<!--
Copyright (C) 2015 The Android Open Source Project

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
-->

<link rel="import" href="../bower_components/polymer/polymer.html">
<link rel="import" href="../bower_components/iron-dropdown/iron-dropdown.html">
<link rel="import" href="../behaviors/keyboard-shortcut-behavior.html">
<link rel="import" href="../behaviors/rest-client-behavior.html">
<link rel="import" href="gr-ajax.html">
<link rel="import" href="gr-diff.html">

<dom-module id="gr-diff-view">
  <template>
    <style>
      :host {
        background-color: var(--view-background-color);
        display: block;
      }
      h3 {
        margin-top: 1em;
        padding: .75em var(--default-horizontal-margin);
      }
      .jumpToFileContainer {
        display: inline-block;
      }
      .downArrow {
        display: inline-block;
        font-size: .6em;
        vertical-align: middle;
      }
      .dropdown-trigger {
        color: #00e;
        cursor: pointer;
        padding: 0;
      }
      .dropdown-content {
        background-color: #fff;
        box-shadow: 0 1px 5px rgba(0, 0, 0, .3);
      }
      .dropdown-content a {
        cursor: pointer;
        display: block;
        font-weight: normal;
        padding: .3em .5em;
      }
      .dropdown-content a:before {
        color: #ccc;
        content: attr(data-key-nav);
        display: inline-block;
        margin-right: .5em;
        width: .3em;
      }
      .dropdown-content a:hover {
        background-color: #00e;
        color: #fff;
      }
      .dropdown-content a[selected] {
        color: #000;
        font-weight: bold;
        pointer-events: none;
        text-decoration: none;
      }
      .dropdown-content a[selected]:hover {
        background-color: #fff;
        color: #000;
      }
      button {
        background: none;
        border: none;
        font: inherit;
        padding: .3em 0;
      }
    </style>
    <gr-ajax id="changeDetailXHR"
        auto
        url="[[_computeChangeDetailPath(_changeNum)]]"
        params="[[_computeChangeDetailQueryParams()]]"
        last-response="{{_change}}"></gr-ajax>
    <gr-ajax id="filesXHR"
        auto
        url="[[_computeFilesPath(_changeNum, _patchRange.patchNum)]]"
        on-response="_handleFilesResponse"></gr-ajax>
    <gr-ajax id="configXHR"
        auto
        url="[[_computeProjectConfigPath(_change.project)]]"
        last-response="{{_projectConfig}}"></gr-ajax>
    <h3>
      <a href$="[[_computeChangePath(_changeNum)]]">[[_changeNum]]</a><span>:</span>
      <span>[[_change.subject]]</span> —
      <div class="jumpToFileContainer">
        <button class="dropdown-trigger" id="trigger" on-tap="_showDropdownTapHandler">
          <span>[[_path]]</span>
          <span class="downArrow">&#9660;</span>
        </button>
        <iron-dropdown id="dropdown" vertical-align="top" vertical-offset="25">
          <div class="dropdown-content">
            <template is="dom-repeat" items="[[_fileList]]" as="path">
              <a href$="[[_computeDiffURL(_changeNum, _patchRange, path)]]"
                 selected$="[[_computeFileSelected(path, _path)]]"
                 data-key-nav$="[[_computeKeyNav(path, _path, _fileList)]]"
                 on-tap="_handleFileTap">[[path]]</a>
            </template>
          </div>
        </iron-dropdown>
      </div>
    </h3>
    <gr-diff id="diff"
        change-num="[[_changeNum]]"
        prefs="{{prefs}}"
        patch-range="[[_patchRange]]"
        path="[[_path]]"
        project-config="[[_projectConfig]]"
        available-patches="[[_computeAvailablePatches(_change.revisions)]]"
        on-render="_handleDiffRender">
    </gr-diff>
  </template>
  <script>
  (function() {
    'use strict';

    Polymer({
      is: 'gr-diff-view',

      /**
       * Fired when the title of the page should change.
       *
       * @event title-change
       */

      properties: {
        prefs: {
          type: Object,
          notify: true,
        },
        /**
         * URL params passed from the router.
         */
        params: {
          type: Object,
          observer: '_paramsChanged',
        },
        keyEventTarget: {
          type: Object,
          value: function() { return document.body; },
        },
        changeViewState: {
          type: Object,
          notify: true,
          value: function() { return {}; },
        },

        _patchRange: Object,
        _change: Object,
        _changeNum: String,
        _diff: Object,
        _fileList: {
          type: Array,
          value: function() { return []; },
        },
        _path: {
          type: String,
          observer: '_pathChanged',
        },
        _loggedIn: {
          type: Boolean,
          value: false,
        },
      },

      behaviors: [
        Gerrit.KeyboardShortcutBehavior,
        Gerrit.RESTClientBehavior,
      ],

      ready: function() {
        app.accountReady.then(function() {
          this._loggedIn = app.loggedIn;
        }.bind(this));
      },

      attached: function() {
        if (this._path) {
          this.fire('title-change', {title: this._path});
        }
        window.addEventListener('resize', this._boundWindowResizeHandler);
      },

      detached: function() {
        window.removeEventListener('resize', this._boundWindowResizeHandler);
      },

      _handleKey: function(e) {
        if (this.shouldSupressKeyboardShortcut(e)) { return; }

        switch(e.keyCode) {
          case 219:  // '['
            e.preventDefault();
            this._navToFile(this._fileList, -1);
            break;
          case 221:  // ']'
            e.preventDefault();
            this._navToFile(this._fileList, 1);
            break;
          case 65:  // 'a'
            if (!this._loggedIn) { return; }

            this.set('changeViewState.showReplyDropdown', true);
            // No break here. Allow to fall through.
          case 85:  // 'u'
            if (this._changeNum) {
              e.preventDefault();
              page.show(this._computeChangePath(this._changeNum));
            }
            break;
          case 188:  // ','
            this.$.diff.showDiffPreferences();
            break;
        }
      },

      _handleDiffRender: function() {
        if (window.location.hash.length > 0) {
          this.$.diff.scrollToLine(
              parseInt(window.location.hash.substring(1), 10));
        }
      },

      _navToFile: function(fileList, direction) {
        if (fileList.length == 0) { return; }

        var idx = fileList.indexOf(this._path) + direction;
        if (idx < 0 || idx > fileList.length - 1) {
          page.show(this._computeChangePath(this._changeNum));
          return;
        }
        page.show(this._computeDiffURL(this._changeNum,
                                       this._patchRange,
                                       fileList[idx]));
      },

      _paramsChanged: function(value) {
        if (value.view != this.tagName.toLowerCase()) { return; }

        this._changeNum = value.changeNum;
        this._patchRange = {
          patchNum: value.patchNum,
          basePatchNum: value.basePatchNum || 'PARENT',
        };
        this._path = value.path;

        this.fire('title-change', {title: this._path});

        // When navigating away from the page, there is a possibility that the
        // patch number is no longer a part of the URL (say when navigating to
        // the top-level change info view) and therefore undefined in `params`.
        if (!this._patchRange.patchNum) {
          return;
        }

        this.$.diff.reload();
      },

      _pathChanged: function(path) {
        if (this._fileList.length == 0) { return; }

        this.set('changeViewState.selectedFileIndex',
            this._fileList.indexOf(path));
      },

      _computeDiffURL: function(changeNum, patchRange, path) {
        var patchStr = patchRange.patchNum;
        if (patchRange.basePatchNum != null &&
            patchRange.basePatchNum != 'PARENT') {
          patchStr = patchRange.basePatchNum + '..' + patchRange.patchNum;
        }
        return '/c/' + changeNum + '/' + patchStr + '/' + path;
      },

      _computeAvailablePatches: function(revisions) {
        var patchNums = [];
        for (var rev in revisions) {
          patchNums.push(revisions[rev]._number);
        }
        return patchNums.sort(function(a, b) { return a - b; });
      },

      _computeChangePath: function(changeNum) {
        return '/c/' + changeNum;
      },

      _computeChangeDetailPath: function(changeNum) {
        return '/changes/' + changeNum + '/detail';
      },

      _computeChangeDetailQueryParams: function() {
        return { O: this.listChangesOptionsToHex(
            this.ListChangesOption.ALL_REVISIONS
        )};
      },

      _computeFilesPath: function(changeNum, patchNum) {
        return this.changeBaseURL(changeNum, patchNum) + '/files';
      },

      _computeProjectConfigPath: function(project) {
        return '/projects/' + encodeURIComponent(project) + '/config';
      },

      _computeFileSelected: function(path, currentPath) {
        return path == currentPath;
      },

      _computeKeyNav: function(path, selectedPath, fileList) {
        var selectedIndex = fileList.indexOf(selectedPath);
        if (fileList.indexOf(path) == selectedIndex - 1) {
          return '[';
        }
        if (fileList.indexOf(path) == selectedIndex + 1) {
          return ']';
        }
        return '';
      },

      _handleFileTap: function(e) {
        this.$.dropdown.close();
      },

      _handleFilesResponse: function(e, req) {
        this._fileList = Object.keys(e.detail.response).sort();
      },

      _showDropdownTapHandler: function(e) {
        this.$.dropdown.open();
      },
    });
  })();
  </script>
</dom-module>