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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.
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<link rel="import" href="../bower_components/polymer/polymer.html">
<link rel="import" href="../bower_components/iron-input/iron-input.html">
<link rel="import" href="../behaviors/keyboard-shortcut-behavior.html">
<link rel="import" href="gr-ajax.html">
<link rel="import" href="gr-button.html">
<link rel="import" href="gr-request.html">

<dom-module id="gr-reviewer-list">
  <style>
    :host {
      display: block;
    }
    :host([disabled]) {
      opacity: .8;
      pointer-events: none;
    }
    .autocompleteContainer {
      position: relative;
    }
    .inputContainer {
      display: flex;
      margin-top: .25em;
    }
    .inputContainer input {
      flex: 1;
      font: inherit;
    }
    .dropdown {
      background-color: #fff;
      box-shadow: 0 1px 3px rgba(0, 0, 0, .3);
      position: absolute;
      left: 0;
      top: 100%;
    }
    .dropdown .reviewer {
      cursor: pointer;
      padding: .5em .75em;
    }
    .dropdown .reviewer[selected] {
      background-color: #ccc;
    }
    .remove,
    .cancel {
      color: #999;
    }
    .remove {
      font-size: .9em;
    }
    .cancel {
      font-size: 2em;
      line-height: 1;
      padding: 0 .15em;
      text-decoration: none;
    }
  </style>
  <template>
    <gr-ajax id="autocompleteXHR"
        url="[[_computeAutocompleteURL(change)]]"
        params="[[_computeAutocompleteParams(_inputVal)]]"
        on-response="_handleResponse"></gr-ajax>

    <template is="dom-repeat" items="[[_reviewers]]" as="reviewer">
      <div class="reviewer">
        <gr-account-link account="[[reviewer]]" show-email></gr-account-link>
        <gr-button link
            class="remove"
            data-account-id$="[[reviewer._account_id]]"
            on-tap="_handleRemoveTap"
            hidden$="[[_computeCannotRemoveReviewer(reviewer, mutable)]]">remove</gr-buttom>
      </div>
    </template>
    <div class="controlsContainer" hidden$="[[!mutable]]">
      <div class="autocompleteContainer" hidden$="[[!_showInput]]">
        <div class="inputContainer">
          <input is="iron-input" id="input"
              bind-value="{{_inputVal}}" disabled$="[[disabled]]">
          <gr-button link class="cancel" on-tap="_handleCancelTap">×</gr-button>
        </div>
        <div class="dropdown" hidden$="[[_hideAutocomplete]]">
          <template is="dom-repeat" items="[[_autocompleteData]]" as="reviewer">
            <div class="reviewer"
                data-index$="[[index]]"
                on-mouseenter="_handleMouseEnterItem"
                on-tap="_handleItemTap"
                selected$="[[_computeSelected(index, _selectedIndex)]]">
              <template is="dom-if" if="[[reviewer.account]]">
                <gr-account-label
                    account="[[reviewer.account]]" show-email></gr-account-label>
              </template>
              <template is="dom-if" if="[[reviewer.group]]">
                <span>[[reviewer.group.name]] (group)</span>
              </template>
            </div>
          </template>
        </div>
      </div>
      <gr-button link id="addReviewer" class="addReviewer" on-tap="_handleAddTap"
          hidden$="[[_showInput]]">Add reviewer</gr-button>
    </div>
  </template>
  <script>
  (function() {
    'use strict';

    Polymer({
      is: 'gr-reviewer-list',

      properties: {
        change: Object,
        mutable: {
          type: Boolean,
          value: false,
        },
        disabled: {
          type: Boolean,
          value: false,
          reflectToAttribute: true,
        },
        suggestFrom: {
          type: Number,
          value: 3,
        },

        _reviewers: {
          type: Array,
          value: function() { return []; },
        },
        _autocompleteData: {
          type: Array,
          value: function() { return []; },
          observer: '_autocompleteDataChanged',
        },
        _inputVal: {
          type: String,
          value: '',
          observer: '_inputValChanged',
        },
        _inputRequestHandle: Number,
        _inputRequestTimeout: {
          type: Number,
          value: 250,
        },
        _showInput: {
          type: Boolean,
          value: false,
        },
        _hideAutocomplete: {
          type: Boolean,
          value: true,
          observer: '_hideAutocompleteChanged',
        },
        _selectedIndex: {
          type: Number,
          value: 0,
        },
        _boundBodyClickHandler: {
          type: Function,
          value: function() {
            return this._handleBodyClick.bind(this);
          },
        },

        // Used for testing.
        _lastAutocompleteRequest: Object,
        _xhrPromise: Object,
      },

      behaviors: [
        Gerrit.KeyboardShortcutBehavior,
      ],

      observers: [
        '_reviewersChanged(change.reviewers.*, change.owner)',
      ],

      detached: function() {
        this._clearInputRequestHandle();
      },

      _clearInputRequestHandle: function() {
        if (this._inputRequestHandle != null) {
          this.cancelAsync(this._inputRequestHandle);
          this._inputRequestHandle = null;
        }
      },

      _reviewersChanged: function(changeRecord, owner) {
        var result = [];
        var reviewers = changeRecord.base;
        for (var key in reviewers) {
          if (key == 'REVIEWER' || key == 'CC') {
            result = result.concat(reviewers[key]);
          }
        }
        this._reviewers = result.filter(function(reviewer) {
          return reviewer._account_id != owner._account_id;
        });
      },

      _computeCannotRemoveReviewer: function(reviewer, mutable) {
        if (!mutable) { return true; }

        for (var i = 0; i < this.change.removable_reviewers.length; i++) {
          if (this.change.removable_reviewers[i]._account_id ==
              reviewer._account_id) {
            return false;
          }
        }
        return true;
      },

      _computeAutocompleteURL: function(change) {
        return '/changes/' + change._number + '/suggest_reviewers';
      },

      _computeAutocompleteParams: function(inputVal) {
        return {
          n: 10,  // Return max 10 results
          q: inputVal,
        };
      },

      _computeSelected: function(index, selectedIndex) {
        return index == selectedIndex;
      },

      _handleResponse: function(e) {
        this._autocompleteData = e.detail.response.filter(function(reviewer) {
          var account = reviewer.account;
          if (!account) { return true; }
          for (var i = 0; i < this._reviewers.length; i++) {
            if (account._account_id == this.change.owner._account_id ||
                account._account_id == this._reviewers[i]._account_id) {
              return false;
            }
          }
          return true;
        }, this);
      },

      _handleBodyClick: function(e) {
        var eventPath = Polymer.dom(e).path;
        for (var i = 0; i < eventPath.length; i++) {
          if (eventPath[i] == this) {
            return;
          }
        }
        this._selectedIndex = -1;
        this._autocompleteData = [];
      },

      _handleRemoveTap: function(e) {
        e.preventDefault();
        var target = Polymer.dom(e).rootTarget;
        var accountID = parseInt(target.getAttribute('data-account-id'), 10);
        this._send('DELETE', this._restEndpoint(accountID)).then(function(req) {
          var reviewers = this.change.reviewers;
          ['REVIEWER', 'CC'].forEach(function(type) {
            reviewers[type] = reviewers[type] || [];
            for (var i = 0; i < reviewers[type].length; i++) {
              if (reviewers[type][i]._account_id == accountID) {
                this.splice('change.reviewers.' + type, i, 1);
                break;
              }
            }
          }, this);
        }.bind(this)).catch(function(err) {
          alert('Oops. Something went wrong. Check the console and bug the ' +
              'PolyGerrit team for assistance.');
          throw err;
        }.bind(this));
      },

      _handleAddTap: function(e) {
        e.preventDefault();
        this._showInput = true;
        this.$.input.focus();
      },

      _handleCancelTap: function(e) {
        e.preventDefault();
        this._cancel();
      },

      _handleMouseEnterItem: function(e) {
        this._selectedIndex =
            parseInt(Polymer.dom(e).rootTarget.getAttribute('data-index'), 10);
      },

      _handleItemTap: function(e) {
        var reviewerEl;
        var eventPath = Polymer.dom(e).path;
        for (var i = 0; i < eventPath.length; i++) {
          var el = eventPath[i];
          if (el.classList && el.classList.contains('reviewer')) {
            reviewerEl = el;
            break;
          }
        }
        this._selectedIndex =
            parseInt(reviewerEl.getAttribute('data-index'), 10);
        this._sendAddRequest();
      },

      _autocompleteDataChanged: function(data) {
        this._hideAutocomplete = data.length == 0;
      },

      _hideAutocompleteChanged: function(hidden) {
        if (hidden) {
          document.body.removeEventListener('click',
              this._boundBodyClickHandler);
          this._selectedIndex = -1;
        } else {
          document.body.addEventListener('click', this._boundBodyClickHandler);
          this._selectedIndex = 0;
        }
      },

      _inputValChanged: function(val) {
        var sendRequest = function() {
          if (this.disabled || val == null || val.trim().length == 0) {
            return;
          }
          if (val.length < this.suggestFrom) {
            this._clearInputRequestHandle();
            this._hideAutocomplete = true;
            this._selectedIndex = -1;
            return;
          }
          this._lastAutocompleteRequest =
              this.$.autocompleteXHR.generateRequest();
        }.bind(this);

        this._clearInputRequestHandle();
        if (this._inputRequestTimeout == 0) {
          sendRequest();
        } else {
          this._inputRequestHandle =
              this.async(sendRequest, this._inputRequestTimeout);
        }
      },

      _handleKey: function(e) {
        if (this._hideAutocomplete) {
          if (e.keyCode == 27) {  // 'esc'
            e.preventDefault();
            this._cancel();
          }
          return;
        }

        switch (e.keyCode) {
          case 38:  // 'up':
            e.preventDefault();
            this._selectedIndex = Math.max(this._selectedIndex - 1, 0);
            break;
          case 40:  // 'down'
            e.preventDefault();
            this._selectedIndex = Math.min(this._selectedIndex + 1,
                                           this._autocompleteData.length - 1);
            break;
          case 27:  // 'esc'
            e.preventDefault();
            this._hideAutocomplete = true;
            break;
          case 13:  // 'enter'
            e.preventDefault();
            this._sendAddRequest();
            break;
        }
      },

      _cancel: function() {
        this._showInput = false;
        this._selectedIndex = 0;
        this._inputVal = '';
        this._autocompleteData = [];
        this.$.addReviewer.focus();
      },

      _sendAddRequest: function() {
        this._clearInputRequestHandle();

        var reviewerID;
        var reviewer = this._autocompleteData[this._selectedIndex];
        if (reviewer.account) {
          reviewerID = reviewer.account._account_id;
        } else if (reviewer.group) {
          reviewerID = reviewer.group.id;
        }
        this._autocompleteData = [];
        this._send('POST', this._restEndpoint(), reviewerID).then(function(req) {
          this.change.reviewers.CC = this.change.reviewers.CC || [];
          req.response.reviewers.forEach(function(r) {
            this.push('change.removable_reviewers', r);
            this.push('change.reviewers.CC', r);
          }, this);
          this._inputVal = '';
          this.$.input.focus();
        }.bind(this)).catch(function(err) {
          // TODO(andybons): Use the message returned by the server.
          alert('Unable to add ' + reviewerID + ' as a reviewer.');
          throw err;
        }.bind(this));
      },

      _send: function(method, url, reviewerID) {
        this.disabled = true;
        var request = document.createElement('gr-request');
        var opts = {
          method: method,
          url: url,
        };
        if (reviewerID) {
          opts.body = {reviewer: reviewerID};
        }
        this._xhrPromise = request.send(opts);
        var enableEl = function() { this.disabled = false; }.bind(this);
        this._xhrPromise.then(enableEl).catch(enableEl);
        return this._xhrPromise;
      },

      _restEndpoint: function(id) {
        var path = '/changes/' + this.change._number + '/reviewers';
        if (id) {
          path += '/' + id;
        }
        return path;
      },
    });
  })();
  </script>
</dom-module>