// Copyright 2016 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.

export default class ConsolePrompt extends UI.Widget {
  constructor() {
    super();
    this.registerRequiredCSS('console/consolePrompt.css');
    this._addCompletionsFromHistory = true;
    this._history = new Console.ConsoleHistoryManager();

    this._initialText = '';
    /** @type {?UI.TextEditor} */
    this._editor = null;
    this._eagerPreviewElement = createElementWithClass('div', 'console-eager-preview');
    this._textChangeThrottler = new Common.Throttler(150);
    this._formatter = new ObjectUI.RemoteObjectPreviewFormatter();
    this._requestPreviewBound = this._requestPreview.bind(this);
    this._innerPreviewElement = this._eagerPreviewElement.createChild('div', 'console-eager-inner-preview');
    this._eagerPreviewElement.appendChild(UI.Icon.create('smallicon-command-result', 'preview-result-icon'));

    const editorContainerElement = this.element.createChild('div', 'console-prompt-editor-container');
    this.element.appendChild(this._eagerPreviewElement);

    this._promptIcon = UI.Icon.create('smallicon-text-prompt', 'console-prompt-icon');
    this.element.appendChild(this._promptIcon);
    this._iconThrottler = new Common.Throttler(0);

    this._eagerEvalSetting = Common.settings.moduleSetting('consoleEagerEval');
    this._eagerEvalSetting.addChangeListener(this._eagerSettingChanged.bind(this));
    this._eagerPreviewElement.classList.toggle('hidden', !this._eagerEvalSetting.get());

    this.element.tabIndex = 0;
    /** @type {?Promise} */
    this._previewRequestForTest = null;

    /** @type {?UI.AutocompleteConfig} */
    this._defaultAutocompleteConfig = null;

    this._highlightingNode = false;

    self.runtime.extension(UI.TextEditorFactory).instance().then(gotFactory.bind(this));

    /**
     * @param {!UI.TextEditorFactory} factory
     * @this {Console.ConsolePrompt}
     */
    function gotFactory(factory) {
      this._editor = factory.createEditor({
        devtoolsAccessibleName: ls`Console prompt`,
        lineNumbers: false,
        lineWrapping: true,
        mimeType: 'javascript',
        autoHeight: true
      });

      this._defaultAutocompleteConfig = ObjectUI.JavaScriptAutocompleteConfig.createConfigForEditor(this._editor);
      this._editor.configureAutocomplete(Object.assign({}, this._defaultAutocompleteConfig, {
        suggestionsCallback: this._wordsWithQuery.bind(this),
        anchorBehavior: UI.GlassPane.AnchorBehavior.PreferTop
      }));
      this._editor.widget().element.addEventListener('keydown', this._editorKeyDown.bind(this), true);
      this._editor.widget().show(editorContainerElement);
      this._editor.addEventListener(UI.TextEditor.Events.CursorChanged, this._updatePromptIcon, this);
      this._editor.addEventListener(UI.TextEditor.Events.TextChanged, this._onTextChanged, this);
      this._editor.addEventListener(UI.TextEditor.Events.SuggestionChanged, this._onTextChanged, this);

      this.setText(this._initialText);
      delete this._initialText;
      if (this.hasFocus()) {
        this.focus();
      }
      this.element.removeAttribute('tabindex');
      this._editor.widget().element.tabIndex = -1;

      this._editorSetForTest();

      // Record the console tool load time after the console prompt constructor is complete.
      Host.userMetrics.panelLoaded('console', 'DevTools.Launch.Console');
    }
  }

  _eagerSettingChanged() {
    const enabled = this._eagerEvalSetting.get();
    this._eagerPreviewElement.classList.toggle('hidden', !enabled);
    if (enabled) {
      this._requestPreview();
    }
  }

  /**
   * @return {!Element}
   */
  belowEditorElement() {
    return this._eagerPreviewElement;
  }

  _onTextChanged() {
    // ConsoleView and prompt both use a throttler, so we clear the preview
    // ASAP to avoid inconsistency between a fresh viewport and stale preview.
    if (this._eagerEvalSetting.get()) {
      const asSoonAsPossible = !this._editor.textWithCurrentSuggestion();
      this._previewRequestForTest = this._textChangeThrottler.schedule(this._requestPreviewBound, asSoonAsPossible);
    }
    this._updatePromptIcon();
    this.dispatchEventToListeners(Events.TextChanged);
  }

  /**
   * @return {!Promise}
   */
  async _requestPreview() {
    const text = this._editor.textWithCurrentSuggestion().trim();
    const executionContext = UI.context.flavor(SDK.ExecutionContext);
    const {preview, result} =
        await ObjectUI.JavaScriptREPL.evaluateAndBuildPreview(text, true /* throwOnSideEffect */, 500);
    this._innerPreviewElement.removeChildren();
    if (preview.deepTextContent() !== this._editor.textWithCurrentSuggestion().trim()) {
      this._innerPreviewElement.appendChild(preview);
    }
    if (result && result.object && result.object.subtype === 'node') {
      this._highlightingNode = true;
      SDK.OverlayModel.highlightObjectAsDOMNode(result.object);
    } else if (this._highlightingNode) {
      this._highlightingNode = false;
      SDK.OverlayModel.hideDOMNodeHighlight();
    }
    if (result) {
      executionContext.runtimeModel.releaseEvaluationResult(result);
    }
  }

  /**
   * @override
   */
  willHide() {
    if (this._highlightingNode) {
      this._highlightingNode = false;
      SDK.OverlayModel.hideDOMNodeHighlight();
    }
  }

  /**
   * @return {!Console.ConsoleHistoryManager}
   */
  history() {
    return this._history;
  }

  clearAutocomplete() {
    if (this._editor) {
      this._editor.clearAutocomplete();
    }
  }

  /**
   * @return {boolean}
   */
  _isCaretAtEndOfPrompt() {
    return !!this._editor && this._editor.selection().collapseToEnd().equal(this._editor.fullRange().collapseToEnd());
  }

  moveCaretToEndOfPrompt() {
    if (this._editor) {
      this._editor.setSelection(TextUtils.TextRange.createFromLocation(Infinity, Infinity));
    }
  }

  /**
   * @param {string} text
   */
  setText(text) {
    if (this._editor) {
      this._editor.setText(text);
    } else {
      this._initialText = text;
    }
    this.dispatchEventToListeners(Events.TextChanged);
  }

  /**
   * @return {string}
   */
  text() {
    return this._editor ? this._editor.text() : this._initialText;
  }

  /**
   * @param {boolean} value
   */
  setAddCompletionsFromHistory(value) {
    this._addCompletionsFromHistory = value;
  }

  /**
   * @param {!Event} event
   */
  _editorKeyDown(event) {
    const keyboardEvent = /** @type {!KeyboardEvent} */ (event);
    let newText;
    let isPrevious;
    // Check against visual coordinates in case lines wrap.
    const selection = this._editor.selection();
    const cursorY = this._editor.visualCoordinates(selection.endLine, selection.endColumn).y;

    switch (keyboardEvent.keyCode) {
      case UI.KeyboardShortcut.Keys.Up.code:
        const startY = this._editor.visualCoordinates(0, 0).y;
        if (keyboardEvent.shiftKey || !selection.isEmpty() || cursorY !== startY) {
          break;
        }
        newText = this._history.previous(this.text());
        isPrevious = true;
        break;
      case UI.KeyboardShortcut.Keys.Down.code:
        const fullRange = this._editor.fullRange();
        const endY = this._editor.visualCoordinates(fullRange.endLine, fullRange.endColumn).y;
        if (keyboardEvent.shiftKey || !selection.isEmpty() || cursorY !== endY) {
          break;
        }
        newText = this._history.next();
        break;
      case UI.KeyboardShortcut.Keys.P.code:  // Ctrl+P = Previous
        if (Host.isMac() && keyboardEvent.ctrlKey && !keyboardEvent.metaKey && !keyboardEvent.altKey &&
            !keyboardEvent.shiftKey) {
          newText = this._history.previous(this.text());
          isPrevious = true;
        }
        break;
      case UI.KeyboardShortcut.Keys.N.code:  // Ctrl+N = Next
        if (Host.isMac() && keyboardEvent.ctrlKey && !keyboardEvent.metaKey && !keyboardEvent.altKey &&
            !keyboardEvent.shiftKey) {
          newText = this._history.next();
        }
        break;
      case UI.KeyboardShortcut.Keys.Enter.code:
        this._enterKeyPressed(keyboardEvent);
        break;
      case UI.KeyboardShortcut.Keys.Tab.code:
        if (!this.text()) {
          keyboardEvent.consume();
        }
        break;
    }

    if (newText === undefined) {
      return;
    }
    keyboardEvent.consume(true);
    this.setText(newText);

    if (isPrevious) {
      this._editor.setSelection(TextUtils.TextRange.createFromLocation(0, Infinity));
    } else {
      this.moveCaretToEndOfPrompt();
    }
  }

  /**
   * @return {!Promise<boolean>}
   */
  async _enterWillEvaluate() {
    if (!this._isCaretAtEndOfPrompt()) {
      return true;
    }
    return await ObjectUI.JavaScriptAutocomplete.isExpressionComplete(this.text());
  }

  _updatePromptIcon() {
    this._iconThrottler.schedule(async () => {
      const canComplete = await this._enterWillEvaluate();
      this._promptIcon.classList.toggle('console-prompt-incomplete', !canComplete);
    });
  }

  /**
   * @param {!KeyboardEvent} event
   */
  async _enterKeyPressed(event) {
    if (event.altKey || event.ctrlKey || event.shiftKey) {
      return;
    }

    event.consume(true);

    // Since we prevent default, manually emulate the native "scroll on key input" behavior.
    this.element.scrollIntoView();
    this.clearAutocomplete();

    const str = this.text();
    if (!str.length) {
      return;
    }

    if (await this._enterWillEvaluate()) {
      await this._appendCommand(str, true);
    } else {
      this._editor.newlineAndIndent();
    }
    this._enterProcessedForTest();
  }

  /**
   * @param {string} text
   * @param {boolean} useCommandLineAPI
   */
  async _appendCommand(text, useCommandLineAPI) {
    this.setText('');
    const currentExecutionContext = UI.context.flavor(SDK.ExecutionContext);
    if (currentExecutionContext) {
      const executionContext = currentExecutionContext;
      const message = SDK.consoleModel.addCommandMessage(executionContext, text);
      const expression = ObjectUI.JavaScriptREPL.preprocessExpression(text);
      SDK.consoleModel.evaluateCommandInConsole(
          executionContext, message, expression, useCommandLineAPI,
          /* awaitPromise */ false);
      if (Console.ConsolePanel.instance().isShowing()) {
        Host.userMetrics.actionTaken(Host.UserMetrics.Action.CommandEvaluatedInConsolePanel);
      }
    }
  }

  _enterProcessedForTest() {
  }

  /**
   * @param {string} prefix
   * @param {boolean=} force
   * @return {!UI.SuggestBox.Suggestions}
   */
  _historyCompletions(prefix, force) {
    const text = this.text();
    if (!this._addCompletionsFromHistory || !this._isCaretAtEndOfPrompt() || (!text && !force)) {
      return [];
    }
    const result = [];
    const set = new Set();
    const data = this._history.historyData();
    for (let i = data.length - 1; i >= 0 && result.length < 50; --i) {
      const item = data[i];
      if (!item.startsWith(text)) {
        continue;
      }
      if (set.has(item)) {
        continue;
      }
      set.add(item);
      result.push(
          {text: item.substring(text.length - prefix.length), iconType: 'smallicon-text-prompt', isSecondary: true});
    }
    return result;
  }

  /**
   * @override
   */
  focus() {
    if (this._editor) {
      this._editor.widget().focus();
    } else {
      this.element.focus();
    }
  }

  /**
   * @param {!TextUtils.TextRange} queryRange
   * @param {!TextUtils.TextRange} substituteRange
   * @param {boolean=} force
   * @return {!Promise<!UI.SuggestBox.Suggestions>}
   */
  async _wordsWithQuery(queryRange, substituteRange, force) {
    const query = this._editor.text(queryRange);
    const words = await this._defaultAutocompleteConfig.suggestionsCallback(queryRange, substituteRange, force);
    const historyWords = this._historyCompletions(query, force);
    return words.concat(historyWords);
  }

  _editorSetForTest() {
  }
}

/**
 * @unrestricted
 */
export class ConsoleHistoryManager {
  constructor() {
    /**
     * @type {!Array.<string>}
     */
    this._data = [];

    /**
     * 1-based entry in the history stack.
     * @type {number}
     */
    this._historyOffset = 1;
  }

  /**
   * @return {!Array.<string>}
   */
  historyData() {
    return this._data;
  }

  /**
   * @param {!Array.<string>} data
   */
  setHistoryData(data) {
    this._data = data.slice();
    this._historyOffset = 1;
  }

  /**
   * Pushes a committed text into the history.
   * @param {string} text
   */
  pushHistoryItem(text) {
    if (this._uncommittedIsTop) {
      this._data.pop();
      delete this._uncommittedIsTop;
    }

    this._historyOffset = 1;
    if (text === this._currentHistoryItem()) {
      return;
    }
    this._data.push(text);
  }

  /**
   * Pushes the current (uncommitted) text into the history.
   * @param {string} currentText
   */
  _pushCurrentText(currentText) {
    if (this._uncommittedIsTop) {
      this._data.pop();
    }  // Throw away obsolete uncommitted text.
    this._uncommittedIsTop = true;
    this._data.push(currentText);
  }

  /**
   * @param {string} currentText
   * @return {string|undefined}
   */
  previous(currentText) {
    if (this._historyOffset > this._data.length) {
      return undefined;
    }
    if (this._historyOffset === 1) {
      this._pushCurrentText(currentText);
    }
    ++this._historyOffset;
    return this._currentHistoryItem();
  }

  /**
   * @return {string|undefined}
   */
  next() {
    if (this._historyOffset === 1) {
      return undefined;
    }
    --this._historyOffset;
    return this._currentHistoryItem();
  }

  /**
   * @return {string|undefined}
   */
  _currentHistoryItem() {
    return this._data[this._data.length - this._historyOffset];
  }
}

export const Events = {
  TextChanged: Symbol('TextChanged')
};

/* Legacy exported object */
self.Console = self.Console || {};

/* Legacy exported object */
Console = Console || {};

/**
 * @constructor
 */
Console.ConsolePrompt = ConsolePrompt;

Console.ConsolePrompt.Events = Events;

/**
 * @constructor
 */
Console.ConsoleHistoryManager = ConsoleHistoryManager;