/*
 * Copyright (C) 2014 Google Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
 *     * Neither the name of Google Inc. nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/**
 * @unrestricted
 */
Sources.EditingLocationHistoryManager = class {
  /**
   * @param {!Sources.SourcesView} sourcesView
   * @param {function():?Sources.UISourceCodeFrame} currentSourceFrameCallback
   */
  constructor(sourcesView, currentSourceFrameCallback) {
    this._sourcesView = sourcesView;
    this._historyManager = new Sources.SimpleHistoryManager(Sources.EditingLocationHistoryManager.HistoryDepth);
    this._currentSourceFrameCallback = currentSourceFrameCallback;
  }

  /**
   * @param {!Sources.UISourceCodeFrame} sourceFrame
   */
  trackSourceFrameCursorJumps(sourceFrame) {
    sourceFrame.textEditor.addEventListener(
        SourceFrame.SourcesTextEditor.Events.JumpHappened, this._onJumpHappened.bind(this));
  }

  /**
   * @param {!Common.Event} event
   */
  _onJumpHappened(event) {
    if (event.data.from)
      this._updateActiveState(event.data.from);
    if (event.data.to)
      this._pushActiveState(event.data.to);
  }

  rollback() {
    this._historyManager.rollback();
  }

  rollover() {
    this._historyManager.rollover();
  }

  updateCurrentState() {
    const sourceFrame = this._currentSourceFrameCallback();
    if (!sourceFrame)
      return;
    this._updateActiveState(sourceFrame.textEditor.selection());
  }

  pushNewState() {
    const sourceFrame = this._currentSourceFrameCallback();
    if (!sourceFrame)
      return;
    this._pushActiveState(sourceFrame.textEditor.selection());
  }

  /**
   * @param {!TextUtils.TextRange} selection
   */
  _updateActiveState(selection) {
    const active = this._historyManager.active();
    if (!active)
      return;
    const sourceFrame = this._currentSourceFrameCallback();
    if (!sourceFrame)
      return;
    const entry = new Sources.EditingLocationHistoryEntry(this._sourcesView, this, sourceFrame, selection);
    active.merge(entry);
  }

  /**
   * @param {!TextUtils.TextRange} selection
   */
  _pushActiveState(selection) {
    const sourceFrame = this._currentSourceFrameCallback();
    if (!sourceFrame)
      return;
    const entry = new Sources.EditingLocationHistoryEntry(this._sourcesView, this, sourceFrame, selection);
    this._historyManager.push(entry);
  }

  /**
   * @param {!Workspace.UISourceCode} uiSourceCode
   */
  removeHistoryForSourceCode(uiSourceCode) {
    function filterOut(entry) {
      return entry._projectId === uiSourceCode.project().id() && entry._url === uiSourceCode.url();
    }

    this._historyManager.filterOut(filterOut);
  }
};

Sources.EditingLocationHistoryManager.HistoryDepth = 20;

/**
 * @implements {Sources.HistoryEntry}
 * @unrestricted
 */
Sources.EditingLocationHistoryEntry = class {
  /**
   * @param {!Sources.SourcesView} sourcesView
   * @param {!Sources.EditingLocationHistoryManager} editingLocationManager
   * @param {!Sources.UISourceCodeFrame} sourceFrame
   * @param {!TextUtils.TextRange} selection
   */
  constructor(sourcesView, editingLocationManager, sourceFrame, selection) {
    this._sourcesView = sourcesView;
    this._editingLocationManager = editingLocationManager;
    const uiSourceCode = sourceFrame.uiSourceCode();
    this._projectId = uiSourceCode.project().id();
    this._url = uiSourceCode.url();

    const position = this._positionFromSelection(selection);
    this._positionHandle = sourceFrame.textEditor.textEditorPositionHandle(position.lineNumber, position.columnNumber);
  }

  /**
   * @param {!Sources.HistoryEntry} entry
   */
  merge(entry) {
    if (this._projectId !== entry._projectId || this._url !== entry._url)
      return;
    this._positionHandle = entry._positionHandle;
  }

  /**
   * @param {!TextUtils.TextRange} selection
   * @return {!{lineNumber: number, columnNumber: number}}
   */
  _positionFromSelection(selection) {
    return {lineNumber: selection.endLine, columnNumber: selection.endColumn};
  }

  /**
   * @override
   * @return {boolean}
   */
  valid() {
    const position = this._positionHandle.resolve();
    const uiSourceCode = Workspace.workspace.uiSourceCode(this._projectId, this._url);
    return !!(position && uiSourceCode);
  }

  /**
   * @override
   */
  reveal() {
    const position = this._positionHandle.resolve();
    const uiSourceCode = Workspace.workspace.uiSourceCode(this._projectId, this._url);
    if (!position || !uiSourceCode)
      return;

    this._editingLocationManager.updateCurrentState();
    this._sourcesView.showSourceLocation(uiSourceCode, position.lineNumber, position.columnNumber);
  }
};