currentTraceTextChunks_ = undefined;
          resolve(traceText);
        }

        function tracingFailed(err) {
          clearListeners();
          this.recording_ = false;
          reject(err);
        }

        this.conn_.setNotificationListener(
            'Tracing.tracingComplete', tracingComplete.bind(this));
        this.conn_.req('Tracing.end', {}).then(
            function end() {
              // Nothing happens here. We're really waiting for
              // Tracing.tracingComplete.
            }.bind(this),
            tracingFailed.bind(this));
      }.bind(this));
    },

    defaultTraceName: function() {
      return 'trace.json';
    }
  };

  return {
    InspectorTracingControllerClient: InspectorTracingControllerClient,
    appendTraceChunksTo: appendTraceChunksTo
  };
});
</script>